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“

ANNALS

OF THE

NEW YORK ACADEMY

OF SCIENCES

VOLUME XXVII

Zc eaonian Instit,,- Sy

a4aas

| Mu useye

NEW YORK

PUBLISHED BY THE ACADEMY

1916, 1917

Editor

‘ RALPH W. TOWER

“e

—-

ee 75

IVIN7/

: Page

Bmore acter Tort erets steven ier clieicecleneietaterererensieleyesiers dis ache eave dacs oee.8 selews & i

WOIMECIES Mer eter rey erat neeiAe rele hel elei craic) eras wiaiave ave euslaeis slicis elsie eiecs siaisie eee ee'wa ili

Dates of publication and editions OhetherDrOCHUPES tye a clemis elerae + eisiaieve olellels ee ilk

Ese Ola MISE ATIONS|: cee setae sieie is) + c's oe erelepelole o's cl sivicyeisisiv ce ele oisie vis) eeeice eres iv

Some Remarks upon Matthew’s “Climate and Evolution.” By T. BargBour.

With Supplementary Note by W. D. MATTHEW..............++-205 a

An Extinet Octodont from the Island of Porto Rico, West Indies. By J. A. |

PANES HIN PM (CEM ATO Suit Wi) ) satay a taztt so tole ai'srare)slieis -«) o-Wie enieiie aileiie's oie; s; siletjoie eile as! ea le's 17 |

New Sirenian from the Tertiary of Porto Rico, West Indies. By W. D. |

IVIGAUDHISENM VW irarsee recieve ty cere ielaiat ciayaiisicie eure Seis ls oie eles Steins tee tects cee ees 23.

Theories of the Origin of Birds. By WitLIAM K. GREGORY.............+ 31 i

A Study of the Morrison Formation. By C. C. Mook. (Plate VI)......:. 39 .

Preliminary Report of Fossil Mammals from Porto Rico, with descriptions

of a new genus of ground sloth and two new genera of hystricomorph

rodents. By H. EH. AntHony. (Plates VII-XIV)................. 193

Physiography of the Skykomish Basin, Washington. By Warren S.

SMITH......... asl Sh ae RRS Re IG ap de ge a ee 205

Operating Features of the Audion. By H. H. ARMSTRONG................ 215

Records of Meetings, 1916. By R. W. TowmR................cc cece eecees 245

Membership Lists, 81 December, 1916............ 2... cc ccc w eee cece e ees 315

ULC SNGEP MA Tenet seep veqaierenadar ciate evans) eve rete eheveter esis, Sig's urate Gt aiae ee aes Gis wrote ele alee 329

DATES OF PUBLICATION AND HDITIONS OF THE BROCHURES

Edition

Pp. 1-15, 25 January, 1916 1175 copies

Pp. 17-22, 25 January, 1916 1100 copies

Pp. 23-29, 28 January, 1916 1175 copies

Pp. 31-88, 4 May, 1916 1050 copies

Pp. 39-191, 12 June, 1916 1050 copies

Pp. 193-203, 9 August, 1916 1100 copies

Pp. 205-214, 31 January, 1917 1500 copies

Pp. 215-248, 2 August, 1917 1500 copies

Pp. 245-336, 30 November, 1917 1500 copies

LIST OF ILLUSTRATIONS

Plates

I.—Skull and Lower Jaw of Jsolobodon portoricensis gen. et sp. noy.

II.—Lower Jaw and Dentition of [solobodon portoricensis gen. et sp. nov.

IiI.—Scapula, Humerus, Ulna and Radius of Jsolobodon portoricensis gen. et

sp. noy.

IV.—Sacrum of Jsolobodon portoricensis gen. et sp. nov.

V.—Femur and Tibia of Jsolobodon portoricensis gen. et sp. noy.

VI.—-Map Showing the Distribution of the Morrison Formation.

VIil.—Right Femur of Acratocnus odontrigonus.

VIII.—Linb Bones of Acratocnus odontrigonus.

IX.—-Limb Bones and Vertebre of Acratocnus odontrigonus.

X.—Skull of Acratocnus odontrigonus.

XI.—Skulls of Acratocnus odontrigonus and Heteropsomys insulans.

XII.—Skull of Heteropsomys insulans.

XIITI.—Skull of Hlasmodontomys obliquus.

XIV.—Skul! of Hlasmodontomys obliquus.

Text Figures

Page

?Hualitherium antillense, lower jaw, ieft ramus, type specimen............ 25

?Halitherium antillense, parts of cervical (right) and anterior dorsal (left)

vertebree of type Specimen ss cis sae teh cease sieiels oe olen eee 27

Generalized section of Rocky Mountain hog-back, showing the usual plhysi-

ographic position of Morrison oUtcrops.....................5-eeue ‘ee 5 A

Generalized section of a Rocky Mountain or Great Plains river canyon,

showing a common position of Morrison Outcrops.................-- 42

Section of the Morrison and overlying and underlying beds at Laporte,

CWOLORAMO! Ka ieee es oie beers Sables SALE He ALOE A SERED eon See ee 46

' Section of the Morrison and adjacent formations east of Lyons, Colorado.. 46

The Morrison formation at Morrison, Colorado, looking south............. AT

The Morrison formation at Morrison. Colorado, looking east............. 48

View northeast from Fremont Peak, near Canon City, Colorado........... 49

Site of the Marsh-Hatcher dinosaur quarry near Canon City, Colorado.... 50

Near view. of the central portion of the above:..... 22... os... eee 50

Exposure of the lower beds of the Morrison formation about 100 yards

northeast of the Marsh-Hatcher dinosaur quarry, near Canon City,

COLOLAMOE eee cow oeancs Sa ae ede ae aie el sake eh Stes Saar 51

The Cope dinosaur quarry northwest of the Marsh-Hatcher quarry, near

Gafion City) Colorado. scissile ss ace cya eieleeust ayers ei cisele ois ees 01s) eee 52

The “Nipple,” west of Garden Park, Colorado, looking east............... 53

Section of the Morrison and related formations at Garden Park, near

Canon City, COVOEAMO Hs ile ieicreunte nuciete eile ert penete! aileire ede ede rae) see) ee 5D

pperspart of the Garden Parks SeChOmiey yee tleilatel= lo) ole) =) eee ener 55

Teat Figures

Lower part of the Garden Park section.............. Dery ea eee ype ona ie eset

The “Nipple,” looking west from Garden Park, Colorado.................

Section of the Morrison and related formations in Plum Canyon, Colorado.

Section of the Morrison and related formations in Red Rocks Canyon,

(GLO Opmrryrwew ise Me Mencia ihe aiepetn visu aielensSimjede em calalies cb. eiterie, Wehaca Whe sieve a aes

Composite section of the upper part of the Morrison formation in the

Huerfano quadrangle, Colorado............ cece cee eee eee eee tee eens

Section of the Morrison and related formations in Rio Cimarron Canyon,

14 miles east of Folsom, New Mexico................ cece eee eeteee

Section of the Morrison and related formations in the canyon of Rio

Cimarron, east of Long Canyon, New Mexico..................-.----

Section of the Morrison and adjacent formations in the canyon of Rio

Cimarron, near Hxeter post-office, New Mexico..................----

Section of the Morrison and adjacent formations in the escarpment north

COfmse nimi clits Ne@ wa MGxAC Os si cie wis sie <i ele siets ania ding » slope oleh eisleled) debate eee

Section of the Morrison formation in the Telluride quadrangle, Colorado. .

Section of the Morrison formation on Dexter Creek, Rico quadrangle, Colo-

HGNC Muerte ete ctr cee rns) aa oes ravate euotec Sane ieee Uahealiate wlsiteia itilellone! once cayietie cos opiled areal ca te euesaus

Section of the Morrison formation in Gunnison Canyon at the mouth of

Nei Serr UHl Cle GC OLOMRAG Orie seicreoin oral ole steriewcadle ee Gre alele sce ee ie ctane ts evsace ile eee

Morrison formation south of Grand Junction, Colorado, looking west.....

Grand Mesa, south of Grand Junction, Colorado, looking south. Morrison

OULCKOMS, IM The LOFESTOUME <5 Fcc ee ec cre ects eee eis eae ale a oie ee ie cece

Morrison formation south of Grand Junction, Colorado, looking north.....

Section of the Morrison formation near Mack, Colorado..................

Monoclinal fold near Mack, Colorado...............0 cece cece eet c ere eres

Outerops of the Morrison formation near Mack, Colorado................

Section of the McEHlmo formation near Green River, Utah................

Outerop of the Morrison formation near Jensen, Utah...................

Section of the Morrison formation in the Electric Coal Field, Montana... .

Seetion of the Morrison formation on Belt Creek, Montana...............

Section of the Morrison formation near Shannon Creek, Montana.........

Seetion of the Morrison formation on South Fork of Rock Creek, north-

WERE OF IBHMGRIO, ANA CUMIN E desoaaouunedosO odds boM Sn cDeG oe doduoueo

Seetion of the Morrison formation on the south side of Muddy Creek,

southwest of Buffalo, Wyoming. ...............50.0.2--26--0- ere,

Section of the Morrison formation north of Middle Fork of Crazy Woman

Giree lea VEY OTIMTIN ae cas cpeieeen ae lettuce daca, clint naepce luheteatere eierclereni'e ¢ a.gree/ kus

Section of the Morrison formation near Beaver Creek, Wyoming..........

Section of the Morrison formation south of Fort C. F. Smith, Montana....

Section of the Morrison formation near Tensleep, Wyoming..............-

Section of the Morrison formation on Alkali Creek, Wyoming.............

Section of the Morrison formation on the Shoshone River, Wyoming.......

Section of the Morrison formation on Trail Creek, northwest of Cody, Wy-

OTN ee aaa ere te er caer etsy ie tcye) 5s eyiavelie’'e save’ ayo) 5 cherie anmue etehenat ele

Section of the Morrison formation south of Clark Fork Canyon, Wyoming.

Section of the Morrison formation near Watson’s ranch north of Owl

Clase, NONE Bone Shoo cbe Gos bus oO poe oe bOrS coe ancic molccd Ucn on

Text Figures

Section of the Morrison and Sundance formations in east bluff of North

Platte. River, WyOMiIngs:. 2.0. odecc cc cles cule obice sce sds clecees Dee

Section of the Morrison formation on Red Creek, three miles east of Black

Mountain summit, Wyoming............ ccc cece cece ec eect e eee nceace

Section of the Morrison formation in Como Bluff, Wyoming..............

Section of the Morrison and Sundance formations on the north side of

Como Anticline, Wyoming:........0 05. <2 ocho s cous en cde cece eee

Exposures of the Morrison formation in Como Bluff, Wyoming...........

Section of the Morrison and Sundance formations at Como Bluff, Wyoming

Section of the Morrison and Sundance formations on the south side of

Medicine Anticline, or “Bone Cabin Draw,” Wyoming................

Section of the Morrison formation in the Freezeout Hills, Wyoming.......

Section of the Morrison formation at Sioux Fault, Wyoming.............

Section of the Morrison formation in the Freezeout Hills, Wyoming.......

Section of the Morrison formation at Red Mountain, ‘Wyoming Ms cts.

Section of the Morrison formation at Red Mountain, Wyoming............

Section of the Morrison formation on the east slope of the ridge west of

Downey Soda: Lakes, WYOMING... 6.65 2 coin weiss a + alec ofols eilclenehe ne terenenenas

Section of the Morrison formation on the South Fork of Horse Creek,

A110) 901s een eh nr er A AS MEAG A GO ooo f005

Section of the Morrison formation in drill hole in floor ot coal mine at

Cambria; WYOMIDS 5.656 series w arsisscses, co e-s:c eee nis els ale, 0 6 elena ee nee

Section of the Morrison formation on north side of Sourdough Creeks Six

miles north of Hulett, Wyoming. 2222. .5....- «sso. -ec seie eee

Section of the Morrison formation on ridge south of Lytle Creek, Wyoming

Section of the Morrison formation 4 miles east-southeast of Devil’s Tower,

SWOT oo ese acny ana eS 8 ah ty aber oud ise lagu evans ahanere’e clece eiel seu aWeusceyee peter Reema

Section of the Morrison formation on north side of Deer Creek, 10 miles

northeast of Hulett, Wy Omi... 3. 16.5. 2 cicicc a coe ccciese © 010 0 lepeneueueeieneele

Section of the Morrison formation near head of Burnt Hollow, 4 miles

northwest. of Hulett, W yori: ol.) 5 2 c0s aie © cc's e euols crn olepevetc iene © erences

Section of the Morrison formation a short distance east of the above......

Section of the Morrison formation on the north side of Moores Canyon, 214

miles northwest of Hulett, Wyoming..................--ceceeeeeees

Section of the Morrison formation 214 miles west of Bellefourche River,

AWAY OMIM irc cts orcye Sicuc lel sel staice else, Sele isicigheiues ata Gicieieleresereieuniscsdone gh et eee

Section of the Morrison formation 3 miles south of Rapid Gap, South

TES) DNS Oe eee caatiee ec Toe (ure e NE etal ancagualalisve love cNevtecalle Glos iaverele teak Catan ea

Section of the Morrison formation on the Bellefourche River, Wyoming...

Section of the Morrison formation on Inyan Kara Creek, Wyoming.......

Section of the Morrison formation at Sheldon Post-office, Wyoming.......

Section of the Morrison formation at Kara Peak, Wyoming...............

Section of the Morrison formation on Beaver Creek, Wyoming............

Sections of the Morrison formation showing decrease in thickness from

southwestern Colorado northward.......-.....seee eee cece eee e reece

Sections of the Morrison formation showing decrease in thickness from

southwestern Colorado northeashward. sceo.c.s se. .es.e «sce

Page

101

103

104

105

Test Figures

Page

Sections of the Morrison formation showing decrease in thickness from

MESternECOlLOLAGOVCASEWALG. «6 lisse cnc cca s deselccuceneeseessccvese 114

Type of cross-beding usually known as the stream type.................. 116

Type of cross-bedding usually known as the wolian type................. 117

Diagrammatic section of the exposure of the Morrison formation at the

Marsh-Hatcher dinosaur quarry, near Cafion City, Colorado.......... 118

Red hematitic grit, from the top of the Morrison formation at Garden

Bark. near Canon City, Colorado: ...sc06.. 02. cece esas esc s cc ec cree 119

Fine grit, from near the top of the Morrison formation at Garden Park,

SE DHREESEC OEE aM r feeer as Say erie oe cairo fait oaldla vicw seh ee aiviietee Gea ede 120

Argillaceous limestone or calcareous clay, from the lower part of the Mor-

rison formation, near Mack, Colorado................eee eee eeceeees 121

Calcareous sandstone, from the lower beds of the Morrison formation at

Cra RGen meat Kee COLOLAM OM a: sishite, siaiexsns.cieieid esis ee sis ach eialees ¢eiele selva eveua este 122

Calcareous arkosic sandstone, from the lower beds of the Morrison forma-

tionmabiGarden Park. \COlOTaAdOn. s.:26 sos ccc cece ec wees ce seleeiee ules 123

Caleareous argillaceous sandstone, from the Morrison formation near

Waiirome CiGyAn COOL ATOZ irsce ler ctevele lee sieilclavaneigusvele wie are duds lain eipiarenete eceeelelse 124

Fossiliferous limestone, from the Morrison formation near Cafion City,

MOTT Ol Olneyeres erecta hoiereteis niece re cicleteee cose gd ai eteslaberelsiel crs slehs Greets ure Shere Bie 125

Caleareous arkosic sandstone, from the Morrison formation near Cafion

SHIRT 60.0'a Cab BG RiBIS CIO eed Carano PRONE EONS NCI tf te Sirliaea Pa 127

The same slide and field as above, with crossed nicolS.................-.-- 128

Caleareous arkosic sandstone; the same as above..................-45--- 129

A tributary of the Grand River near Mack, Colorado..................-. 167

Cascade peneplain. From head of Miller River Basin.................... 206

Skykomish Mountains at Berlin. Skykomish River in foreground........ 206

Sleykounishmvallev at CLMM Aci. iets sede atensiere,siclsloe efeievea lisie ain eiselsia ace eles 207

Glacial lake. La Bohn Mountain in distance. On Foss River trail....... 207

Lake Katharine. Glacial trough lake on Foss River drainage............ 208

Run-off at Berlin from Miller River drainage basin................0e0e2. 208

Block diagram of a portion of the Skykomish Basin..................... 209

ATHONOM,. BAL TEARS seo SSIS oy CRORE CREOLE SRC RTM ICS ry ae ra ge 216-241

vii

Cs AB: Ge

; fe ee

‘s y ae , ta?

; PRN Wo Dae te pepe ade

. : is 9 0 4. 0ee ©

—™

ieee =D. BARBOUES Fe ty

_ WITH SUPPLEMENTAL NOTE

pa F W. D. Marriew

. _ NEW YORK a

_ PUBLISHED BY THE ACADEMY — cok

Seg 25 JANUARY, TOTG sc Se eee

oP THE. B XE YORK AC Ee

Sea eE . Orrioeas, 1916

President Mona snake Puri, Columbia Univesity te

Vice-Presidents—Bnwwst E. Sirs, J. McKrnn CATTELL, | .

. _Doveras W.J OHNSON, “Hermann VON We

reir er—Henry J. Cocnran, 389 Fifth fea re ae ne

se | Librarian—Ratpu We. Tower, American Museum i peace

ne Bditor—Epuunp Ons Hovey, American Museum ee: ok

oe "SECTION OF ASTRONOMY, PHYSICS AND CHEM.

i . one Back = Mitean Kh. Surrn, ED. Bast 41st Street = o aa

- --Seeretars es B. Lavine, College of Physicians and 3

a 4 y a F y Foy de

ee eS REO TION ON BIOLOG RVs

be a. Chairman —Feraann von W. Souvere, College of Phy i

. : Surgeons aap a ohh

3 Seer eta y—Wiuta K. Grngory, American Musenm

rl svoaes SBOTION OF GBOLOGY AND. MINERALOOY

Esa ee Chairinin Dowd AS W. JOHNSON, Colum! p1a University

Secretary —Curesten A. Repos, American Museum :

Chaltman Sie McKEen eae. ‘Columbia ge ee ae

- Secretary—Rowert H. Lowrs, American Museum | .

s “The sessions of the Bewleny are Hela on Monday ‘evenings gs a

ey “clock from October to sore inclusive, at the American. iene

[Annats N. Y. Acap. Scr., Vol. XXVIJ, pp. 1-15. 25 January, 1916]

SOME REMARKS UPON MATTHEW’S “CLIMATE AND

EVOLUTION” ?

By T. BarBour

WITH SUPPLEMENTARY NOTE

By W. D. MattHew

| (Presented by title before the Academy, 13 December, 1915)

“Climate and Evolution,” which is really more than its title would

imply an essay on the origin and dispersal of vertebrate life, appeared

in February, 1915, from the pen of Dr. W. D. Matthew.? It is by far

the most scholarly and carefully constructed essay of its kind which has

appeared and it demands a careful reading by all who take interest in

perhaps the greatest of biological problems—the why and wherefore of

the dispersal of animal life as we find it to-day and the past history of

present conditions.

’ Matthew’s thesis, in a few words, is that the permanence of the conti-

nents and ocean basins is a surely established fact, that cyclical climatic

change has been the principal known cause of the present distribution of

land vertebrates, and that this distribution has been effected by successive

southward migrations from a holarctic center of dispersion, and that the

impetus for these migrations is to be found in the theories of the “Alter-

nations of moist and uniform with arid and zonal climates, as elaborated

by Chamberlin.” There is small occasion for me to review or criticise

the great bulk of evidence which Matthew has presented, specially where

he has drawn upon his profound knowledge of recent and fossil mammals.

In the main his contentions are highly convincing, especially where he

also draws conclusions from the mammals, a group for which geologic

record is adequate in comparison with the fragmentary evidence regard-

ing the history of recent birds, recent reptiles and amphibians. With

some of these groups, as, for instance, Hylids and Cystignathids, it is

hard to rid oneself of the belief that their origin was antarctic and not

holaretic, for the northern outpost species seem to be so obviously the

depauperate offshoots of the elaborate southern stock. Matthew, however,

would argue by analogy with mammalian evidence that these species are

i Manuscript received by the Editor 22 October, 1915.

2Ann. N. Y. Acad. Sci., vol. 24, pp. 171-318. 1915.

2) ANNALS NEW YORK ACADEMY OF SCIENCES

reéntrants into the area of origin, and that the great result of speciation

which we see now in the southern headquarters of Hylids and Cystig-

nathids shows that this region was peripheral in relation to their area of

origin. The steps of reasoning whereby Matthew arrives at these con-

clusions are carefully presented in his essay and there is no object in

recounting them here.

It is of the general question of land bridges and of the relation which

some islands bear to continents that I have been thinking for some time.

and it is only because I have had some field experience and have given

thought to these matters that I have the temerity to take issue with Dr.

Matthew, knowing full well that many will maintain that his opinion

outweighs mine—a possible assertion I am by no means ready to deny.

I take exception to statements such as this, where in speaking of land

bridges (p. 179) Matthew says, “I can see no good reason why the only

animals which availed themselves of such continental bridges should be

the ones which might be accounted for in other ways, while those which

would furnish conclusive proof are invariably absent.” (Italics are

mine.) I have maintained elsewhere that a waif fauna is easily recog-

nized as such, and that the presence of burrowing amphibia, onycho-

phores, cyprinodont fishes and many other groups of delicate organisms

which are balanced to one particular environment cannot by any stretch

of the imagination be distributed by “flotsam and jetsam” methods; and

further that the element of the vast extent of geologic time does not in

any way affect the probability of such dispersal, since it cannot be sup-

posed ever to occur. .

Again, on page 187, we read that Austromalaya is the debatable ground

between the Oriental and the very distinct Australian region; but that

the consensus of opinion classes it by preference with the Australian. It

includes, we are told, Celebes, the Moluccas, Timor and the smaller

islands and is separated from the Oriental region by “Wallace’s Line.”

This is surely a step backward, for “Wallace’s Line” marks the limit of

but a small fraction of the whole species total of the Indonesian fauna,

while the area from the Lesser Sunda Islands and Celebes on the one

hand to Papuasia on the other represents a great transition zone, where a

dominance of Malayan types may be found in the western part which

merges into a predominance of Australian types in Papua. There is no

real boundary line in the entire area and no reason to expect one.

Again Dr. Matthew in his “Summary of Evidence” (p. 308) states

that “the continental and oceanic areas are now maintained at their dif-

ferent levels chiefly through isostatic balance and it is difficult to believe

that they could formerly have been reversed in any extensive degree.”

BARBOUR, MATTHEW'S “CLIMATE AND EVOLUTION” 2

Then, on page 309: “A rise of 100 fathoms would unite all the continents

and continental islands, except perhaps Australia, into a single mass, but

would leave Antarctica, New Zealand, Madagascar, Cuba and many

smaller islands separate.” These four areas Matthew believes to have

been always isolated islands, and if we can show a probability that any

one of them was continental, we can at least make more reasonable a

proposition that they all were once united to some other continental land.

This point will be returned to later on.

Now a word regarding isostasy. There is hardly a principle in geology

concerning which there is greater uncertainty among geologists than the

matter of isostatic balance. Only one thing is sure, isostasy must meet

and conform to known or presumably known facts, and the fact that

fundamental changes have taken place in the form of the earth’s surface

in recent geologic time is not to be denied. Such features as the Great

Rift Valley of Africa and its continuation, the Red Sea and the Dead

Sea, the Black Sea, the Basin of the Mediterranean, are held now by

geologists to be the results of nothing but gigantic and not at all ancient

down-thrown fault-blocks. For other examples of changes of land and

sea level with relation to each other, the Valley of the Po and the Central

Valley of California are good evidence. The argument of isostatic hal-

ance may probably be held to control the conditions in the Pacific Basin

as a whole, but isostasy cannot be used effectively as an argument in a

relatively small area anywhere. Professor R. A. Daly tells me that there

is clear evidence of the fragmentation of a great land mass, including the

Fiji Islands and New Caledonia, but that there is no evidence known at

present of such a condition outside of a line joming Yap, in the Caroline

Islands, the Fijis, Kermadecs and New Zealand. Besides this radiolarian

ooze has long been known from Barbadoes, Trinidad, Aruba, Buen Ayre

and Curacoa, supposedly only to be derived from the deep sea, but the

origin of this series of deposits has been somewhat in dispute. ‘Two re-

cent papers by Dr. G. A. F. Molengraff, however, describe deposits of

which there can hardly be any question whatever; one is “On Oceanic

Deep Sea Deposits in Central Borneo,” * while the other is entitled “Over

mangaan Knollen in mesozoischen diepzeeafzettingen van Borneo, Timor

en Rotti, hun beteekenis en hun wijzer van Opstaan.”* These papers

show that on the islands of Borneo, Timor and Rotti, at an elevation of

about 4000 feet, very extensive deposits occur which a microscopical ex-

amination shows to be composed of radiolaria, together with the manga-

nese nodules so characteristic of the deep sea. In other words, Molengraft

2 Kon. Ak. Wet. Amsterdam, Reprint from Proc. of meeting June 26, 1909, pp. 141-

147. [Reprint, pp. 1-7.]

4IXon. Ak. Wet. Amsterdam, vol. 23, pp. 1058-1073. [Reprint, pp. 1-16.]

4 ANNALS NEW YORK ACADEMY OF SCIENCES

has found an extensive area of deep sea floor raised to 4000 feet above

the present sea level. On the southeast coast of Africa, W. M. Davis

noticed the truncation by the present shore line of extensive concentric

terraces, traceable far inland, which could only mean the down-faulting

of a gigantic block of material to bring the shore line into its present

state. It will be said at once that some of these changes of level have

taken place in zones known to be in incomplete isostatic adjustment, but

this is a matter of no moment whatsoever in comparison with the fact

that change of level may be found to have occurred in the very areas

where the islands under discussion are to be found. Celebes does not lie

upon the continental shelf and yet the island has an obviously continental

fauna, and Dr. Matthew has told me himself that Celebes has been a

source of no small worry to him. Cuba has similarly a large fauna, de-

rived from the American continent, although it does not lie upon the

continental shelf. Vaughan, a thoroughly conservative observer, believes

(in litt.) that Cuba was quite possibly separated, by the down-faulting

of blocks of material, from both Haiti and the mainland. Dr. Matthew

(in litt.) says: “The fault block theory is of course a very familiar one;

its application to continental movements is undoubtedly extensive, al-

though it is just now somewhat of a fetish among stratigraphers, as folds

were fifty years ago. But on land the great fault blocks are largely com-

pensated by erosion, so that they do not involve so extensive a displace-

ment of adjoining surfaces as one might at first suppose. Their applica-

tion to explain submarine conditions where such compensation does not

occur brings them into an apparent conflict with isostatic adjustments.

Considering that we cannot possibly prove their responsibility for the

sudden changes from shallow sea to abyssal depths in any case, I am in-

clined to avoid hasty ascription to such features as block-faulting. JI have

passed beyond the stage of immaturity when one is unreasonably certain

about things.” I can only add that I am as far from being unreasonably

certain regarding isostatic adjustments in general as Dr. Matthew is re-

garding marine down faults. To the zodlogist these geologic problems

seem so differently interpreted by different and equally gifted and trust-

worthy students that one is inclined to relegate them all to the limbo of

where “you pay your money and take your choice.”

Vastly different, however, is the matter of the zodlogic evidence pre-

sented by the faunas of some islands as indicative of the island’s geologic

or geographic history. Dr. Matthew lays great stress upon the importance

of the mammalian element in the fauna. Here a word of caution is not

amiss, for mammals act queerly upon islands and often have a way of

being most strangely absent, as this is the group which has greatest diffi-

BARBOUR, MATTHEW'S “CLIMATE AND EVOLUTION” 5

culty in surviving in a limited area. Trinidad, a large island separated

by a very narrow strait from Venezuela, has a reasonably full quota of

mammalian inhabitants, while the large and heavily wooded island of

San Miguel, just off the coast of Panama, has but a few small mammals,

quite a contrast to Coiba Island, farther north off Honduras, where even

a peculiar deer is known still to occur. Gorgona Island, off Colombia,

also with luxuriant vegetation, has a peculiar Cebus (Cebus curtus

Bangs), a peculiar Proechimys, and so far as known no other mammals.

Yet these differences are all among islands on the shelf and near or fairly

near the shore; and I could multiply the examples!

Now I do not believe, with Matthew, that the Antilles are oceanic

islands—islands which have received their fauna by fortuitous trans-

portal. My reasons for thinking as I do are these: First, I believe that

the islands of the Antillean chain have too evenly distributed and homo-

geneous a fauna for it all to have been fortuitously derived; secondly, I

consider the fauna to be composed of too many different animal phyla;

and thirdly I believe that many of these elements are not of a nature to

have withstood “flotsam or jetsam” dispersal. We must now consider

Matthew’s exposition of the natural raft hypothesis (p. 206 et seq.). He.

states: “1) Natural rafts have been several times reported as seen over a

hundred miles off the mouths of the great tropical rivers such as the

Ganges, Amazon, Congo and Orinoco. For one such raft observed, a hun-

dred have probably drifted out that far unseen or unrecorded before

breaking up.” This is obvious and undoubted. But, and this is most

important, these rafts, even the very large ones, float low in the water;

they soon become soaked with salt water in a calm sea, rippled over or

broken over if the sea be choppy or rough as it is in the trade wind or

monsoon belts. Only organisms or their eggs which are encapsulated or

otherwise naturally resistant can withstand these conditions. Molluscs

are stimulated to activity by dampening, but most are killed by salt

water—although some such as Cerion are resistant. Scincs and Gekkos

show by their distribution that they may be carried about in this way.

Amphibians, amphisbeenians, naked gastropods, earthworms, fresh-water

fishes or crayfishes, Peripatus and a host of such delicate creatures simply

cannot withstand salt water. No such creatures have ever been observed

upon any raft, of the very few recorded, and to transport cyprinodonts,

ampullarias and the host of other fresh-water types one meets with in

Cuban ponds, for instance, the raft would have to include a puddle, at

least, of fresh water. Supposing that an amphisbeenian, to take a good

example, withstood an ocean voyage upon a raft, how would the landing

take place? The raft would have to make a haven and then ground in

6 ANNALS NEW YORK ACADEMY OF SCIENCES

such a way that a very delicate, blind and legless lizard would be enabled

to reach a suitable environment on shore. I only ask the reader to tramp

West Indian shores with this in mind. If a pair or a gravid female did

not make the voyage the process would have to be repeated promptly.

Now consider the number of rafts each of which would have to carry an

~ amphibian or a pair of them and which would have to start on their

journeys before one would reach shore so as to permit a landing such as

I have indicated Think of the number broken up at sea, and the still

ereater number broken up on a tropic beach—where the sun would in-

stantly lall crawling amphisbenians—and we see at once how excessively

improbable is a single occurrence such as this. But the important point

is that five West Indian Islands support peculiar amphisbeenians; two

species occur upon Cuba, two others related to these two on Haiti and

two others similarly related to the Haitian types on Porto Rico, while

but one type is as yet known upon St. Thomas and Sta. Cruz. To ac-

count for the presence of these creatures, then, eight practically mcon-

ceivable voyages must be postulated, and I have only cited one improb-

ability out of many hundred necessary to derive all the organisms prac-

tically or wholly incapable of such sea travel and which are found in the

Greater Antilles. A few such cases as Amphisbzena settle the status of

the greater Antillean fauna to my mind absolutely, paucity of mammals

and possibly disputable geologic evidence to the contrary notwithstanding.

Matthew’s second premise is: “2) The time of such observation of

rafts covers about three centuries (I set aside the period of rare and oc-

casional exploring voyages). The duration of Cenozoic time may be

assumed at three million years (Walcott’s estimate).” But is it not true

that this multiphcation of time or any other, of course, affects only the

number of rafts and does not in any way alter the resistance to raft con-

ditions of the creatures which I have already chosen above as examples

or the possibility of their being able to swim. It really carries no weight

in this connection.

Matthew’s third point: “3) Living mammals have been occasionally

observed in such records of natural rafts. Assume the chance of their

occurrence (much greater than of their presence being noted) at one in

a hundred.” We readily agree to the assumption and know that during

the few years of human observation rafting mammais have been observed.

It occurs to us, however, that multiplying the three hundred years’ time

of human voyages by the ten thousand necessary to occupy even the short

Cenozoic period and then with this condition met, we find mammals

infinitely rarer upon all islands than they should be if rafted according

to Matthew’s postulate. Similarly we find many of the reptiles most

BARBOUR, MATTHEW'S “CLIMATE AND EVOLUTION” Dy)

capable of withstanding transport by rafts conspicuously absent in the

West Indies; for example, Basiliscus, almost semiaquatic, is absent in the

Antilles, as Varanus is absent upon Madagascar: they were possibly de-

rived in common with many other of the islands’ original continental

inhabitants and have failed to survive. We know that some edentates

and a few rodents have become extinct in the West Indies, some within

the last half century ; why, in some cases, we cannot guess; probably more

have gone the same way, of which we have unfortunately no fossil re-

mains. So also the boa-constrictor, which has been observed to be carried

once to St. Vincent from the Orimoco and which has probably come com-

paratively often, has never succeeded in establishing itself. Why some

types fail to survive upon islands while others of apparently similar habit

flourish is one of the enigmas for which no mite of answer has appeared.

Matthew’s arguments, which he numbers 4 and 5, may be considered to-

gether: “4) Three hundred miles drift would readily reach any of the

larger oceanic islands except New Zealand. Assume as one in ten the

probability that the raft drifted in such a direction as to reach dry land

within three hundred miles. 5) In case such animals reached the island

shores and the environment afforded them a favorable opening, the propa-

gation of the race would require either two individuals of different sexes

or a gravid female. Assume the probability of any of the passengers sur-

viving the dangers of landing as one in three (by being drawn in at the

mouth of some tidal river or protected inlet), of landing at a point where

the environment was sufficiently favorable as one in ten, the chances of

two individuals of different sexes being together might be assumed to be

one in ten, the alternate of a gravid female as one in five. The chance of

the two happening would be 1/10 + 1/5 == 3/10. The chance of the spe-

cies obtaining a foothold would then be 3/10 + 1/3 + 1/10 = 1/100.”

He then continues, “If then we allow that ten such cases of natural rafts

far out at sea have been reported, we may concede that 1000 have prob-

ably occurred in three centuries and 30,000,000 during the Cenozoic. Of

these rafts, only 3,000,000 will have had living mammals upon them; of

these only 30,000 will have reached land, and in only 300 of these cases

will the species have established a foothold. This is quite sufficient to

cover the dozen or two cases of Mammalia on the larger oceanic islands,

“T have considered the case only in relation to small mammals. With

reptiles and invertebrates, the probabilities in the case vary widely in

different groups, but in almost every instance they would be considerably

greater than with mammals. The chance for transportation and survival

would be larger and the geologic time limit in many instances much

longer. Wind, birds, small floating drift and other methods of accidental

8 ANNALS NEW YORK ACADEMY OF SCIENCES

transportation may have played a more important part with inverte-

brates, although they cannot be invoked to account for the distribution of

vertebrates. The much larger variety and wider distribution on infra-

mammalian life in oceanic islands is thus quite to be expected. And the

extent and limits of such distribution are in obviously direct accord with

the opportunities for over-sea transportation in different groups.”

In the estimate which Matthew has made there seems to be an obyious

error, for should we postulate 1000 rafts in 300 years we would have

10,000,000 rafts during the 3,000,000 years of Cenozoic time, not 30,000,-

000 as Matthew has it, and the chances of the whole concatenation of

events are reduced by 66 per cent. But even this reduced estimate would

if true bring more mammals to most islands than we find. Let us, how-

ever, for the sake of argument, admit that some mammals might be

transported in this way, is the premise true that other creatures will be

more easily carried? Some will, and these types by their haphazard oc-

currence can now be recognized easily; others most certainly will not.

Matthew has not realized the enormous sum total of different species

which go to make up the fauna of such islands as Cuba and Haiti. Such

a vast number of species would require squadrons of rafts at frequent

intervals, even if only ancestral stocks were transported from which many

species arose after coming to the island by some sort of adaptive radia-

tion. Another important point has also been missed. Almost all of these

isolated groups of individuals have grown to be well differentiated

island species. Distinct from the related forms of the mainland and

neighboring islands, they represent types evolved in complete isolation ;

an occasional raft bearing individuals from the parent stock would by

preventing breeding in, at least in some cases, prevent speciation by isola-

tion taking place.

Let us for a moment consider the Antillean chain as a whole; it is

utterly impossible that ocean currents could now or in the past have

brought rafts with equal frequency to all parts of this island are, and yet

the same types reappear upon island after island all the way from Cuba

to Grenada. Rafting from island to island could certainly not have oe-

curred, since there could never have been large rivers on them had they

always retained their present size. The fauna is far larger in number of

species upon the Greater Antilles than upon the Lesser, as the conditions

favorable for the survival of species are obviously better upon the large

islands with their luxuriant vegetation than upon such barren islets as,

for example, Sombrero or Redonda. The types, however, which have been

able to survive upon Sombrero or Saba are just those which are found,

along with many others, upon Cuba or Haiti. In my “Herpetology of

BAKBOUR, MATTHEW'S “CLIMATE AND EVOLUTION” 9

Jamaica” and “Zodgeography of West Indian Reptiles,” I have gone into

this matter in detail and there is no need of repeating what has been said

there. This homogeneity of the fauna is the best possible proof that

winds (tornados, hurricanes, etc.), birds, small floating drift, etc., have

played no considerable part in populating the island by carrying eggs or

adults, since it is inconceivable that by these means the same improbable

choice of passengers would be carried to so many islands.

Matthew, upon the basis of the mammalian fauna of Madagascar en-

tirely, he believes, derivable from a few waifs, and from the fact that the

island is not upon the present continental shelf, concludes that it is an

oceanic island. We may grant that all the lemurs have radiated from a

single type, and this may have been a waif type—all this for the sake of

argument—but what does the rest of the fauna show? We find abundant

amphibians of many different families, as well as a great host of other

land and fresh water organisms which cannot by any stretch of the im-

agination be considered as more probably capable of surviving raft trans-

port than mammals, nor in very many cases of possibly surviving such

transportation at all. Yet such types as these are most abundant upon

Madagascar, in individuals and in species—species representing wholly

unrelated mainland stocks and not those which might possibly have arisen

after coming to the island.

My friend Dr. G. M. Allen has contributed the following note regard-

ing Madagascar which is interesting in this connection. He writes me:

“The total absence from Madagascar of any native species of the typical

Murine seems to be a striking bit of negative evidence against a chance

population of the island. All the nine genera of indigenous rodents are

Cricetine in their affinity, though now considered to represent a special

subfamily by themselves—Nesomyine. The Cricetine-like rodents are

abundant still in the Americas, less so in number of species in northern

Eurasia. The African Lophiomys is nearly related. If we consider the

more specialized typical Murine as representing a later development of

the Muride, it is easy to account for their absence from America, if for-

' merly, as now, their northward range did not extend to the Hast Siberian

region, whence they could have crossed by land bridges if such existed.

That no member of so widespread and successful a type in the Old World

as Mus (in the broad sense) has reached Madagascar, it seems evident

that it is because none have been able to cross the intervening water. If

nine distinct genera of Cricetine-like rats or their ancestor or ancestors

could have reached Madagascar by chance methods, it seems inconceivable

that no single Murine could have done so, despite the great adaptability

and abundance of the representatives of this group. The most attractive

im.

10 ANNALS NEW YORK ACADEMY OF SCIENCES

explanation of this fact is that the more primitive Cricetine-like rodents

reached Madagascar by land connection from Africa and that they were

subsequently isolated there before the advent of the more specialized and

successful Murine, which have now totally replaced them on the main-

land.”

So much for the question of rafting—some creatures can be carried

and some—many more—cannot survive such conditions. We may recog-

nize by their haphazard distribution and by their habits in the field those

waifs which can withstand raft transport. Yet even these resistant types

are very often strangely absent; there are no Varanids in Madagascar,

and yet we should naturally suppose that they would be among the very

first immigrants by raft carriage.

This whole question is really but a side issue with Matthew. He is

far more absorbed in other problems; hence it is only fair to say that this

island question is of secondary interest to him. Dr. Matthew’s masterly

handling of his chapters dealing with mammals is beyond praise. He

has surely shown that the present distribution of most if not all of the

recent mammal groups may be plausibly explained without having re-

course to postulating extensive changes of land forms. But Matthew

deals with some other matters as one without authority, and one feels

that his opinions would be different had he seen and not merely read

about the rafts, and the landings of the rafts, of which he must perforce

write to explain his ideas.

Many will notice triflmg inaccuracies in the text, such as the statement

that the large ground-birds of modern times are “to-day peculiarly im-

habitants of arid regions.” There is the New Zealand Kiwi in the rank

damp fern forest and the host of different cassowaries in Ceram, the .

Papuan Islands, New Britain, Queensland, and anyone who has ever tried

to hunt cassowary knows how well they are adapted to getting about in

the densest jungle in the world. However, such points are of so small

import that it is hardly worth while mentioning them. My final word is

not to advise but to adjure everyone who aims at a wider knowledge of

natural history to read Dr. Matthew’s paper.

MATTHEW, SUPPLEMENTARY NOTE ae

SUPPLEMENTARY NOTE:

By W. D. MatTtHEew

Before replying to Dr. Barbour’s criticism I will say that it is of the

sort that is peculiarly welcome, not merely because of its courteous and

considerate tone, but because of the author’s wide field experience and

knowledge of the practical conditions and circumstances of environment

that govern the probabilities of any theories of distribution. However we

may differ in our interpretation of the evidence, we agree in emphasizing

these factors, in the impossibility of solving such problems by the study

of any one group of animals, and especially in the need for securing more

complete distributional data, towards obtaining which he has devoted so

much time and energy. |

Many a false theory gets crystallized by time and absorbed into the

body of scientific doctrine through lack of adequate criticism when it is

formulated. I should be very sorry to see that happen to the views that

I have maintained and hope that adequate and competent criticism will

serve to sift out truth from error before they are either adopted or dis-

carded.

Concerning the question of isostatic adjustment I do not think it neces-

sary to make any especial comments. I stated in the outset that I was

applying the geological views set forth by Chamberlin and others. The

evidence that Barbour cites was known to me and is covered by the quali-

fying phrases that I used; but the general discussion of the permanence ~

of ocean basins I shall continue to avoid.

Dr. Barbour devotes considerable space to a criticism of my attempt at

a statistical presentation of the possibilities of “rafting.” He is indeed

far less critical of its assumptions than J am. I tried to make it clear

that its sole purpose was to show that the hypothesis involved not “mire-

cles of transportation” or infinitesimal chances but reasonably probable

chances. The quite inexcusable error in my figures to which he calls at-

tention is not really material, nor is his conclusion that the calculation

shows too many mammals for the known or inferential instances (I do

not see that it does, by the way; but as the point is immaterial will pass

it by). The main reason for introducing a calculation based upon a

series of highly inexact approximations was to determine whether this

method of transportation would afford a reasonably probable alternative

to continental connection, in accounting for the presence of mammals on

5 Manuscript received by the Editor 12 November, 1915.

12 ANNALS NEW YORK ACADEMY OF SCIENCES

certain oceanic islands, in which it appeared impossible to explain the

characters of the mammal fauna upon any reasonable hypothesis involy-

ing continental union.

When it comes to applying the rafting theory to lower vertebrates and

invertebrates, Dr. Barbour is quite right in insisting that one should

have a special knowledge of the particular habits of each group in order

to judge of possible or probable methods of its transportation. Because

I lack that especial knowledge and field experience I avoided discussing it.

I do not know how far the rafting theory is applicable to account for

their distribution, and how far it may be more reasonably explained in

other ways. But I do notice that Barbour appears to consider only the

transportation of the adult animals, and says almost nothing about the

possible transportation of their eggs. It is just because mammals do not

lay eges that their presence in oceanic islands seems peculiarly difficult

to account for, save through former union with continents. Wallace, it

will be remembered, for this reason regarded their presence as a depend-

able criterion of such union. Like most students of geographic distribu-

tion, I started from Wallace’s views as a basis, and if I have modified

them in an opposite direction from many of my confreres it is because I

found that in certain particulars they did not fit the details of distribu-

tion, past and present, in the groups with which I am best acquainted. If

mammals laid eggs, and especially if the eggs were numerous and of very

small size, I should find it far easier—indeed quite too easy—to account

for their presence on oceanic islands; the difficulty would be to account

for their general absence. It is because they do not that I was compelled

to discuss a rather complex hypothesis to account for their presence in

Cuba, Madagascar and elsewhere. There are numerous other accidental

means of transport which might be and have been invoked to account for

dispersal of lower animals, but the ones J discussed were the only ones

that, so far as I could see, would be possible for mammals. And for very

large terrestrial mammals these seemed to me physically impossible. But

no such mammals closely allied to continental ones are found on any

oceanic islands;° those remotely related are derivable from the much

smaller and more generalized ancestors which we find living in older

epochs on the continents, and it is these small common ancestors whose

dispersal must be accounted for.

It is the above considerations that underlay the remark to which Bar-

bour takes exception on page 2. I do not think his objection is war-

ranted, for while I do not question his judgment as to the improbability

6 There are certain exceptions to this statement—Malta, Cyprus, Crete and Celebes.

These exceptions do appear to call for continental union.

_—————————

MATTHEW, SUPPLEMENTARY NOTE 13

of transporting certain types of adult reptiles, amphibians or inverte-

brates in the particular way that I have used to account for certain pecu-

larities in mammalian distribution, yet the transport of their eggs is a

much less serious difficulty, and there are several other possible methods.

These have been extensively discussed by others and I need not go into

them. While it does not seem physically possible, for instance, that a

mammal could survive being caught up by a hurricane or tornado, car-

ried a long distance and dropped, I do not see any particular impossi-

bility mm the transport of young or eggs of amphibians or reptiles or in-

vertebrates by such means. Indeed there is considerable evidence along

this line on record. And if it be not a physical impossibility, then the

element of geologic time does enter into the question of its probability.

So far as the West Indies are concerned, I do not at all suppose that no

one of them has ever been united to any other. All are in lines of great

disturbance and uplift; several are united by shallow platforms, and I

see no reason at all against accepting Vaughan’s view that Cuba and

Haiti were probably united during the Tertiary, although now separated

by a deep water channel. The mammalian evidence would accord well

with that view, and recent discoveries in Porto Rico rather suggest that

that island, as well as the Bahamas, may have been included in the union.

But the mammalian evidence seems to me distinctly against any direct

union with either North or South America in the middle or later Ter-

tiary, and fairly conclusive against any such Pleistocene union. Indirect

union, with an isolated Central American or Floridian island serves to

raise problems of dispersal more difficult than any that it solves, because

we have no past distributional evidence to go upon. It is too speculative

to be worth discussion.

Dr. Barbour’s criticisms deal, as he very cordially and generously in-

sists, with a side issue of the main discussion in my paper. I may add

that it is a side issue concerning which I have no desire to be dogmatic

or positive.

My- statement that the large ground birds are to-day peculiarly inhab- _

itants of arid regions should have been more carefully qualified. It re-

ferred especially to the three large forms—the ostrich, rhea and emu—

characteristic of the arid interior of the three southern continents. I had

not meant to say that there was any such uniform association of habitat

as the remark may seem to imply.

In reply to Doctor Allen’s argument concerning Madagascar Cricetines,

the following points may be considered :

1) All the Malagasy rodents belong to a peculiar group of Cricetines,

the Nesomyine ; that is to say, if the classification is a natural one they

14 ANNALS NEW YORK ACADEMY OF SCIENCES

are descended from a single stock, a single ancestral type, and as the

group is peculiar to the island the inference would be that its differentia-

tion took place after it reached the island and not before. The arrival of

that type represents therefore one invasion and not nine.

2) The Cricetines are the older group, prevalent in Holarctica since

the beginning of the Olgocene and presumably widely spread in the

Ethiopian and Oriental regions during the Middle and later Tertiary.

The Murines are a much later development and comparatively recent

immigrants into the tropical Old World, where they have supplanted the |

older Cricetines more completely than in the less accessible tropical New

World. The Cricetines have therefore had a much longer time than the

Murines to reach Madagascar through accidental transportation ; it is to

be expected that the single stock which arrived should be a Cricetine.

3) The Malagasy lemuroids, Gregory has recently shown, all belong to

a single group, distinct from any of the continental lemuroids, and may

equally be supposed to represent a single invasion. But the wide differ-

entiation indicates that this invasion must be a much earlier one than

that of the Cricetines.

4) The Carnivora—all viverrines—are not so clearly derivable from

a single stock, but they may be so (Cryptoprocta, although highly special-

ized, is fundamentally a Middle Tertiary viverrine). The date of arrival

ean hardly be much later than Oligocene, and certainly not earlier.

5) The insectivores—all Centetidee—are likewise derived from a single

stock, peculiar to the islands, its only continental relative being the

Potamogalids. The diversity of the ec: Centetids indicates an

early Tertiary invasion.

6) The pigmy hippopotamus must be a late arrival, for the Hippo-

potami were not evolved until the late Tertiary, and no adaptive radiation

has occurred in Madagascar.

7) An Hocene land connection and subsequent isolation might account

for the Lemurs and Centetids, but would not allow of land invasion by

Viverrids, Cricetines or Hippopotami. We should expect also that at

least some remains of the Eocene ungulates and creodonts would survive,

since they were not displaced by higher types as on the mainland.

8) An Oligocene land connection with isolation before and after might

explain Lemurs, Centetids and Viverrids, but not the Cricetine group

and certainly not the Hippopotami, and would be difficult to reconcile

with the absence of monkeys and of the primitive ruminants and pro-

boscideans (all already in Africa in Lower Oligocene).

9) A Miocene or Pliocene land connection with isolation before and

after would explain the Cricetines, and either the Viverrines (if early)

MATTHEW, SUPPLEMENTARY NOTE 15

or the Hippopotamus (if late), but hardly both. It would be irrecon-

eilable with the presence and diversity of the Lemurs and Centetids, the

absence of monkeys and of the rest of the later Tertiary mammal fauna

of Africa.

10) A land connection throughout the Tertiary would account for the

presence of the few mammal types that have reached the island, but not

for the complete absence of the very numerous groups of several succes-

sive faunas which are not present. The amount and character of the

adaptive radiation among the half dozen stocks that are present indicates

the absence of monkeys, ungulates, cats etc. in the past as well as in the

present, as also that the half dozen different elements of the mammalian

fauna were due to invasion by single types at several different epochs.

The indicated epoch corresponds in each case to the time at which the

geologic record indicates that their ancestral stocks were prevalent on

the adjacent mainland.

11) Madagascar, it should be remembered, is an island of almost con-

tinental size and great geologic antiquity. It is not a transitory islet,

such as Barbour cites in support of his contention that mammals behave

strangely on oceanic islands. Ifa continental fauna once gained access

to it there would be no reason for its extinction, nor opportunity for the

expansive radiation of a few stocks. If Doctor Allen’s explanation were

correct, the relations of the fauna to the Ethiopian should be similar to

those of Borneo or Sumatra to the Oriental mainland fauna, save for a

wider amount of differentiation from the late Tertiary and Pleistocene

invaders of the Ethiopian region. The briefest summary of its character,

such as is given above, is enough to show how widely it differs from that

type.

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| EXTINCT OCTODONT FROM THE

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wap vone .

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We So wo PANUARY, 1916 0 -2c se Oe se

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_ [Awwats N. Y. Aca. Scz., Vol. XXVII, pp. 17-22, Pll. I-V. 25 January, 1916]

AN EXTINCT OCTODONT FROM THE ISLAND OF PORTO

RICO, WEST INDIES *

By J. A. ALLEN

(Presented in abstract before the Academy, 8 November, 1915)

CONTENTS

Page

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SinTETEDIERT. oo ¢ OOD aE nen OO CBS De Die ODDIE Oo ais Oe nico ao Crt 22

INTRODUCTION

The mammal remains here described were taken from a cave near the

center of the island of Porto Rico in excavations directed by Dr. Franz

Boas, in charge of the anthropological division of the Natural History

Survey of Porto Rico, now being carried on jointly by the New York

Academy of Sciences and the American Museum of Natural History, in

. codperation with the Government of Porto Rico. These remains have

been kindly placed in my hands by Dr. Boas for determination. Aside

from a few human bones, they consist almost wholly of the bones of a

large rodent allied to Plagiodontia.? With them are a few bird bones,

too imperfect for satisfactory identification. These have been referred to

Mr. W. De W. Miller, Assistant Curator in Ornithology in the American

Museum, who informs me that they represent, principally at least, a

pigeon and a parrot, the latter probably referable to the genus Amazona.

In reply to my inquiries regarding the manner of occurrence of these

1 Manuscript received by the Editor, 27 November, 1915.

2There is a single dorsal vertebra of a much larger animal, as yet not determined.

(17)

18 ANNALS NEW YORK ACADEMY OF SCIENCES

remains, Dr. Boas has kindly furnished me (in litt.) with the following

details: “The remains were found in a heavy deposit of ashes in a cave

in the Jobo district, between Utuado and Arecibo. In the same deposit

was the burial of a child. A very large number of shells of crabs and of

various kinds of snails were found. The deposit was undoubtedly arti-

ficial. I do not believe that it was purely an accumulation of kitchen

refuse. It seems more likely that it was made for some other purpose.

There is no indication of post-Columbian disturbance of the deposit, but

I do not presume that it is more than a few hundred years old.”

The mammal remains include nearly 400 pieces, representing- nearly

all parts of the skeleton, and all are apparently referable to a single spe-

cles. They are for the most part fragmentary, but some of them are

complete, there being entire bones of all the principal parts of the skeleton '

except the vertebrae and the feet. They are lightly coated with a gray

ashy covering, easily removed with a soft brush, and have the appearance

and general character of recent bones, having undergone no mineraliza-

tion nor much discoloration. These remains may be listed as follows:

20 skulls, none of them quite complete, the occipital and parietal, re-

gions and the nasals being usually lacking, while many consist of only the

middle portion of the skull.

150 mandibular rami, including a score or more in nearly perfect con-

dition ; in many the condylar portion is defective or wholly lacking.

15 scapule, including several nearly entire.

1 clavicle, the distal end wanting.

15 humeri, several complete and others nearly so.

30 ulne, mostly well preserved. ae

10 radii, mostly in good condition.

25 femora, some perfect, others nearly complete.

40 tibiz, many in good condition. ~

5 fibule, mostly in fair condition.

1 sacrum, almost perfect. ;

50 ribs, many well preserved.

50 imnominate bones, a few with the ‘borders only shghtly abraded,

but the greater part are fragmentary.

Besides the above, there are several hundred fragments of little or no

scientific value. aa

These remains indicate an animal about the size of Capromys pilorides,

but with a broader and shorter skull, and a slenderer body and longer

limbs. It differs widely in dentition from Capromys, in which respect it

approaches Plagiodontia, as it does also in the size and shape of the skull.

It is generically distinct from either, and may be described ‘as follows:

Al =e,

Seal ‘

Rta

ALLEN, HXTINCT OCTODONT FROM PORTO RICO 19

Isolobodon ®* portoricensis gen. et sp. nov.

Type, No. 38409a, from the Cuerva de la Seiba, near Utuado, Porto Rico;

coll. Dr. Franz Boas. The type skull has the nasals and entire upper dentition

complete, but lacks part of one zygoma and the braincase posterior to the

fronto-parietal suture.

DESCRIPTION

Skull—The skull (Plate I, Figs. 3-8) closely resembles in outline and

proportions that of Plagiodontia, being shorter and broader than the skull

of Capromys. ‘The most nearly complete skull of the series (No. 38409bD),

which lacks only the nasals, the occipital region and most of the teeth,

when laid over F. Cuvier’s outline figure of the skull of Plagiodontia* is

found to be essentially of the same size and form. The lower jaw is of

the same size, but differs somewhat in the form of the condylar portion,

which, however, is not well shown in Cuvier’s plate. The nasals are of

nearly uniform breadth from base to tip, widening only slightly and

uniformly from the base anteriorly.

The most nearly complete skull of the series is above the average in

size, and is also evidently the skull of a very old individual. This skull

affords the followimmg measurements: front border of premaxillaries to

occipital suture, 73 mm.; length of frontals on midline, 28; length of

parietals on midline, 25; length of rostrum, 25; width of rostraah at

anterior root of bonuses 13; depth of rostrum at same point, 19; inter-

orbital breadth, 25.4 ; somatic breadth, 48.5; greatest breadth of brain-

case (at posterior ee of zygomata), 24; palatal length, 33.5; breadth of

palate between premolars, 3; breadth of aillate between last molars %, the

toothrows being strongly convergent.» The type skull, fully adult but

smaller and evidently younger than No. 38409b, furnishes the following:

Interorbital breadth, 22; length of frontals on midline, 25; length of

nasals, 25; breadth of nasals at base, 8.2; breadth of nasals near front

border, 9; length of maxillary toothrow (crown surface), 16.5; palatal

length, 33.5; palatal breadth between premolars, 2.5; palatal breadth

between last molars, 7.5; greatest breadth of skull ae base of

zygomata), 26.

The size of the lower jaw (Plate I, Figs. 1-2; Plate IL Figs. 1-4, 8-9)

varies greatly in different specimens, appar ong due mainly to age but

perhaps partly to sex. Adult mandibular rami vary in total length (base

of incisor to tip of angular process), from ahout 48 to 56 mm.; depth at

%fcos, equal; NoBds, lobe; ddWy = dd0vs tooth. In allusion to the equal lobes of the

molar teeth.

4 Ann. des Sci. Nat., ser. 2, VI, 18386, pl. 17, fig. 3.

90 ANNALS NEW YORK ACADEMY OF SCIENCES

m*, 12.5 to 14.5; depth at coronoid process, 17 to 22; depth at condylar

process, 18 to 24 mm.

The maxillary toothrow (crown surface) varies in length, in adults,

from 15.5 to 17 mm.; the mandibular toothrow from 17.5 to 19 mm. ‘The

teeth evidently increase in size with age, not only in length and breadth

but in height, becoming more hyposodont as well as larger in old adults,

and the angles of the folds more prominent. |

Dentition—In Capromys the transverse axis of the molar teeth forms

a right angle with the axis of the toothrow; in Plagiodontia the trans-

verse axis of the molars is highly oblique to the axis of the toothrow

(Plate II, Fig. 10) ; in Isolobodon the obliquity is about 45° °. The in-

cisors are weak, nearly flat on the outer face, without grooves, and rounded

on the inner face. Their color, still well preserved, is pale yellow.

The molariform teeth in Isolobodon (Plate II, Figs. 5-7) resemble

those of Plagiodontia in size and shape, in the obliquity of their inser-

tion, and in the number of folds on the outer and inner borders, but not

at all in the enamel pattern. They are thus modeled on a basis common

to both types, and both thus differ widely from the teeth of Capromys.

In Plagiodontia the cement area of the crown surface of each tooth con-

sists of three transverse divisions, united and continuous, thus constitut-

ing a single sigmoid area, deeply cut by the infolding of the enamel

border. In Isolobodon the cement of the crown surface of each molar

forms two transverse, nearly equal oval lakes, entirely separate and encir-

cled by an enamel border. The enamel walls of the two loops touch each

other by a slight point of contact near the outer border of the upper teeth

and the inner border of the lower teeth. The enamel pattern of the lower

molars differs from that of the upper through a deep indentation of the

anterior enamel lake by the infolding of the enamel border on the inner

side of the front third of the tooth.

All of the molars have each two vertical ribs or folds on both the ex-

ternal and internal borders, but the upper premolar differs from the

molars in having three external and two internal. The lower molars have

each three external and two internal folds. The lower premolar has three

folds on each side, but the anterior fold is greatly reduced in depth, and

thus gives rise to a small trefoil termination to the crown surface of the

front border of the tooth.

The upper teeth successively decrease in size from the premolar to m°,

5 If the upper molar series is correctly represented in Cuvier’s plate, the maxillary

teeth in Plagiodontia have the transverse axis of the teeth nearly coincident with the

longitudinal axis of the toothrow, while in the mandibular series the angle is only about

45°, as in Isolobodon. I cannot resist the impression that the obliquity of the maxillary

teeth is highly exaggerated in Cuvier’s drawing.

ALLEN, HXTINCT OCTODONT FROM PORTO RICO o1

which is only about half the size of m*. The lower teeth are of nearly

equal size, except that the premolar is narrower than the molars, with the

anterior third terminating in a narrow projecting terminal angle, and is

thus slightly trilobed on the anterior face.

Scapula.—The scapula resembles that of Capromys pilorides,® but is

longer and narrower, in correlation with the more slender form of the

whole animal (the skull excepted) in Isolobodon. It has a total length

of 45 mm., and a breadth at the middle of 24.5 mm. The free end of the

spine (acromian process) is nearly as long as the attached portion. (For

further details see Plate III, Figs. 1-4.)

Clavicle—A single fragment, if identifiable as this bone, is much

_longer and slenderer than the corresponding bone in Capromys pilorides.

It lacks both epiphyses, but still has a length of 26 mm.

Humerus.—Greatest length, 45 mm.; diameter of proximal end, 11.5

X 9.5; transverse diameter of distal end, 11.5 X 5mm. The supratroch-

lear foramen is of medium size and the deltoid ridge is rather strongly

developed (Plate ITI, Figs. 5-7).

Ulna and radius—Length of ulna without distal epiphysis, 57 mm.

Olecranon process is strongly developed, forming about 1/6th of the

length of the bone. All of the radii lack the distal epiphyses. The length,

minus this portion, is about 46 mm. (Plate III, Figs. 8-14).

Sacrum.—The single sacrum in the collection is fortunately well pre-

served. It consists of four perfectly ankylosed vertebre and presents

nothing of noteworthy importance. It has a length of 51 mm.; breadth

at the proximal end, 31 mm., at the distal end, 15mm. It is represented

in three views, all natural size, in Plate LV, Figs. 4-6.

Pelvic girdle.—Of the many innominate bones in the collection all are

to some extent abraded on their epiphysial borders, but several of them

are sufficiently complete to show all of the essential characters. The one

chosen for representation in Plate LV, Figs. 1-3, of which three views are

given, natural size, indicate its general character. The main axis is nearly

straight, not slightly convex dorsally, as in Capromys pilorides. The

usual tuberosities are strongly developed. The total length is about 81

mm., of which the ilium constitutes about two thirds. . Greatest breadth

of ilium, 24 mm., of the ischium and pubis, opposite the middle of the

thyroid foramen, respectively 9 and 6mm. The thyroid foramen is large,

oval in outline, nearly twice as long as broad, the length in adult speci-

mens being about 20 mm.

6 The only pertinent skeletal material available for comparison with that of Isolobodon

is a ligamental, badly diseased menagerie skeleton of Capromys pilorides, to which my

comparisons are here necessarily restricted.

22 ANNALS NEW YORK ACADEMY OF SCIENCES

Trbia and fibula.—Most of the tibie lack the distal epiphysis. The

greatest length of a complete adult tibia is about 64mm. The digital —

fossa is very deep, and there is a slight indication of a third trochanter in

old individuals (Plate V, Figs. 1-4). The fibule are all except one more

or less fragmentary, lacking the distal epiphysis. The single complete

bone has a length of 44 mm. (Plate V, Figs. 5-9). The bones of the hind

limb in Capromys pilorides are about one fifth shorter and much thicker

than in Isolobodon.

SUMMARY

Isolobodon, like Plagiodontia, is evidently of recent extinction. In the

case of Plagiodontia, the only extant specimen, so far as known to me, is

the type of the species in the Paris Museum of Natural History, described

by F. Cuvier in 1836, to which account all the subsequent references re-

vert. Cuvier had apparently only a single specimen, sent to him from

Santo Domingo by M. Ricord, from whom Cuvier’s brief account of its

habits was doubtless derived. It is mentioned as being nocturnal and

frugivorous, its flesh as very good to eat, and that for this reason “les

Haitiens, qui en sont trés friands, les recherchent si soigneusement, quwils

ont fini par rendre ces animaux tres rare.” In all probability it was soon

after completely exterminated. It is also probable that Isolobodon had

already become extinct in the neighboring island of Porto Rico, doubtless

from a similar cause, and perhaps not long prior to the discovery of the

island by Europeans. At least the fresh condition of its remains found

in Seiba Cave seems to imply recent extinction. 3

vie Ss of a paratype sl ull, ath r older and Boe than the |

_ type skull. | (Natu al ——) ;

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ANNALS N. ACAD. SCI. VOLUME XXVII, PLATE

PLATE II

LOWER JAW AND DENTITION OF Isolobodon portoricensis gen. et sp. nov.

ies. 1-4.—Right mandibular ramus of a young adult. (Natural size.)

Fic. 5.—Lower toothrow, left ramus. From same specimen as Pl. I, Figs. 1

a: and 2. (Twice natural size.) :

Fic. 6.—Lower toothrow, right ramus, of a young adult. Krom same specimen

as Figs. 1-4. (Twice natural size.)

Fie. 7.—Right maxillary toothrow. (Twice natural size.)

Fies. 8 and 9.—Upper and lower views of the left mandibular ramus shown in

Pl. I, Figs. 1 and 2. (Natural size.)

Fic. 10.—Upper and lower dentition of Plagiodontia edum F. Cuvier, for com-

parison with that of Jsolobodon. After F. Cuvier, Ann.

des Sci. nat., ser. 2, Vol. VI, 1836, pl. xvii, figs. 4 and 5.

(Natural size.)

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ANNALS N

PLATE III

SCAPULA, HUMERUS, ULNA AND RADIUS OF Isolobodon portoricensis gen. et sp.

z nov.

Fics. 1-4.—Three views of the scapula and its articular face. (Natural size.)

Figs. 5—7.—Three views of the humerus. (Natural size.)

Figs. 8 and 9.—Two views of the ulna. (Natural size.)

Figs. 10-12.—Three views of the radius. (Natural size.)

Fies. 13 and 14.—Proximal and distal articular surfaces of the radius. (Nat-

ural size.)

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ANNALS N. Y. ACAD. Sct. VoLtumME NNVII,

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ree views of the sacrum. (

sACRUM OF Isolobodon portoricensis gen. et sp. nov.

ee views of a right innominate. bone. (Natural size.)

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PLATE V

FEMUR AND TIBIA OF Isolobodon portoricensis gen. et sp. nov.

Fies. 1-3.—Three views of a right femur. (Natural size.)

Fic. 4.— Distal articular surface of the same femur. (Natural size.)

Fies. 5-7.—Three views of a right tibia. (Natural size.)

Fies. 8 and 9.—Views of the articular faces of the same tibia. (Natural size.)

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ANNALS N. Y. Acap. Sct. VOLUME XXVII, PLATE V

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[Awnats N. Y. Acap. Scr., Vol. XXVII, pp. 23-29. 28 January, 1916]

NEW SIRENIAN FROM THE TERTIARY OF PORTO RICO,

WEST INDIES +

By W. D. Matturw

(Presented before the Academy, 8 November, 1915)

CONTENTS

Page

Introduction............. ROSA Se CHA OO REEDY nme Son OCA teeta sR oA Ue re 23

DESELIP LOMO SWECIESm aie cio clerad ew) <osa 5 ie als slaves bo eisieleis aise Save ale ducts 25

DI VOM OSI Samet narsdenstnre len are nareniaa o foleta bemi be iat AN aE TSE eM lege sins aac 25

JETRO) Oe ON KS) PR HUD OHH VES IM he ees UP Segarra A PU a a 26

PIAceOimonlcingor the WUsOMss sels shee es Bie es He wb wee @usis ewes 27

Molar-premolar formula in Sirenians............ 0.0... ccc reece ete eeeeee 28

STOTT O SANTO eele were. cles ele eye exes NEARS SNEED CECI att ee RE Ne Tea ARS 29

INTRODUCTION

Two specimens of fossil mammals were secured by Dr. Chester A. Reeds

from the Tertiary limestones of Porto Rico while on the natural history

survey of that island undertaken by the Academy. One consists of a

lower jaw and two vertebre, the other of a few incomplete ribs. The

second specimen is probably sirenian but not further identifiable. The

lower jaw, however, is nearly complete, with the molar teeth preserved

and alveoli of the premolars, and is of considerable interest.

Tertiary mammals have been practically unknown from the West

Indies. The only one recorded in scientific literature, so far as I know,

is represented by the skull and jaws from so-called Hocene of Jamaica,

described many years ago by Owen under the name of Prorastomus sire-

noides. It is also asirenian, of a more primitive and generalized type. In

the March, 1914, number of the magazine “Revista de las Antillas,”

Senor Narciso Rabell Cabrero has published photographs of two mammal

bones from the Porto Rican Tertiary, a scapula and axis, and discussed

their possible affinities. He did not compare them with Sirenia, and nat-

urally found the relationship to terrestrial mammals very perplexing.

The scapula is characteristically sirenian, having the peculiar curvature

and backward extension of the blade clearly indicated and agreeing in

1 Manuscript received by the Hditor 27 November, 1915.

(23)

Def. ANNALS NEW YORK ACADEMY OF SCIENCES

other features with the older stages of the Halicoride. The axis agrees

with the same types, comparing with Halitheriwm, but is less certainly

identifiable.

The lower jaw found by Dr. Reeds is clearly distinct from Prorastomus *

and from the modern manatee (Manatus == Trichechus), and appears to

be related to Halitherium of the European Oligocene. Unfortunately the

front of the jaw is missing, so that the identification is in some degree

provisional ; but the form, proportions and spacing of the teeth preserved

or indicated by their alveoli agrees with this genus, as does also the form

of the lower jaw. It is with some hesitation that I refer it to an Old

World genus, but the known range of the manatee in Africa and tropical

America, with fossil representatives in Belgium as well as along the At-

lantic coast of the United States, makes it quite reasonable to believe that

Halitherium also ranged on both sides of the Atlantic in Tertiary times.

Its modern descendants, the Dugongs, are found in the Indian Ocean and

Red Sea.

The lower jaw here described is about the size of a manatee jaw, and

with the same great depth of angle, high condyle, heavy coronoid process,

deep pterygoid fosse. It is much deeper and heavier posteriorly than in

Prorastomus and somewhat deeper under the molars. Three molars are

preserved. Although badly worn and the inner sides much damaged by

weathering, it is evident that they were rather short-crowned teeth of the

usual primitive sirenian pattern of five robust cusps arranged in two

cross-crests and a small heel. The last molar was apparently considerably

longer than the second, with a much more distinct heel supported on a

small median posterior root which the anterior molars lack. The first

molar appears considerably smaller than the second, but this is chiefly

due to its being more worn. Of the differentiation of m, from m, and m,

there is no question. The premoclars are indicated by alveoli. P, (more

probably dp,) was two-rooted, much smaller than m,. P, has a single

oval root, with a diastema behind it equal to its own greater diameter.

P, is doubtfully indicated by an obscure round alveolus with a diastema

separating it from pz.

In front of this the jaw is broken off obliquely and it is impossible to

say what it was like. So far as they go, the characters agree with [Hali-

therium schinzi, save for the somewhat shorter and deeper posterior por-

-tion of the jaw, smaller molars, and greater reduction of the premolars.

From Manatus the jaw differs in the reduction of the premolars and dif-

ferentiation of the last molar; from Prorastomus in the much greater .

depth of the jaw posteriorly, reduction of the premolars and larger size

of the molars.

a a ee ee

eee a ee ee Se ee Pee ae ares Bed

RICO 95

—--=~

-- =~.

WEE

= thy 4 < ta

= a

SSS ——ed

SS ——)

————=—=_====—_—Z

—

SS z

Fic. 1.—? Halitherium antillense, lower jaw, left ramus, type specimen, one-half natural

size ;

Porto

External view, symphyseal region missing. Tertiary shales near Juana Diaz,

Rico, found by C. A. Reeds, 1915.

DESCRIPTION OF SPECIES

? Halitherium antilense sp. noy.

Type: a lower jaw lacking symphyseal region and anterior teeth; the

molars damaged on inner side; a middle cervical and the first dorsal

vertebra associated, neither complete.

Type locality: Shale bluff, west bank Jacagnas River, 1 km. north, 1

km. west of Juana Diaz, Porto Rico.

Horizon: Tertiary calcareous shales of uncertain age.

Collector: Chester A. Reeds, N. Y. Academy of Sciences-Porto Rico

Survey, July 1, 1915.

Diagnosis.—Size and proportions of jaw in accord with H. schinz, pre-

molars more reduced, the third (fourth of Lepsius) having but one root

96 ANNALS NEW YORK ACADEMY OF SCIENCES

and the roots of the fourth (milk-molar, dp,) indicating a smaller tooth

than the corresponding tooth in H. schinzi. It agrees better with Abel’s

diagnosis (Abel, 1904, p. 16, 25) of H. christoli Fitz., from the upper

marine Molasse of Linz (Middle Miocene), but Fitzinger’s (Fitzinger,.

1842) figures of the jaw in this species are not accessible.

Probable Affinities.—Accepting provisionally the reference of the Porto

Rico sirenian to Halitherwum, it may be of interest to note where it stands

in the evolutionary history of the Sirenians.

It is generally accepted at present that this group is descended from a

common stock with the Proboscidea—-that is to say, they are derived

from terrestrial ungulates with short five-toed plantigrade feet, a com-

plete series of teeth, bunodont molars, four or five cusped, the posterior

premolars partly molariform, the anterior ones simple, canines not notably

enlarged, but a tendency to enlargement of a pair of upper and lower

incisors—and a variety of other characters which I need not notice.

Meritherium, of the Upper Eocene and Lower Oligocene of Egypt, stands

not very far from this common stock; but whether or not it be really

ancestral to the Proboscidea it has gone a short distance in that direction,

the limbs being somewhat long and straight and the teeth and skull ap-

proaching in some degree the Proboscidean specialties more clearly shown

in Paleomastodon of the Egyptian Oligocene.

Prorastomus, on the other hand, may be taken as representing the

primitive Sirenian. Unfortunately we do not know its skeleton charac-

ters. But being found in a marine limestone it probably was already

adapted to aquatic life. The long narrow skull, rather slender jaws,

teeth conforming to the primitive type indicated and not widely different

from those of Meritherium, all point to its ancestral position.

From this primary stock we find three or four diverse lines of speciali-

zation. In the Manatee the front teeth disappear and the cheek teeth all

become molariform and appear to increase in number, pushing upward

and forward in the jaw to replace those lost by wear. This increase in

number of the cheek: teeth is supposed to be due to reduplication of the :

molars from behind, a fourth, fifth, sixth true molar etc. appearmg

de novo (Thomas and Lydekker, 1897).

In the Dugongs, on the other hand, one pair of upper incisor teeth 1s

retained and enlarged into tusks, while the cheek teeth are progressively

reduced in number, the premolars becoming smaller and simpler and the

anterior ones disappearing, while there is no tendency to increase in

number of the true molars. The skull in both Manatee and Dugong is

much shortened and widened, the jaws deepened and the front of muzzle

and jaw bent downwards and covered with horny plates for triturating

MATTHEW, NEW SIRENIAN FROM PORTO RICO oO”

the food. Various other specializations occur in the skull, carried con-

siderably further in the Dugong.

A third line, closely related to the Dugong in most of its skull struc-

ture, but lacking the tusks, and with the reduction of the cheek teeth

- carried to complete disappearance, is represented by the recently extinct

Rhytina of the North Pacific.

A fourth and very distinct line is represented by an imperfectly known

genus Desmostylus found in the Miocene of Japan, California and Ore-

Fic. 2.—? Halitherium antillensé, parts of cervical (right) and anterior dorsal (left)

; vertebre of type specimen

. Posterior views, half natural size.

gon. In this the skull retains more of its primitive proportions, while

the tusks are large in both upper and lower jaws and the cheek teeth

become hypsodont or high-crowned and of a very curious pattern.

Halitheriwm is generally accepted as an ancestral Dugong. Hothervwm

Owen, Hosiren Andrews, Protosiren Abel, Archeosiren Abel, all from the

Hocene of Egypt, are a closely related group of genera, all but the first due

to the activity of recent investigators in the Fayim faunas, especially

Andrews and Abel. They represent collectively a primitive stage in the

Dugong line.

PLACE OF ORIGIN oF THE DUGONGS

As the Manatees have not been found outside the Atlantic Basin, it is

commonly assumed that they originated there or else migrated from the

Tertiary Mediterranean Basin. The oldest fossil Dugongs being found

in Heypt and Italy, later stages in Germany, France and Belgium, the

modern forms in the Red Sea and Indian Ocean, it has been assumed that

they originated in the Mediterranean Basin, found their way to the north

European shores and in the opposite direction into the Indian Ocean,

and thence perhaps finally to the North Pacific, but never reached the

western coasts of the Atlantic.

The discovery here presented would seem to show that the distribution

of primitive Dugongs in the North Atlantic was wider than was sup-

28 ANNALS NEW YORK ACADEMY OF SCIENCES

posed. Why they disappeared in this region, while the rival group of

Manatees survived is an interesting question; but the evidence as to the

distribution and range of the Sirenia during the Tertiary is so scanty and

incomplete that any further speculations are scarcely worth while.

Monar-PREMOLAR FORMULA IN SIRENIANS

The molar-premolar formula in the Sirenia is difficult to state cor-

rectly, partly because of certain peculiarities in the premolar replacement,

partly the doubtful interpretation of alveoli where the teeth themselves

are not known. So far as the Manatees are concerned, I have accepted

the interpretation placed by Thomas and Lydekker upon the cheek teeth,

involying an actual increase in the number from the primitive formula

of four premolars and three molars which pretty certainly characterized

the ancestors of all placental mammals, This increase in number of

molars would appear to be attained by extension of the dental lamina

posteriorly and budding from the tooth germ of the third molar, thus

continuing the process by which the third is derived from the second and

the second from the first. That such an increase, whether by this or other

means, does occur normally in the number of true molars in certain other

placental phyla, appears beyond question. Otocyon, Centetes, Myrme-

cobius and yarious Cetaceans may serve as illustrations. The abnormal

occurrence of an extra molar or premolar in the series is not a rare occur-

rence among other placental mammals; this is usually ascribed to re-

duplication.

It is by no means clear that there is any such increase in the number

of either premolars or true molars in any of the other Sirenians living or

extinct. Andrews ascribes four lower molars and four premolars to

Eosiren, and Lepsius gives the formulas as: i 5 c ; p : m : in Pro-

: bie noe oe 1-2

rastomus; 1 . yc = m-, in falitherwm ; iS oP Poog

in Halicore. This would seem to indicate four true molars as the normal

number in this family. Abel, however, has shown (Abel, 1906) that the

fourth milk molar in the Halicoride is retained exceptionally late m life,

and sometimes intercalated between the last successional tooth and the

first true molar. He accounts in this way for the apparent series of eight

postcanine teeth in the lower jaw of Hosiren, Halithervwm and the later

Halicoride without finding it necessary to suppose the addition of a

molar from behind to the usual placental series. Possibly the eight post-

canine teeth of Prorastomus are to be explained in this way; but the inter-

MATTHEW, NEW SIRENIAN FROM PORTO RICO 29

pretation of the alveoli in the jaw in this and other genera is apparently

somewhat doubtful. Pending the publication of Abel’s final conclusions,

it seems best to accept his present views provisionally, as I have done in

the above diagnosis and discussion of affinities of H. antillense. The

number of true molars is considered as unchanged from the primitive

series of three, and the alveoli of the tooth preceding them are considered

as of milk-molar four, although there is no proof that this tooth had a

successor in Halithervum.

BIBLIOGRAPHY

ABEL, O.: Die Sirenen der mediterranen Tertiarbildungen Oesterreichs. Abh.

k. k. Geol. Reichsanst. Bd. XIX, Heft 2, ss. i-vi, 1-223, taf. i-vii. 1904.

ABEL, O.: Die Milchmolaren der Sirenen. Neues Jahrb. Jahrg. 1906, Bd. II,

ss. 50-60. 1906. :

APEL, O.: Die eocinen Sirenen der Mittelmeerregion. Palsontographica, Bd.

LIX, s. 288-360, taf. xxx-xxxiy. 1912.

ANDREWS, C. W.: A Descriptive Catalogue of the Tertiary Vertebrata of the

Faytim, Egypt., pp. 1-324, pll. i-xxvi. Published by the British Museum,

London, England. 1906.

Firzincer, L. J.: Bericht uber die in den Sandlagern von Linz aufgefunden

fossilen Reste eines urwelthichen Singers. Ber. Mus. Franec.-Car. in Linz,

pp. 61-72 mit 1 taf. 1842.

Lepsius, G. R.: Halitherium schinzi, die fossile Sirene des Mainzer Beckens.

Abh. Mittelrhein. geol. Vereins. Bd. I, s. 1-200, taf. i-x. 1882.

LYDEKKER, R.: On a remarkable Sirenian Jaw from the Oligocene of Italy and

its bearing on the Evolution of the Sirenia. Proc. Zool. Soc. London, 1892,

pp. 77-83. 1892.

THOMAS, OLDFIELD, and IiyDEKKER, R.: On the Number of Grinding Teeth pos-

sessed by the Manatee. Proc. Zo6él. Soc. London, 1897, pp. 595-600, pl.

xxxvi. 1897.

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[Annats N. Y. Acap. Scr., Vol. XXVII, pp. 31-38. 4.May, 1916]

a 897,

THEORIES OF THE ORIGIN ai BIRDS « 0 1910

By Witiiam K. Grecory \ Yona) yy

OW aig

(Presented before the Academy, 13 December, 1915, in connection with

Mr. OC. W. Beebe’s paper on “A Tetrapteryx Stage

in the Ancestry of Birds”)

Comparative anatomists of the nineteenth century demonstrated that

birds, in the entire ground plan of their brain, skeleton, reproductive

organs and all other structures, as well as in their mode of development,

are “glorified Reptiles,’ or “feathered saurians.” In this instance the ~

unanimous findings of comparative anatomy may be regarded as practi-

cally decisive.

But while all authorities agree that the assumed very remote ancestors

of birds that lived in the Carboniferous and Permian periods of the

earth’s history were very probably scaly, lzard-like reptiles, there is no

such unanimity regarding the structure and habits of the more imme-

diate ancestors of birds, during the ages when scales were gradually

transforming into feathers and the art of flying was still in its earliest

stages. Professor Osborn, in 1900, after reviewing the evidence for the

well-known view that birds and dinosaurs had been derived from a com-

mon ancestral stock that lived during the Permian period, said:? “In the

origin of the birds we have to imagine, first, a terrestrial stage, in which

bipedal was gradually substituted for quadrupedal progression; it would

appear probable that the bipedal progression was first acquired during a

terrestrial stage because the foot of birds is primarily a walking, and not

a climbing, organ; second, a cursorial bipedal or, more probably, an

arboreal stage, in which both fore limb and tail enjoyed a change of

function contemporaneous with the acquisition of feathers.” .

In 1906 Mr. W. P. Pycraft, of the British Museum, argued that*® in

the stage preceding Archwopteryx (the oldest known fossil bird, of the

Jurassic period) the ancestral birds probably lived in the trees, leaping

from branch to branch and from tree to tree. “In these movements,” he

1 Manuscript received by the Editor 24 February, 1916.

2“Reconsideration of the Evidence for a Common Dinosaur-Avian Stem in the Per-

mian,’ The American Naturalist, Vol. XXXIV, No. 406. 1900.

*“The Origin of Birds,““ Knowledge and Scientific News. September, 1906, pp. 531-532.

(31)

32 ANNALS NEW YORK ACADEMY OF SCIENCES

continues, “we may reasonably suppose the fore limbs were used for

grasping at the end of the leap. The use of the fore hmb for this work

would naturally throw more work upon the inner digits—1-3—so that

the work of selection would rapidly tend to the increased development of

these, and the gradual decrease of the two outer and now useless mem-

bers. Correlated with this trend in the evolution, the axillary mem-

brane—the skin between the inner border of the arm and the body—

became drawn out into a fold, while a similar fold came to extend from

the shoulder to the wrist, as the fore limb, in adaptation to this new fune-

tion, became more and more flexed. While the fingers, upon which safety

now depended, were increasing in length, and growing more and more

efficient, they were, at the same time, losing the power of lateral exten-

sion and becoming more and more flexed upon the fore-arm. And the

growth in this direction was probably accompanied by the development

of connective tissue and membrane along the hinder, post-axial border

of the whole limb, tending to increase the breadth of the limb when

extended preparatory to parachuting through space from one tree to

another, long claws being used to effect a hold at the end of the leap.

“The hind limbs, though to a less extent, were also affected by the

leaping motion, resulting in the reduction of the toes to four, and the

lengthening and approximation of the metatarsals 2-4 to form a ‘cannon’

bone.

“The body clothing at this time was probably scale-like, the scales

being of relatively large size and probably having a medium ridge, or

keel, recalling the keeled scales of many living reptiles. Those covering

the incipient wing, growing longer, would still retain their original over-

lapping arrangement, and hence those along the hinder border of the

wing would, in their arrangement, simulate in appearance and function

the quill feathers of their later descendants. As by selection their iength

v creased, so also they probably became fimbriated and more and more

cfficient in the work of carrying the body through space.

“There is less of imagination than might be supposed in this attempt

at reconstructing the primitive feather, inasmuch as there is a stage in

the development of the highly complex feather of to-day which may well

represent the first stage in this process of evolution. Creatures such as

are here conjured up would bear a somewhat close resemblance to Arche-

opteryx, and it is contended that the discovery of earlier phases of avian

development, phases preceding Archwopteryx, will show that this fore-

cast was well founded. But in Archeopteryz, it is to be noted, the

feathers differ in no way from the most perfectly developed feathers

known to us.”

GREGORY, THEORIES OF THE ORIGIN OF BIRDS 33

Mr. Pycraft summed up this theory in his restoration entitled “One

of the ‘Pro-Aves.’” This hypothetical animal, as thus represented, stands

about half way between a normal lizard-like reptile on the one hand and

Archeopteryx on the other. It is represented as volplaning down from

the trees, with arms outstretched. It is covered with scales, which on the

back of the arm and sides of the tail have begun to lengthen out and

transform into feathers.

_ The next year (1907) Baron Francis Nopesa, in the Proceedings of

the Zoological Society of London,‘ after reviewing the many resemblances

between birds and running dinosaurs and showing that birds both in their

mode of flight and in their limb structure differ in many important re-

spects from bats, flying squirrels and other primarily tree-living animals

that are provided with webs of skin for volplaning, came to the following

conclusions :

“Tf we, after these preliminaries, now suppose that Birds, before at-

taimmg the Archwopteryz-state, origimated from quadrupedal arboreal

animals and only after having learnt to fly became bipedal, it is difficult

to understand why they in general show Dinosaurian affinities, why they

did not use both hind and fore limbs to the same extent for flight as they

would have done for arboreal locomotion, why the bones of the pectoral

region and of the wings show more primitive traces than the hind parts

of the body, and why they did not, like all other quadrupedal flying ani-

mals, develop a patagium; whereas, if we consider that in Archeopteryx

the anterior extremities, though bearing the most important ectodermal

pinions, are less modified than the posterior extremities, which are al-

ready perfectly bird-like, and if we then suppose that Birds originated

from bipedal Dinosaur-like Reptiles, it is easy to understand what in-

duced the Birds to attain an Archwopteryz-like stage of evolution, for at

first a certain amount of bipedal, and only afterwards a volant, modifica-

tion would be required.

“While we can safely state that a bipedal animal never could or did

develop a patagium without giving up bipedalism, this cannot be said of

feather-bearing forms, for we may quite well suppose that birds origt-

nated from bipedal long-tailed cursorial reptiles which during running

oared along in the air by flapping their free anterior extremities.

A double running and flapping action would—somewhat in accordance

with Pyeraft’s views on this subject—subsequently easily lead to an en-

largement of the posterior marginal scales of the antibrachium, and at

the same time produce a certain amount of bipedal specialization.

4“Tdeas on the Origin of Flight.’”’ Proceedings of the Zodlogical Society of London,

June 12, 1907.

34. ANNALS NEW YORK ACADEMY OF SCIENCES

“By gradually increasing in size, the enlarged but perhaps still horny

hypothetical scales of the antibrachial margin would in time enable the

yet carnivorous and cursorial ancestor of Birds to take long strides or

leaps, much in the manner of a domesticated Goose or of a Stork when

starting, and ultimately develop to actual feathers; this epidermic cover

would also raise the temperature of the body, and thus uel to increase

the mental and bodily activity of these rapacious forms.”

In 1913 Doctor Robert Broom described the skeleton of a small fossil

reptile from the Upper Triassic beds of South Africa, which he named

Euparkeria capensis. This animal, the type of which is in this museum,

belonged to an ancient group of reptiles called “Pseudosuchia,” some of

which are found in the Triassic of Connecticut and others in the Upper

Triassic of Scotland, Germany and South Africa. This group is of ex-

ceptional interest to paleontologists because of the largely primitive

character of certain of its genera, which show marked evidences of affinity

with such diverse later groups as Dinosaurs, Pterosaurs and Crocodilians.

In discussing the affinities of this group Dr. Broom’ said:

“There is still another group to which some Pseudosuchian has prob-

ably been ancestral, namely, the Birds. For a time one or other of the

Dinosaurs was regarded as near the avian ancestor. The resemblance of

the hind limb and pelvis seemed to make this extremely probable, and

Huxley, Marsh, Cope, and others have all favored this view. Others,

however, were more impressed by the apparently avian characters in the

skeleton of the Pterodactyls, and especially in the striking avian appear-

ances in the brain, and have argued in favor of a close affinity between

the Birds and the Pterodactyls. Osborn, while recognizing the affinities

to both groups, and especially to the Dinosaurs, believed that the Birds

and the Dinosaurs had a common ancestor, probably in the Permian.

Seven years ago, when describing the skeletogenesis of the Ostrich, I

argued that the bird had come from a group immediately ancestral to

the Theropodous Dinosaurs. The Pseudosuchia, now that it is better

known, proves to be just such a group as is required. In those points

where we find the Dinosaur too specialized we see the Pseudosuchian still

primitive enough. The bird pelvis has probably developed from a type

like that of Ornithosuchus by the pubis turning further back and the

symphysis becoming lost. Whether the union of the metatarsals is a

primary or a secondary character is a debatable point. The question is

really whether the bird ancestor was a hopping bipedal animal before it

flew, or if it only hopped after the wing had became specialized. I am

® Proc. Zool. Soc., 1918, pp. 631-632.

: “é

“

GREGORY, THEORIES OF THE ORIGIN OF BIRDS 35

strongly of the opinion that it was a hopping animal first, and that the

metatarsus became strengthened to support the weight of the body en-

tirely borne by the hind feet. It is easy to understand a hopping animal

taking to an arboreal life and ultimately developing a wing out of a four-

toed hand, while it seems unlikely that the hind foot could ever have

developed by arboreal habits. It is interesting to note that while the

ancestor of the Pterodactyls had four toes in the manus, there is very

clear evidence from the skeletogenesis of the bird that the latter also had

a four-toed ancestor.

“A Pseudosuchian which through a bipedal habit had developed a

strengthened ankle-jomt and a firm metatarsus, and had lost the 5th

digit from the manus oo meet all the requirements of the avian an-

cestor.”

The theory that the immediate ancestors of birds were aor Al animals

has also been supported by Professor Abel,® of Vienna, who maintained

that the birds and carnivorous dinosaurs arose from a common arboreal,

ancestral group with climbing feet. The carnivorous dinosaurs soon re-

verted to terrestrial habits, while the birds, remaining arboreal, only

returned to terrestrial life long after the acquisition of flight. The cleft

between birds and carnivorous dinosaurs runs back perhaps to the begin-

ning of the Trias. Professor Abel’s conclusions rest partly on the facts

that both the hands and the feet of the smaller dinosaurs show marked

resemblances to those of the arboreal bird Archeopterys.

Mr. D. M. 8. Watson,* on the other hand, holds that the backwardly

directed first toe of some of the earliest dinosaurs was not a perching

adaptation, but served as a strut, or prop, for the support of an animal

in the early stages of walking upright.

Quite recently Professor S. W. Williston’ has expressed the belief (an

litteris) that the consolidation of the instep bones in the oldest birds was

an adaptation to digitigradism, or the habit of raising the body upon the

toes, and that flight originated by leaping from below upward, not by

gliding downward.

Still more recently Mr. C. W. Beebe, of the New York Zoological Park,

has made certain discoveries which lend additional evidence for the view

that the immediate ancestors of the birds were arboreal animals. In a

paper entitled “A Tetrapteryx Stage in the Ancestry of Birds”® Mr.

6 Grundziige der Paliobiologie der Wirbeltiere. Stuttgart, 1912.

7“Mhe Cheirotherium,’’ Geol. Mag., Decade VI, Vol. I, No. 603, September, 1914, pp.

395-398. :

8 “Trimerorhachis, a Permian Temnospondyl Amphibian,’ Journ. Geol., Vol. XXIII,

No. 3, April-May, 1915.

® Zoologica, Scientific Contributions of the New York hae Society, Vol. II, No. 2,

November, 1915.

36 ANNALS NEW YORK ACADEMY OF SCIENCES

Beebe found that in the young of various species of doves, pigeons,

jacanas and owls there is a reduced pelvic wing, consisting of a row of

degenerate flight feathers and a second overlapping row of “coverts,” all

stretched upon the patagium, or skin-fold, behind the femur. Owing to

the lateness of the season, it was impossible at this time to extend further

his observations on the “pelvic wing” of birds; but he states that “judging

merely from the pterylosis of the adult, many species of Coraciiformes,

Scansores and Piciformes should show most interesting developments of

this tract in the young birds.” Mr. Beebe was naturally delighted to

find that in the Berlin specimen of Archwopteryx there were some

strongly marked impressions of feathers on both sides of the tibia and of

still larger feathers lying between the pelvis and the bent back head,

which he interprets as evidence of the “pelvic wing” in this oldest known

bird. Partly from these data Mr. Beebe and Mr. Dwight Frankln have

made their series of restorations to illustrate the evolution of birds from

a “tetrapteryx stage,’ with four wings and a long segmental tail, to the

modernized two-winged stage, with a normal fan-tail.

Thus Mr. Beebe, along with Pycraft, Abel and others, conceives the

immediate ancestors of birds as arboreal animals with the habit of scaling

downwards through the air after the fashion of flying squirrels; to this

theory his discovery of a vestigial pelvic wing in modern birds lends

obvious support.

For some vears past the present writer has taken special interest m the

problem of the origin of birds, partly for the reason that the subject

forms one of the major problems in the Columbia University graduate

course on the evolution of the vertebrates. Hach year we hold a seminar

on this subject, in which the various theories of the origin of the birds

are duly advocated by graduate students, and the rival claims of the dino-

saurs and other reptilian groups to close kinship with the birds are con-

sidered. From this annual review arises the impression that from the

clash of conflicting hypotheses the following approximation to the facts

may, from present evidence, be provisionally made out:

Far back in the Carboniferous ages the remote common ancestors of

birds, dinosaurs, pterosaurs and other reptilian groups were very primi-

tive lizard-like reptiles with extremely small brains, comparatively slug-

gish habits and a highly variable body temperature. This general de-

scription would doubtless fit many of the already known reptiles from

the Carboniferous and Permian, but no one of these can yet be recognized

as a direct ancestor to the later types.

In the harsh arid ages of the Permian and Trias were evolved hardier

and more active carnivorous saurians, represented by the earliest dino-

GREGORY, THEORIES OF THE ORIGIN OF BIRDS 37

saurs, and especially by the “Pseudosuchians,” such as Ornithosuchus,

Euparkeria. Some of these small reptiles may have reared up on their

hind legs in running, as certain lizards do; indeed the hind feet of Hupar-

keria, according to Broom, exhibit incipient adaptations to bipedal pro-

gression, while others were in all probability actively hopping types. But

none of these animals show any very pronounced bird-like characters in

the skeleton. Their structure, however, was, on the whole, of so general-

ized a type that the diverse peculiarities of the birds, pterosaurs and other

groups could readily be derived from this source. In some of the Pseu-

dosuchians the body is known to have been covered with horny plates, but

others may have been clothed with the overlapping scales which must

have preceded the evolution of feathers.

Thus the paleontological record as to the immediate ancestry of the

birds is regrettably indecisive, but the principles of comparative anatomy

appear to lead to some pretty safe inferences, as follows:

The transformation of long overlapping scales into feathers, whenever

it did occur, was one of the critical steps in the evolution of birds. This

transformation took place apparently over the whole surface of the body

and along the legs and arms. No doubt it was correlated with the higher

vitality and improved circulation of the pro-avis as compared with the

ancestral reptile; no doubt also the air-retaining mesh of the feathery

covering not only prevented undue radiation of heat from within during

cold periods, but also screened off some of the burning heat of the sun.

Possibly this feather-armor would also protect the ambitious aviator in

his many falls from the branches. The pro-Aves were surely quick run-

ners, both on the ground and in the trees, but it is not yet clear whether

the upright position was first attained upon the ground or in the trees.

They very early acquired the habit of perching upright on the branches,

as shown by the consolidated instep bones, grasping first digit and strong

claws of Archwopteryx. Their slender arms ended in three long fingers

provided with large claws which were at first doubtless used in climbing.

These active pro-Aves contrasted widely in habits with their sluggish

remote reptilian forebears. In the pursuit of their prey they jumped

lightly from branch to branch and finally from tree to tree, partly sus-

tained by the folds of skin on their arms and legs and later by the long

seale-feathers of the pectoral and pelvic “wings” and tail. That they

held the arms perfectly still throughout the gliding leap still appears

doubtful, for all recent animals that do that have never attained true

flight. I cannot avoid the impression that a vigorous downward flap of

the arms, even before they became efficient wings, would assist in the

“take off” for the leap, and that another flap just before landing would

check the speed and assist in landing.

38 ANNALS NEW YORK ACADEMY OF SCIENCES

In correlation with this active arboreal life the brain became highly

developed; the olfactory lobes grew smaller, the cerebra, optic lobes and

cerebellum attained large size and high development. The brain-case

was correspondingly expanded, while the skull as a whole acquired a very

light construction. The earliest birds retained the sharp conical teeth

implanted in distinct sockets which were characteristic of their “theco-

dont” ancestors (such as Huparkeria). ‘The teeth and jaws were adapted

for quickly snapping at living prey, perhaps insects. These entirely rep-

tilian teeth, which in the case of Marsh’s “toothed birds” bore an extra-

ordinary resemblance to the teeth of mosasaurs, were retained long after

the main adaptations for flight were established. ‘But perhaps during

the Cretaceous period the ancestors of modern birds lost their teeth as

the horny beak at the front of the jaws grew backward.

The skull of birds is of a modified reptilian type and has no doubt

been derived simply by the loss of the upper temporal bar, by the inturn-

ing of the pterygoid bones and by the enlargement of the internal nares.

In short, the whole architecture of the bird skeleton, as indeed the whole

internal anatomy, are unquestionably a modification of a primitive rep-

tian type. The consensus of opinion is that this ancestral type was

nearly related to the primitive Archosauria (Diapsida), or two-arched

reptiles, and was very widely removed from the mammals, mammal-

reptiles, turtles, plesiosaurs and ichthyosaurs.

The hypothesis that the ratite birds have come off from some group of

reptiles other than that which gave rise to the carinate birds is, in the

writer’s judgment, entirely untenable: first, because an examination of

the skulls of various ratites and carinates shows agreement in funda-

mental plan, with minor, though well-marked, differences in details; sec-

ondly, because the entire organization of the ratites indicates merely a

cursorial readaptation of carinate types; thirdly, because the tinamous

are in many characters allied both to the ratites and to the carinates, and

thus strengthen the conservative view that the class Aves is broadly

monophyletic in origin.

ee . ae 5 oe oF THE e 2 5 | aie % ay : A : : = a

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PRESS or JUDD & DETWEILER, INC., WASHINGTON, Bae Sh aie

Rite ap

i 5 ave Be, 3 % ant

Editor, EpMuND OTIS Hovey 2

OF THE MORRISON FORMATION

CHartes Crarg Moox

NEW YORK

PUBLISHED BY THE ACADEMY

He DUNE NOME eee

‘THE NEW YORK ACADEMY OF SCIENCES. .

(Lyceum or NATURAL History, 1817. os

Orrrorrs, 1916

President—MicuHatL Ipvorsky Pupin, Columbia University

, Vice-Presidents—ErRnest EH. SuityH, J. McKeen Carreqt,

Dovetas W. Jounson, Hermann von W. Scuuurs

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[Annats N. Y. Acap. Sct., Vol. X XVII, pp. 39-191, Pl. VI. 12 June, 1916] .

STUDY OF THE MORRISON FORMATION Gnian ao)?

/ @ AY

By Captus Craic Mook /.” 1) G 9R10

hv rat & fd & |

(Presented before the Academy, 8 May}19t5)

CONTENTS ~ Steinmann

: Page

Introduction............... Beye ee ee Siaspayaee caste Ts is wer te a ere mys tee tol aaaual GAN anata ar orekers 40

FMA ANIA, SROMIAIK Sis cosisietesie woes ole calscaie © eis dm col alavagele dey niere Sete ols di dieseiiovese 40

MSTA OTINRO fei BOT A ELOTN (5 acs ey syscstaefalal2) orehec) S00.0 ares aero aiaismsre Seid a eh wereld es 41

Physiographie occurrence and distribution of the Morrison formation. 42

Purpose and scope of present Work............ cc. c cece eect cece ees 43

Suds Teeaitod CaTeCANO LN NVgr pees seta rercdaions (alc dcars ere uaraneied sie vanes eles. eie> «icy savy aveesvceenceucleaimrend! sucreleimes 3

Morrison formation in eastern Colorado and New Mexico........... 43

CET T Ue ce rere ieieal ap LPR Sen RG MWe ele lara SS Uc cutter <anayal ny aie RO 43

INOREMEe TEM COOMA OG a circ sreee es oie soa tae eo alae ro ieior ue sls elveRRS euene 45

IVT Tete S © Tavera sire teva pistc aco cea roles Gust ae Sees el at ee aioe Satara aman, See ace Gia AT

(Geriavonn) OTA SESH has sus 5s 6 Coe ey NS epee ICIS on Rate aE Ri gece a ae coe eu Sear 48

Canyons of southeastern Colorado..................00200 0c eeee 56

Hastern New Mexico and Oklahoma........................0.. 61

Morrison formation in western Colorado and eastern Utah.......... 66

CE TANT RV CTD TCA ee raebe Hey ec ene W OBR rane sifcitev Shieh. SaMELG oy RPS Re Rago Hcettengtuby nae rel

Northeastern Utah and northwestern Colorado................. 7S

Morrison formation in Montana and Wyoming (except the Black Hills

GUI EL)) SSS TASS Bis cy CON ERENS CRLINT r rcnt cee ae a per Te UE it Oe oe SOR 80

Centmaleandnsouthern Mombaae sels. 2 es co. 6.240 sd oo sees ime secs 80

AVANT OTM MOMMA AVIS sheers ahs lates cena fe altereya: Sack le! close) sae: Sosneuelatelseotele wicheceraie 82

‘STincay ST nyDvan@s RUG Sie TeyeyeaU OVO See Se ON) inch rg er et ee en pe ceca i ae a

Central and southern Wyoming.................cccccececcccece 87

Morrison formation in the Black Hills area........................ 99

Atlantic coast representative of the Morrison....................... 109

Ayundel formation: of Maryland... 2. ...sse2 secs ce cee eee cen 109

Summary of stratigraphic relations and characters of the Morrison

TROUT GTMOVOY es 2 asc seas PN OE ee et ec tate oT eC) ee a Ca re 110

JD TISNEIET CHU UETIOMOYES Sor YG so ee coro eats Se ee CE te re a 110

RelAoOne FO. UMaerl yale GOCKS is vcd sce sec sce dacs s lhc dew nee 110

IBelamonmaroTOVebhyine, HEUSss. succes chs. oo ee PAIR CRE ON Sia 112

MhTekMeSS. 53. .6..0.- Ce ane Less. ci Saeco Poa NS Mai tacret ERE SN Recah Maat 113

Lithologie characters.............. ie ra op AE Rai rere LE RU BL 115

Varianle character, Of SechlonS. (0.26 fad oobi en cea ee le ce. epeny ea tas

SEU CLUReGH A CMe EEO Siac eyes tise iat: + esp ale sine 8 cla da wie ww else Sue eke apeuehe 115

Structural features of the Morrison formation..................... 115

Petrographic characters of the Morrison formation.................. 119

1 Manuscript received by the Editor 18 May, 1915.

40 ANNALS NEW YORK ACADEMY OF SCIENCES

PATCONTOLOLY: 6: o'< ais-cate secs 4 Sie eww © eve o.6 eieteie is evelessee ts Dele Reenter Rae ee ene

Hora of the Morrison formation. 2s... -= osc ese core eee

Invertebrate fauna of the Morrison formation......................

PeleCypod aiid... ce 5 saeisw seve s owls paeme stele Cen tena 126

Gastropoda. wo. ocd. sc cele: oh Ree Eee in. ee ‘129

Ostracodatic oo. 20s sce teens aes CR Ee nee io ces 6. 130

ATUMGE! LOLS. o55 5 bis, Ge eo ole ws wvstias acces ey el eehe Graliete eters ena ee 130

Vertebrate fauna of the Morrison formation....................... 131

VTA MMMATIA. 5 vig 55.5 6 ese 28 bod: eieheu oc atig 8 lot Silat lot, siete is WOR oe 131

INOS Eb oie S.dce 16. 5 a eane oa alee enagueretchayaiehe aaeier 3 sue CLOSE Set 134

ROP ULV 0. ees So 8S wake isilele cldeuetaces anes leteueherral ees ERI ee 134

DinOSaUrias «<2. .4s 34 oe Siw sess we ee ee eee etn eee eee 134

SaUropoda ais ccc leis cid werd wlessuo ardigueee Sao te roe 134

THeropoda. wy... 64 OAS Aa wns OLS OO ae ee 140

Predentata . 2... vane els ee 6 o alee Boe ee eee 1438

Rhynchocephalia...... 6... 5200 se oho eee ele eee 148

Crocodiliai. 56.66 3. oe Rese SRG WR eee Hebden ae See ee 148

Chelona so 68... eae Se ee oe oie et ee 149

PCO OSA UT TA Hee ais oahete, edleilo derautveie ye ach cneiiene ue le tena tone eee s\n ea aan 149

PIS COG is iio day She iets aralis: ais b.-siatioreuen toe Gieaaristysle tale ie GarOlG POR One e ee 149

Age’ of: the Morrison formation. ..:. 3... 0 000. 2 2 opts oe 2 woe eee ee 150

Origin and interpretation of the Morrison formation............:....... 157

Summary of characters. \.025 sc aretimes Gos hicks nee 157

History of previous opinions as to the origin of the formation....... 161

Discussion of previous theories of the origin of the formation....... 163

Preliminary statement of present interpretation........... "So end Ae OE

Characteristics of recent alluvial plains..........................:- 165.

Colorvot Sediments: oy a4.0 oa wai eldieae © ad Se Re 167

Interpretation of the origin of the Morrison formation.............. 169

Biblioerapliynss eases acca hed aos AG e slave ae elbele oe Diels bene Pa nee 172

INTRODUCTION

PRELIMINARY REMARKS

The present paper is the result of a study of the Morrison formation

undertaken by the writer in connection with the monograph on the Sauro-

poda now in course of preparation for the United States Geological Survey

by Professor Henry Fairfield Osborn. Library and laboratory work was

done during the winters of 1912-1913, 1913-1914 and 1914-1915 at the

American Museum of Natural History and at Columbia University.

Field work was done in the summers of 1913 and 1914. The writer

desires to express his thanks to Professor Osborn for the opportunity of

studying the Morrison formation in the field, and for permission to use

MOOK, STUDY OF THE MORRISON FORMATION AL

data gathered for use in the above-mentioned monograph. Conferences

have been held with Professors A. W. Grabau, C. P. Berkey and D. W.

Johnson, of Columbia University, who have made suggestions in regard

to the work. Messrs. W. T. Lee, N. H. Darton, W. Cross and C. T.

Lupton have added data regarding the distribution of the Morrison in

the southern areas, and the director of the United States Geological Sur-

vey has given permission to use these unpublished data, and to use the

map which was redrawn by Survey draughtsmen from an original by the

writer. Valuable information has also been given by Mr. S. H. Knight,

of Columbia University.

DEFINITION OF FORMATION

The name. Morrison was first applied to the series of deposits under

discussion, by Cross, in the Pike’s Peak folio of the United States Geolog-

ical Survey. It was proposed to include the series of clays, sandstones

and shales which underlie the Lakota-Dakota series and overlie a white

sandstone, which in turn rests on the Red Beds, at the village of Morrison,

nearly west of Denver, Colorado. The names “Jurassic Beds,” “Dakota

Beds,” “Variegated Beds,” “Beulah. Shales,’ “Atlantosaurus Beds,”

“Como Beds,” “Gunnison Formation,” “McEImo Formation” and “Flam-

ing Gorge Formation” have all been applied to beds in various regions

im a general way equivalent to the Morrison in eastern Colorado, though

im some cases these terms have included more than the typical Morrison.

The name Morrison has been used extensively in the publications of the

United States Geological Survey for this formation in other areas than

the original area in eastern Colorado. As it was the first geographical

name applied to the formation, it may be used as the valid formation

name for the deposits concerned. In the present paper it will be used

for the areas in western Colorado and Utah, where the beds have been

known as Gunnison, McElmo, and in part Flaming Gorge, as well as for

the more eastern representatives. The local names are often convenient,

however, to designate the formation in particular localities.

The series is composed essentially of beds of variegated clays or marls,

often described as “joint-clays,” sandstones and shales, with minor ele-

ments of fresh-water limestones.

The formation has produced a small and not especially characteristic

invertebrate fauna, a scant flora of cyeads and fossil wood and a very

characteristic and varied vertebrate fauna.

AQ ANNALS NEW YORK ACADUMY OF SCIENCES

PHYSIOGRAPHIC OCCURRENCE AND DISTRIBUTION OF THE MoRRISON

FoRMATION

The Morrison formation is generally exposed at the surface in two

characteristic ways. The usual occurrences are in the steep faces of hog-

backs and in the walls of river canyons. The hog-backs are long, even-

topped ridges running practically parallel with the axes of mountain

uplifts, with a comparatively steep slope on either side, but one side often

Fic. 1.—Generalized section of Rocky Mountain hog-back, showing the usual

physiographic position of Morrison outcrops.

1.—Pre-Cambrian crystallines. 4 —Sundance.

2.—Paleozoic. 5.—Morrison.

3.—Red Beds. 6.—Capping sandstone (usually Cloverly

or Lakota).

being steeper than the other. They are formed through uplift followed

by erosion of the tilted and raised sedimentary beds which formerly

covered or lapped against the mountains. The softer material is quickly

eroded away, leaving ridges protected by cappings of harder strata. The

Morrison formation is typically non-resistant, and so is usually found in

Fie. 2.—Generalized section of a Rocky Mountain or Great Plains river canyon,

showing a common position of Morrison outcrops. ;

1.—Capping sandstone. 3.—Red Beds.

2.—Morrison.

the erosion cliffs on the inner sides of the hog-backs. Hxposures of this

kind occur in eastern Colorado, extending north into Wyoming and south

into New Mexico, around the Black Hills, on both sides of the Laramie

Mountains; around the Bighorn and Owl Creek Mountains; around the

Wind River Mountains; south of the Uinta Mountains; and in the Grand

MOOK, STUDY OF THE MORRISON FORMATION 43

Hogback, which extends all along the western border of the Rocky Moun-

tains in Colorado. The river canyon exposures of the Morrison are also

widespread. They occur in the canyons of streams east of the Rocky

Mountains, such as the Huerfano, Purgatoire, Cimarron and Apishapa;

in the canyons of the McElmo, Dolores and other rivers in western and

southwestern Colorado; and in central Montana.

Other outcrops occur as combinations of hog-back and canyon ex-

posures, such as at Cafion City, Colorado; as local surface rock, such as

in southeastern Colorado (see distribution map), and near Grand Junc-

tion, Colorado; and in the erosion of local anticlines, such as Como Bluff

in south-central Wyoming, and in faulted masses, such as the Sioux Fault

exposure in Wyoming. ,

PURPOSE AND SCOPE OF THE PRESENT WorRK

The purpose of the present paper is to interpret the Morrison forma-

tion, if possible, in regard to age, origin and paleophysiography. It is

also desired to give a summary of the present knowledge, so far as it is

available in the literature, together with some new field observations.

Among the problems which have been connected with the Morrison

formation is that of its age. Some writers have held that it is Jurassic,

and others that it is Comanchean. Still others have held that it is both

Comanchean and Jurassic. It is desired to show that the Morrison is

essentially Comanchean, but that some portions of it, especially in the

western areas, may possibly be Jurassic.

Various opinions have been held regarding the origin of the Morrison.

It has been considered marine, lacustrine, fluviatile and combinations of

these. An attempt will be made in the present paper to show that the

Morrison is essentially a broad alluvial plain, formed of coalescing alluvial

fans, and possibly a true delta in the southeastern areas. It must have

been deposited under conditions somewhat similar to those now existing

in the great alluvial plains in eastern China.

The fauna and flora are listed for purposes of reference and summary.

STRATIGRAPHY

Morrison ForMATION IN EKASTERN CoLoRADO AND New MExXtIco

GENERAL

The Morrison formation outcrops along the front of the Rocky Moun-

tains in Colorado in a nearly straight line, from the Wyoming border to

New Mexico, and south in New Mexico to a point a few miles south of

44 ANNALS NEW YORK ACADEMY OF SCIENCES

Las Vegas. The main line of outcrops then swings northeastward to a

point 15 miles or so southwest of Clayton. The outcrops along the moun-

tain front in Colorado and New Mexico occur in hog-backs. The north-

east-southwest line of surface occurrence in New Mexico is an irregular

cliff. The lines of outcrops are not completely continuous. At Golden

the Morrison has been crowded out by igneous action, and at Manitou and

other places it has disappeared through faulting. Outcrops also occur in

the canyons of the Purgatory, Apishapa and other rivers in Colorado, and

of the Cimarron in New Mexico and Oklahoma.

A. R. Marvine (1874, 3), in the seventh Annual Report of the U. S.

peelegial and Geographical Survey of the Territories, describes the

“Jurassic” or the beds overlying the red series of supposed Triassic age

as follows:

“General characters—The series of strata lying next above the red

beds form a group of rocks in which the thin-bedded and shaly element

decidedly predominates. The outcropping edges of these beds have there-

fore generally been more eroded away than the harder beds above and

below, so that they generally appear in valleys; and being soil covered,

they are not usually well exposed.

“The arenaceous element still predominates, though argillaceous Sine

rial is often present to a very large extent, while beds of impure limestone

occur—one of which appears very persistent—and gypsum is frequent im

thin layers, and sometimes occurs in workable quantities and of good

quality. As before, red is the prevailing color, though a series of marked

variegated shales occur, and weathering frequently produces an ashen-

gray tint upon the surface. aie

Some of these beds are probably of lower horizon than the true Morri-

son.

The following description of the Morrison formation east of the Rocky

Mountain front is given by Darton (1904, 8): “Its general character is

nearly uniform throughout, a series of light-colored, massive clays, “joint

clays, with thin beds of limestone and sandstone of fresh-water origin

containing bones of saurians of the so-called ‘Atlantosaurus’ fauna. Its

thickness averages less than 200 feet in most cases. It presents frequent

and rapid variations in the local succession of beds, but the predominance

of joint clays of chalky aspect and the occurrence of maroon and purplish

layers among them are characteristic features.” Lee speaks of the Morri-

son as “uniformly variable,” a term especially applicable.

In the extreme northern part of Colorado the Morrison is said to rest

upon the marine Sundance beds. Throughout most of the northern Colo-

rado area it rests upon the red beds of the Chugwater formation. Fur-

MOOK, STUDY OF THE MORRISON FORMATION 45

ther south in Colorado it rests upon the Fountain or Badito formations.

South of Beulah, in southern Colorado, the Morrison rests directly upon

the crystallines. In the canyon of Rio Cimarron, in New Mexico, it rests

on the Exeter sandstone. |

“The basal unconformity is one of widespread planation, with local

shallow channeling, but no perceptible discordance of dips” (Darton,

1904, 8).

‘The Morrison is present at intervals from the Platte River to Colorado

City. North of the gateway to the Garden of the Gods it is 130 feet

thick and rests upon a bed of gypsum. It is partly exposed at Colorado

City, where the beds are vertical. It is exposed again, after being cut off

by faulting for a few miles south of Manitou, along the mountain front

to the vicinity of Canon City. It is also well exposed in this vicinity in

a structural basin north of Canon City. South of Canon City the forma-

tion is not present for a considerable distance. It is present near Beulah,

where it rests on the gneisses. North of Beulah the “Dakota” is said to

rest directly upon the Fountain formation, showing the presence of an

erosion interval between the Red Beds, or possibly the Morrison, and the

“Dakota.” 'The formation is exposed in the Greenhorn Mountains, where

it rests partly upon the red beds and partly upon the gneisses. ‘The more

important areas of Morrison outcrops in the eastern region have been well

described in various reports, and summaries of these descriptions are

given below.

The Morrison formation is overlain by the Lakota-Dakota series, the

lower beds of which are known in the southern Colorado area as the

Purgatoire formation. The contact is essentially conformable, but it is

sometimes extremely sharp, as north of Cafion City, and it is quite prob-

able that in many areas at least there is a stratigraphic break of slight

extent between the two formations.

NORTHERN COLORADO

The following sections are given by Darton of the Morrison formation

in northern Colorado (1904, 8) :

Section northwest of Laporte, Colorado

: Feet

“Dakota,’’ Coarse sandstone, with conglomerate at base............... Be

Gray massive shales, with thin limestone bed about 20 feet

DEVO We WO Ob aortic aco Tete CR aes REET NS ye Err pan Sere ESP er tal ae 80

MGUEEISOnuiMmestone /oray, With: Alle .:. sc ssa% he esses ves oe ov space sedan 6

Sandy shale, reddish to buff, partly massive................ 20

Pinkish and buff sandstone at top of Red Beds................0.0.00- 60

46 ANNALS NEW YORK ACADEMY OF SCIENCES

Section east of Lyons, Colorado

Feet

“Dakota,” Sandstone, hard massive, buff.. ..

Olive green massive sbale, with

some sandstone layers....... 150

Light grayish green massive

Shale. who ae ee eerie 30

Soft to hard gray sandstone,

(OS FAIBIMNINEC oo ancobosooaobd 15

Red, maroon, and green massive

Shales. i site suael apevacven peste steneners 150

Morrison, Massive buff sandstone, moder-

bib vino cisets obo somone Go pee)

Grayish green to maroon mas-

sive shale, with thin layers of

fine grained sandstone....... 40

COYONIAe: He lfreeLT) Cleachc errs Mecrene etn Ie 25 2

Upper Wyoming, Soft buff sandstone...... 30 :

Fic. 3.—Section of the Morrison and over- Fic. 4.—Section of the Morrison and ad-

lying and underlying beds at Laporte, jacent formations east of Lyons, Colo-

Colorado. rado.

A-B = Morrison. Scale, 125 feet to 1 1.—Lakota; 2.—Morrison; 3.—Red Beds.

inch. (Darton.) Scale, 125 feet to 1 inch. (Darton.)

The Morrison formation in the vicinity of Boulder was described by

Fenneman (1905, 9). The following remarks on the formation in this

district are based on Fenneman’s description. Sections of the Morrison

at various places in this area differ greatly. In the main, however, the

formation contains a large proportion of light-colored clays, some mod-

erately indurated and others of flinty hardness, much gray sandstone,

often calcareous, and at various horizons beds of highly compact lime-

stone. A very much generalized section would present the beds in about

the following order, beginning at the base: sandstone, clays, limestone,

clays. The first and last members of the series are persistent, but the

intervening clays and limestone may show two or three alternations and

may inclose prominent sandstones. Fenneman estimates the maximum

thickness to be a little less than 400 feet. The formation in this district

MOOK, STUDY OF THE MORRISON FORMATION AY

overlies the Lykins division of the Red Bed series. ‘The basal sandstone

varies from 10 to 20 feet in thickness. It is persistent and massive and

is used for building stone. It is somewhat calcareous. The lowest bed

of limestone varies in level, but may be within 15 feet of the basal sand-

stone. ‘The intervening levels are composed of clay which is covered by

waste material. One bed of limestone 40 feet thick, according to Fenne-

man, occurs at South Boulder Canyon. At one locality there are three

distinct limestones separated by sandstones, the uppermost of the three

being about 30 feet thick. Next follows 75 to 100 feet of covered beds,

probably soft clays. Limestones and clays interbedded follow this cov-

ered series, in turn followed by 15 feet or less of calcareous, iron-stained

sandstone. Above this sandstone the formation is composed of dense,

hard clays and argillaceous sandstones.

MORRISON

The deposits of the Morrison formation are not very well exposed at

the village of Morrison, six or seven miles west of Denver, from which

the formation takes its name. ‘The beds outcrop on the western slope of

the hog-back at this locality and are mostly covered by talus from the

Hesse REE S : ae =

Wie. 5.—Vhe Morrison formation at Morrison, Cclorado, looking sonth

48 ANNALS NEW YORK ACADEMY OF SCIENCES

heavy sandstones of the Lakota-Dakota series at the summit of the hog- —

back. The first discoveries of remains of the large dinosaurs of the so- —

called “Atlantosaurus fauna” were found about half way up the slope of

the hog-back, on the northern side of the gap, through which Bear Creek

crosses the hog-back.

The hog-back is capped by a ledge of heavy cross-bedded sandstone of

the Dakota formation, underlain by white sands of the Lakota series.

Beneath these sands are the soft shales and clays of the Morrison for-

lig. 6.—Vhe Morrison formation at Morrison, Colorado, looking east.

mation. ‘They are mostly pale green at this locality, with a few thin

bands of sandstone and some variegated clays and red sandstones. The

thickness here is evidently less than at Garden Park, near Canon City,

farther south, but more than in the exposures farther north in Wyoming.

The upper and especially the lower contact could not be accurately deter-

mined. The formation appears to rest upon a coarse white sandstone,

which in turn rests on deep red sandstones of the Red Bed series.

CANON CITY AREA

The Morrison formation is extremely well exposed in a number of

localities north of Canon City. A structural basin of A-shape, formed

MOOK, STUDY OF THE MORRISON FORMATION 49

by down-faulting and down-folding, has protected the Paleozoic and

Mesozoic sediments of the district so that they are bounded on the east,

north and west by the crystallines.

A hog-back capped by the Lakota-Dakota sandstones extends northeast

from Canton City, and a similar hog-back extends northwest from a point

a few miles east of Canon City. The dips of these two hog-backs are

steep at their southern ends, but as they converge the dips become less

and change in direction. Instead of being toward the southeast and

Fie. 7.—View northeast from Fremont Peak, near Canon City, Colorado.

A indicates locality of the Marsh-Hatcher dinosaur quarry, B indicates the Morrison

outcrops in the hog-back near Cafion City.

southwest respectively, the dip at the point where the Lakota-Dakota

capping of the two hog-backs becomes continuous is towards the south. A

short distance north of this point the dip lessens until the strata are nearly

horizontal. Oil Creek, a tributary of the Arkansas River, cuts through

this flat area, exposing the underlying rocks in a series of cliffs. North

of this point a wider valley has been excavated, having the ‘Triassic and

lower beds as a floor. This valley is known as Garden Park.

The Morrison formation is exposed on the steeper eroded sides of the

hog-backs, in the narrow gorge of Oil Creek and its tributaries, and in the

ANNALS NEW YORK ACADEMY OF SCIENCES

Fic. 9.—Near view of the central portion of fig. 8.

An erosion Channel in the lower clays, filled with a coarse sandstone, is shown.

MOOK, STUDY OF THE MORRISON FORMATION 51

steep cliff on the western border of Garden Park. At this latter point

the beds are exposed from base to summit, affording a complete section.

Several productive bone quarries have been operated at this point, and as

these quarries exhibit the structure of the formation very well in some

cases, they will be described in detail. The most important of these

quarries is that which was operated by Professor O. C. Marsh, and later

by J. B. Hatcher for the Carnegie Museum. This quarry is situated on

the northeast hank of a dry brook-bed which joins Oil Creek just south

lie. 10.—Hazposure of the lower beds of the Morrison formation about 100 yards

northeast of the Marsh-Hatcher dinosaur quarry, near Canon City, Colorado.

of the entrance to Garden Park. The uppermost beds exposed at the

quarry are red and brown joint-clays. Below these clays is a bed of

rather coarse, heavy-bedded sandstone, about 5 feet thick. Below this is

the bone-bearing sandstone, about 3 feet thick. It is a soft, coarse-

grained sandstone, somewhat arkosic. In the exposures on the opposite

side of the gulch the bone-bearing sandstone is distinctly cross-bedded.

Below the bone-bearing sandstone is the sandstone of the quarry floor.

This sandstone is heavy-bedded and is cross-bedded on a large scale. ‘This

cross-bedding makes the exact thickness difficult to determine. It is

52 ANNALS NEW YORK ACADEMY OF SCIENCES

‘about 5 feet on the average, and the variation in thickness is not great.

Two distinct types of crogs-bedding are present in this sandstone. It is

underlain by a bed of clay 1 or 2 feet thick. This clay is underlain by

another sandstone with a lense-shaped cross-section. It is about 15 feet

thick at its thickest portion and about 2 feet thick at a point 60 or 80

feet on either side of its center.2 Below this sandstone is a bed of clay,

8 feet thick, bearing small obscure shells. Below this clay is a limestone

1 foot thick, which is underlain by 9 feet of clays. These clays are under-

Wie. 11.—The Cope dinosaur quarry northwest of the Marsh-Hatcher quarry, near

Canon City, Colorado.

lain by a bed of lime concretions, 1 foot thick, underlain by more clays.

The beds below are not exposed in the gulch, but are exposed on the west

bank of Oil Creek about a hundred yards northeast of the quarry. ‘The

section at this point is as follows: clays at the top, underlain by about

3 feet of sandstone, which are in turn underlain by about 5 feet of the

bone-bearing sandstone. Below this are 3 feet of the quarry-floor sand-

stone. ‘There is a sharp contact between this sandstone and the under-

lying clays. Below the quarry-floor sandstone there is a series of beds,

*See discussion of structures, p. 117.

MOOK, STUDY OF THE MORRISON FORMATION 53

36 feet in total thickness, which is mostly clay, but may contain thin beds

of limestone or concretions where it is covered by a thin clay talus. Be-

_low this clay series is a heavy-bedded sandstone about 8 feet thick. This

sandstone is underlain by a series of clays interbedded with thin layers

of limestone and nodules. This series may be taken as the base of the

Morrison formation in this region. It is underlain by the reddish arkosic

sandstones of the underlying formation.

Another important quarry in this region is that operated for Professor

E. D. Cope in 1877. This quarry is situated about 600 yards northwest

Wig. 12.—The “Nipple,” west of Garden Park, Colorado, looking east.

of the Marsh-Hatcher quarry. It is situated at the top of the hill, and

the beds exposed in it are the brown and white clays.of the uppermost

beds of the Morrison formation in this district: They are overlain by the

coarse white sandstone of the Lakota or Purgatoire formation. The con-

tact between the two formations is very sharp.

Another quarry operated for Professor Cope is situated about 500 yards

east of the above-mentioned Cope quarry. It is situated at the base of a

small conical hill, locally known as the “Nipple.” It is at the top of the

cliff which forms the western boundary of Garden Park. The productive

Bal ANNALS NEW YORK ACADEMY OF SCIENCES

bone level at this point is 20 feet or so below that of the other Cope quarry

to the west. It is much higher than the bone level in the Marsh-Hatcher

quarry. From the summit of the “Nipple” to the base of the cliff a.

complete section from the base of the Purgatoire to the upper members

of the Red Bed series is exposed.

A section from the summit of the “Nipple” to the uppermost beds of

the Red Bed series is as follows:

Feet Inches

1. At the summit of the “‘Nipple”’ and about 25 feet above the top

of the cliff, white sandstone of the Purgatoire series....... 1

AMS TOW TN J OULC]AY:.. sieve sueleners aioli ehaten ieee slisesbearet Micha RntoateR sae 4

oo BLOWN: MOMMIES f3. (06 oS PS ies Satara Sauna oe ee of 4

ASB PO WANS CLAY s:payils s22 5 Susser dk colayee yah Soa Seer eye aa aT ane ze Saar 15

5. Gray clay (at the top of the cliff, contains dinosaur bones and

is the productive bed of the above-mentioned Cope quarry) . oD) 2

Gi SAM ASEOME iis ciate os alee Sli ae Seeren hice ae ee eae aaa OO Sor ES eT RE ee 1

Ties Maayan ese Sic age Sede br eb fessatirs a setToa eo cae eo en cpr i

Sh (0504 @)) len iaeyshles: Grae! @lehyoganconcanoeadaoudaucoscognoce Beers

Spi Variegated si Clavie sceicre Sich soma Siteee ele eevee eae st See ree ee 9 6

LOS Sanadstome § Meck Bs Ole osc aetareeue te eeeiae pele eee ee ero eee ae 4

DSSS CVA yH tea alte hia ey aieerce astute laa a ashe ah abe rake Se ENEH TOPS te Rates TE a ae Ae 6

P22 ES AT SEO este Re ee aie tesa tals Shas ray no tac sien TUR A eas : 3

13. Variegated clay, gray, purple and green®..................... 204

14. Cross-bedded sandstone............. 00.002 ccc e cere eee eee 8

WES RG ei a re aN eT Set EC ie ALL re Re 1

GIGS BT GIS COIS Hiss elses Oa cose ata ia Tt Se aaele cs Fa she nn eo 1to6

USTs SOM eay Soe oe Seay site en Map athe pe Rea eee SE SEC UNE A S/n ie Pg 6

USS AMASEOME eyo ers Latent, Lae Adena ole veuek ai ee aetiee Ree ne ARE eee ee 1

UDO yes ea hk foaita Se eT Ue pate ete ay Se tp OP enc Te ae a 40

ZOTASATMGSE OME) neers ose whecen ttre Blerrial ero iene nus eueiet cee ey ie a EE aa it

PA) ARN OIE Ric nee ty ens «Sci een eae mae MN teats Nee RARE NTR IAN eT Sa Bod Sh i 8

222 SANG S LOMO ie Ve cah eheies erage tat eee Acaee ace Nn a ia acne a aM erat rn en 1

piso chr Ol Fh aici retard i 2

ZAOGS BMS COM Coe ese nee wile: Sy ck Siceeae ny way aloasct sit Svea aes ee EcSIa OE Ca Reno ae 1

SDN tralian Shoe at lenseasuctre aah am pa pS ee ee ad aut ss TA a ae aE 319 1

319 Tf

25. Arkosic conglomerate. This conglomerate is here considered as belonging

to the underlying Red Bed series, though it is possible that it may be

the basal member of the Morrison formation. In the latter case the

thickness of the formation would be increased by 40 or 50 feet.

The contact with the underlying beds is very indistinct, and the pres-

ence of an erosion interval between the Morrison and these underlying

beds cannot be determined from the outcrops alone.

2The outcrop of this clay series is covered in many places with a thin clay talus,

which may conceal some thin beds of limestone or nodules.

MOOK, STUDY OF THE MORRISON FORMATION 55

Marine fossils of Washita age have been found by Stanton (1905, 11)

near Canon City in beds immediately overlying the Morrison formation.

This limits the age of the Morrison deposits near Cafion City to a certain

extent. This question will be taken up again in the section on the age

of the Morrison.

The general features in the Cafon City area which are especially

worthy of notice are the prevalence of variegated joint-clays in the upper

Fic. 13.—Section of the Morrison and re-

lated formations at Garden Park, near

Canon City, Colorado.

1.—Purgatoire; 2.—Morrison; 3.—Cal-

careous arkosic sandstone, probably the

basal member of the Morrison, but may

belong to the Red Bed series. Scale, 125 1.—Purgatoire; 2.—Morrison. Scale, 12%

feet to 1 inch. (Section by the writer.) feet to ~.1 inch.

lig. 14.—Upper part of the Garden Park

section. (Fig. 11.)

portion of the formation; the relatively larger amount of limestone, lime

concretions and sandstone in the lower portion; the distribution of the

dinosaur remains throughout nearly the whole thickness of the formation,

though these remains appear to occur in definite levels ; the sharp contacts

of the sandstones and clays in the formation; the relatively small thick-

ness of the individual sandstone members in most cases; and the lense-

shaped cross-section of one of the principal sandstones.

ANNALS NEW YORK ACADEMY OF SCIENCES

The lense-shaped cross-section of one of the sandstone members indi-

cates that it was deposited by a stream in a relatively narrow basin, which

Fic. 15.—Lower part of

the Garden Park sec-

tion.

Scale,

(igs 1)

12% feet to 1

inch.

had been eroded in the underlying clays. The fre--

quent occurrence of cross-bedding in connection

with sandstones which have sharp contacts at the

top and bottom appear to indicate deposition by

streams or wind; the structure of the cross-bedding

sometimes being that usually assigned to stream

deposition, and in other cases being of the type

usually assigned to deposition by wind. The fre-

quent sharp contacts in the formation point to the

period of deposition of the formation in this region

as a period of alternating deposition and erosion,

deposition being the dominant process in the long

run.* The sharp contact at the top of the forma-

tion also indicates a period of erosion before the

deposition of the basal sandstones of the overlying

formation. This erosion interval may have been of

long or short duration, so far as direct evidence

from the contact 1s concerned.

CANYONS OF SOUTHEASTERN COLORADO

Lee (1901, 7) has described the Morrison for-

mation in some of the river canyons in southeast-

ern Colorado. He reports it to vary considerably

in thickness from place to place, being 85 feet thick

at the mouth of Plum Canyon, 132 feet in Red

Rocks Canyon and 175 feet in Chaquaqua Canyon.

The formation is made up largely of variegated

clay-shales or joint-clays. Sandstone occurs in

subordinate amounts, varying much in its position

in the column, from one point to another. In Red

Rocks Canyon there is a prominent sandstone at

the base; there is none at all: in Plum Canyon; in

Chaquaqua Canyon, four miles from the mouth of

Plum Creek, there is a coarse, cross-bedded sand-

stone 50 feet or so from the top of the formation.

Across the canyon from this point, perhaps two

miles away, 30 feet of limestone is found at the

same horizon. Some of the sand is very pure and

is used as a flux in assaying. The limestones also

* 4See discussion of structures, p. 118.

MOOK, STUDY OF THE MORRISON FORMATION 59

vary much in their occurrence. They are usually more or less argil-

laceous. “The relative amount and position of sandstones, shale and

limestones at any one point is no indication that a similar relation will

be found at any other point. There is no abrupt lateral change, but the

various beds blend into each other or pinch out laterally in a gradual

though somewhat rapid manner, so that, while no sudden change is seen,

a comparison of sections a few miles apart may show a total change in

kind and relation of materials” (Lee, 1901, 7; 1902, 5). Dinosaur bones

lig. 16.—The “Nipple,” looking west from Garden Park, OColerado.

This view is in the opposite direction from that in fig. 12. The section shown in fig. 13

was taken in this cliff.

were found at many horizons. Some of these have been identified by

Barnum Brown as Morosaurus and Diplodocus.

The Red Beds, Morrison and “Dakota” all have the appearance of being

conformable, though critical examination has shown that there is evidence

in favor of concluding that there is a stratigraphical break both above

and below the formation. ‘There is distinct evidence of erosion at the

surface of the Morrison, below the “Dakota (Purgatoire), in the presence

of undulations in the line of contact with the “Dakota” (Purgatoire).

The Morrison lies on beds of gypsum in these localities. This gypsum

58 ANNALS NEW YORK ACADEMY OF SCIENCES

is not differentiated sharply from the underlying Red Beds. ‘There is

often a transition from Red Beds into gypsum. ‘The change from the

gypsum to the lower members of the Morrison is abrupt, and the gypsum

often decreases in thickness where the Morrison is thick, and the reverse.

“Tt is possible, therefore, that the gypsum beds were exposed and slightly

eroded previous to the deposition of the shales” (Lee, 1901, 7). .

The following sections of the Morrison in this area are given by Lee

(1901, 7):

Section near Mouth of Plum Canyon

Feet Inches

Dakota (Purgatoire). Two massive sandstone layers separated by

a soft shale of varying thickness; leaf

impressions near the top of the upper —

GUVASTON Ss ais ec Ses 5 Se eaciley ces ete eae EL 140

Morrison, Greenwich clay shale, soft and fine grained............ lal: ue

Dull red clay shale, soft and fine grained............. a ies

Brown. to yellow? shales. 22 a. cnar seni ees cree nee 10 ‘

Argillaceous limestone; numerous fine dark laminze.... .. 6

Butt colored: Wale a o-seerer cic oioveon erates teeta ope Ce Pete yl Lis)

Argillaceous limestone; numerous fine dark laminw.... .. 6

Variegated: joint telaiygas Somacietan wie seus nieions stoke en eee ate

Argillaceous limestone, fine grained and hard, with con-

TOLCEG Vamimee res. S55 ok als: ssvaters el eee eee ke a Oe 2 an

Variegated shales; very soft and easily eroded......... 30

Red Beds, Dark shales containing irregular masses of gypsum.... 15 aye

Gypsum containing streaks of clay................... an 18

Variegated shale containing nodular-like masses of gyp-

sum which vary in size from grains to masses a foot

or more in diameter. About one third of the mass is

VETO SUNN shel Slsyhn, Siero teu ane tole tay les Gon aoe Rae aR elke Nes ana eae 8

Gypsum in well-defined layers. Often separated by

LAV ERS LO fas Clay re a eyiscee oh eae ore SN ate 25

INEAS SIV GOV) SUMMA se 5s sheikh cies ateca a fouos ely vans bstereie cn hee Ieeee 5

Red gypsiferous shales, soft and regularly bedded.. 30 to 40

Red calcareous sandstone, oolitic, cross-bedded. Indi-

vidual layers variable in thickness and character.

Near the top it becomes shaly and passes gradually

into the gypsiferous shales above.................+- 60

Red sandstone, massive, cross-bedded............. 175 to 200

Red “arenaceous “Shaler s ashes ces soe siete ie ao eee eee 6

PEG SANSOME Re rete a laden Cee een DIA a rae las, eae all

PNG PEM SIAN e a Sea Sy ad eaonetiorsen eo deve ter agate Crave asteuelars ane 4

Even-bedded red sandstone..............2-.02-cesceee 9

Red: arenaceousi Sale sy cesses, eer sious Riche Chote seueheyuacre chee Gneee 2

Red sandstone, cross-bedded; the individual layers thin

OUE Tater Uys csaae oy Serene eae eree nie rarer ee tes aeicic sate ee 40

Poorly cemented red sandstone alternating with layers

OL SIA ee ciety eee chi ee es ratio repenistis atone eteege ee uae nets rc towers 15

MOOK, STUDY OF THE MORRISON FORMATION 59

Feet Inches

Massive red sandstone..............02-2e-eeee ae eee 5 ae

Soft red sandstone containing hard layers which are

Eipple=niarked 25 auccecw seigees s slaeetelee Rasen aye eevee 30 we

Hard, white, argillaceous limestone composed of numer-

ous thin layers; greatly contorted..... Sei eee deer : 4 aie

: Red sandstone in thin flaky layers............. Brain ee 15 ee

(River bottom. )

fic. 17.—Section of the Morrison and re- Fic. 18.—Section of the Morrison and re-

lated formations in Plum Canyon, Colo- lated formations in Red Rocks Canyon,

rado. Colorado.

1. — Purgatoire-Dakota ; 2. — Morrison ; 1.—Purgatoire; 2.—Morrison; 3.—Gyp-

3.—Gypsum at the top of the Red Beds. sum and Red Beds. Scale, 125 feet to 1

Seale, 125 feet to 1 inch. (Lee.) inch. (Lee.)

Section in Red Rocks Canyon

Feet Inches

Dakota (Purgatoire) sandstone.

Brick red arenaceous shale, containing bands of hard,

fine-grained Sandstone... ...,..0.00c8cce oc cce esse ees 25 6

Reddish limestone having a conchoidal fracture and

WET WDTUCGI Cl soeseena nrfcbcvs eiscalens salves) cueselale nie tes Meow eVabaloae 3 tod Oe

Oni walaislkencl Aya Slater cna eleretecaslei tts eke he siete cree ee) Oi oe

Light brown clay shale.....................-. Lia aee sre a Ue Re

Areilaceous IIMESEOMC TS ec cid <lonoreisiaieseis wise le elo a tuck eats ah 6:

Brown shale.............. Hevea RC Nata siesca rer ues, wilersiteter Sesyay cibieus 7 66

Concretionary limestone...............0c ccc e cece cece 1 ots

Variegated clay shale; joint structure.... ........... 7 Go

Hine tyellow paper Shaler... ci. c 6. ws ee oe be cee ce ee Sanaa

Argillaceous limestone, finely laminated............... one 6

Fine shale....... BEART al cis stole ean epeceta arama e epee sists darts Mea sees

VAIO SITTVES HONS eee cera ce calsce) enone averey aud acdc wasnens ohavale srauace 1 $4

60 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet Inches

Argillaceous limestone, finely laminated............... she 8

Wellow “Shallow es Sits srcctie tetenle ciel cherete arene te aie ee cc tere eee 4

Sandstone containing agate either in concretionary

masses half an inch or more in diameter or dissemi-

nated generally throughout the mass................ al

Sandstone, easily crumbling; made up of thin layers... §

Massive sandstone, poorly indurated.................. 2 a

Hine paper-shail Gen. 6 oc eacsre oie «lage use el Beene sles) he eee One 2

Massive sandstone, poorly indurated..................

Gypsum interstratified with layers of clay........ 12 to. 20

Red sandstone (Red Beds)...............--------eeee

R. C. Hills (1900, 7) describes the HOEUSOd of the Walsenberg quad-

rangle as follows:

“Morrison formation—This formation aggregates about 270 feet in

thickness at the southern extremity of the Greenhorn Mountains, where

there is a narrow outcrop extending along the foothills a distance of

about 5 miles and passing on beyond the west boundary of the quadrangle.

It is also exposed along the canyons of the Cuchara and Huerfano for a

distance of over 20 miles. About midway between the extremities of the

Greenhorn Mountains outcrop the inclination varies from 45° to nearly

vertical. The lower portion consists of about 60 feet of soft, white sand-

stone having a conglomerate layer at the base. ‘This is followed by hard,

shaly beds of pinkish and greenish tints, breaking into fragments with

conchoidal fracture. ‘The upper portion consists of variegated shales and

clays alternating with bands of hard, fine-grained limestone, often con-

taining vermilion-colored cherts. One band of conglomerates a few feet

thick contains green pebbles. At one point the basal sandstone overlaps

the Badito formation, and rests on the Archean at an angle of 15°. In

the canyons of the Huerfano and Cuchara the strata have but slight in-

clination except where an upward bulge brings an area of the Fountain

to the surface. Here the thickness of the Morrison is less than 100 feet,

and corresponds to the upper, variegated part of the Greenhorn outcrop,

the lower part being entirely wanting. There is still considerable doubt

as to the true position of this formation in the time scale, and the assign-

ment to the Jura-trias is therefore provisional.”

In the Apishapa quadrangle the Morrison consists of blocky lay or

argillite, according to Stose (1912, 7), with thin beds of limestone and

some soft sandstone. The argillites are of brilliant colors, ranging from

white to dark brown or red, and to green and drab. Only 120 feet of the

formation is exposed in the quadrangle. Stose gives the following com-

posite section of the upper part of the Morrison in Huerfano Canyon:

MOOK, STUDY OF THE MORRISON FORMATION 61

Feet

Sandstones of the Purgatoire formation.

Variegated shale and compact argillite, green drab, and dull maroon in

ROCHON UTE “O ivan COMETS Cicietn ec: sitelc ohetay le elas Suave e\'s' w eliela\e cic e'eis, wie ses «re eicle si ee. ie

Massive gray sandstone having ocher colored spots, with soft fine-

grained chocolate colored sandstone above and red layers toward the

top. Largely covered. Exact relation not known..................05 58

Greenish-gray shale and compact argillite with 6-inch beds of impure

limestone and short lenses of sandstone. The limestones contain

small fresh-water gastropods and lamellibranchs....................

Two miles above the mouth of Jones Lake Fork

there is an exposure of 100 feet of the formation.

The uppermost beds at this point are covered, but

there is about 30 feet of reddish shale with cal-

careous concretions, underlain by 8-10 feet of lime-

stone. At the base is green argillite.

Gilbert gives the following partial section at the

mouth of Jones Lake Fork (Stose, 1912, 7):

Feet

Thin sandstone and gray shale (Purgatoire for-

mation). ;

Chocolate colored shale.....................205- 16

Soft pale gray sandstone freckled with brown,

weathering pale brown............-..-scceees 10

Variegated compact blocky shale, red, chocolate,

green and white, with bands of fine sandstone,

some tough and brown. ‘The lowest sandstone

is a fine-grained rock freckled with pale yellow. «51

Fic. 19.—Composite sec-

ws tion of the upper part

7 of the Morrison forma-

EASTERN NEW MEXICO AND OKLAHOMA tion m the Huerfano

quadrangle, Colorado.

The Morrison occurs a few miles east of Fol- 1.— Purgatoire; 2.—

Morrison. Scale, 125 feet

som, New Mexico, in the canyon of the Rio Cimar- 4, 4 inch. (Sisee)

ron (Lee, 1902, 5). It consists, at this point, of

25 to 50 feet of variegated clay-shales overlying the upper gypsum mem-

ber of the Red Bed series. These clays thicken farther east, and 14 miles

east of Folsom they are about 200 feet thick. The following section by

Lee was measured at this point:

Dakota (Purgatoire). Sandstone, massive and quartzitic, somewhat conglom-

eratiec in places.

Shales (Morrison). 200 feet of varicolored shales with local beds of brittle

limestone and lime concretions. A coarse, loose-tex-

tured, cross-bedded sandstone occurs near the top.

_Red Beds. Deep red sandstone.

62 ANNALS NEW YORK ACADEMY OF SCIENCES

Still farther east, below the junction of Long Canyon and Rio Cimar-

ron, the Morrison formation is exposed in an isolated mesa which stands

in the midst of the canyon. A section at this point, measured by Lee, is

as follows:

Section in Canyon of Rio Cimarron east of Long Canyon

Feet

Dakota (Purgatoire). Sandstone, massive, quartzitic, cross-bedded, slightly

conglomeratie in places. A thin seam of blue

clay 100 feet from the base......... od deo alee

Shales (Morrison). Colored shale containing layers of athillaceate sand-

Stone and limestoness-5.. 2 eee sd ee

Coarse grained loose textured sandstone.................. sel OO)

Conchoidal limestone with

clay and coarse sand at

tHE ASCs Se eet coarser

10 ee SeeBs Save saces

Arenaceous Shale......... 10

Conchoidal limestone.... 1to3

Variegated shale......... . 40

Argillaceous limestone... . 3

Shale containing irregular

Seams and masses of 1

agate - like concretions,

colored in varying shades

of blue and pink........ 40

Sandstonewe cece senate 5

Red Beds. Gypsum interbedded with

Clay enn Ae ae itt se 20

Red to purple sandstones

and shales.......... eHereiiitiace

Fic. 21.—Section of the Morrison and re-

Fie. 20.—Section of the Morrison and re- lated formations in the canyon of Rio

lated formations in Rio Cimarron Oan- Cimarron east of Long Canyon, New

yon, 14 miles east of Folsom, New Mezx- Mexico.

160. 1. — Purgatoire-Dakota ; 2. — Morrison;

1.—Purgatoire; 2.—Morrison ; 3.—Exeter. 3.—Red Beds and gypsum. Scale, 125: feet

Seale, 125 feet to 1 inch. (Lee.) to 1 inch. (WLee.)

‘

}

’

MOOK, STUDY OF THE MORRISON FORMATION 63

The formation was traced by Lee eastward from Folsom to a point

seven miles east of the boundary between New Mexico and Oklahoma.

The formation is made up, as usual, of variegated clays with minor

amounts of sandstone and limestone. “All the members of this forma-

tion vary laterally in character and thickness. No two sections exhibit

the same order of succession nor the same relative proportion of mate-

rials” (Lee, 1902, 5). One member which is persistent in this area is

a thin bed of agate-like concretions near the base of the formation.

“Tn the vicinity of Exeter post-office the shales are separated from the

underlying Red Beds by a well-marked unconformity. The Red Beds

were thrown into gentle undulations and these undulations eroded pre-

vious to the deposition of the younger sediments upon them. Several

miles west of Exeter post-office the shales rest upon the eroded edges of a

local arch, from the top of which about sixty feet of the Red Beds had

been removed previous to the deposition of the shales. The gypsum,

which is here considered as the top of the Red Beds, appears in the flanks

of the truncated arch. From this point eastward for several miles angu-

Jar unconformities were noted at the top of the Red Beds” (Lee, 1902, 5).

Another section was measured by Lee a few miles east of Exeter post

office. The formation is exposed on buttes and mesas in the midst of the

canyon. Limestone is an important constituent of the formation at this

point. The section is as follows: }

Section near Exeter Post Office, in the Canyon of the Rio Cimarron

Treet Inches

Dakota (Purgatoire). Hard quartzitic sandstone................ 78

Shales (Morrison). Shale, arenaceous in places.............. 10 to 15 fs

IT CH COM CEELIONS ig cages siatioye coy dais sickens eta /ale's wiein Sie eanelees ss 6

VCC eaS hall Oierapseeesr cece tasters siavnrsinbie eee Guakge ae a ethos eee 8

Nall GS COM emeetera eer cnlspae oder cnt snelercnare aieb a aun one a seeeniaue aie dios 4

Sandstone and shale (debris covered in places)........ 50

DD Arleonre densa excretee esau cevsanne Wis erchonsc c aid bower mela wus 30

WOATSE NSA CShOMES aspen iy acco cee Bisee eet: coe Se 4

TBIINES GENS a Si ete Steed iicichd cho Bb SRROIaENE Coole Eno eRe eens Bue Ege 2

Gail CHMEOUSME] Aven ocr te oo cesioe ean) ores Sask aiereps ookieesl Che seek Wares 2

Blue clay shale with seams of limestone............. 30

Hard brittle limestone..................-..... Peeps nus 1

Shale with thin seams of limestone................... 20

Shale with impure limestone and sandstone bands and

irregular masses of agate...............00-000. 10 to 15

Hard brown, nearly pure limestone................... 5

UWE OSEU Poreeeeven eneyerererecl occ els! cleusnanaie: vyauaseue ah sued cull woetel skates 20

Exeter. White sandstone, massive below but passing to well de-

MME RAVES FADOVE. xe sc ka kyace a ease oslo does Seles a hie teetons 35D

Loose textured and readily weathering sandstone...... 8 a

64 ANNALS NEW YORK ACADEMY OF SCIENCES

: Feet Inches

Massive chalky white sandstone, cross-bedded and ecay-

ELNOUS “WEA TMERIM Beco v7... ce. booteue) olanclatcroleoa selene eaters eae 15

Soft shaly Sandstone; 2.23... eee ee eee 2

Massive evenly laminated sandstone, ranging in color

from red at the base to white at the top............ Tiaueee

Red Beds. Red sandstone layers interstratified with red and purple

SWAT OS eat rees obi bb lasanase orale ateiens. = Sie areata iy saealen tel atane neue Roe niet

Near Exeter post office a sandstone formation

appears between the Morrison and the Red Beds.

It lies unconformably upon the Red Beds. It ap-

parently underlies the Morrison conformably . It

is a firm, hard and rather coarse but evenly lami-

nated sandstone, pink to white in color. The lower

members are pink, while those above are lghter

colored. It has the appearance of being composed

of the coarse material eroded from the Red Beds.

The sandstone has a maximum thickness of 75 feet,

and extends from a point several miles west of

Exeter, where it thins out, eastward to the Okla-

homa-New Mexico line, where it drops beneath the

canyon bottom. No fossils of any kind have been

found in this sandstone. It occurs in a series of

nearly perpendicular cliffs, making a broad con-

tinuous band along the canyon sides (Lee, 1902, 5).

The Morrison in this locality, according to Lee

(1902, 5), “rests in turn (1) upon the gypsum

Tee open se ane conformably; (2) upon the gypsum and underly-

Morrison and adjacent 1ng Red Beds unconformably; (3). upon the Exeter

formations im the Can- sandstone conformably.”’ Lee also notes that the

yon of Rio Cimarron, Ms

near Exeter post-ofice, Morrison shales, as a formation, do not vary to any

bean considerable extent in character or thickness at this

Weueina ee oat locality. “Whatever may have been the physical

4.—Red Beds. Scale, 125 conditions prior to the deposition of the shales

feet to 1 inch. (Lee.) [Morrison], it is evident that the shales were de-

posited over a well-graded surface. It follows also that there was a

somewhat notable time-interval between the Red Beds and the shales. A

part at least of this time-interval is represented by the unconformity

between the Red Beds and the Exeter sandstone. It is uncertain whether

there is a time break between the Exeter sandstone and the overlying

shales. However this may be, the seeming conformity which exists in

many places between the Red Beds and the shales is deceptive. The con-

MOOK, STUDY OF THE MORRISON FORMATION 65

tact really represents the whole time indicated by the unconformity be-

tween the Red Beds and the Exeter sandstone and the time required to

form the Exeter sandstone, besides the possible period between the deposi-

tion of the Exeter and that of the shales” (1902, 5).

The Morrison formation is exposed in the canyon of the Canadian

River. This river flows in a narrow gorge for fifty miles or so, then in a

broad valley bordered by high escarpments. The thickness of the forma-

tion is approximately 300 feet. ‘The beds are composed mainly of varie-

gated clay-shales and friable sandstones. Limestones also occur in lim-

ited extent. In some localities the limestone layers are all near the top,

and at others they are differently distributed. In no two sections do the

limestones occur at the same horizon. The sandstones comprise a con-

siderable part of the formation, perhaps one-third. The separate beds

are in some cases firm and in others very friable. They grade from sands

of pure silica to nearly pure clay. A slightly cross-bedded sandstone of

considerable persistence may be seen in places near the middle of the

formation. The shales contain red, brown and green members.

The contact with the overlying Purgatoire is abrupt, but without defi-

nite evidence of disconformity. A coarse, massive, pink sandstone occurs

at the base. The contact with the underlying beds is sharp, but without

distinct disconformity (Lee, 1902, 5).

The following section was measured by Lee, north of Bell Ranch:

Section at the Hscarpment north of Bell Ranch

Feet

Dakota (Purgatoire). Sandstone, coarse, massive and quartzitic......... 250

Shales (Morrison). Variegated shale containing numerous thin bands of

limestone and sandstone.......................06 50

Arsillaceousi HSsilemSandStomen. ecm ss nhs en es ie ieee cies 10

COATSEVESATMOSTOMEeetcaseictee Sater tee ai eens eae cE eee ee hele 13

Bluish-green shale with a few bands of sandstone and im-

POUL MULMMES TOM Els sAratete te cee eee ere eee eee RCS Sere eee is lhcb 45

Coarse Massive SandsStome, ses sic Stee es A ee Sisie wat 15

Variegated clay shale............. FF ATONE ORES BI BoC 12

ANA ESET AY oetS) aca Sarena teeth en ee tea aaa Ee See eRe oe Need etre en eR eat i)

Coarse white sandstone, cross-bedded in places............. 13

Coloredmsandye Slievlersry.... aelseleice we setol vee to We deveetcwsniaitcs we tants 15

ALSHTACeOuUSiTSan dStOMe. sn oeieiece eine e-eiorees acl Oe suelo dcarwo neem on 6

Coarse sandstone containing lime concretions in places...... 15

Variegated shale containing thin layers of sandstone........ 36

VCC ATI OMS RECN SIIANTES sc) Nala testtea ateve/ se os gl vere eee eaeney ater olny aellew ante 12

Poorly exposed. Shale seen at intervals................... 65

Rusty brown to red sandstone with bands of red clay.. 10to 50

?Sandstone. Massive pink to white sandstone. Forms a persistent cliff. 50 to 100

Red Beds. Friable sandstones and shales in thin layers, red to deep pur-

MOLE Meas COM Oe eres rasrastae sian a) Sisk sunt, Sea aeons aceeeroe io reat a oes

66 ANNALS NEW YORK ACADEMY OF SCIENCES

Fig. 238.—NSection of the

Morrison and adjacent

formations in the es-

carpment north of Bell

Ranch, New Mexico.

1. — Purgatoire - Da-

kota ; 2.—Morrison ; 3.—

Exeter; 4.—Red Beds.

Scale, 125 feet to 1 inch.

(Lee. )

Morrison ForRMATION IN WESTERN COLORADO

AND HASTERN UTAH

A series of variegated clays and shales occur in

many localities in western Colorado and eastern

Utah, which correspond lithologically and strati-

eraphically with the Morrison formations east of

the Rocky Mountains. The meager invertebrate

fauna of these clays and sands agrees with that of

the eastern Morrison, and the discovery by Riggs

in 1900 of a vertebrate fauna in these beds, con-

sisting of practically the same forms as the fauna

of the eastern Morrison, proves that some part, at

least, of these western clays corresponds to all or

certain parts of the Morrison formation east of the

Rocky Mountains.

The clays under discussion have been referred to

- in different localities as the Gunnison formation,

McElmo formation, Flaming Gorge formation,

“Lower Dakota” and “Jurassic beds.” 'The strata

included under some of these terms undoubtedly

contain beds that do not correspond with any part

of the eastern Morrison formation. This fact does

not preclude the probability that in general these

beds correspond with the eastern Morrison.

The western representatives of the Morrison for-

mation occur in isolated areas preserved by fault-

ing, as at Crested Butte; in hog-backs, as in the

exposures east of Vernal; and in the walls of river

canyons as at Grand Junction. Detailed descrip-

tions of the formation at some of the better known

localities are given below.

The following description of the Gunnison for-

mation in the Crested Butte quadrangle is given

by Eldridge (1894, 3):

In the Anthracite-Crested Butte quadrangles the

Gunnison formation rests unconformably on the

maroon and older formations. It consists of

quartzites and shales, with a minor amount of

limestone. Its thickness is from 300 to 450 feet.

At the base of the formation is a heavy white

ee ee

‘

MOOK, STUDY OF THE MORRISON FORMATION 67

quartzite, 50 to 100 feet thick, usually in a single bed. Above this is a

blue limestone, which contains shells of Limnea, Valvata and Cypris.

In some cases this limestone is succeeded by more sandstones, and in

other cases these sandstones are absent. The upper part of the formation

consists of gray, drab, pink and purple clays and marls, through which

run thin intermittent beds of drab limestone.

The lower part of this formation may correspond to the La Plata sand-

stone rather than to the McElmo or Morrison. It is quite probable,

however, that most of the formation is equivalent to the latter.

This locality is about midway between the eastern front of the Rocky

Mountains and the areas west of the mountains, where the Morrison has

a great thickness. The presence at this point of Morrison beds of medium

thickness indicates the probable former extension of the deposits across

the country now occupied principally by the crystallines of the Rocky

Mountains.

Peale (1877, 2) describes “Jurassic shales” in San Miguel and Dolores

canyons and in the Uncompahgre Valley. The creeks tributary to the

Gunnison cut through Dakota and soft “Jurassic” shales into the under-

lying red sandstones. The San Miguel cuts through “Jurassic shales.”

The following section on a creek tributary to it is given by Peale:

1). Upper Dakota sandstone.

2). Lower Jurassic shales.

3). Jurassic variegated beds.

+). Massive red sandstone, light colored.

At one point the “Jurassic shales” rest on the gneiss, according to

Peale. He discusses the “Jurassic shales’ as follows: “Immediately

above the red beds is a group of shales and marls, with thin bands of

limestone near the base. These beds are variegated in color, and corre-

spond, lithologically and stratigraphically with the beds that, in eastern

and central Colorado, I referred to the Jura. . . . They appear to

correspond closely with the beds measured in the section on the Gunnison |

in 1874.” ;

The Gunnison formation of Eldridge was divided by Cross in the

Telluride folio into two formations, the La Plata formation corresponding

to the lower part of the Gunnison formation of the Crested Butte section,

and the McEImo formation corresponding to the upper part of the orig-

inal Gunnison. The McElmo corresponds much more closely with the

eastern Morrison than the La Plata, but in some localities it is difficult

to separate the La Plata from the McHlmo, and it is possible that some

portions of the La Plata are represented in the eastern Morrison.

68 ANNALS NEW YORK ACADEMY OF SCIENCES

In the present discussion the McElmo will be considered as related to

the eastern Morrison formation. The following descriptions are from

Cross (1899, 3) in the Telluride folio of the United States Geological

Survey: 4

The McElmo or Morrison formation in the Telluride quadrangle is a

variable series of shales and sandstones, with the latter more prominent

than is usual in this formation. The thickness varies from 650 to 900

feet. The sandstones are generally fine-grained, quartzose, yellow or

gray, and usually friable. Some of the sandstone beds are massive and

reach a thickness of 50 feet. More often they are separated by shale

layers. Cross-bedding occurs in some of the sandstones. Many of the

sandstones contain small flat flakes of green shale.

The shales or clays are reddish or greenish, or a mixture of both colors.

They are generally calcareous and sandy. Sandstone layers oceur in the

shale. In following the formation along the walls of the San Miguel

Canyon a shale stratum may be found to change, within a short distance,

to an alternation of sandstone and shale. ‘The reverse change often occurs.

in the case of sandstone beds. :

At the base of the McElmo in this area is a highly colored shale resting

on the La Plata sandstone.

The following is a typical section of the McElmo formation in the

Telluride area:

Feet

Sleeper erar i crests aise as oi ap circ) dive dete cocks leita dab Skea a tet one Rel ee nan eee aa 11

Sandstones rather time oraimedia. js. «24 5 cece aes on eee eee 27;

Shale, sandy, with many thin layers of fine-grained sandstone........... 53:

Sandstone, coarse, grading into conglomerate of quartz and chert pebbles

BERIT ASC agepca ces ea dos eel let ohteSyemes alain toplerdouene sevallanal ecu waSeu basa tin eat cae 24

Shale, dull red or green, with subordinate thin bands of very fine-grained

CaleEarequsmSAMASEOME so 2 28 oid cccrate we ieseh soa) Sena eiehe ds blo Si eee ee 155.

Sandstone, coarse grained, cross-bedded.................0-cccce se eceuee As.

ln ee icy iicceate wean tame ere erections Atay eel 2 ARUN eae es A RR ee VW

Sandstoney MA SSivye: se. sas waleare minke sadiote oe ieUne Walesa leetoneee Gls ee eo en ae eee 16

Shale, red, with thin sandstone layers..............00..ccteeceecccsecs 53:

SS AMESHOM SMW NH OR pow Ps faos see raictcd aie ox Susie) cat aratlaweekwics tle Go eiiece cove: anaini oas Seapets 11

Shale, red, with thin sandstone layers............0..0cccc eee ecceeceees 29:

Sandstone; whites cross-heddedi =o .4.. ese asia 6+ see sass scl eee eee By,

Alternating red shale and gray sandstone..................2-eccceceeee 85:

Sandstone, massive in lower part, but with thin red shale partings above. 80

Shaile; Ws aim diye) ch nero uses ance Hoe che tepals vos acre ee eae Laie eel ecko ae, acon ic 32

SAM ASEOMES sf ieidiais ole ch eaceai ape crore hs one cc tesa eRe oaeLe pra nie orc aasie > CEN 8

Shale, sandy, chocolate colored in upper part, thin layers of sandstone in

UPPEI WaATEeieos SE ees os Peers Ge Oe Re ee ele ae Sh ore Glee Oe 64

"Potalskisticael eae oe te eee at ae IS ee nacre eaceidt Al 3. ie 724

MOOK, STUDY OF THE MORRISON FORMATION 69

«Other sections show many changes in the relative development of

sandstone and shale at any given horizon. The conglomerate, number 14

of section, is similar to the Dakota in character,

but is very variable in development. Holmes noted

the presence of a conglomerate near the top of his

‘Lower’ Dakota in the plateau country westward,

and sporadic developments of the same in the Mor-

rison beds may be seen in various places at the

pase of the Front Range.” Owing to the similarity

of the McElmo beds with the Dakota on the one

hand and the La Plata on the other, it is difficult

to determine the exact upper and lower boundaries

of the formation.

The Morrison (McElmo) in the Rico quad-

rangle, according to Cross (1900, 10), is 500 feet

or less in thickness. It is composed largely of

shales at this point, usually of apple green or dark

red color, occasionally variegated red or green.

The shales alternate with sandstones in varying

proportions. The sandstones are white, even

grained, and friable; they often grade laterally

into sandy shale and finally into clay shale.

In the Ouray quadrangle, the Morrison (Me-

Elmo) beds are described by Cross and Howe

(1907, 6) as a series of alternating shales and

sandstones, which vary in thickness and character.

The average thickness in this district is from 500

to 700 feet, the maximum being about 800 feet.

The shales are varied in color. Green predomi-

nates, but in the lower beds reds and browns are

conspicuous. Many of the shale beds are fine-

grained and porcelain-like, but usually they con-

tain sand. Sandstones are numerous, and are

usually quartzose, fine-grained, gray and friable.

They vary considerably in thickness in short dis-

tances, and often show transition to shale or clay

beds. The separate sandstone layers seldom ex-

ceed 20 feet in thickness.

The following section of the Morrison (Mc-

Elmo) formation is given by Cross and Howe for

a locality south of Dexter Creek in the Ouray

quadrangle :

Fic. 24.—Section of the

Morrison formation in

the Telluride quadran-

gle, Colorado.

Seale, 125 feet to 1 inch.

(Cross. )

v0) ANNALS NEW YORK ACADIMY OF SCIENCES

- Feet

Shales, slaty, black, alternating with shaly bituminous sandstone; indi-

vidual layers less than 2 feet thick........7.5,020.-5 408 see Seen 16

Sandstones, yellowish or greenish, with shaly layers.................... 14

Quartzite, “dense; -Oray.c sds sec e loa eas. 0 5k hie ice e Crayon ene oe eee 6

Shales, sandy, black; and fine-grained sandstones, largely quartzitic, thin

DOG ere ert ero. 5 Sie; so) oe bie css suey are olla rg Mor nara ane tee I OREN Ile ee none 23

Quarizite, hard, White... .... cece. eee siesis aye oo 8 oie ie eleye es ye) s eee

Sandstone, striable, white, containins) claiy.s.2 + .. 4s seers re eee eee yee)

Porcelain shales and thin argillaceous Ssandstones....................--- 21

Shales, fine-grained. near top, dense, porcelain-like below, with sandy

VERVE D2 het alece cetene fee: 6 ow ai ay-coena io)9 ierayau spa, reo wane ohoke ten pede road dite tan ra eee rr 42

Quartzite, massive, white, more friable below, with thin clay layers near

ASCP crete Si SlscSe sayin vorieivet = ud save suse) Ruaetrala vad oan ces anen Me Sa ee ile lel uote RRS ait ate eae 5

Sandstone, coarse, white, lower portion indurated and containing a 2-foot

cS) 02g ho) ee ee ere ee Pein ere een Imac hGab OO c 50 i125

Shale, green, with some purple and gray layers, very fine grained, much

of it hard like porcelain; some sandy layers, more numerous near base;

dark red; rests upon 5 feet of very white and massive porcelain shales. 50

Shale, red, sandy and containing shaly sandstone....................... 16

Green and red porcelain shales and sandstones with a 2-foot pink, fine-

erained! limestone at: the top. y ssi sien ses clsct mice ole clece bleh cnet ae een 78

Sandstone, massive, green above, white below. Li tke 9

Sandy shales and shaly sandstones, green, white and roa vb so dee eS 69

Sandstone wihiterssaccharoidala ate cis ae ie ce eee ee eine eee 20.

Sandstones and sandy shales, with some porcelain layers, red and green.. 26

Sandstone, massive, fine-grained, gray, white.......................-... 10

Sandy shale and sandstone, alternating green and red................... 20

Sandstone, fine, greenish white, becoming red and shaly below........... ier

Sandstone, extremely massive, white; red stains from shales above;

quartzite in lower part and a thin green shaly layer near base......... 70

Sandstones, with thin limestones and calcareous shaly layers; some reds

and pinks, prevailing colors buffs and yellows.......................-. 120

Sandstones, heavy bedded, saccharoidal....................2.00000000ee 11

Shale and thinly bedded buff sandstone..........................00.00- 10

Quartzite; light colored: with bluish stains... . 4222... 22s > le. see ener 18

Sandstonestam dash alese med aes yeas nieve clave a eleva guessvale, oeiay oa eae ee 65

779

La Plata sandstone. .

In the La Plata quadrangle the Morrison (McElmo) is described by

Cross, Spencer and Purington (1899, 4) as a series of alternating shales

and sandstones, from 400 to 500 feet thick. The sandstones are usually

characterized by the presence of green shale flakes; 50 or 60 feet below

the top of the formation, there is a bed of coarse white conglomerate

separated from the “Dakota” by a series of red and green shaly beds.

The conglomerate contains white and dark quartz pebbles, and is 10 to 15

feet thick. :

MOOK, STUDY OF THE MORRISON FORMATION v1

_ The Morrison (McElmo) formation is described

by Cross (1910, 4) in the Engineer Mountain

quadrangle, as follows:

“Tn the Engineer Mountain quadrangle the Mc-

Elmo has a thickness of 400 to 500 feet. It is here

composed more largely of shale than in the Tellu-

ride quadrangle, where its thickness on the San

Miguel River is nearly 1000 feet and where sand-

stone forms its most important element. Shale

and sandstone alternate in the formation in vari-

able proportions. The beds of shale as a rule are

colored some shade of green, but are locally pink

or deep Indian red, and they include some varie-

gated red and green bands. ‘The shales are fine

grained and sandy and occur in homogeneous

bands, in places several feet thick, with little or no

distinct lamination. The sandstones are fine and

even grained and friable in texture; those of the

_ lower portion resemble the La Plata sandstone, and

at least one of the upper beds is very similar to the

Dakota sandstone. The arenaceous layers are

white or yellowish and locally grade horizontally

and vertically into sandy shale and thence into clay

Shale. In the upper part of section there is a fine-

grained conglomerate which is practically identical

with the lowest conglomerate of the Dakota. The

large number of crumbling beds in the formation

cause numerous gaps in all discovered exposures,

and no detailed section can be given.”

GRAND RIVER AREA

The Morrison (McElmo) formation is well ex-

posed along the Grand River, from its junction

with the Gunnison River westward into eastern

Utah. For some distance east of the junction with

the Gunnison River it is also exposed in the walls

of the canyon of the Grand River. West of Grand

Junction, the beds are exposed on the south side

of the river only. The exposures are usually sev-

eral miles south of the river, and occur partly in

the high cliff which forms the northern boundary

Wie. 25.—Section' of the

Morrison formation. on

Dexter Creek, Rico

quadrangle, Colorado,

Seale, 125 feet to.1 inch.

(Cross. )

"oO ANNALS NEW YORK ACADEMY OF SCIENCES

of the Uncompahgre Plateau, and partly in a lower southward facing

cliff a short distance farther north.

A short distance west of Mack the river turns sharply to the south, and

cuts across the formations, giving complete sections of several of the

formations.

Riggs (1901, 4) describes the Morrison (McElmo) beds near Fruita

as a series of four principal members, aggregating 600 to 700 feet in

thickness. ‘The lowest of the four he assigns to a marine origin. It is

100 to 120 feet in thickness, consisting of bluish-gray, gypsum-bearing

clays, with thin layers of fine-grained sandstone, and very thin layers of

nodular limestone. This division grades into the second, which he

assigns to a fresh-water origin. The second division contains no lime-

stone, and consists largely of homogeneous and massive clays. A ledge

of fine-grained sandstone occurs near the base. ‘The second division is

about 100 feet thick, and consists of greenish clay shale, containing occa-

sional ledges of green sandstone and a few layers of clay nodules. Con-

spicuous banding is not present. The third division consists of a darker

zone containing frequent ledges of cross-bedded sandstone. This series

is 40 to 50 feet thick. The sandstones vary from fine-grained to coarse-

grained, and from thin layers to massive layers. They are often rich im

iron and brown in color. In places this division is entirely absent. ‘The

fourth division consists of variegated clays 300 feet or more in thickness,

characterized by brilliant coloring and conspicuous banding. “The alter-

nation between green and purplish bands does not mark any variation in

the nature of hardness of these massive joint clays.” Thin layers of eal-

careous nodules and sandstones occur. Nodular gray sandstone and thick

ledges of cross-bedded sandstone, and lenticular masses of sandstone oecur

locally.

Lee (1912, 6) has described the Morrison (McKlmo) beds in the Grand

River region as a variegated sandstone and shale formation lying between

the red beds and the Cretaceous beds. The formation here has a thick-

ness of 682 feet. The upper hmit is marked by an erosional uncon-

formity. The formation is divisible into two general divisions which

are distinct lithologically, but still represent continuous deposition. ‘The

lower member | Nos. 9-17 in section] consists principally of even-bedded

flaggy sandstone. This is the series Riggs referred to as the marine

Jurassic. It contains some limestone. ‘The upper member [ Nos. 5-8 in

section ] consists principally of variegated shale with a coarse conglomerate

near the top.

The following section of the Morrison (McElmo or Gunnison) forma-

tion is given by Lee:

Sat

MOOK, STUDY OF THE MORRISON FORMATION 73

Section of Rocks exposed in Gunnison Canyon at the

Mouth of Wells Gulch

Feet

1. Sandstone in thin flinty layers separated by

pdark colored: Shale... 2 s.< yee esc s ae es ee ess 20

Zi, (CHOBIL ois 6S SSeS NG chem eek Petia ee Ac re a 3

Seales GarbOMaGOUS...52-.se0cc6nes esse ce yess 8

4. Conglomerate, quartzitic, gray to buff (Da-

EUAN) Borers ak NS NS cece cactaee payanate eae aie abe ea oor aar st Skee 15

[Base of Dakota and top of Morrison.]

5. Sandstone, conglomeratic, with beds of varie-

gated shale. The conglomerate contains

many pebbles of qartz and jasper......... 100

Gest Mlen VATICSALEO Hac cag ews cde rca eee wee nous 175

7. Sandstone, white, argillaceous............... 5

8. Shale, soft, variegated; contains pockets filled

with pebbles of jasper, chert, argillite, ete. ;

also globular lenticular bodies of pink to

red calcite, having a maximum diameter of

3) THESES eee etre. arore ore ee IG AOE IE ae ee eae 200

9. Sandstone, gray, coarse-grained, cross-bedded. 50

10. Sandstone, brown, massive.................. 8

Malem nell lati aT Keeler etsyenera ecto’, ciel avelenyo olstecee lo Bw 6 wave 10

12. Sandstone, brown, massive.................. 15

ale yee Slav SEUTN yates cons crevat ets eh icme e Gheloiha ce ele Side wie 10

EE SANGdSLOMEe. MING Yas viscose ccc sc aisle «Ge sieusie ee e's 4

om Sale: Variegated? oc .45 6. cece che ce ee a lee 30

16. Shale and limestone, evenly bedded.......... 25

17. Shale and sandstone in thin regularly bedded

WEAVE TES aera stat seen aree iene erane ce oso nial SPehes mie cede gxenationets 50

Unconformity by erosion.

18. Sandstone (red beds).................2.000- (?)

728

The Morrison (McElmo) formation is very well

exposed a few miles southwest of Mack, where the

Grand River makes a sharp turn and where a trib-

utary cuts directly across the strata. The bend in

the river cuts directly across a large monoclinal

fold, exposing the underlying beds. Good expos-

ures occur for considerable distances, and it is pos-

sible to make a complete section of the formation

at a number of points. The chief characteristic of

the formation in this district is the presence of a

number of heavy, white, cross-bedded sandstones,

which stand out as prominent ledges. Sandstones

Fic. 26.—Section of the

Morrison formation in °

Gunnison Canyon at

the mouth of Wells

Gulch, Colorado.

1.—Dakota; 2.—Mor-

rison. Scale, 125 feet to

1 inch. (Lee.)

Hie. 27.—WMorrison formation south of Grand Junction, Colorado, looking west.

Fic. 28.—Grand Mesa, south of Grand Junction, Colorado, looking

‘ outcrops in the foreground.

Fig. 29.—Morrison formation south of Grand Junction, Colorado, looking north.

are especially characteristic of the lower portion of the formation, but

heavy beds occur at intervals up to the top. A bed of limestone 2 feet

thick is also present in the lower portion. The following section was

measured by the writer in 1914:

Section of McHlmo Formation near Mack, Colorado

Feet

38. Dark, arkosic sandstone, taken as base of the “Dakota”............ 2

Be. CIB nea 56 Con bn co mine Spade paul aNosiee ke etaraibeqtetza ue ais ta levis elie, o) Ale oe Necionanielte oe . 3d4e.

31. Sandstone ........ a etes SECM mere neato ache raya lane Netctnntarcsmetie etl aia eames MS oe Ge

BUM COVELEO. sock sescts ciotie See eee eee see e8 tnt) its OM REE RSE RETO ae i)

29. Cross-bedded white sandstone.......... Wea Spe ee tats Ae ging Onda ate aie 11

PISMO AVere hase ia a clacavereveh oceans BUSS Ee nceeh nessa WM Fe ae lot estat seca ss elena nist ai’ 40

PH ross bedded swihtite: SAMOStONG: 2. ca oe. s sk see woke so Cece cose enna. ala

DAO VAY v6.0 1s 06 aie ao aa Ieee rape aes Gets eae OR ee Shoes eld cudyd ue. ete e havea eke 9

745... IDSA OM GER bigs store co peo Sei piC Ooo Gur CnN Sree aS nae cars ear il

24. Variegated clays................. RP Nee etre ai cc Mian ec ouetesie euskenees tar Beye fd)

23. White sandstone of varying size of grain.......................-. 3

22. Green sandstone, in places conglomeratic.....................--.- 2

POL Ve OLECEMISM ita EOD she cia, creceieic ole ais srs dvee oale osc d coee Se eeiaeieie We mga 16

OMIM TTI CHIN PPL tO eo harank svar a sa catand + okey eal POI Lakes 3

(lis NRAGHITE WCE a: Sich case aene nee aaa een eet eee Eel She Rime Smee sete

"6 ANNALS NEW YORK ACADEMY OF SCIENCES

Fic. 30.—Section of the

Morrison formation

near Mack, Colorado.

The overlying forma-

tion is the ‘Dakota,’

and the underlying is

the La Plata sandstone.

Scale, 125 feet to 1 inch.

(Section by the writer.)

Feet

19) Red sandstone, or Shalex ere ceeeeee 1%

18: (6. "Clay, white atitop: 2c. Gases ene eee eee 7

b. Red shale....... oa ap Saad ate avebaneee che eee it

Ge ClAY veo chew wd Serene Ree eee 25

17. White, coarse, cross-bedded sandstone with

clay and shale members near the top.... 30

16.6.6. (CB * Solos fa see eee 16

b: Nandy, compact clays eee eee eee 1

@: CIAY sa8. 45 toe SER SAS Eee eee 271%

15. White, cross-bedded sandstone........ ee = 17

VAS Clay. 6 Asks een oe Mid etaoic 30

13. Heavy, cross-bedded sandstone............. 2

12. Clay, may cover sandstone or nodule layers. 57

Ad. -Sandstonmes, 2). 955 30 eee eee 1

10: Covered) cece elvis pele ee eee paps

9. Heavy, cross-bedded sandstone..... Pe ec bi 31

8. Variegated clay with lumps, especially at

GOP. ace ey eis awh a Sat iy cle sree aera see cpanel

72 GIMeEStOne * hak a ob on ee eee

6ii6. ClayS.2 owe ee ee ee eee Pee ioe

b. Sandstone. 22.22). ae he. ee

a. Cross-bedded sandstone................: 25 e.

Sandstones and clays alternating. Mostly

sandstones in beds 1—2 feet thick. Sand-

stone sometimes dies out and is replaced

by clay, with or without nodules........ 20

4, Red sand clay with nodules............... 25

3: Gray Sale. ow... viva, cies eee eee ene 7

2. White sandstone with some clay........... 24

i Pinkish) white Sandstones.. +... os. see eee 80

MOA eicekee acters eee eee 766

The Morrison is underlain by the La Plata

sandstone in most of the southwestern Colorado

areas, with apparent conformity. Beneath the La

Plata, which is Jurassic in age, there is a well

marked stratigraphic break. At different local-

ties the La Plata les upon the Dolores beds, of

Triassic age, upon the Cutler and Hermosa for-

mations, of late Paleozoic age, and upon pre-Cam-

brian crystallines (Cross and Larsen, 1914, 7).

The McElmo formation near Green River, Utah,

has been recently described by Lupton (1914, 3).

It is from 1000 to 1200 feet thick at this place.

Marine fossils in the lower part indicate, however,

that part of the beds included in Lupton’s section

may belong to the underlying Jurassic beds.

The section is as follows:

MOOK, STUDY OF THE MORRISON FORMATION vad

Fic. 31.—WMoncelinal feld near Mack, Colorado.

The Morrison beds are seen to the left, resting on the La Plata sandstone in the center.

Fic. 32.—Outcrops of the Morrison formation near Mack, Colorado.

The section shown in fig. 30 was taken at this point.

"8 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet Inches

Sandstone, gray, weathers brown; contains clay-ball concretions

MD) HOV ANCES shears cal hetero: cts uttcireietevs ce sisrs tee, ace aces enone Sere a CROC or fo Be ae

Clay, bluish gray; contains a little limestone about 5 feet below

10) CS EEA ei Renee crc een ener Pannen SPEER ETS om hora un eer oo uo o 28) 6

Clay, brick red, eray and purplish, sandy; contains several thin

beds OL era: LO) Whe SANESCOMe. ey. cine veusncneneye renehenel cholerae ten nets ANG se

Sandstone, gray; weathers brown; indurated at base, conglomer-

ALICaNnd quaLtzitie im) places; lenticullaras 5 eerie iro 5 Aas

Clay; sbrick med: sSam iy i os. sien sc:em ce cietencuere ee eens ceo th eee eee 52 sae

Sandstone, brick Ted: MASSIVE s....01-5 saysia coosecielstoricle oneterele erterere 14> tas

Clayec brick reds Sandy. aoneisctese oe cua ee Roe he ieee 12 a

Sandstone, gray, conglomeratic; contains some interbedded gray

Tondo by feats) 013) Ce Bente ete na een teeny niet atl AlN ics Uo ois obo 0 5S oer

Sandstone, reddish, calcareous: fo. «science sini seiner ike 2

Sandstone, gray to white, soft, cross-bedded in places........... 10 ne

Sandstone, red and gray, soft, caleareous....... HSH 42 Ss

Sandstone, gray to white, soft, massive; contains a little argil-

TACCOUSHIN AEST era es nie lararn oc aeilatfan a Rabenetehes SRA Mee Sree eee ICRC ir eee

Sandstone, grayish brown, interbedded with gray and reddish eal-

careous and argillaceous sandstone.....................--.«- Patt

Sandstone, white, weathers reddish brown..................... 12

Sandstone, red with streaks of green, calcareous............... 20

Sandstone, grayish brown, with calcareous layers..............- 50 ie

SAM EGSEOM Es TOMI Sees lea rae anes cetera easy ra Ie ay nt ev orc rny SuraUInU EN ee overt ened a De ave

Sandstone ccGalCareOuss ssn. cers ale sc enede eee Set enetar oravenat ee cre Ione T erent eaene 5 F

Sandstone, grayish brown, medium bedded..................... A ee

Sandstone, red below and gray above, very calcareous; contains

Tb yer SMe AO CULES ye tee otn) = 2 epe)e Ve) seu cl ote eect een eee ee 40...

Sandstone, brick red, thin and medium bedded. This sandstone

is believed to be calcareous. It bears manganese ore in the

Tif 0) 0123 0h) OF: 6) Rana AME AT oie nts SEO MeN denEES ETN ae 128s

Sandstone, -redipmassives cok... acy sirtiss bieeicints ele cisions keene ete Oe 400+ ..

NORTHEASTERN UTAH AND NORTHWESTERN COLORADO

The Flaming Gorge formations in northwestern Colorado and north-

eastern’ Utah have been described by H. 8. Gale (1910, 6) as dark-

greenish shales and sandstones, with fossils. Above the fossiliferous beds

are 75 feet of dark thin-bedded, ripple-marked sandstone. This part of

the Flaming Gorge represents the marine Jurassic which is character-

istically represented in Wyoming by the Sundance formation. Above the

marine beds are 650 feet of varicolored beds, usually of light pink and

green. The Carnegie Museum of Pittsburgh has been operating a dino-

saur quarry in these beds near Jensen, Utah. The beds in this vicinity

are largely dark colored variegated clays, with interspersed layers of

SE eee ee

Pies)

MOOK, STUDY OF THE MORRISON FORMATION "9

coarse sandstone of moderate thickness. The sandstones are resistant to

erosion, and the beds dip steeply toward the west. The sandstones cap

ridges underlain by the softer clays, making a series of parallel or con-

SS errr ary

SCee®e ee oe

see

Fig. 33.—NSection of the McElmo formation near Green River, Utah.

This section probably includes more than Morrison, as marine Jurassic fossils have been

found in the base. Scale, 125 feet to 1 inch. (Lupton.)

centric hog-backs, the outer one of which is capped by the “Dakota” sand-

stone. The contact of the marine and non-marine beds is obscure and

difficult to determine at the site of the Carnegie Museum’s quarry.

80 ANNALS NEW YORK ACADEMY OF SCIENCES

Fic. 34.—Outcrop of the Morrison formation near Jensen, Utah.

Morrison Formation in Montana AND WyomiIncG (EXCEPT THE

Buack Hitus AREA)

CENTRAL AND SOUTHERN MONTANA

The Morrison formation has not been mapped or described from many

localities in Montana. It occurs in the Great Falls coal field and neigh-

boring localities and around the northern end of the Bighorn Mountains.

It probably occurs elsewhere, but either has not been mapped, has nat

been separated from the Kootenie, or is buried beneath younger forma-

tions. The relation of the Kootenie to the Morrison, and its lithological

similarity, may possibly indicate that the Kootenie may be in part equiva-

lent to some parts of the Morrison.

The Morrison occurs in the Electric coal field, and has been described

by Calvert (1912, 2). Calvert gives the following section:

Feet Inches

Sandstone, brownish, soft. capped by 1 foot of intrusive.......... 23

Shale, variegated, and sandstone, alternating, the latter reddish

| Ov HOA Ree erage ame R ee PEO oy MPO ate Ce es Ce oe dine itera apes a ok 65 tie

TMGPUSTME: Meike ee Sarthe ees Nh ae ee eth at &

Shale, purplish and maroon, alternating with thin reddish-brown

SANASTONE ee a ee Se ee eee Ble ee ee oe tae tt ee 79 ue

MOOK, STUDY OF THE MORRISON FORMATION 81

Feet Inches

Sandstones, thin, and sandy shale, with 2 feet of brown sandstone

185+ 8

The Morrison in this locality les over the Ellis limestone, correspond-

ing to the Sundance beds of Wyoming. There is a break below the Ellis,

indicating an erosion period of considerable length.

In the Great Falls region the Morrison has been

described by Fisher (1907, 3; 1909, 11; 1909, 13).

He gives the following brief description of the out-

erops of the Morrison: “The formation is gener-

ally exposed in a narrow band on the inner rim of

a low ridge formed by the harder overlying rocks

of the Kootenie formation. It outcrops all along

the base of the Little Belt Mountains from the

east end of the district to Smith River. Good ex-

posures occur along the upper courses of Sage,

Skull, Running Wolf, Hazlett, Surprise, Geyser,

and Otter creeks, and in the bluffs for some dis-

tance back from the mountains along Belt Creek,

Sand Coulee, Smith River and its tributary, Ming

Coulee.” The Morrison rests with apparent con-

Wie. 35.—Section of the

Vorrison formation in

the Electric Coal Field,

Montana.

Seale, 125 feet to 1 inch.

(Calvert. )

formity on the Ellis *formation, which in turn rests unconformably on

Carboniferous beds. The Kootenie overlies the Morrison conformably.

Fisher gives the following sections:

Section of the Morrison Formation on the east side of Belt Creek, Montana, in

ile 1a, Va Sae, BU, AM, ais} oy 1S CC Tale

Cirayenunin-pedded Sandstone. a a-mema ee ae ee cis isles

Pebbly conglomerate occurring in lenses..............

Maroon amdwereen) shaletnis cee 5 wee ce Sect ce od Gabel ou

Green shale capped by 11% feet of gray sandstone.....

Calcareous sandstone, weathering light brown.........

(GIPSON, SUES Bie ARS Bit eR SS at a ie aie

Massive sandstone, weathering light brown............

Dark-green shale containing thin limestone layers.....

Ellis formation.

Feet

ne Hdiiolglaite bia bicioonis al

Spar aroratererersteyiane che 5

Wea ie Jehonceaerent ete 9

82 ANNALS NEW YORK ACADEMY OF SCIENCES

Section of the Morrison Formation in the N. EH. %& Sec. 3, T. 16 N., R. 10 £.,

near Shannon Creek, Montana

Feet Inches

Kootenie formation.

SBROGS COMSAT ISM ne cer ra ete Se iter assis ae re ete 20

Shales, red and green, containing ironstone layers at base........ 46

Limestone, light colored, fossiliferous.................-..--es+2. 5

Shaleyvereens San diya. FOSSTIPELOUS scan. lsicstcretelitstete iste cine eee isan eee 25 ;

Limestone, white, fine-grained, thin-bedded...................... Be) 6

SHaAlercereen ys ‘SAMMY sie ic eho sic eve e: hancioue velereroceleceveileietetekene veel cater heen aera 13

109 6

Fic. 36.—Section of the Morrison forma- Fic. 37.—Section of the Morrison forma-

tion on Belt Creek, Montana. tion near Shannon Creek, Montana.

Seale, 125 feet to 1 inch. (¥Fisher.) Scale, 125 feet to 1 inch. (Wisher.)

BIGHORN MOUNTAINS

The Morrison formation is exposed along the eastern, northern and

western sides of the Bighorn Mountains. The following description is

taken largely from Darton (1906, 2).

The band of outcrops is almost a continuous one, except in a few local-

ities where it is overlain by Tertiary deposits. Owing to the softness of

the material of the formation, most of the outcrops are poor and are often

covered with talus.

The thickness of the formation varies from 100 to 250 feet. West of

Greub it is 160 feet, southwest of Buffalo 250 feet, northwest of Buffalo

150 feet, on Little Rapid Creek it is 200 feet, on Wolf Creek less than

100 feet, on Little Tongue River 120 feet, on Amsden Creek 150 feet,

and about 150 feet or a little less on the northeastern side of the moun-

tains in Montana. There is a considerable variation on the southeast

side of the mountains. [ast of Barnum it is about 150 feet, east of

Houck’s 100 feet, near Griggs 200 feet, on the uplift south of Tisdel’s

ranch it is 250 feet. In the vicinity of Tensleep it is about 250 feet.

On Alkali Creek, north of Cloverly, it is 282 feet, and in the region of

Thermopolis, 120 to 130 feet.

Near Cloverly, where the dip is low, the outcrops cover large areas.

In most localities the Morrison occupies a low saddle between the slopes

MOOK, STUDY OF THE MORRISON FORMATION 83

of the Chugwater-Sundance ridge on the one hand and the hog-back of

the Cloverly on the other.

The formation is mostly made up of hard clay or massive shale, vary-

ing in color from pale greenish to maroon, with darker clay at its summit.

Several beds of light gray sandstone 2 to 20 feet thick are usually in-

cluded. “These sandstones are usually soft, and on weathering exhibit

thin, irregular bedding planes which generally have a peculiar wavy sur-

face suggestive of incipient cross-bedding.” ‘There is apparently a con-

formable contact between the Morrison and Sundance beds. In the first

Fie. 38.—Section of the Morrison forma- JG. 39.—Section of the Morrison forma-

tion on South Fork of Rock Creek, tion on the south side of Muddy Creek,

northwest of Buffalo, Wyoming. southwest of Buffalo, Wyoming.

Scale, 125 feet to 1 inch. (Darton.) Scale, 125 feet to 1 inch. (Darton.)

hollow south of South Fork of Rock Creek, northwest of Buffalo, the base

of the Morrison consists of 40 feet of soft greenish-gray and pale-buff

sandstones; then 80 feet of clays, 15 feet of the typical sandstone above

described, and at the top 30 feet of clays, maroon, buff and greenish

below and dark above. A mile south of Muddy Creek, southwest of

Buffalo, there is an exceptionally good outcrop of the Morrison formation.

Tt exhibits at the top 10 feet of reddish shale which grades down into

dark shale, followed by 240 feet of hard, chalky clays of maroon and

green color. ‘This series of clays contains occasional thin sandstone part-

ings, and one bed 6 feet thick near the middle. This bed is hard, hght-

colored, and weathers in thin beds with irregular wavy surface. Near

the base of the series the clay is red. Next below is an 8-foot bed of

white sandstone. Below this sandstone and resting on the Sundance beds

are a few feet of soft gray and buff sandstones. On Little Poison Creek

“a

84 ANNALS NEW YORK ACADEMY OF SCIENCES

the characters are very similar to those on Muddy Creek. A mile north

of Middle Fork of Crazy Woman Creek the section is as follows:

Feet

Chalky clays, light green above, maroon below.................++-«+08: 80

Grayish-buff sandstone containing plants and saurian bones......... 6to 12

Maroon and light green chalky clays with thin sandstone layers......... 70

White soft massive sandstone resembling the Unkpapa of the Black Hills

TO ST OW a ia russ Sore ea ap iain saree wire -aauinv onan Wed foie Uaste ne eye rome esas easton EEL oe 12to 15

Greenish sandy clays (may belong to the Sundance formation).......... 20

188 to 197

Fic. 40.—Section of the Morrison forma-

tion north of Middle Fork of Crazy

Woman Creek, Wyoming.

Wie. 41.—Section of the Morrison forma-

1.—Morrison formation; 2.—Sundance x

tion near Beaver Creek, Wyoming.

formation. Scale, 125 feet tol inch. (Dar-

ton. ) Seale, 125 feet to 1 inch. (Darton.)

Near Beaver Creek the section is as follows:

; Feet

Light green to maroon chalky clays containing a 2-foot bed of lime-

stone: 10: feet-below the top 2.280. 5 oc kk ele cc be eleue cues a oie epee renee 50

RSE aN0 ISH mac eel arte tana AU cite tren AOU ARR Rae Pein BRA Can atm ARIE oi 5.0 4

Clays) in parh Margo OR Yee e wes aie Re aie eS Seis ke eee 25

Sandstone [thickness not given, probably very thin].

SST Si PA INTE aI eNO Te Pa US oth Sel dick dual at til le os ee Ge rr 10

Limestone swith moO fossil sees. alec popeteds tore vsreicc elovel rei spevousieionerecs teislaronsl core atone 1%

Red to maroon clays with thin sandstone layers...................-. 25

Thin-bedded sandstone........... ete ep ena intra eae ee Bal oo '5 2

Soft, massive. white: Sandstone. seine eso seine eis eis cies ol eee 20

Clays (a few feet).

13874%+

South of Fort C. F. Smith, Montana, the following section occurs:

Feet

Greenish-gray sandy shale, upper part soft (unconformably overlain by

Cloverly “Sandstone ).e ec bcos ose epee ee tein tls ce leis syste eee 18

Bil -SamdsStomes occ oisscede eure areas so eyete «Be nekereherio othe ctelle ele tel syle'1suies a tayteerel eee eae 5

MOOK, STUDY OF THE MORRISON FORMATION 85

Feet

MIASSIVE Seay SPIOCIIOMN. GadoocodecunecobucouopoUIn coool Oona coo 20

Variegated shale; pale red and green tints....... eat a cue Aa UG ERE eC eg 75

Light colored, fine-grained, soft sandstone lying on brown sandstone of

the Sundance formation.......... 8S Perey CoC ARORA RLERCRS. CESSES Het nen see 25

143

The section near Tensleep is as follows:

Feet

Gray shale capped by Cloverly sandstone... 40

METRES devs CLAYS cls < csic csi es spevslana sere = 100

Maroon EOMTed: ClAYS|.\ioe se ses so ss Ge tn tee 50

SRM SHOE Mianre can acemtonciefohVe 6a e's) clic, \eistple cs cucve = ov 58

Greenish-gray to reddish sandy shale....... 50

298

Wic. 42.—Section of the Morrison forma- lig. 43.—Sectien of the Morrison forma-

tion south of Fort C. F. Smith, Montana. tion near Tensleep, Wyoming.

Scale, 125 feet to 1 inch. (Darton.) Scale, 125 feet to 1 inch. (Darton.)

The following is a typical section of the Morrison on Alkali Creek:

; Feet

Pale green massive shale (overlain’by Cloverly sandstone).............. 50

‘Thin-bedded gray sandstone, brown on surface...................-00-0. 15

HEME RAE CI PIM ASST VIC) SIAL OR ars ieice yee ctccuclebeticiisuciers esse akeisie syese Sale euareune em wie dee om 5

EMNTeS ler Cems We Cetera nen a cuvercuchatartarc era hieralsroner siete artes Beata te up lel e ehos eter eltebe els 10

NED EOOMMELITASSHVEN Ss MEN CHI ewentuer aeteweureveouare ses rakp are Selisy ceil clemettrer sone onevelsawene estes 10

Nees Nt CIMA SSTIV.El Glvall Os ec pyscsrseesaieser ol auane royale ou od alana Gi cusleievslletals a ale slave erelaus 45

Einineneddedeeray, “SAndStome nee vaca as oc ehele we cie ses psa sinels cis secs ee ws abies 6

Variegated massive shale, drab, purple and maroon.................-... 65

Pale green to white sandstone...................0000000- By sar te anyet tis 6

Pale green and maroon massive shale................00cees ces eeeeseees 85

PAG STeeM) MASSIVE: SANGStONE. «2.0.6 kecsis es ee ccc ea vice sae eee une ne cee 45

Red sandy shale (lying on the Sundance formation).................... 40

382

North of Thermopolis the formation contains, near its middle, a

massive fine-grained, soft, greenish-gray sandstone 50 feet or more in

86 ANNALS NEW YORK ACADEMY OF SCIENCES ;

thickness. Above this are 400 feet of

sandy shales, some dark maroon in

color, then 10 feet of very dark con-

glomerate loosely cemented, and at

the top about 10 feet of highly car-

bonaceous shale merging into dirty-

buff clay.

Fic. 44.—Section of the Morrison forma- Fic. 45.—Section of the Morrison forma-

tion on Alkali Oreek, Wyoming. - tion on the Shoshone River, Wyoming.

Seale, 125 feet to 1 inch. (Darton.) Seale, 125 feet to 1 inch. (Hewett.)

SHOSHONE RIVER REGION

The following section of the Morrison formation was made by Hewett,

on the Shoshone River, Wyoming (1914, 2):

Feet

Shale, maroon and gray, sandy...........- DE SO RNR oS oc <a eer

Samed stome,. Duties ccteierssteeis eis) seks cronstelietor ar iete ketal ohana er oe «o-oo Pree 0)

Shale: gray, Sandy oo. l wic saeco lone © wise ayeteleleio ie dete iors oie = 0) na) 0 12

Sandstone, sbilts os / Moye cde esse Sahel ene oleate eleheie Geil ere lel =)> in '-) 29s poe a »

SMUG) Eaeiy, SAIN Ss ocanhpooaccse bos Po ee ere AA S So cao 2 2 10

Sandstone, buff, cross-bedded...... 2... 2. eee ee cee eee eee eee eee eee ees 8

Clay, STAY; SAMGY 5 = 10s een sci is ool = eaten he ete te oie eee nota) =| ace ene eee. A

—eor |

MOOK, STUDY OF THE MORRISON FORMATION 87

Feet

Sandstone, buff, fine-grained, evenly bedded and ripple-marked.......... 6

Wiivsmaroon and: yellows SANG Ys... os2e. 8. soccer ce ee ces cee ees esocneas 44

Clay, dark brown to black, containing saurian vertebrie, limb bones, and

DASIEOMEINS SSO Coco a AO Oe OCOD CeO RL CREED Rear Giese eRe ea nea 20

Sand, gray, argillaceous, only locally indurated, containing wood silicified

in places, aS well as rounded pebbles of similar material; carbonized

plant remains and small calcareous concretions...................+--. 50

Se yAMBIML AT OOMMESAI GY sctare sis aycis. acetals eistfe elclere aie sie citys sels Giaiaeie sa'e Sos eS a8 6 ae eles 55

Sandstone, white, homogeneous, only locally indurated.................. 25

Clay, prevailingly gray and olive colored, but with three broad maroon

bands, sandy.............. PCS ERELO ena OA One ITER See SEca ea Cer eR ae Nee 100

Shale, green sandy, transitional to upper sandstone of the Sundance for-

TERAOD 555 'c:5 eno Bice a ee eR RO TSE cee ey ee a 140

580

CENTRAL AND SOUTHERN WYOMING

©. A. Fisher (1906, 4) describes the Morrison formation in the Absa-

roka and Owl Creek Mountain regions as follows:

“Along the western side of the basin [ Bighorn] the Morrison formation

is about 150 feet thick. It consists of alternating layers of gray fine-

grained sandstone and dark-gray sandy shale. Near the base there is

often a thin bed of gray limestone. In one locality near the southern

end of the Cedar Mountain anticline a deposit of gypsum 8 feet thick

was observed near the top of the formation.” Fisher gives the follow-

ing sections :

Section of Morrison Formation on Trail Creek, northwest of Cody, Wyoming

Feet

Cloverly formation.

Green, sandy shales alternating with green clay containing thin layers of

SAA iMe STONE: (MLO WAM OME is ctrcbsiaie = sis es 4.0 eeia wie sO. 0) Sie asain sie eelevele sib vevslese 100

Massive, fine-grained gray sandstone lying on Sundance formation....... _ 30

130

Generalized Section of Morrison Formation south of Clark Fork Canyon,

Wyoming

Feet

Cloverly formation.

MASSIVE orLeenish-eray SANGSEONE. <2 ac 20 se oe cess ect ne tie cue tins wees ess 80

AE STSESTN S10 Cl MV arene WaT IE etal eae ie ratio eae foyer Siic tade Sule wiloe Wig fsls ioataue sis noses AS eeieteus 60

WD kaso vali CSHOMCR rey sete ies oe ere sone Goin ae elles coe We Neue Steeles 1

Dark gray sandy shale lying on Sundance formation................... 20

88 ANNALS NEW YORK ACADEMY OF SCIENCES

' Section of Morrison Formation near Watson’s Ranch, on Embar Road, just —

: north of Owl Creek, Wyoming

Feet

Massive’ gray Sandstone... 0. 6.2.0. cose die cies Seid ose eee ee eee eek)

Concealed material, evidently soft and sandy.......................+-e- 125

135

Fic. 46.—Section of the Morrison forma-

‘ tion on Trail Creek, northwest of Cody,

Wyoming. Vic. 47.—Section of the Morrison forma-

1.—Morrison formation; 2.—Sundance tion south of Clark Fork Canyon, Wyo-

formation. Scale, 125 feet to 1 inch. Te

(Fisher. ) Scale, 125 feet to 1 inch. (Wisher.)

The following section of the Morrison formation in the Douglas o1]

and gas field, Wyoming, is given by Barnett (1914, 1):

Section of the Morrison and Sundance Formations in east bluff of North Platte

River, in Sec. 9, T. 31 N., R. 71 W.

Feet

‘Morrison formation :

Shale, blue and red, with a 6-foot carbonaceous shale near top...... 180

Limestone) ‘compact, tossiliferous.: 24... se cece dee eee eat 3

Sundance formation :

Shale, blue and pink, calcareous and sandy, fossiliferous in lower part 60

SAN GSLOME, a Me iach ae ets eralinei ciate iste 16 (Sie late UR a Ren rene eee 10

Shale, bluish gray, with few bands of sandstone.................... 60

SAMASEOME! ae es Sisco ote cena eee rsle arene ie" Sub oan One ICMe Le aL aES el Ree a 12

Shate,: DUWISH (Shay SAM OY sila enti) sce ested wis Sob cuelie ehoioie evelel se kote 30

Sandstone, gray, heavy bedded onic. sis oe tise deca le cia’, « =:0 Sree See ris)

430

In central and southern Wyoming the Morrison formation has been

well described by Darton (1908, 1). The formation outcrops along the

eastern border of the Wind River Mountains, along both sides of the Ow!

Creek Mountains, on the north side of the Rattlesnake Mountains, in the

Shirley and Freezeout Hills, south of Casper and Douglas and east of

Medicine Bow and Rock Creek. It also occurs near Sheep Mountain,

MOOK, STUDY OF THE MORRISON FORMATION 89:

east of Jelm, and in the Centennial Valley. Outcrops occur on both the

east and west sides of the Laramie Mountains. In the vicinity of Lander,

the thickness of the formation is 225

feet, consisting mainly of pale green

to maroon massive shales, with thin

beds of sandstone. Near Fort Wash-

akie it is 200 feet thick, and has a 4-

foot sandstone bed near the middle.

The thickness in the Owl Creek re-

gion varies from 100 to 250 feet, in

general diminishing from east to

west. In this region the formation

consists principally of pale green

sandy shale, with some darker tints.

A thick bed of soft sandstone usually

occupies the central portion. “In ex-

tensive exposures on the east side of

- lic. 49.—NSection of the Morrison and Sun-

Fic. 48.—Section of the Morrison forma- dance formations in east bluff of North

tion near Watson's ranch on Embar road Platte River, in sec. 9, T. 31 N., R. 71 W.,

just north of Owl Creek, Wyoming. Wyoming.

Seale, 125 feet to 1 inch. (¥Fisher.) Seale, 125 feet to 1 inch. (Barnett.)

Red Creek, 3 miles east of the summit of Black Mountain, the formation

is about 150 feet thick.” Darton gives the following section at this point:

; Feet

At the top, soft massive sandstones, mainly of buff color, also pink, lying

OMe Cera Cera OOM CLAY Sin ces isles crore otsneie es olelclicvsicisiens) ssPelalicys>s =) =) «:2)cieis Ya) ele) euenae 50

Red sandy clays, with a few sandstone layers from 6 inches to a foot thick 50

Massive sandy clays of alternating bands of gray and maroon........... 50

The Morrison formation is well exposed in the vicinity of Medicine

Bow. In Como Bluff, a few miles east of this place, a good series of

outcrops occur, while on the opposite side of the anticline of which it

forms the southern limb, another series of outcrops are less well exposed.

“F, a

‘a

Dinosaur remains have been found in great abundance in this region,

and a number of very productive bone quarries have been opened. The

following section of Como Bluff is given by Darton:

90 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet

White, massive sandstone, conglomeratic (Cloverly).

Bluish. togreenish” Shaless.) 6.2. is .0s0e tae oeide ase ee eee nen Sane . 50

Limestone, lumpy............... duis ajo Gcavasens wcleua et Gp rah eaveuel wie bere reuew aes aa on ell

Bluish. to olive green shales... 26.5 05.5.3 bie eo sic ole oarete ores oi duels) OE eee 30

Limestone, lumpy........ Sa eraer wale See Sr acetic oe alenae-e ode ee 1

Blue and red shale........ | adsvahs Bishan dete eile JP eiehe isbetacwteus. Reve ety ene 20220,

202

Fig. 50.—Section of the Morrison forma-

tion on Red Creek, 3 miles east of Black

Mountain summit, Owl Creek Mountains, Big. 51.—Section of the Morrison forma-

Wyoming. tion in Como Bluff, Wyoming.

Scale, 125 feet to 1 inch. (Darton.) Scale, 125 feet to 1 inch. (Darton.)

Three sections in the north and south sides of the Como anticline and

in the Medicine anticline or “Bone Cabin Draw” are given by Loomis

(1901, 6) as follows:

Section on north side of the Como Anticline

Dakota [Cloverly ] Feet

Straw. vellow jSandstomec sie 0as og eee elec oleic eos) elena oe ol eieretee nee 120+

Blacks sandStomeyacsstccic ec eee ee Sah SR aaa aca ohare eS sgt te

Wellow: Sandstone ic sic occas Wetec w alerates Sst ind aA OD eS RIG sassy aD

Jurassic [Morrison and Sundance]

Bilwish=Sreen Clay sss alec ee aia ee ese Gieyeret a eeee ae Oleh a eal ela eile) ouside one 20

Ee 59 TNO) Th gana aan a Gi RRC Pa MARAE ai tar eearie CPN Pon RAI ERE ON o 5 oo oon 40

Vat a scsi vee yaneeu senate rattmer avelcn sisters tainpalies seanepancarattuaeave cin ac eens eae 1/3

GREED “CLAY ab sessei aceasta a eee ee bie ae eee ssa dhe Sa 5 la)

Coneretions ............. Sialyaltasoncus avene Garmgeunye a seeinne ceo asa". S00 et eee 2

Green CLAY ees seek eee ee ea ee Pe Eee ella hace Sie aha ol Oo 9

Green clay with small concretions. ................2cecceeeecees 9

Maroon clay with small coneretions...................-. é Shaye MG 28

CE =e) 11081 © 2 Ih gene ae Seater OR etree ted 1 Me Nt A ie tLe ETL AIS y-d J.0 0 6 5 20

SANOSTOME sees Sai ee eee cleanse Ue REE PI et tees) cocci nee 2

MOOK, STUDY OF THE MORRISON FORMATION 91

Feet

Giraen, GN. cebbiocBused 6 om one HION.0D CCC GSE ena acre erie nen ene aoa ee 9

SHUI, cag a edad claua 6c 0 05. oc anon Ont ece a cena ricci ieee 2

Green, maroon, red clay......... Mere Pen Ata uay ara ad roteceach Mier gaat 26

SHO SEOMC aeereerietel ciate wienaye res setote Mancketavereyas erste tas Gue es witeveftreiwudelmyelavib wens Ls 1%

(GE CICLO as tolacare/s het ats one ayer ee MntMaiele miei aleie e Sralale Minded wie Sb maies 20

ATG SOM Gum rete kare iat MaE I RR Ese tare etal syais mtcccoce esealoye lc Me eats e evaverane 2

COMGCMECIAY 6 cide o's ooh e aueeteern ale SIE OOP RGD, CES RLREOS te TC Riana eae 60

SAMO SCOM OM Ee erties se ehh ee ees cas we 1%

Maroon eclay.. CODE O RED G.OSnIOe Mme cecinn ior 20

SAM SCOMe Merger ates a serra son olin etaieets 1%

Purple clay with limestones............ 20

Brown clay with limestone beds........ 70

I Total of Jurassic [Morrison and

SMUIAMNGE bc ocnsostoouoebsnoouos 378 5/6

Section on south side of the Como Anticline, or Como

Bluff

Dakota [Cloverly] Feet

SHILIMOS ROIVe) aete a cramteraitae Sic Soran GA wide oe 200+

Black and red sandstone................ 4

Straw yellow sandstone................. 20

2 Jurassic [Morrison and Sundance]

IMA OOM: (CLA svepais a sue UaNSUe SO ee si oes 10

Biluishssreene clay. dis cg cies casos seause sale a 15

; Wellowe Sreem' Clayasic 2 ee cctyeneie wievo ve) Div elec os 13

Bluishm sreeniiGlayis.rs, <ces scisseseers eee ecere 6 15

MS AIG yen Gl ay aaneds cle seers Ocuat suse Tee are AT cats. 5

(GES Aiysa trae tsay eteichecarene erecta slices onelevanetD seis 2

WONCEET OMS Hier rece sis cee ieee ERTIES 1

Fie. 52.—Section of the Greene’ Clay es Bosesictereveye: sue, creeteuaiem rece bok aa 15

eee ere Neandcions Sh ee |. 4

north side of Como Green Claire Aiaiic eros re ene eta Soh erare aie. 10

Anticline, Wyoming. Green clay with small concretions........ 25

1.—Morrison forma- Maroon clay with small conecretions...... 20

tion; 2.—Sundance for- ERECT CLAI es Mena een so Sar ointdaialeie ie ys aid tele ote 9

mation. Scale, 125 feet TR CCere lave PaRe eee: rs See eo A Ser ee 5

to 1 inch. (Loomis.) =

WIR ITRO CTA TOIS I vets 45 ccoren SS ee oo PL EE Roa eae (-

TRO CUBIS s5 cg ehard ht nee eral Oto 8-5 Se SI Siete eu IC aCe oe eae EH age 8

(CHEESY SEDOKOISTIOTIYS s. p-ckaore Sree oleh es oe TERE cece One R Aare eels ae tes OA at 28

ND) FAV ig eas TEC CMM CL DAV At eee aeett eee beyierc eesieustee eben Gt devel alg isuseere,gitsL gel Sie mateicoueiatacaye 10

SMMC ISTOMG ~ oooh 6 6 ois Soca eich Olean RCN Ecce oe es ae co ene na eS, 1%

EWS Ol AIOE CM Clianyay een suenceree hk oe sci nsa real tener alee hauiet susie ay 18 ened’ alele SSneuevenemoae 10

SED CSL ONC Mere Per ae tare Teen UNREAL Sector ck cate reste Seetre ea eae oe civeilculanie: apie siayande ce pave teers 2

(CRECTNCI ype er HAE Eee Bo rag eect arecet Oe eos SMe ee BM Guay ecde atures Sema 6S 25

SANG SLOT CMe Peye ra aes tao r toi ciecy sy cel aie ean are ae cer RMN OL crs A Lees ea 12

Punplesclavs swaibliy, MIMESTOMES: Jif a Je/apecegsresechess ss) elem ole) shel nie c)er er eiaisiel e sleve 15

Girabyse Orval ayitepurive sik caret erotacsy sud cies avoNeraialare abies eaetetaricualte Wha smlogaile welds alenesete 55

Total of Jurassic [Morrison and Sundance]................. 332%

Fic. 53.—Exposures of the Morrison formation in Como Bluff, Wyoming.

After Osborn.

Fic. 55.—NSection of the Morrison and Sun-

Fic. 54.—Section of the Morrison and Sun- dance formations on the south side of

dance formations at Como Bluff, Wyo- Medicine Anticline, or “Bone Cabin

ming. Draw,” Wyoming.

1.—Morrison formation; 2.—Sundance 1.—Morrison formation; 2.—Sundance

formation. Scale, 125 feet to 1 inch. formation. Scale, 125 feet to 1 inch.

(Loomis. ) (Loomis. )

Section on south side of Medicine Anticline, or “Bone Cabin Draw”

Dakota [Cloverly] Feet

Yellow ‘Sandstone. 6. 2.20.0 ects tee. eee 245

BlackusamdstOne:. saree cco selene escrito hetea cot =) olka 2

Gray sandstones.) ws. 5.65: ee wie ea ro: na 30

MOOK, STUDY OF THE MORRISON FORMATION 93

Jurassic [Morrison and Sundance] Feet

[echmbshn’ gerpaeetain CII eae sees I se ech IS ee eect ae

Re TEC ESTING CAN derenete ns vee etre Niet aimee Pe eI es ale See ak er cliaie ch aleve Sy arg/e IS die lees PAD) 8

TESTOIE cy Sieg SRNR RB ee a, 6 0 ar ie a a 1/3

REDRESS AMO SCONE: tis aerate ee meee yet Revs (oi Sae ais ene ae 4 shseleteygvereiea ec 8) spre 10

(COT GCIRETEIGTOS | ooo Siete resto spic a cng: tote ee aa aA Mtoe ae erie ee 2

(GARG CIB IN Gs SiG aay bene ake Bc berate et ic ea ciate me egne Beara ane RES a ee 3

Sin GCOS Pais rie a eeou tora Sik 8 Ged chia are ns CRE cil eae nee 14%

Sip aeinl CIA al Miele reece Sik CAO DYESS EEOC ICRC Ne a Ene eta tres m e 8

Greens ely swith; CONCEKEHONSE eeicis cs a nse sere were ole whe eer cuererele ae, eus 10

Maroon clay, wath small Coneretions. .2 5. ..-..0.42-2-- 25-56-22 10

STE UD ISA OVINE 5 GS poe RS ata OED CUE OO RCC ee nectar eee ion

ERECTING LAV Seer e ee Pelee ean ie ee re eens Re iene ea treet ene ay raat 8

SSUOCIROINO OS 4 ehele crore eee hen d cee Ceans oan RL RSet eet ci eaten tea ne nes 1

TR@Gl CUB Hea elerons Gia Ciera G paca anete ee les ieee Rane Ute pe LY ee ae 5

SoC SEOM CMnae et sente reine tote a tet cpa eae miianatn ane He cea vane: sn laretela acum Sich. wile ete 2

GMECTIPRGLAN Ae re creosote reales te Meee ens ate ee a Deon ene aad Be 6

ST TICLE og ad Sasi aE ot EO ESR ae AAR se aa OR 1%

VCO SECCTIMATMNAT OOM CLAY cher stetere creo otnsia chs ic rs Berea wieseseveeene ere miele iP

SPOT STOLE: TES Stic orci RONG on EE REP RR ERE PL pe ck et Oe On Sara ae 2

NAR OOMs OTE pT COMO] AY ctarce tanec eer are ee te ae ey eier Seg ane ers woigig tes! elisa 10

SAIMGISROMNE® pista tec sche cai ROR ICRC DIC sae rence cen renee ts eee 2

GHRECT, CAR AS 5 Ge ie Biche Bote cect ise aR RR Recent es ce ae hee 22

SANE SHON Creare tren alee etn a ee) ene a eel coca, Graton Sra glue s uae alee aiereee alee to ens 1

ECCT CAV PRINT ee O ORe na cen enim Lelia eo yale MS hinge, She RU Ree ee Fai 20

JRO KONSTD, CIES itt rate tera ps OUP haa ERC R ACLS SSRONA > CeRE at ae aaa Wa eee Nae ara 20

SMTA CLS LOT Ciel reece Nat MRT ace ho soah pare eMart ona, Give canbe, Jee yom R Ok: Jee Sy om 1%

Green sandy shale........ SV risers elec OEM RCO NC as en SNe ete 6

Epp lemelayacwachy IMESTONES os caa leche oie leone © wv oie tena ais ceoeiertionepene = 22;

INA CUN awe INTE SEOMe reer asy seer wceey Nene cele, shes. ara fake cwuaeends ee encacehaye 1

OUT CLD VE Ree RTL ne eee et ais ces al sence Sr otey hat ieee 43

Total of Jurassic [Morrison and Sundance]............... 274 5/6

In these sections the Morrison is interpreted as beginning with No. 13.

The contact is not very distinct.

Logan gives the following section for the Freezeout Hills (1900, 5):

“Purplish clay containing considerable arenaceous inclusions.......... 40 ft.

“The clay contains, in the lower part, a thin stratum of sandy limestone in

which the following fossils were found: Pentacrinus asteriscus, Asterias

dubium, Pseudomonotis curta, Avicula macronatus, and Ostrea strigilecula.

“The Atlantosaurus Beds—The last stratum is the last one containing ma-

rine fossils, and probably closes the Jura, but some of the non-fossiliferous

beds lying above may belong to that formation. The succeeding stratum

varies so much in thickness that it may represent the eroded surface of the

Jura upon which the Atlantosaurus Beds were deposited.

“16. Fine-grained, grayish-white sandstone.................. 10 ft. to 125 ft.

“The above stratum varies much in thickness within short distances. At

Q4 ANNALS NEW YORK ACADEMY OF SCIENCES

one point on the Dyer ranch it has a thickness of only 10 ft., while a few

miles southeast it reaches a thickness of 125 ft. The sandstone composing

the layer is of nearly uniform color and texture. Its induration is only mod-

erate, and it weathers into many grotesque forms. Cross-bedding is well ex-

hibited by it in many localities.

“17. Purple to greenish-colored Clay............-0c-cesensecccreereces 60 ft.

“This is apparently an unfossiliferous layer, except in the uppermost hori-

zon, where species of dinosaurs belonging to the genera Brontosaurus and

Morosawurus oceur.

“18. Sandstone, grayish to light brown...................... 10 ft. to 20 ft.

“The above sandstone presents some very interesting stratigraphic phe-

nomena. It has, at the base, a layer of conglomerate about 2% ft. thick.

The conglomerate is composed of small silicious and argillaceous pebbles, and

is not very coherent. Something like two feet of sandstone rests upon the

conglomerate; the bedding planes of the sandstone are oblique to the bedding

planes of the beds above and below. Succeeding the sandstone above is 6

in. of sandstones in very thin layers, with lignitic seams along its horizontal

but wavy bedding planes. The above is overlain by 4 in. of conglomerate,

followed by 1 in. of sandstone with oblique bedding planes. Overlying this

layer is a thin layer of sandstone in which the bedding planes are horizontal.

The remainder of the stratum is made up of sandstone with the bedding

planes as follows: One ft. oblique; then 3 in. horizontal; then 2 ft. oblique;

and finally 3 in. horizontal. The stratum furnished in one place the trunk of

a large fossil tree and a large number of fossil cyeads. Fragments of fossil

wood were found in a number of places, but cycads in only the one. Frag-

ments of a hollow-boned dinosaur were found in one place in the horizon.

19D ralb=COlOLed! sel awa sos ce.5 3 he Sos, eas) S.aese ep elena alee rene aepeme nee mea 30 ft. to 40 ft.

“This stratum contains the bones of the large dinosaur, Brontosaurus.

Otherwise it appears to be quite unfossiliferous.

CAN, IOUS, lOO nMISin, SEVNORONSS 5565 bescospbcddocuosuocods5oc 4 ft. to 5 ft.

“No fossils were found in this sandstone, and the most characteristic feature

about it is its uniformly brown color. It seems to be moderately persistent,

as its occurrence in many places in the hills was noticed.

“31. Bluish-green clay containing very small concretions.............. SOetts

“In the bone quarries of this horizon, which furnished species of Bronto-

saurus, Morosaurus, and Diplodocus, were found specimens of (Planorbis)

veternus and Valvata leet. This is the lowest horizon at which any of these

non-marine invertebrates were noticed. It is probable that they will be found

lower down, as the dinosaurs occur much lower.

“22. Brown to bluish-gray arenaceous limestone......... EOE AOS 8 in. to 1 ft.

“This stratum contains the following non-marine invertebrate forms: Unio

knighti, U. baileyi, Valvata leei, and (Planorbis) veternus. Species from the

Same genera have been described by Meek from a similar stratum of limestone

in the Black Hilis. As these occupy much the same stratigraphical position

they are probably the same age. The Lioplacodes seem to be identical with

that described by Meek in the Geology of the Upper Missouri.

#93. Drab-colored clay..............- = 60) ft:

«Species of the genera Brontosaurus, Dip-

todocus, Morosaurus, Stegosaurus and Allo-

saurus occur in this horizon. Portions of

species of all these genera were found in one

quarry by the Kansas University collecting

party. The clay is of that quality usually

designated as ‘joint’ clay. It contains in

places iron and argillaceous concretions of

small size. The iron, and sometimes the

bones, are covered with selenite crystals.

“24. Grayish-white sandstone......... 50 ft.

“This layer forms a conspicuous capping

for the hiils, and is the highest remnant of

the anticline. It breaks up into large blocks,

which lie scattered along the slopes of the

underlying softer beds. Its erosion and dis- -

Fie. 56.—Section of the Morri-

son formation in the Freezeout

integration is accomplished chiefly by sap- Hills, Wyoming.

ping. No fossils were found in this stratum, — 1.—Cloverly formation; 2.—

and its true position is in doubt.” Morrison formation. Scale, 125

feet to 1 inch. (Logan.)

The following sections are given by W. C. Knight (1900, 2):

Sioux Fault Section

‘Cretaceous:

Dakota conglomerate and sandstone.

Jurassic : Feet

1. Variegated marls and clays shading from dark yellow to dark

LANGOOMN, Wall OChinoselnyeteial mEMBNINS sh ososcnoganoscnsooeeodce 381%

3. Bluish and yellowish marls, containing Brontosaurus at top and

MIOROSTUIPUIS. AME WWERBGabsa0c0gugoconn conse Le ca TEN tO EL OREO 22%

APD FAM CALCARCOUSE SAMOSLOME Sa rie ay aiieia cis) errs cael elo i ela eie «oles 1%

5. Light colored clays and marls, with thin bands of sandstone... 24

6. Clays and marls varying from light gray to brown............ 23%

K(eeclard sbandeotesltcihtecraive Claiie cm micnels enclose ccicitie so eincin soe Gs 41h

See ral eam Gi or Ceil Sly) CVA Sioa. open Geo es a ae bis aah ek Ruareeside oes 221%

SES SEOMOe Ree ie, ae eee ees ane Ce Al) 2

10. Yellow, greenish and light brown marls shading into maroon in

LEAVE)“ WHO OXSIE TOON 6 Sere cree is mina so cicier a Sat emee oePnee Rene eh ae ei 381,

PUMICE TARVIN SHOINCS opens oe siies ewes cr cia ea eee eso ec Lorch ois ee, cuavaten mans) Sesnete ote 3

Te IBIS) ereehy. CLEANS nic Caen pete oreo care ie cle GU me oie ea Gees ole 4

13. Bluish and drab clays interstratified with yellowish bands..... 38%

Total thickness of fresh-water beds [Morrison].......... 226

14, Variegated clays and marls with bands of sandstone........... 43%

15. Yellowish sandstone.......... PE Teler wropersva el atelenattera mane ater oieena ayia 8%

Fic. 57.—Section of the Morrison forma-

tion at Sioux Fault, Wyoming.

ANNALS NEW YORK ACADEMY OF SCIENCES

Feet

Dark shale beds with remains of Baptanodon, Belemnites, Os- Ae

trea, Tancredia, Camptonectes and a few Septaria.......... 38%

. Yellowish sSandstone........seeceee cere reece cee eerces Shale ee

. Gray sandstone.........-+e-+e-e+- PPE A MEAN GIs6 cco 7c wo owe

Yellowish sandstone alternating with thin clay bands.......-- 6%

Thin bedded gray sandstones with a few bands of clay....... 3 5%

Total [Shirley or Sundance].........---+--+-+-++-+- oi ee LS

Fic. 58.—Section of the Morrison forma-

tion in the Freezeout Hills, Wyoming.

1.—Morrison formation; 2.—Sundance 1.—Morrison formation; 2.—Sundance

formation. Seale, 125 feet to 1 inch. formation. Scale, 125 feet to 1 inch.

(Knight. ) (IXnight. )

Freezeout Hills Section

Cretaceous:

1. Dakota conglomerate.

Jurassic :

s© 9

Drab marls and clays with a few thin bands of light colored

sandstone containing remains of Dinosaurs.........-----+--:

Hard clay and sand containing fresh-water molluses and croco-

PG HIVHeOe ae nee ab AGO casing BOC ORO CCUM Om CmGOOCIS.G pio C OSC 5

Drab marls and clays with a few bands of calcareous sandstones

with remains of Alloscurus, Diplodocus, Brontosaurus, Moro-

saurus, Stegosaurus, Ceratodus and (Mirtles i. 0 ac. Sei

Drab marls and clays with thin beds of soft sandstone.......- ;

Yellowish soft sandstone with cycads and petrified wood......

Brown sandstone, cross-bedded.......---2+-+e+e steers trees os

Drab shales, clays and marls......--.----++++e- see ce sete s ees

Greenish sandstone........ Pr oa o ee eR MNES Arise. oc 0.0

Total fresh-water beds [Morrison]..........----- isto

Feet

10.

11.

12.

13.

14.

_ 1.

Fic. 59.—Section of the Morrison forma-

tion

MOOK, STUDY OF THE MORRISON FORMATION

Feet

Reddish and brown shales and clays...............ccc00eee0e- 49

Dark fossiliferous limestone with Camptonectes and Ostrea.... 3B

Greenish shales with dark bands of clay and sandstone, with

clay containing concretions of limestone rich in fossils. Fos-

sils present: Belemnites, Pentacrinus, Astarta, Grammato-

don, Ostrea, Pseudomonotis, Pleuromia, Pinna, Lima, Megatl-

neusaurus, Baptanodon and Plesiosaurus................00- 50

Gaya SANA SEO ME a2 aie) corps tetaret erate ctalere tis eratevs bale stan ie cjchaie lar sna evahede aleiave 4

Red and brown shales with concretions and a few fossils...... 44

White sandstone with upper band containing fossils........... 30

Total marine beds [Shirley or Sundance]............... 179

tion at Red Mountain, Wyoming.

- Fig. 60.—Section of the Morrison forma-

1.—Morrison formation; 2.—Sundance

at Red Mountain, Wyoming. formation. Scale, 125 feet to 1 inch.

Seale, 125 feet to 1 inch. (Knight.) (Darton.)

Red Mountain Section

Cretaceous: Dakota removed but present in most instances.

Jurassic:

CHARDAWK WD

Drab marls and clay with two thin bands of limestone and one

of chert and chalcedony with Dinosaur remains..............

ID pelITMESEOM CR eyreearscs er epetie a! seoeesce, Sheiaie tase oe wer gilonere erenes biascderate la aieieve sats

. Variegated marls with Dinosaur remains.....................+.

GrAVeAIMMeSTONG recente iste oars ecouea eke Greke leone Be vaettoyaie hee

AMO) Teed LoD NTA Sos TT Cl x CLAY Sova ocx os)o'e cevreue ues ee aos Jat ane) ¢) a) ace #gpavanmilen seme eueliaheneiose ope

Pan CATV ASEAN SLOT) GE y ah eats eo amare ea ee ece rao la Lenereninis Sie eel Seana vailel ay au naar

See OT: pM TNT Are Sieh TN OCU ANY Gis ata wg se ese oay ens! Sealer we Syehe syerauaderesekevepe teverGanareeye

. Gray sandstone and some conglomerate.............-....--.+e+.

PD rahe an dered emarls! Amd. | Clay Siac: st. wile © sus eusccusrn ictal cio cs svepeusmeensseuuens

Notalealle fresh=water! DOGS iss cits veces a cueevenar et ceckocedevetes headers

ANNALS NEW YORK ACADEMY OF SCIENCES

tes

oa)

Darton (1908, 1) gives the following section at Red Mountain:

Feet

Bluish ‘SHAlESS.sisek a eicwn. oes cle ce wees bd alee ce nee e els siete cae Aneta een .. 40

TIMESTOME Heer Aes eek co ele os doene evel aoe sheds Stetetevars Soles 22 oe See ts 1

Biwish Vehales sees ose ee nce eee REE NASM IE StS cn ~ > rey

THIMESCOME eee iiss oles a oe wie eee se 5 el od teicleve Stn eeete yor ouIaven a Stee Sear aaa a 2

Bluish Shales sociale acc cee wf aein es Oe Re MO Se ULE IE Cl ece ae 36

128

“The Morrison formation outcrops on the west bank of Laramie River

just below the ridge a mile northwest of Laramie. ‘There are 3 feet of

dark shale at base, then 20 feet of soft, massive light colored sandstone,

and at top 10 feet of gray shale with several thin, slabby limestone layers,

one of which is pebbly, and a thin layer of gray sandstone. In slopes

11% to 2 miles south-southwest of Howell station are soft, massive buff

Fig. 61.—Section of the Morrison forma- lic. 62.—Section of the Morrison forma-

tion on the east slope of the ridge west tion on the South Fork of Horse Creek

of Downey Soda Lakes, Wyoming. (east of the Laramie Mountains), Wyo-

1.—Cloverly; 2.—Morrison. Scale, 125 HCE

feet to 1 inch. (Darton.) Seale, 125 feet to 1 inch. (Darton.)

sandstones overlain by typical gray and greenish gray massive shale or

clay with thin limestone, cherty, and sandstone layers. One of the latter

is 2 to 3 feet thick. At the top are very dark shales, which have been

prospected for coal; these are overlain by coarse Cloverly sandstone”

(Darton, 1908, 1).

Darton also gives the following section of the Morrison formation on

the east slope of the ridge west of Downey Soda Lakes:

: ~ Feet

Cloverly sandstones and shales.

Drab to olive ‘green Shaleg sy. 0c ree keto eceiaiooe nce ae he eee 30

Soft, coarse-grained, disintegrated sandstone, with caleareous matrix,

containing’ teeth and: DONES sci oe Cen ete ete ote sub cne ase eee 6

Drab: torbivevsnaler eka si ieicreuceee ee A et re eG Oe od 15

MOOK, STUDY OF THE MORRISON FORMATION 99

Feet

PRG CHUT cae IME STOIC ea sreaials vrs suchelelsbene)eiete cele coete nls cles Sue's, ¢o eieeie!s eum eieveyelo es 1-2

ie Shale... ........ wiht gate ges, aN A GAN oa eR ME ae 50

STN S HOMO ME erat rel Sian Crevice) Seteianenerei aa Sorel meet ee ARES Sse kee: wale isle telcd 2

@oncealed, probably blue shale...... 2.0... 26. ee eee eet eee cee 30+

135+

On the east side of the Laramie Mountains Darton (1908, 1) describes

the Morrison in the first canyon south of South Fork of Horse Creek as

consisting of the following: pale green and maroon massive shale on 30

feet of light colored massive shale which contains several limestone layers,

one being 6 feet thick. “On South fork of Horse creek, the 6-foot lime-

stone member is conspicuous, underlain by 20 feet of gray shale lying on

a 1-foot limestone bed at supposed base of formation. ‘he total thick-

ness here is about 200 feet, which appears to be the average amount, ex-

cept on the southernmost prong of Horse creek, where it is less than 150

eee

Morrison FORMATION IN THE BLAcK HILLs AREA

The Morrison formation occurs in the Black Hills area in eastern

Wyoming and western South Dakota. It is present in the hog-backs sur-

rounding the central area of the Black Hills. Outcrops are present

around almost the entire circumference. For a short space on the south-

eastern side it is absent, however, the Lakota sandstone lying directly

upon the Unkpapa sandstone. The significance of the absence of the

formation at this point will be discussed later. The Black Hills Morrison

is usually underlain by a reddish, banded, porous sandstone, known as the

Unkpapa; in some areas, however, it rests directly upon the Sundance

beds. The thickness of the formation in the various sections that have

' been measured are as a rule less than the thickness in the various central

Wyoming areas and much less than the areas in western Colorado.

The following general description of the Morrison and Unkpapa for-

mations in the Black Hills area is from Darton (1909, 5). Detailed de-

scriptions of the formation in various quadrangles will be given later.

The Unkpapa sandstone has been fully described by Darton. This

formation is a characteristic one in the Black Hills region. It is more

extensively developed in the southern than in the northern part of the

area. In the northwestern and western part of the region it consists of

a thin yellowish sandstone. In the southern and southeastern part of the

area it is represented by uniform-textured, fine-grained sandstone of vary-

ing colors. ‘The following thicknesses are given by Darton: near Sturgis,

iy °—'

100 ANNALS NEW YORK ACADEMY OF SCIENCES

60 to 70 feet; near Tilford and Piedmont, 40 feet; south of Rapid, 30 to

50 feet; a mile north of Rapid, 150 feet; in the Bellefourche region, 10

to 30 feet (not clearly separated from the Sundance) ; very thin in the

Aladdin and Sundance regions. It is usually clearly separable from the

Sundance below and the Morrison above.

The Unkpapa is usually soft, white, buff, red or purple in color; it

contains considerable material, and is often strongly banded. This band-

ing is usually parallel with the bedding, but occasionally makes a marked

angle with it. The rock is extremely porous and often exhibits interest-

ing examples of microfaulting in hand specimens.

The name “Beulah shales” has been applied to the Morrison of the

Black Hills region. The formation consists of the usual series of clays

and shales, with thinner layers of sandstone and calcareous nodules. ‘The

prevailing color is gray, but other colors, such as red, maroon, pink and

purple sometimes occur. Carbonaceous matter is sometimes present im

the upper members. The following thicknesses of the Black Hills Morri-

son are given by Darton: near Rapid, 165 feet; east of Piedmont, 220

feet; rapidly decreasing to 70 feet in nearby locality; 4 miles north of

Tilford, 110 feet; 1 mile south of Rapid, 90 feet; 3 miles south of Rapid,

165 feet; in the region about Sundance, 150 feet; at Aladdin, 60 feet;

east of Aladdin, 80 feet or more; in Redwater Valley southwest of Belle-

fourche, 50 feet; near Lookout Peak, 100 feet; about Table Mountain

and north of Hothen, 150 feet; near Alva, about 100 feet; in Barlow

Canyon, 85 feet; 3 miles north of Hulett, 150 feet; on Miller Creek, 7

miles southeast of Devils Tower, 160 feet. The thinnest section recorded

is in Barlow Canyon north of Devils Tower, the thickness there being 40

feet. Dinosaur bones of great size have been found in the Morrison near

Piedmont, apparently belonging to a sauropod of great specialization, re-

semblng Diplodocus.

In the Newcastle quadrangle the Morrison deposits are mostly of light

eray color, but some portions are buff, pale green and maroon. ‘The

thickness averages a little more than 159 feet and is greatest in the north-

ern part of the quadrangle. The beds outcrop along the inner side of

the hog-back below the Lakota conglomerate and sandstone. In the

region east of Salt Creek they occur in extensive outliers overlain by pro-

tecting caps of Lakota, and in the sloping plateau north of Newcastle

they are revealed in the deep canyons. ‘The outcrops are often obscured

by talus derived from the sandstone cliffs above and by wash along the

slopes. The contact with the Sundance shows an abrupt change in the

character of the material. At Cambria a drill hole in the floor of the

coal mine penetrated 12 feet of sandstone with coaly layers at the base

MOOK, STUDY OF THE MORRISON FORMATION 101

of the Lakota and passed through the following beds, probably all of

which belong to the Morrison (Darton, 1904, 4) :

Feet

BER Mees meCo McD PROTA Sere apo cvctn es Sts) seavenccen etal nexchene, «jictie) o's, Selassie eit Sve cste €ele iw -atevese o 6s 3

Sandstone, light gray, moderately hard............................00. 1%

abatement l Uy Pr ee Poh aes icra chaser orca war eieever sisi er clore die wire csrecels ieee ly “svarerahinn ease: Secs T%

Sandstone, gray, upper half very hard...........-......2.--..2ee eens 4

SHaleswulead colored, soft at base: . 45 5.. 020. .00. be le ss eben eet eee 11

Strenlke graeol” TabaVey MSe ado Beeson aeeicteis 3h Cie aGinC OIG octets Seen = Marto er nen re ear 3

SS trest MMU SN ACV AS one aces eats) Sue eassa ee Mcgee wuss deems coe ave stetcsta m otek ele, Spevlacg # le 18

Sunastones moderately Nard ..ci cede ce cae eee cece wees sewer ee eee e cee 1

Clay, bluish and purplish, hard below....................200. eee ees 20

The Morrison formation in the Aladdin quadrangle has been described

by Darton and O’Harra (1905, 6). It is a thin but persistent deposit of

massive shale between the Sundance and Lakota formations. Its color

is generally a characteristic pale-olive green, with

local bands of gray and maroon. In fresh ex-

posures some of the beds are darker and in some

localities portions of the deposit are black. “The

thickness is variable, owing to local unconformity

on its surface, and its measure is difficult to deter- Fre. 63.—Section of the

mine at most localities owing to talus and land- = 4arrse ated o

slides along the base of cliffs of Lakota sandstone.” — coal mine at Cambria,

The shale includes thin beds of sandstone, most of — "¥"™"’

which is fine-grained and light in color. Nodules a Leen Bogne

of hard clay occur in some of the beds. The for-

mation outcrops extensively along both slopes of the northern extension

of the Bear Lodge Mountains and outlying ridges; in the ridge between

Deer and Medicine creeks; in the basins at the heads of Pine, Alum and

Hay creeks; in ridges north and south of Aladdin; and in the anticline

east of The Forks.

Darton and Smith (1904, 5) have described the Morrison formation

im the Edgemont quadrangle. In this quadrangle the Morrison consists

of massive shales and clays, partly light gray and partly red or maroon,

with occasional layers of fine-grained white sandstone. - West of Minne-

kahta the thickness is about 100 feet, but eastward, northwest of Cascade

Springs, the formation thins and dies out completely. Just west of

Cascade Springs the Lakota lies directly upon the Unkpapa sandstone.

The Morrison is exposed in the upper part of the slope at the base of

Lakota cliffs in the northern face of the hog-back westward. As the dip

is low and the formation is relatively thin, the outcrop is somewhat irregu-

lar. The formation is exposed in Hell and Falls canyons and in the

102 ANNALS NEW YORK ACADEMY OF SCIENCES

canyon south of Parker Peak, lying on the Unkpapa sandstone. In Hell

Canyon the formation extends to within about a mile of the Cheyenne

River. It is variable in thickness at this point and consists mainly of

gray and red sandy clay. On the west side of Falls Canyon the formation

is about 60 feet thick, greenish at the base, darker above, and light green

and maroon in its upper portion; on the east side it thins to about 20 feet.

There are exposures of the Morrison in Chilson Canyon a mile south-

west of Chilson, and in the heads of branches of Bennett Canyon, where

it is pale greenish, massive clay, with thin, white, fine sandstone members.

3 to 10 inches thick. It is also cut through by Cheyenne River east of

Edgemont. In an exposure in Red Canyon, where the formation is 80

feet thick, there is a thin limestone layer containing remains of alge at

the base. In a well at Edgemont the formation appears to be about 150

feet thick. “In the western part of the quadrangle the Morrison shale

is distinctly separated from the Sundance formation, and in the eastern

part from the Unkpapa sandstone, by an abrupt change in character and

material, but there is no evidence of erosional unconformity.”

The Morrison in the Sundance quadrangle has been described by Dartom

(1905, 5). The formation here shows the usual light gray and maroon

colors, with buff and purple. It contains thin beds of sandstone and

occasional layers of limestone. The average thickness is about 150 feet-

The outcrops form a zone extending across the western and southwestern

parts of the quadrangle. The deposits are distinguished from those of

the Sundance by the color and massive texture of the shale. The most

outcrops are in the ridges adjoining Beaver Creek, along Mason Creek,

in Skull Creek Valley north and west of the Holwell ranch, in Black

Canyon, along Oil Creek and in Oil Creek Valley.

The following sections of the Morrison formation in the Black Hills

region are given by Darton, from O’Harra (1909, 5):

Section of Morrison Formation on north side of Sourdough Creek, 6 Miles

north of Hulett, Wyoming

Feet

Shale, yellow at top, red at bottom.............. seve lnule. 6 iiiere areucuele eee 18

BVA CRE SMA Ohara ty cise a aheites cueyia tetia lees ene vars eucsecotoies PN Miloocah choo cab ichaid cease dia eee 14

Black shale with 4-inch sandstone near top, slight purple or pink tinge

throughout and rather conspicuous near the middle........ Peis 68 VW

Black Shalessa se, Poe Mh le ale Sea FS cs Oi one G lke 0 ble tee 26

Slightly sandy green soft shale; some lime nodules near base............ 10

WHITE: SAIMASEON EE 6.24 :.2 poh soi ape oce bwin ensene er etenee citeileneioucie ceiartel-<\vate, susie een eaene 2

Green shale........ ae SRY Pee CONG Sia ne ih nC Ae NOPE ERE ERS oc OG OOS 5

White sandstone, carbonaceous streaks.............. 2c eee eee ee ee eee ene 2

Gray and). reddish: Slalesiay \ icc sie: sree ein On ere ears 4 aise.» csieoees nee 40

Section of Morrison Formation on Ridge south of Lytle Creek, 8 Miles southeast

of Devils Tower, Wyoming

MOOK, STUDY OF THE MORRISON FORMATION 103

é Feet

oA CCOUS MIME TONE: cus sce siicie one cles Muesli eiele oe cle Sou alte s cae ees 2

MONAT CMe Claman tet ey of= cs) =a) ave as esa fonernteseficliselolln, si wees. wicis Soe!S Sve cs sdwce elle @ Gia, or 8 es, 3

EMT ACCOUS IIIMESTOM Cs. s,< etencuele sfosersievelleis/ rm o scla!s's Sle de suse G ge'e eevee he wire oe 1

Grayish soft Shale..........0..6..00 ee eee UEP aia et Na eee Ae Meparap eee eee aes 12

MEN ACCOUS, UIMICSTOMES .) 205. sex eens dle al) soe oles Lele nye ee; sere se siehajelennimle-cie.gpe cue alt

EMO WA Se Oa vat SWAG. apse uesis cre citenticyscorene ss. 5 cirayle Se) eyo ower ea: @) estore ile) «le wire. anid 6

PRE LT CEO US ee MIMES COMES eiets s 5) 0s otemerebs isl etal ese a) esas) o)o)lelie lose isis he) sfclicials © aleyele ave 1

MEE TIE SIO SINAC Netrce rebate area vetericyar co skajoneasyasie lecveslatane cis assicasisiedaa alee lel aus te tO se retavers:avetage 40

PeBeMMNACCOUS! HTHEStONES)..--- 2 eae. es Renae BS OR eten ee ea a0)

ERECT laters Hen] Cb eveyay lerccs, enc aus f sdeicuaveiensretele lain teievene ayereusiecem ot © eihins le eiaieteroye 30

961%,

The upper and lower contacts are not clearly shown at this place.

Fie. 65.—Section of the Morrison forma-

Fig. 64.—Section of the Morrison forma- tion on ridge south of Lytle Creek, 8

tion on north side of Sourdough Oreek, miles southeast of Devils Tower, Wyo-

6 miles north of Hulett, Wyoming. ming. ;

Seale, 125 feet to 1 inch. (Darton after Scale, 125 feet to 1 inch. (Darton after

O’Harra.) O’Harra.)

Section of Morrison Formation on prominent Lakota-capped Hill, 4 Miles

east-southeast of Devils Tower, north of Lytle Creek, Wyoming

Feet

Impure fire clay, containing rough nodular layer............. Ce ane 2

ESN Re CTA SIME) Os cee pawettenes tate wae taape rai wea be caitsliaron ey suchas el Give take eiacias lolloucualle- eto velaneea ai etelouelevs 12

SamMoky Iti Glens orien oercrn a ee OG Olea i CL NG: ICES CLE Oreo OD eiet Ceen nee tener 1

Fine green shale, locally with purple tinge...................00.ccceee. 70

AO VTYT = CLA geen SVAN Creve ccione core vets carrera cle vacuer ceere siiciei sasienece. sae) eie, avs vata iazelleve le teins acclahar cand 6

Hinewereenand, drab. Shale: ic. scene coh shrew es siete cis nese wes Riad Side anneds 12

Green shale with some lime-clay nodules..............00..nceesccsccces 16.

MAME CRONE HST hye aon ll TCEOUSNaINe shoe sree Lidia ete e ca diane sis lath biscse'e eaca gare 6

125:

Section of Morrison Formation on north side of Deer Creek, 10 Miles northeast

of Hulett, Wyoming

Dark purple shale, weathers to light purple..............-...e..eeceees 9

NESS Thums DC SHOM CME ears cucu pevsures cutnecs Guard erase lanat ene tte croverer miesoieete Meualonere cera 1

104 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet

Parple gshall es vectaseisievertereiateters ee tonovcustseuers “sialls'a a. 8 etshelie s leusuel bt eaevekel cane eee een 10

GOnGOBTOd 6 oicc5iso.o:6: Go ave ace ws lols alate lors se'cecau tale lnlenedauene ke ye) cae tel noe eR ae 8

Purplish-cray Shale... co. eccrine cece emo os 00's, sein eo 5c sie ool telnet a enna 12

Dark purplish Shale....... 2.002.005 56. close ecce ole o ot oe cote a) stl elon tet eet eames Om

Very darks Shales oe cio cae «occ les ole. s oreretencterstereteue eaeicete Venera roRetn anaes tae 14

Gray. SWaAles ease oo eee Bak Se eee eee) cleo stel elie elstet cot ee Nee ee al(es

Goncealed:; contains: Some’ Sand... 5.500 52 els eee else eae 24

Green and: purple shale... < c.g eo cdot eee oe ieee a eee 6

Samdiy “Shales ayc', «cise sveis cls) iele a ersierereus oie eto s eianatellsts cist scanner ee ee 4

White sandstone, weathering to a dirty velvety brown.................. 1

Grayish-white ‘shale... 2:0. 05 Jo. c ie cidienw wleietelahere cove « cle oceeieue eet ee eee 5

Green’ shale! ooo. oss. ssid k dds ar tere Sines eee ease Se Oe eee 2

Missile: purple Sale. 03 ....5 cise See Siero oct ieibisie ooo 0) 6: Gio late eae eMane pol take Renee 6

Grayish-green shale with some lime nodules............................ 16

155

Fic. 66.—Section of the Morrison forma- Vie. 67.—Section of the Morrison forma-

tion 4 miles east-southeast of Devil's tion on north side of Deer Creek, 10

Tower, Wyoming. miles northeast of Hulett, Wyoming.

Scale, 125 feet to 1 inch. (Darton after Scale, 125 feet to 1 inch. (Darton after

O’Harra.) O’Harra.)

Section of Morrison Formation near head of Burnt Hollow, 4 Miles northwest

of Hulett, Wyoming

Feet

Very black shale, resembling a coal outcrop on weathered surface; may

possibly represent the horizon of the Aladdin coal.................... 10

Gray shale....:5.....5:: Sick oigetiathaed autistie Bit chaeahs la larere alls eee Se 32

Samd Stoner oot sce ees Sire a ssi oy Sep wl olen ses a evohaiouchel ne Athy de auanshay al

Shale with poorly preserved plant impressions......................... 3

Interbedded shales and thin sandstones................... cee cccceceee 18

Feet

Very black shale, as in above section.....................2eeeeeeeesees 10

Brownish-eray, and purple Shalescsenneesecee cieici isis cere isos, 14

NOPD OY0 (o) 00) 0, ae ee nes cam ere nen riers iG Sy a Aare MRO CS dic Coc ooc 2

MOOK, STUDY OF THE MORRISON FORMATION 105

Feet

SLD SUMUGs C466 Gail 6 BIC BO eS G10.6 CH CISC. Ole SRL Ieee aa en 40

Spee pm AeA Vagt SL A) 22 tote clecd sy oh ch shar Vay ah ou vaneuohiayeravoney cycustarano/ ess svdhersnalancie ws a6 ee lb ond ah hve 36

110

Fie. 68.—Section of the Morrison forma- Fie. 69.—Section of the Morrison forma-

tion near head of Burnt Hollow, 4 miles tion a short distance east of the fore-

northwest of Hulett, Wyoming. going section. (Fig. 68.)

Scale, 125 feet to 1 inch. (Darton after Seale, 125 feet to 1 inch. (Darton after

O’Harra.) O’Harra.)

Section of Morrison Formation on north side of Moores Canyon, 2% Miles

northwest of Hulett, Wyoming

Feet

DVS UL Ome SIND Bes eaten t ec, fic pe: cad aos) neve scares oRGeke o eeeielare nets, ates atau ola ole 2

OV ARKGE ULI MmSIN A Cpr ee teh cacao cic lis iio orareudie: Sieg ss croton soele ci eunhenden aeShca aaleetd 36

NMellowish-ashehthyssandy: Shales. gsc dec oo seis os See cms es eide sien aecied 4

Neo Ghivl ear el any Tesmecwerray sy Peace cre che (ene, ei.ay ses o Phaua leone Gado eid SMe ae Me UNE Sal se lets 1

WB) earskO TE CTIS MSA Ve SMA Oly ort sioner «les: esis ols: 51S = aisle GG.© SURI mere omtensleteeslele'e Suse a4 10

TOO RTGITE. RETR a er ay cana eee ed ChE TB Ra eee TE Pee re ne il

EARLE SIN ALON te, teens secictette eeterenccnicy Sectaual sic slatavene ole caeiae sume ate als Hee Sa Mielbrove were 6

Dark gray shale with lime-clay nodules............... 00.00. cee cece eee 2

JOEY). - SLOW er Soc Biky: seca Chey ie OM SION IO ca ERE EL a a 8

METS VAESORCR SAM CiyacSI all Cxevarcieve solo. coche sucsayosiein lee oe) erereve aoe sinless et ausueceis etuile eb eel sue 8

Section of Morrison Formation 24% Miles west of Belle Fourche River

Feet

Purple, gray and yellowish shale with one or two thin sandstones....... 60

Flaggy to massive white sandstomes............ cc ccc cece cece eect eeeees 4

Purple and green shale with a few limestone nodules................... 60

124

Feet

Concealed to base of Lakota sandstone.................. 2c eee ee eee eeees ; 20

Mostly green shale® partly Concealed. 5.2%. .i.cccs wie cece se cee sc eccccsee 40

Dark green shale, weathering into small fragments..................... 6

MASSIVE erayeSAan OSUOMC@ ra sce s-corss, s\ sieve sss cus tete eG eisrbis os meher elec cena elelbens d 5

106 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet

Green and purple massive shale, with some sand; iron stains............ 12:

Soft. thin Sandstone... dc. cbc c aie wiles. wwe wuctetenlole @ clam e eke ne ene Py

Green sandy: Shales 23. i205 sce 655 cise be cGis ei Sane! Oe he eee eee en Oe eee ey

Soft sandstone, green and Sray..... 2. ccc cece cs ence sw ciees s «> dele ceeeneeeene)

Green shale with some Samdse.....00 oa cee ciel chore ole tee Sree ane tee 12

Purple. Shalemecss chew n cat ces eee Lode suai o een 4

Calcareous nodular layer.

Massive shale, green and purple................... PE PERO S Ob ooo c Zi

Purple shale, with calcareous nodular layer........ ao ae ee 4

Caleareous: nodular Walyer: ei. sf si.gs elle cis 6 breve wc lo anes neice ee 1

Massive shale, green and purple... ...c...0.6e sce cece cee erernereene 3.

Massive but soft sandstone; light red and brown at bottom, but mostly

white; slightly brecciated near the top and containing some ealcite.... 20

Massive red shale with some sand.............---------++22e+eereeeees f2;

Massive shale with calcareous nodules, purple and yellowish............ 5

Soft) bright red: argillaceous) Shaleses. toe sen ee ee cee 3

165.

Fic. 70.—Section of the Morrison forma- Fic. 71.—Section of the Morrison forma-

tion on north side of Moores Canyon, 2% tion 21% miles west of Bellefourche

miles northwest of Hulett, Wyoming. River, Wyoming.

Scale, 125 feet to 1 inch. (Darton after Scale, 125 feet to 1 inch. (Darton after

O’Harra.) O’Harra.)

The following sections of the Morrison formation in the Black Hills

region are given by Loomis (1902, 7):

Section on Bellefourche River, Wyoming

: Feet

Olive rereem eC] aiy eis eaeee hie: slarececusnhrs oid ore aareneiere ree several ued Mane he eee 70:

Yellow-green clay with small coneretions.......................ccee+e0n 12

ME rOOM VCVAY.S Se Sensis Becece hoe ic ieic sens, oh aueze ocala ee CR RESTOR OTE A OE ON 10:

GEOOM: CLAVE « coibehetepe cane a tene elle SSeS. 6 Lae RT EIR SU ac 6:

Limestone COmCreEtlOM sa srevers oie cies’ < 5 aus isveve sie ele evedsloteler chore ies, & Se Laer eee al

GmreenWelays..- sone DELS a ilay heroic bk eicie slew id Meeiaunoae elelbts Sly ote 6.

Maroon clay with small concretions............ Wie os 6

Green clay, with ‘small concretionsias- eee hieieiicitieiiey aetna eee 10

IuiMESTOME? CONCrELIONS ae Hee aero cee See Ris Java ya(s ays iar oeushis ee eee eon eye ki

Green! CLAY. adios eager sete lerd as Sie ecyeteeh tated elelcasge tere eesoce le ease he oe ene 4

Limestone *Coneretions .cc-sciites 3 <0 os wsctsie ee alensis fale! aati ele chettmaleusie eee eee Ren oe

MOOK, STUDY OF THE MORRISON FORMATION 107

ey Feet

CECE IIRC LAV Caren T ernie ra tere atarratole rater betel atccs faire eink xlealone Belvlaedaa vec wah 6

SOV WO Wer SAMUSCONCG os es manly alc dese sos ca ose snc vecdleatec sees csuwes 2

Green clay...... Sige cucher et AGaLA Hel & & Sycic0) & doa a eige ee Rete aon aS Alen Pe ee 7

SSR EMEC MOM MES AILS COM Cais nchsvstat ae vorenere rs aerel crails iee, ev teres terete bce te stone sue calle wala Rede ng 2

144

Fic. 72.—Section. of the Morrison forma-

tion 3 miles south of Rapid Gap, South M¥ie. 73.—Section of the Morrison forma-

Dakota. tion on the Bellefourche River, Wyo-

Scale, 125 feet to 1 inch. (Darton after ming.

O’Harra.) Seale, 125 feet to 1 inch. (Loomis.)

Section on Inyan Kara Creek a

Feet

MVS CCMMmel Ayame artes eye en har eta ehauess aie elaiciee ei Aiare a Wis egies Hah arta e aR wes 40

Moe oT CO Tiles CLA Ee oecncrse to Se encesee oie es oy ee wee a sae aide (ela bus: Suah'olle'e a tae wig payee sate 12

Maroon clay with small concretionS..............00 cc cece eee e eee e eee ees , 10

Green clay with small concretions..............0c cc ccc cece cece eccees is 5

TREGL GLANS bi6:. a coh io ot IO RG Oa oe ORCC CEN eee UES Slee Ce 5

REC OTIEG] AVA eRe et Sites hen Abr ICL eats Ce We od Slob is aise Rae MANERA 5

VIET C] Any cas Meena hee se Reese as repel eas pels Si cits padie ahs istiotetene lalistdians iceseuti euacevenereit 6

MEE O TINE Les ete Memevere terre Nate Anas epecch og wekin cu e'se Hoye cis, dea cho lbs: wate venaua aie ieanete Mies 20

MATIN ESTOME RA COM GCREELONG sco sucseoe ey sisce rate ocho ce oleh Se cerelovei.ocle ein Sie are velave arsdeueier shy 1

EMO WaSAMOStOM Ohare ier seyr ree ere ienaie dyclekanysa aya semerscavences elie glans, Susieie evalecnclane! eibes 9

Dense gray sandstone........... Kid DIC oO UU ERT OOS Ce eictele COROT OOO nt Sine re 8

ET OWeISAIN SEO Crt ti cocte cierto tenet etenes ales cist wilarstataye ed oveibie ees aie isteustele as aleve 5

ITM ESEOME SCOMCEE CIOS eis iou rence aeweicteloce aka oie) siceretorsi oer eystoile ole Gis oie bp alievelete wis il

Yellow sandstone............ ay RL SEAT 8 oY 1s eligi ne See a a Bal

139

Section at Sheldon Post Office

Feet

OU EMOT CCIM! Avance rR are rami wee OSD. Gla, w Sie. Gralla Mets B Elsie Winey MaUREe 30

IM ESLON EM CONCLEELOMSieysoieysiecs oe ois aie avs) aie, sve bere, © oso "er sie, ele eusyend.s iw dusiekere eieuernans 1

(Cad T GEN Aare a es BOS CUA eG a ane en ae DOs Heer Aa CRC RS ACTOR OR oir 10

WHETEOONN “CIBER 61a bts. dibs s oy cuore Gree CER EROR Ie ERIE cE nna Bis Pra rai Se ARIUS eit 5

YES UO PSEA ESTO ON is. See NSO ey Ae Bre oe ee ea AE ge 3)

LEGO GNP Gti bolo oh OS AG Gok GREE NOICREMCE CRC nen He? aaa een ear Area NA 5

MFIIMESEOMEN CONCTELIONS essa nie sigs ewe Se ce ed eee secs title estes lec GRE ae

108 ANNALS NEW YORK ACADEMY OF SCIENCES

Feet

Green. Clays oes closets oes Bete ccs he Geko teres faigcna die bee ershatecetel teh SIO esd ae

Limestone concretions............. de piss HEA See Oooo eee By 1

ROdy SCLAY Sse focus aicre etches oc vietal yates cere pom AE RN MEO G3 7 oie ame 3

Green Clayeg atari sores coe o ele aoe cle are eee te ene PPT RAO mo Oc 5 peter i lo

Limestone Coneretions ......6 646 secs alee lela heirs @ oats oe ne eee Brel

Green: CLAW else ais sos eves oa was Glaltelince ave cdhelole: du evade lave ekal sy «lel Sao OEIC RCO cena a al

Gray “sandstone. .2 3.6. en eee shsuebalteeralte RS eee Sia. feces ¢ ; Be ur74

Fig. 74.—Section of the Morrison forma- Fic. 75.—Section of the Morrison forma-

tion on Inyan Kara Creek, Wyoming. tion at Sheldon Post-office, Wyoming.

Scale, 125 feet to 1 inch. (Loomis.) Seale, 125 feet to 1 inch. (Loomis.)

Section at Kara Peak

Feet

VE CICLAVaeieraiceier nec raaleh see date aiaiatee e Send wie deel biel eco Sa Se TES ne ae ee 3

Green Aclayn2iscaee be oleae eae be nae ork ae Sh ee oe ne eee 3

Cream sandstone................ ES ROR EES het Bt ona sie debedenamees ode d cas

Blue-ereeni slay .3..55 0. gh los we ee nein be ee te ee be ae ee See 6

ROG CL aia aie Baie co ss Sie = MS ics eS ale: ihn we Sle ee ae Be tee Be Ce p 1

MIMEStONE -CONETEELONS se ik ais cca aids wed Bees Slene o blale BRE ES ee 1

Purple :Clayis Ge eae ecsiaid ose se eee ht chis use 8 ea Won ee ee Ee eee 3

PREG CVA elace even okie ak Soe nee eee 5 Deleted sb alten Bee tants a letle loi noei tae ere 2

Cream SANGSEONE 2% ern sss 8 ook 4s ecorsi avs ws fel oe ele even Cael ene einen ee Oe ee 2

Green elayn ots oc Be Es Bes Ne AAU tree MA ae ee 3

CLEA MSA SEOMO Re eaae Asis os ey ware seaioeues ier erie rote are elena oe ete Y al eee i 2

White iSAMadStome ses Gch as his ee ee tele en atts L Slo ivigeatine 6 sha peat 33

Bla eR Clays sce nee See ae eae ere e ees dei lave eee ee ca See 2

White sandstone. os Seis cit geckos OS ce er as Rik hedoa dei Oke 8

YVEllOw SaMdstone cy ses ik co coo he aw ia Ste eLs salle eae oles aiid adenehs ewe 75

Slatevereeni Clay an ekAcco s shene aan niaie Pe arate pistol oe ea iG wie. Baie. ae a0)

Gray Sandstone’ igs Ls ae We ae See cages ey Pete are Saas aise Sabie 3, eR eee 15

195

Section at Beaver Creek

Feet

BrOWMN-STEEM. CLAY.) 5 sehocs See. 5 alle! idl aso Soe ne ayes le vellel eee. © lo ses/eltatce ee 15

Olive: 2reem, ‘Clay oi) oie oa 8 & cua hee ls Ge hens eee Meenas ieee . 66

Green ‘clay, «with Small! coneretions: ...5425ee2 20 oe oe ele oie 15

MOOK, STUDY OF THE MORRISON FORMATION 109

P Feet

Maroon clay with small concretionSs................ eee eee ee ee eee e eee 6

Byraam GIBWss db: Sac teaepoeto nn atu ole 6 2 'dio-0/a io Sore CMICReIEE Ole CII rae once Se aceeeSErn 15

Maroon clay with small concretions................0- eee e eee eee eee 12

@nean GlAYcheccbaododmos gods ccle6 Go coo Cottle d bicio cic Cre mices ico cRerneear itera 6

NGIMES TOME LCOMEHELIOMS 44 so sie ace isin sie ciel eieliey aoe ccs eilerel ose ess eve wim ss re wire |

Sinne green Clehycooodeensoeouscnons 640 cos Uodooun es HOS Oma acne nneoon 8

ATES TING S EOIN W eee var. se erento Sue ete tarer arena ye Reliccay evar Me eae: ale elialiays ts Giereia ws sais 12

111

Fic. 76.—Section of the Morrison forma- Fig. 77.—Section of the Morrison forme-

tion at Kara Peak, Wyoming. tion on Beaver Creek, Wyoming.

Seale, 125 feet to 1 inch. (Loomis.) Scale, 125 feet to 1 inch. (Loomis.) -

ATLANTIC Coast REPRESENTATIVE OF THE Morrison ForMATION

ARUNDEL FORMATION OF MARYLAND

The Morrison formation is apparently represented in the eastern part

of the United States by part of the Potomac series. It was formerly

claimed that the Potomac was a unit formation. Its age has been dis-

cussed by a number of workers, some holding it to be Jurassic, others

Cretaceous. More recently it has been divided into several distinct for-

mations, separated from one another and from the underlying and over-

lying formations by disconformities or stratigraphic breaks. The lowest

formation of the Potomac series, the Patuxent, contains none of the dino-

saurian fauna characteristic of the Morrison, but the middle member, or

Arundel, is characterized by many forms identical with or closely related

to the forms of the Morrison fauna. The Arundel beds have been well

described by Clark, Bibbins and Berry (1911, 5).

The Arundel is the lower part of the “upper odlite,” or “Iron-Ore

Clays” of Tyson, a part of the “Variegated Clays” of Fontaine and Mc-

Gee, and of the “Baltimorean” of Uhler. It is the equivalent of the

“Tron-Ore series” of Ward. It outcrops in an irregular northeast-south-

110 ANNALS NEW YORK ACADEMY OF SCIENCES

west belt, from the head of Bush River, in Hartford County, to Wash-

ington, D. C. |

. The Arundel consists typically of drab, more or less lignitic clays, with

masses of siderite. The nodules and geodes of siderite, when exposed to

the air, often change to brown hematite. The clays are usually free from

erit, but are occasionally sandy, and in places carry pyrite and gypsum.

Ligne beds also occur.

. The thickness of the formation is not great, the maximum being about

125 feet, and usually it is much less than that. It is thickest on the

western side or middle of the belt, and thins eastward as shown by borings.

The Arundel overlies the Patuxent disconformably, and appears to

occupy old drainage lines in the Patuxent. Cross-bedding is occasionally

found in the lower beds, but is not usually present. The formation is

overlain, with disconformity, by the Patapsco formation. The fauna will

be discussed in the section on the age of the Morrison formation.

SUMMARY OF STRATIGRAPHIC RELATIONS AND CHARACTERS os THE

‘Morrison FoRMATION

The stratigraphic relations and characters of the Morrison are sum-

marized in the following pages.

DISTRIBUTION

The Morrison formation has a wide distribution in Utah, New Mexico,

Colorado, Wyoming, Montana, South Dakota and perhaps Idaho and

Arizona. The number of square miles of Morrison outcrops is not very

great, but the area in which the Morrison is overlain by younger deposits

probably includes several hundred thousand square miles. The areas

from which the Morrison has been eroded probably includes many thou-

sand square miles more. .

The formation, after deposition and before burial or erosion, had an.

extremely wide distribution, which may have amounted to four or five

hundred thousand square miles.

RELATION TO UNDERLYING ROCKS

In various areas the Morrison rests on formations of different ages,

ranging from Archean to upper Jurassic. In the southwestern areas the

Morrison or McElmo rests on the La Plata sandstone of Jurassic age.

The contact with the La Plata is apparently conformable, but there is a

decided break beneath the La Plata. The latter lies on the Dolores beds

of Triassic age, in some localities; on the Cutler, Hermosa and Hlbert

MOOK, STUDY OF THE MORRISON FORMATION felt

formations, of Permian, ? Pennsylvanian and Devonian ? age respectively

(Cross and Larsen, 1914, 7) ; and in still other areas on -pre-Cambrian

erystallines. In northwestern Utah, near Vernal, the non-marine portion

of the Flaming Gorge formation, equivalent to the Morrison, rests on

marine beds of upper’ Jurassic age, containing Pseudomonotis curta,

etcetera. The contact is apparently conformable, no sudden change in

lithological characters being observable.

In the areas of Morrison outcrops in Montana, and in most of those

in Wyoming, the formation rests on the Sundance or corresponding beds.

‘These beds have been determined by Stanton (1909, 9) to belong to the

lower part of the upper Jurassic. In certain areas in Montana there is

evidence of a pre-Sundance erosion plane. ‘The contact between the

Morrison and Sundance formations is sharp in some places, while in

other places it is obscure.

Tn general it appears that there was a slight break between the Morri-

son and Sundance formations, but not one of any considerable extent.

In the Black Hills area the Morrison usually hes on the Sundance beds,

often with a sharp contact. In some localities, however, the Morrison is

separated from the Sundance by the Unkpapa sandstone, indicating an

interval between the retreat of the Sundance sea and the peginmme of

Morrison deposition.

In eastern Colorado the Morrison rests on Sundance beds near the

Wyoming boundary. Throughout most of the area in eastern Colorado

and New Mexico the Morrison rests on Red Beds of various ages. In

the northern half of Colorado, except at the extreme northern end, the

Morrison lies on the Chugwater Red Beds. At Morrison the formation

as separated from the Red Beds by a white sandstone of unknown age.

At Colorado City a bed of gypsum lies between the Morrison and the

Red Beds. Farther south in Colorado the Morrison rests on the Foun-

tain or Badito formations. South of Beulah, in southern Colorado, the

Morrison rests directly on the crystallines. . In northeastern New Mexico

the Morrison is underlain mostly by Red Beds, which have been warped

and eroded before the deposition of the Morrison. Near Exeter there is

a distinct sandstone formation between the Morrison and the Red Beds.

‘The uppermost members of the Red Bed series often consist of gypsum in

this area.

It is seen from the above description that there is a widespread erosion

plane beneath the Sundance formation in some areas, and there is evi-

dence of a slight break between the Morrison and Sundance formations.

Js the pre-Sundance erosion plane to be correlated with the pre-Morrison

plane, which is observable where the Sundance is absent, or is the pre-

142 ANNALS NEW YORK ACADEMY OF SCIENCES

Morrison plane to be correlated with the interval between the Morrison

and the Sundance? This question will be discussed in the section on the

interpretation of the Morrison formation.

RELATION TO OVERLYING BEDS

In western Colorado and eastern Utah the Morrison is overlain by the

Dakota sandstone. The contact is fairly sharp, but without definite

Vic. 78.—Sections of the Morrison formation showing decrease in thickness from

southwestern Colorado northward.

A. Telluride quadrangle, Colorado; maximum thickness 900 feet; B. Mack, Colorado,

thickness about 700 feet; C. Tensleep, Wyoming, thickness about 250 feet; D. Belt

Creek, Montana, thickness about 125 feet. Scale, 250 feet to 1 inch.

evidence of erosion of the Morrison prior to the deposition of the Dakota.

In Montana the Morrison is overlain by the Kootenie formation. ‘The

Kootenie is very similar to the Morrison and may belong to the same

deposition cycle. In various areas in central Wyoming, from the Mon-

tana south to the Colorado line, the Morrison is overlain by the Cloverly

formation, the lower part of which is probably equivalent to the Lakota.

In the Black Hills area the Morrison is overlain by the Lakota sandstone.

MOOK, STUDY OF THE MORRISON FORMATION 113

In eastern Colorado and New Mexico the Purgatoire formation overlies

the Morrison. In all three of these last-mentioned areas the contact be-

tween the Morrison and the overlying formation is sharp. Near Canon

City, Colorado, marine fossils of Washita age were found by Stanton in

beds immediately overlying the Morrison.

In general, the contact between the Morrison and overlying beds is

sharp, but there is no evidence of a break of any great extent between

rig. 79.—NSections of the Morrison formation showing decrease in thickness from

southwestern Colorado northeastward.

A. Telluride quadrangle, Colorado, maximum thickness 900 feet; B. Encampment Dis-

trict, Wyoming, thickness 400 feet; C. Como Bluff, Wyoming, thickness about 200 feet;

D. Devil’s Tower, Wyoming, thickness about 100 feet. Scale, 250 feet to 1 inch.

the two formations. As noted by Lee (1915, 2), the Morrison is much

more closely related to the overlying formations than to those under-

lying it.

THICKNESS

In a general way, it will be noticed, on studying the various sections

of the Morrison formation, that the thickness is much greater in the

114. ANNALS NEW YORK ACADEMY OF SCIENCES

western and especially the southwestern areas than in any of the other

districts in which the formation occurs. According to Lupton (1914, 3),

the McElmo is over 1,000 feet: thick near Green River, Utah; in the

Telluride quadrangle, according to Cross (1899, 3), it varies from 400

to 900 feet; in McElmo Canyon it is between 400 and 500 feet; in the

Grand River Valley, at various points between Grand Junction and the

Colorado-Utah line, it is about 700 feet thick; in the region south of the

Uinta Mountains the formation is about 650 feet thick; in the region of

Fic. 80.—Sections of the Morrison formation showing decrease in thickness from western

Colorado eastward.

A. Mack, Colorado, thickness about 700 feet; B. Canon City, Colorado, thickness about

325 feet; C. Red Rocks Canyon, Colorado, thickness about 140 feet. Scale, 250 feet to 1

inch.

the Owl Creek and Bighorn Mountains the formation is usually between

200 and 250 feet thick; in the Great Falls region of Montana, about 100

feet thick. It must be remembered in this connection that some of the

Kootenie of this area may be Morrison. In the Shoshone River region

the formation is 580 feet thick; in the Encampment district, in southern

Wyoming, the thickness is about 400 feet; at Como Bluff and in the

Freezeout Hills about 200 feet; and in the Black Hills usually less than

100 feet, in one locality disappearing completely. In central Colorado

the thickness is about 450 feet; near Cation City, between 350 and 400

MOOK, STUDY OF THE MORRISON FORMATION 115

feet; in east-central New Mexico the Morrison varies from 200 to 400

feet; and in the canyons of eastern Colorado the thickness is about 200

feet.

There is thus a thinning out towards the north, northeast and especially

towards the east.

LITHOLOGIC CHARACTERS

Coarse material occurs throughout the formation, but is much more

abundant and in much thicker beds in the western areas than in those

farther east. Fine material occurs throughout the formation and com-

prises the largest and most typical element in it, but is not usually

abundant near the base.

VARIABLE CHARACTER OF SECTIONS

Sections of the Morrison formation, taken in different areas, present

both similarities and differences. Most sections contain alternating series

of banded or variegated clays or grits and heavy sandstones, with occa-

sional thin limestone beds. No single stratum, however, continues for

long distances, so far as the conditions are known. A bed of sandstone

a certain number of feet from the base in one section may die out and

not be represented in another section, or may disappear and another sand-

stone take its place. Lee has used the term “uniformly variable” for the

Morrison beds, a term which fits Morrison conditions very well.

_ The significance of these features will be discussed in the section on

the interpretation of the formation.

STRUCTURE AND PETROGRAPHY

STRUCTURAL FEATURES OF THE MorRISON FORMATION

Several structural features are often met with in the Morrison, which

have considerable significance in regard to the question of the origin of

the formation. Among these are cross-bedding, of both stream and wind

types, lense-shaped cross-section of beds, and distinct channeling.

The stream type of, cross-bedding, or cross-bedding in one direction

with the inclined beds resting on flat surfaces, is seen throughout the

formation in many places. It occurs on a large scale and also on a small

scale. Usually the discordance of dips is not very great.

The wind type of cross-bedding, or cross-bedding at various angles and

directions, with the inclined beds resting on curved surfaces, is also seen.

‘It has been noticed near Cafion City in the vicinity of the Marsh-Hatcher

116 ANNALS NEW YORK ACADEMY OF SCIENCES

dinosaur quarry. It has been noted by Dr. H. E. Gregory” in the south-

western areas in beds 200 feet or more in thickness.

Channeling is an especially characteristic feature of the Morrison for-

mation. It is widespread and occurs on both large and small scales.

Thinning out of individual beds is common, when erosion channels may

not be visible to the eye.

Several of these features are well shown at the dinosaur quarry worked

by Professor O. C. Marsh’s collectors, and later by Mr. J. B. Hatcher for

the Carnegie Museum. The quarry is situated on the north bank of a

Fic. 81.—Type of cross-bedding usually known as the stream type.

small gulch which empties into Oil Creek, about eight miles north to

northeast of Cafion City, Colorado. The beds for a short distance above

and below the level of the quarry are well shown on both sides of the gulch.

The section of the Morrison in the vicinity of the quarry is as follows:

Feet

Variegated, Clays 05.0 $-A5 jacstieg oelonn the eile shee ar sata aide are a sue ee er oe

White ‘Samdstomeiie seiceescnieis eae, aene arches et & wiles lo eae ateve eles iereloneite octet eee 5 est.

Bone-bearing sandstone, coarse, calcareous, somewhat arkosic, with

EC UNS Ole WONCRIMIKG WHEREIN S 64 oca goon bacos noon noon Ob oUOon4 OD dOKsoSOS 3

Strongly cross-bedded sandstone at the floor of the quarry...... ne ocehate ee

Clay (absent at the quarry but present on the opposite side of the

FA) 1G 1) Men geen ar gPeee coe eae ER CER cool n.6 tan EEC 55 .0.5'5.0 0.0 0.0 1—

Sandstone, white, fairly coarse............--2- 0-502 ee teen eeee 2 to 15

Glay with nodule Jayers:c. oe. ¢ 2 fcc oe ceoeieie hela ei etete oes «iells 0) ole eee

5 Personal communication.

MOOK, STUDY OF THE MORRISON FORMATION 117

The base of the formation is not shown in this section,® but judging

from another outcrop in the bank of Oil Creek, a few hundred feet east

of the quarry, the base of the quarry-floor sandstone is about 80 feet above

the calcareous sandstone which is here considered as immediately under-

lying the Morrison.

The quarry-floor sandstone is cross-bedded; on the north side of the

gulch the cross-bedding is of the stream type, with the beds dipping

north; on the south side of the gulch the upper part of the quarry-floor

sandstone shows cross-bedding of the wind type.

The heavy sandstone member below the quarry-floor sandstone is sem1-

lense-shaped in cross-section and occupies a trough in the clays beneath.

The trough is a hundred feet or so in breadth and about 13 feet deep, the

sandstone which fills and covers it varying from 2 to 5 feet in thickness.

The contact between the clays and the sandstone in the trough is very

sharp. The only satisfactory explanation of this trough is that the clays

Fie. 82.—T ype of cross-bedding usually known as the eolian type.

were eroded and the sandstone deposited over them, by a stream of con-

siderable size. ‘This means a stratigraphic break. While the channel in

the clays was being eroded and before the deposition of the sands filling

it, continuous deposition must have been going on in some other areas.

This break need not have been long, in fact was probably short, as the

same stream which eroded the channel probably deposited the sands on

suffering an increase of load or a decrease of volume or gradient.

The gulch cuts directly across the old channel at this locality, and

therefore exposes its characteristics completely. Stream banks cut paral-

lel to old channels would not show their trough character at all, and banks

exposed obliquely to old channels in position would exhibit a long gradual

thinning out of the beds, without any pronounced lense-shaped cross-

section. Thinning out of this character is common throughout the entire

area of Morrison outcrops, and distinct lense-shaped sections, which are

only exposed under very favorable circumstances, are not rare. Stream

channeling and deposition are consequently especially characteristic fea-

tures of the Morrison formation.

° See also figs. 8 and 9, p. 50.

118 ANNALS NEW YORK ACADEMY OF SCIENCES

The presence of small stratigraphic breaks at many localities and levels

in the Morrison formation emphasizes the force of the statements of

Hatcher, that in the production of a continental formation of the char-

acter of the Morrison, the main process of deposition is not continuous

for any given area. he process is rather one of alternating deposition

and erosion, deposition being the dominant factor. The situation is

analogous with the conditions at the front of a glacier, where the ice

front may stand still, while the actual ice advances, through melting at

the front. If melting goes on faster than ice advance, the front retreats ;

lie. 83.—Diagrammatic section of the exposure of the Morrison formation at the Marsh-

Hatcher dinosaur quarry, near Canon City, Colorado.

if melting goes on slower than ice advance, the front advances. In the

case of a continental formation ultimate deposition of a considerable

thickness would be brought about by excess of deposition over erosion.

If erosion predominated over deposition, there would be no formation

produced, but a great stratigraphic break.

In considering the age of such a formation as the one under considera-

tion, it must be remembered that deposition under the conditions indi-

cated above will be much slower in producing a great thickness of beds

than under conditions of continuous deposition. A total thickness of

MOOK, STUDY OF THE MORRISON FORMATION 119

200-400 feet produced by deposition predominating over erosion, means

a much greater time interval than the same thickness deposited under

conditions of continuous deposition.

Sudden lithotogic changes from one bed to another are very common

in the Morrison. Fine clay-shales will be overlain by coarse cross-bedded

sandstones and the reverse. These abrupt successions do not necessarily

mean breaks or lost time intervals, but rather sudden changes of condi-

tions in definite areas.

Fie. 84.— Red hematitic grit, from the top of the Morrison formation at Garden Park,

near Canon City, Colorado.

The light grains are quartz; the light patches are holes in the slide; the dark areas are

clay stained with hematite. About 28 x.

PETROGRAPHIC CHARACTERS OF THE Morrison FoRMATION

A number of distinct types of sediments occur in the Morrison forma-

tion. Broadly speaking, these are: (1) fine red or brown sandstones ;

(2) clays; (3) calcareous sandstones; (4) limestones; (5) coarse white

sandstones. ‘These grade into each other in a rather complex manner,

120 ANNALS NEW YORK ACADEMY OF SCIENCES

forming many intermediate varieties. Other types are also present, but

in minor amounts.

The most characteristic beds in the Morrison are the so-called “joint-

clays.” These are fine sediments which have the appearance of clay, and

which weather into clays. They are variegated in color, and have been

the cause of the name “variegated beds” formerly apphed to the forma-

tion. These “joint-clays” are composed of a variety of sedimentary types,

Fig. 85.

Fine grit, from near the top of the Morrison formation at Garden Park,

Colorado.

The light grains are quartz; the light patches are holes in the slide; the dark patches

are limonite. About 28 x.

more or less distinct from each other in character, though there are often

gradational varieties. This variety of elements is responsible for the

variegated color. The sediments which make up the “joint-clays” are:

fine-grained hematitic sandstones or grits; true kaolinic clays; fine cal-

careous sandstones; siliceous limestones; and argillaceous limestones.

Intermediate or compound types are also abundant.

MOOK, STUDY OF THE MORRISON FORMATION 121

The first variety of sediment to be considered is the fine hematitic

sandstone. As this is composed largely of fine angular quartz grains, it

will be spoken of as a grit. This grit is usually more prominent in the

upper members of the formation in any given locality, but also occurs in

smaller amount near the base. In the field it is reddish to chocolate

brown in color. In thin section, seen with reflected light, it is red. he

principal mineral constituent is quartz, m small grains. The interstitial

Fic. 86.—Argillaceous limestone or calcareous clay, from the lower part of the Morrison

formation near Mack, Colorado.

About 28 x.

material is clayey matter stained to a bright red by hematite. The origin

of this hematite will be discussed below. he relative proportions of

quartz and hematitic matrix vary greatly.

This red quartz grit grades into fine calcareous sandstone through fine

sands with the interstitial matter partly stained by hematite and partly

made up of fine-grained carbonates. It also grades into the true clays

through members with a similar amount of quartz and a considerable

amount of kaolin. Such a type occurs near the top of the Garden Park

122 ANNALS NEW YORK ACADEMY OF SCIENCES

section (Fig. 85). The iron in this case is sometimes, at least, in the

form of limonite, rather than hematite. Magnetite is present in small

amounts, and dense patches of limonite represent oxidized pyrite. The

kaolin is more or less abundant and is mixed with fine-grained carbonitic

material. Hematite is also present in small amount.

The hematite in the red or brown grits has probably originated through

oxidization of the siderite present in the light colored calcareous sand-

Fic. 87.—Calcareous sandstone, from the lower beds of the Morrison formation at

Garden Park, Colorado.

The clear grains are quartz, and the mottled grains are calcite. About 28 X.

stones. The iron carbonate was probably present in the original deposits.

The a‘teration may have taken place to some extent before burial, but it

is more likely that it is the result of a long-continued process in the

buried rock."

The clays are nearly always impure. They usually contain, along

with the kaolin, a considerable amount of fine angular quartz and very

7 See the discussion of the origin of the formation, p. 168.

MOOK, STUDY OF THE MORRISON FORMATION 123

fine granular calcite and other carbonates. Mixtures of this kind com-

prise a large proportion of the formation.

Fine calcareous sandstones are very common and occur in thick beds.

They consist typically of fine angular quartz with a matrix of fine

granular calcite and probably dolomite and siderite. They grade into the

elays through varieties with more kaolinic matter, and into the limestones

through members with less quartz. 'They also grade into arkoses through

* Fie. 88.—Calcareous arkosic sandstone, from the lower beds of the Morrison formation

at Garden Park, Colorado.

The clear light and dark grains are quartz; the interstitial material is calcite; and the

banded grains are plagioclase feldspar. About 28 <x. ‘(Crossed nicols.)

fine sandstones in which feldspars occur. The latter are especially

abundant in the lower beds of the formation. The calcareous sandstones

also grade into quartz sandstones through varieties with less calcite and

more quartz.

The limestones are usually only a foot or two in thickness. They vary

from practically pure carbonates to siliceous and argillaceous varieties.

Small molluscan fossils are sometimes present.

124 ANNALS NEW YORK ACADEMY OF SCIENCES

Calcareous nodules and concretions often form beds amidst less cal-

careous sandstones or clays.

The coarser sandstones vary from nearly pure quartz sands to highly

calcareous and arkosic members. One of the typical coarser sandstones

is that in which the dinosaur bones occur in the Marsh-Hatcher quarry

near Canon City, Colorado. This sandstone consists largely of medium-

sized to large quartz grains, often well rounded, with finer angular quartz

Fic. 89.—Calcareous argillaceous sandstone, from the Morrison formation near Canon

City, Colorado.

The light grains are quartz; and the dark interstitial material is mixed carbonates and

clay. About 28 x.

grains scattered among them. Feldspars are fairly abundant and often

of large size. Volcanic ash grains occur, some of which are perfectly

fresh, others being altered to masses of granular quartz. Calcite, and

probably some dolomite, occurs in the interstitial spaces. Some of this is

granular and some of it is coarsely crystalline.

Coarse, round-grained sandstones of this type often show xolian cross-

bedding.

MOOK, STUDY OF THE MORRISON FORMATION 125

Hard, quartzitic sandstones, with clay pebbles, often occur.

Conglomerates occur occasionally, but are not especially abundant and

are never very coarse.

Gypsum is fairly abundant in the formation, but not in the form of

distinct beds.

Fie. 90.—Fossiliferous limestone, from the Morrison formation near Canon City,

Colorado.

About 28 x.

The coarse sandstones are often resistant and stand out in cliffs (Fig.

32). In some cases where they are very calcareous, the coarser beds are

friable and crumble easily. The finer materials are usually easily eroded,

but are sometimes resistant to the hammer.

126 ANNALS NEW YORK ACADEMY OF SCIENCES

PALEONTOLOGY

FLora OF THE Morrison FoRMATION

The following species of cycads from the Morrison formation have been

described by Ward:

Cycadella reedii Cycadella ferruginea

Cycadella beecheriana Cycadella contracta

Cycadella wyomingensis Cycadella gravis

Cycadella knowltoniana Cycadella verrucosa

Cycadella compressa Cycadella jejuna

Cycadella jurassica Cycadella concinna

Cycadella nodosa Cycadella crepidaria

Cycadella cirrata Cycadella gelida

Cycadella exogena Cycadella carbonensis

Cycadella ramentosa Cycadella knighti

There is also Cycadella utoprensis (Ward) Wieland, Araucarioxylon ?

obscurum Knowlton, and possibly Pinoxylon dacotense Knowlton.*,

This flora is of no great value in indicating the age of the formation,

but it does signify that the climate in which it lived was warm and prob-

ably moist in places at least.

INVERTEBRATE FAUNA OF THE MorRISON FORMATION

The invertebrate fauna of the Morrison consists of fresh-water pelecy-

pods and gastropods, with a few crustaceans. A number of species have

been described and considerable material collected. ‘There is nothing

in the fauna of any value in determining the age of the formation. The

following species have been described:

PELECYPODA

Umo felchit White, On the Fresh-Water Invertebrates of the North

American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 16, pl. 1, figs.

1-5, 1886.

8 The flora is described and discussed in the following works :

Ward, L. F. Description of a New Genus and Twerty New Species of Fossil Cyca-

dean Trunks from the Jurassic of Wyoming. Wash. Acad. Sci., Proc., vol. i, pp. 253-

300, pls. xiv-xxi, 1900.

Ward, L. F. Status of the Mesozoic Floras of the United States. U.S. Geol. Surv.,

20th Ann. Rep., pt. 2, pp. 211-747, pls. xxi-clxxix, 1900.

Ward, L. F. Status of the Mesozoic Floras of the United States. U.S. Geol. Surv.,

Monograph No. 48, pt. 1, text, 616 pp., pt. 2, plates, 119 pls., 1905.

Wieland, G. R. American Fossil Cycads. Carnegie Inst. Wash., Pub. 34, 286 pp.,

50 pls., 137 figs., 1906.

Berry, E. W. Lower Cretaceous Floras of the World. Md.,Geol. Surv., vol. Low.

Cret., pp. 99-151, 1 fig., 1911.

MOOK, STUDY OF THE MORRISON FORMATION 127

Unio toxonotus White, On the Fresh-Water Invertebrates of the North

American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 1%, pl. 2, figs.

1, 2, 1886.

Unio macropisthus White, On the Fresh-Water Invertebrates of the

North American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 17, pl. 2,

fig. 7, 1886.

Unio iridoides White, On the Fresh-Water Invertebrates of the North

Fic. 91.—Calcareous arkosic sandstone, from the Morrison formation near Canon City.

The clear round grains are quartz and feldspar; the interstitial banded grains are

calcite ; and the large grain at the left, with the dark grain above it, is replaced volcanic

ash. About 28 x. . ;

American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 17, "pl. 2, figs.

3, 4, 1886. :

Umio lapillowdes White, On the Fresh-Water Invertebrates of the North

American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 18, pl. 2, figs.

5, 6, 1886. |

Unio steward: White, Report on the Geology of the Kastern Portion of

the Uinta Mountains and a Region of Country Adjacent Thereto, by J. W.

128 ANNALS NEW YORK ACADEMY OF SCIENCES

Powell, p. 110. U.S. Geological and Geographical Survey of the Terri-

tories, 1876.

Unio nucalis Meek and Hayden, Phila. Acad. Nat. Sci., Proc. 1858, °

“p. 52.

Unio willistoni Logan, The Stratigraphy and Invertebrate Faunas of

the Jurassic Formation in the Freezeout Hills of Wyoming. Kans. ‘

Univ. Quart., vol. ix, p. 133, pl. 31, fig. 10, 1900.

Wig. 92.—The same slide and field as fig. 91, with crossed nicols.

This shows the banded feldspars and the granular quartz which has replaced the volcanic

ash.

Umno knights Logan, The Stratigraphy and Invertebrate Faunas of the

Jurassic Formation in the Freezeout Hills of Wyoming. Ians. Univ.

Quart., vol. ix, p. 134, pl. 31, figs. 7, 9, 1900.

Umo baileyr Logan, The Stratigraphy and Invertebrate Faunas of the

Jurassic Formation in the Freezeout Hills of Wyoming. Kans. Univ.

Quart., vol. ix, p. 134, pl. 31, figs. 4, 6, 8, 11, 1900.

MOOK, STUDY OF THE MORRISON FORMATION 129

GASTROPODA

. Limnea ativuncula White, On the Fresh-Water Invertebrates of the

: North American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 20, pl. 4,

figs. 10, 11, 1886.

Limnea consortis White, On the Fresh-Water Invertebrates of the

North American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 20, pl. 4,

figs. 8, 9, 1886.

Fig. 93.—Calcareous arkosic sandstone; the same rock as figs. 91 and 92.

The large dark grains are partly replaced voleanic ash, and the large grain with

inclusions in the center of the field-is unaltered volcanic ash. About 28 X.

Limnea ? accelerata White, On the Fresh-Water Invertebrates of the

: North American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 20, pl. 4,

figs. 12-15, 1886.

Planorbis veternus Meek and Hayden, Phila. Acad. Nat. Sci., Proc. for

1860, p. 418, 1861.

Vorticifex stearnsii White, On the Fresh-Water Invertebrates of the

130 ANNALS NEW YORK ACADEMY OF SCIENCES

North American Jurassic. U.S. Geol. Surv., Bull. No. 29, p. 21, pl. 4,

figs. 4-6, 7, 1886.

Valvata scabrida Meek and Hayden, Phila. Acad. Nat. Sci., Proc. for

Oct. 1860, p. 418, 1861.

Viviparus gilli Meek and Hayden, Paleontology of the Upper Missouri.

Smiths. Contr. Knowledge, vol. xiv, no. 4, p. 115, pl. 5, figs. 3a, 3b, 1865.

Lioplacodes veternus Meek and Hayden, Phila. Acad. Nat. Sci., Proce.

for Dec. 1861, p. 444 [1862 ?].

Neritina nebrascensis Meek and Hayden, Phila. Acad. Nat. Sci., Proc.

for Dec. 1861, p. 444 [1862 ?].

Valvata leci Logan, The Stratigraphy and Invertebrate Faunas of the

Jurassic Formation in the Freezeout Hills of Wyoming. Kans. Univ.

Quart., vol. ix, p. 133, pl. 31, figs. 1-3, 1900.

OSTRACODA

The following ostracods are reported by White, identified by T. Rupert

Jones:

Metacypris forbesu Jones. |

Metacypris 2? Bears a distant resemblance to “Cypris ? conculcata”

Jones.

Darwinula leguminella Hi. Forbes.

Cypris purbeckensis ? Forbes sp.

Two undetermined species of Cypris.

ARUNDEL FORMS

The following species are reported by W. B. Clark from the Arundel

formation of Maryland:

Bythinia arundelensis Clark, [Systematic Paleontology], “Mollusca.”

Md. Geol. Surv., vol. Low. Cret., p. 211, pl. 21, fig. 6, 1911. .

Viviparus marylandicus Clark, [Systematic Paleontology |, “Mollusca.”

Md. Geol. Surv., vol. Low. Cret., p. 212, pl. 21, figs. 1-3, 1911.

Vwiparus arlingtonensis Clark, [Systematic Paleontology ], “Mollusca.”

Md. Geol. Surv., vol. Low. Cret., p. 212, pl. 21, figs. 4, 5, 1911.

‘Cyrena marylandica Clark, [Systematic Paleontology], “Mollusca.”

Md. Geol. Surv., vol. Low. Cret., p. 213, pl. 21, figs. 8, 9, 1911.

The only reference of importance in connection with the invertebrate

fauna of the Morrison formation not included in the above list is: White,

C. A. Review of the Non-Marine Fossil Mollusca of North America.

U.S. Geol. Surv., 5rd Ann. Rep., pp. 405-550, 32 pls., 1883.

The invertebrate fauna is exclusively fresh-water in character.

MOOK, STUDY OF THE MORRISON FORMATION 131

VERTEBRATE FAUNA OF THE Morrison FORMATION

The vertebrate fauna of the Morrison formation is a remarkable one.

It consists of a number of primitive mammals, a variety of reptiles, and

a few fish. The most conspicuous element in the fauna is the dinosaurs.

Representatives of the three principal groups of dinosaurs are present,

each with a number of forms. The Sauropoda are especially abundant,

being represented by many genera and species. In fact, all the American

Sauropoda occur in beds of Morrison age, or very close to it. It is be-

yond the province of the present paper to enter into an extensive dis-

cussion of the various vertebrate remains in detail. ‘The more important

forms are discussed briefly. References are given to the original litera-

ture on the various forms.

MAMMALIA

Allodon laticeps Marsh

Allodon laticeps Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xxi, p. 511, 1881.

Allodon fortis Marsh

Allodon fortis Marsh, American Jurassic Mammals. Amer. Journ.

Sci., 3rd ser., vol. xxxiii, p. 327 (331), 1887.

Asthenodon segnis Marsh

Asthenodon segnis Marsh, American Jurassic Mammals. Amer. Journ.

Sei., 3rd ser., vol. xxxi, p. 327 (336), 1887.

Dryolestes priscus Marsh

Dryolestes priscus Marsh, Fossil Mammals from the Jurassic of the

Rocky Mountains. Amer. Journ. Sci., 3rd ser., vol. xv, p. 459, 1878.

Dryolestes arcuatus

Dryolestes arcuatus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xviii, p. 396 (397), 1879.

Dryolestes gracilis Marsh

Dryolestes gracilis Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xxi, p. 511 (513), 1881.

132 ANNALS NEW YORK ACADEMY OF SCIENCES

Dryolestes obtusus Marsh

Dryolestes obtusus Marsh, Notice of Jurassic Mammals representing

two New Orders. Amer. Journ. Sci., 3rd ser., vol. xx, p. 235 (237),

1880.

Dryolestes vorax Marsh

Dryolestes vorax Marsh, Additional Remains of Jurassic Mammals.

Amer. Journ. Sci., 3rd ser., vol. xvii, p. 215, 1879.

Ctenacodon serratus Marsh

Ctenacodon serratus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xvii, p..396, 1879.

Ctenacodon nanus Marsh

Ctenacodon nanus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xx, p. 511 (512), 1880.

Ctenacodon potens Marsh

Ctenacodon potens Marsh, American Jurassic Mammals. Amer. Journ.

Sel., 3rd ser., vol. xxx, p. 327 (3833), 1887.

Dicrocynodon victor Marsh

Diplocynodon victor Marsh, Notice of Jurassic Mammals representing

two New Orders. Amer. Journ. Sci., 3rd ser., vol. xx, p. 235, 1880.

Dicrocynodon victor Marsh. (In Osborn, H. F. On the Structure

and Classification of the Mesozoic Mammalia. Phila. Acad. Nat. Sei.,

Journ. (2), ixjp. 186 (263), 1888.)

Docodon striatus Marsh

Docodon striatus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xxi, p. 511 (512), 1881.

Ennacodon crassus Marsh

Enneodon crassus Marsh, American Jurassic Mammals. Amer. Journ.

NGls ord Ser. vOl, Mol pa oe 1 a(aoo)emleome

Ennacodon crassus Marsh, Additional Genera established by Prof. O. C.

Marsh, 1880-1889. Printed privately, probably in 1889.

Ennacodon affinis Marsh

Hnneodon affinis Marsh, American Jurassic Mammals. Amer. Journ.

Sci., 3rd ser., vol. xxxili, p. 327 (339), 1887.

MOOK, STUDY OF THE MORRISON FORMATION 133

Ennacodon affinis Marsh, Additional Genera Established by Prof. O. C.

Marsh, 1880-1889. Printed privately, probably in 1889.

Paurodon valens Marsh

Paurodon valens Marsh, American Jurassic Mammals. Amer. Journ.

Sel, 3rd ser., vol. xxxill, p. 327 (342), 1887.

Stylacodon gracilis Marsh

Stylacodon gracilis Marsh, Notice of a New Jurassic Mammal. Amer.

Journ. Sci., 3rd ser., vol. xviii, p. 60, 1879.

-Stylacodon validus Marsh

Stylacodon validus Marsh, Notice of Jurassic Mammals representing

two New Orders. Amer. Journ. Sci., 3rd ser., vol. xx, p. 235 (236),

1880.

Laodon venustus Marsh

Laodon venustus Marsh, American Jurassic Mammals. Amer. Journ.

Sei., 3rd ser., vol. xxxiii, p. 327 (337), 1887.

Priacodon ferox Marsh

Tinodon ferox Marsh, Notice of Jurassic Mammals representing two

New Orders. Amer. Journ. Sci., 3rd ser., vol. xx, p. 235 (236), 1880.

Tricondon ferox Cope, The Mechanical Causes of the Development of

the Hard Parts of the Mammalia. Journ. Morph., vol. iii, p. 137 (227),

1889. °

Priacodon ferox Roger, Verzeichniss der bisher bekannten fossilen

Saugethiere. Neu zusammengestellt von Dr. Otto Roger, kel. Regier-

ungs-und-Kreis-Medizinrath in Augsburg. Bericht. naturwiss. Vereins f.

Schwaben und Neuberg (a. V.), xxx, p. 1, 1896.

Menacodon rarus Marsh

Menacodon rarus Marsh, American Jurassic Mammals. Amer. Journ.

Sci., 3rd ser., vol. xxxiii, p. 327 (340), 1887.

| Tinodon bellus Marsh

Tinodon bellus Marsh, Additional Remains of Jurassic Mammals.

Amer. Journ. Sci., 3rd ser., vol. xviii, p. 215 (216), 1887.

Tinodon lepidus Marsh

Tinodon lepidus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xvili, p. 396 (398), 1879.

134 ANNALS NEW YORK ACADEMY OF SCIENCES

Tinodon robustus Marsh

Tinodon robustus Marsh, Notice of New Jurassic Mammals. Amer.

Journ. Sci., 3rd ser., vol. xviii, p. 396 (3897), 1879.

Triconodon bisulcus Marsh

Triconodon bisulcus Marsh, Notice of Jurassic Mammals representing

two New Orders. Amer. Journ. Sci., 3rd ser., vol. xx, p. 235 (237),

1880.

The mammals are all archaic in character and belong to primitive

forms of marsupials and monotremes. They are known only from jaws

and teeth.

Valuable information concerning the Morrison mammals is contained

in “American Jurassic Mammals,” by O. C. Marsh; “On the Structure

and Classification of the Mesozoic Mammalia,” by H. F. Osborn; and

“Evolution of the Mammalian Molar Teeth,” by H. F. Osborn. For

further references the reader is referred to O. P. Hay’s “Bibliography

and Catalogue of the Fossil Vertebrata of North America.”

AVES

Laopteryx priscus Marsh

Laopteryx priscus Marsh, Discovery of a Fossil Bird in the Jurassic of

Wyoming. Amer. Journ. Sci., 3rd ser., vol. xxi, p. 341, 1881.

From the Morrison formation of Wyoming, probably from Como Bluff.

Known from part of a skull.

REPTILIA

DINOSAURIA

SAUROPODA ®

Astrodon johnstoni Leidy

Astrodon Johnston, Amer. Journ. Dental Sci., 1859.

Astrodon johnstoni Leidy, Memoir on the Extinct Reptiles of the

Cretaceous Formations of the United States. Smiths. Contr. Knowledge,

xiv, pp. 102, 119, 1865.

This form is known from teeth only. It was discovered in the Arundel

beds of Maryland.

®This group will be treated thoroughly in the forthcoming monograph by Professor

H. F. Osborn.

MOOK, STUDY OF THE MORRISON FORMATION 135

Dystropheus viemale Cope

Dystropheus viemale Cope, On a Dinosaurian from the Trias of Utah.

Amer. Philos. Soc., Proc., vol. xvi, p. 579, 1877.

The type locality of this species is Painted Canyon, in southeastern

Utah. The beds were considered by Cope to be Triassic, but have since

been found to be the McElmo formation. Only a small part of the

skeleton is known.

Atlantosaurus montanus Marsh

Titanosaurus montanus Marsh, Notice of a new and Gigantic Dinosaur.

Amer. Journ. Sci., 3rd ser., vol. xiv, p. 87, 1877.

Atlantosaurus montanus Marsh, Notice of New Dinosaurian Reptiles

from the Jurassic formation. Amer. Journ. Sci., 3rd ser., vol. xiv, p. 514,

SIZ

This form was discovered at Morrison, Colorado. It was the first form

of the Sauropoda found in the eastern Rocky Mountain area of the Morri-

son formation and the one which gave its name to the formation as

“Atlantosaurus beds.”

Camarasaurus supremus Cope

Camarasaurus supremus Cope, On a Gigantic Saurian from the Dakota

HKpoch of Colorado. Paleontological Bulletin No. 25, 1877.

From the uppermost beds of the Morrison formation near Cafion City,

Colorado. A well known and characteristic Morrison form.

Caulodon diversidens Cope

Caulodon diversidens Cope, On Reptilian Remains from the Dakota

Beds of Colorado. Amer. Philos. Soc., Proc., vol. xvii, p. 193, 1877.

Probably from the uppermost beds of the Morrison formation near

Canon City, Colorado. Known only from teeth.

Apatosaurus ajax Marsh

Apatosaurus ajax Marsh, Notice of New Dinosaurian Reptiles from the

Jurassic formation. Amer. Journ. Sci., 3rd ser., vol. xiv, p. 514, 1877.

Type locality, Morrison, Colorado. Characteristic portions of the skel-

eton known.

Morosaurus grandis Marsh

Apatosaurus grandis Marsh, Notice of New Dinosaurian Reptiles from

the Jurassic formation. Amer. Journ. Sci., 3rd ser., vol. xiv, p. 514,

See

136 ANNALS NEW YORK ACADEMY OF SCIENCES

Morosaurus grandis Marsh, Principal Characters of American Jurassi¢

Dinosaurs. Pt. I. Amer. Journ. Sci., 3rd ser., vol. xvi, p. 414, 1878.

. This form is widespread in the Morrison formation. The type locality

and level is the Morrison formation at Como Bluff, Wyoming. Almost

the entire skeleton is known.

Amphiccelias altus Cope

Amphicelias altus Cope, On Amphiccelias, a genus of Saurians from

the Dakota epoch of Colorado. Paleontological Bulletin No. 27 (Amer.

Philos. Soc., Proc., vol. xvii, p. 243), 1877.

Probably from the uppermost beds of the Morrison formation near

Cafion City, Colorado. Known from a small part of the skeleton.

Amphiceelias latus Cope

Amphicelias latus Cope, On Amphiccelias, a genus of Saurians from

the Dakota epoch of Colorado. Paleontological Bulletin No. 27 (Amer.

Philos. Soc., Proc., vol. xvii, p. 248), 1877.

Probably from the uppermost beds of the Morrison formation near

Canon City, Colorado. Only a small part of skeleton known.

Symphyrophus musculosus Cope

Symphyrophus musculosus Cope, On the Vertebrata of the Dakota

Epoch of Colorado. Paleontological Bulletin No. 28 (Amer. Philos.

Soc., Proc., vol. xvii, p. 246), 1878.

font near Canon City, Colorado, probably from ie uppermost beds

of the Morrison formation. Not very well known.

Caulodon leptoganus Cope

Caulodon leptoganus Cope, On the Vertebrata of the Dakota Epoch of

Colorado. Paleontological Bulletin No. 28 (Amer. Philos. Soe., Proe.,

vol. xvii, p. 247), 1878.

Same locality and horizon as above. Known only from teeth.

Atlantosaurus immanis Marsh

Atlantosaurus immanis Marsh, Notice of New Dinosaurian Reptiles.

Amer. Journ. Sci., 3rd ser., vol. xv, p. 241, 1878.

From the middle Morrison beds near Morrison, Colorado. Compara-

tively small part of skeleton known.

MOOK, STUDY OF THE MORRISON FORMATION 137

Morosaurus impar Marsh

Morosaurus tmpar Marsh, Notice of New Dinosaurian Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xv, p. 242, 1878.

Type locality and level, Morrison formation at Como Bluff, Wyoming.

Known from very imperfect material only.

Epanterias amplexus Cope

Epanterias amplexus Cope, A New Opisthoccelous Dinosaur. Amer.

Nat., vol. x11, p. 406, 1878.

Probably from the uppermost Morrison beds near Canon City, Colorado.

Known from very imperfect remains.

Amphiceelias fragillimus Cope

Amphicelias fragillimus Cope, A New Species of Amphiccelias. Amer.

Nat., vol. xii, p. 563, 1878.

From the uppermost beds of the Morrison formation near Canon City,

Colorado. Not well known.

Morosaurus robustus Marsh

Morosaurus robustus Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. I. Amer. Journ. Sci., 3rd ser., vol. xvi, p. 414, 1878.

Type locality and level probably the Morrison formation at Como Bluff,

Wyoming. Parts of skull and skeleton known.

Diplodocus longus Marsh

Diplodocus longus Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. I. Amer. Journ. Sci., 3rd ser., vol. xvi, p. 414, 1878.

From the middle beds of the Morrison formation near Canon City,

Colorado. Several more or less complete skeletons of this form are

known.

Apatosaurus laticollis Marsh

Apatosaurus laticollis Marsh, Principal Characters of American Juras-

sic Dinosaurs. Pt. IJ. Amer. Journ. Sci., 3rd ser., vol. xvii, p. 88,

‘Ls

Only a small portion of the skeleton is preserved.

Camarasaurus leptodirus Cope

Camarasaurus leptodirus Cope, New Jurassic Dinosauria. Amer. Nat.,

vol. xiii, p. 402, 1879.

138 ANNALS NEW YORK ACADEMY OF SCIENCES

From the upper beds of the Morrison formation near Canon City, Colo-

rado. Only a few vertebrae are known.

Brontosaurus excelsus Marsh

Brontosaurus excelsus Marsh, Notice of New Jurassic Reptiles. Amer,

Journ. Sci., 3rd ser., vol. xviii, p. 503, 1879.

This form is perhaps the best known of the Sauropoda. The type

specimen was found in the Morrison beds at Como Bluff, near Medicine

Bow, Wyoming. Other material of the species has been found in the

Morrison beds at various localities. Nearly the complete skeleton is

known. |

Brontosaurus amplus Marsh

Brontosaurus amplus Marsh, Principal Characters of American Juras-

sic Dinosaurs. Pt. V. Amer. Journ. Sci., 3rd ser., vol. xxi, p. 421, 1881.

Morrison formation at Como Bluff. Part of skeleton known.

Diplodocus lacustris Marsh

Diplodocus lacustris Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. VII. Diplodocide, a New Family of the Be

Amer. Journ. Sci., 3rd ser., vol. xxvii, p. 166, 1884.

Morrison Poemation near Morrison, Giclosaden Known from frag-

mentary material only.

Pleurocelus nanus Marsh

Pleurocelus nanus Marsh, Notice of a New Genus of Sauropoda. and

other new Dinosaurs from the Potomac Formation. Amer. Journ. Sci,

3rd ser., vol. xxxv, p. 90, 1888.

From the Arundel beds in Maryland, probably near Muirkirk. Char-

acteristic parts of the skeleton are known.

Pleuroceelus altus Marsh

Pleurocelus altus Marsh, Notice of a New Genus of Sauropoda and

other new Dinosaurs from the Potomac Formation. Amer. Journ. Sci.,

3rd ser., vol. xxxv, p. 92, 1888.

hors the Arundel formation near Muirkirk, Maryland. Part of hind

limb only is known.

Morosaurus lentus Marsh

Morosaurus lentus Marsh, Notice of New American Dinosauria. Amer.

Journ. Sei., 3rd ser., vol. xxxvu, p. 333, 1889.

MOOK, STUDY OF THE MORRISON FORMATION 139:

Morrison beds of Wyoming, probably from Como Bluff. The type

specimen consists of a nearly complete skeleton of an immature individual.

Morosaurus agilis Marsh

Morosaurus agilis Marsh, Notice of New American Dinosauria. Amer.

Journ. Sci., 3rd ser., vol. xxxvui, p. 334, 1889.

From the middle beds of the Morrison formation near Canon City,

Colorado. The skull and a few other parts of the skeleton are known.

Barosaurus lentus Marsh

Barosaurus lentus Marsh, Description of New Dinosaurian Reptiles.

Amer. Journ. Sci., 3rd ser., vol. xxxix, p. 85, 1890.

From the Morrison formation near Piedmont, South Dakota. A com-

paratively small part of the skeleton is known.

Pleurocelus montanus Marsh

Pleurocelus montanus Marsh, The Dinosaurs of North America. U.S.

Geol. Surv., 16th Ann. Rep., Pt. 2, p. 184, 1896.

Type locality and horizon unknown. Very little of skeleton is known.

Barosaurus affinis Marsh

Barosaurus affims Marsh, Footprints of Jurassic Dinosaurs. Amer.

Journ. Sci., 4th ser., vol. vii, p. 228, 1899.

From the Morrison formation near Piedmont, South Dakota. Very

little of the skeleton is known.

Diplodocus carnegii Hatcher

Diplodocus carnegu Hatcher, Diplodocus Marsh, its Osteology, Tax-

onomy, and Probable Habits, with a Restoration of the Skeleton. Carn.

Mus. Mem., vol. i, p. 1, 1901.

From the Morrison beds near Sheep Creek, Wyoming. Most of the

skeleton is well known. Restorations of this form have been installed in

many of the large museums of the world; consequently this is one of the

best known of the Sauropoda.

Elosaurus parvus Peterson and Gilmore

EHlosaurus parvus Peterson and Gilmore, Hlosaurus parvus; a new

Genus and Species of the Sauropoda. Carn. Mus. Ann., vol. i, p. 490,

1902. saane ti

140 ANNALS NEW YORK ACADEMY OF SCIENCES

From the Morrison formation near Sheep Creek, Wyoming. Char-

acteristic parts of the skeleton of a young individual are known.

Haplocanthosaurus priscus Hatcher

Haplocanthus priscus Hatcher, A New Sauropod Dinosaur from the

Jurassic of Colorado. Biol. Soc. Wash., Proc., vol. xvi, p. 1, 1903.

Haplocanthosaurus priscus Hatcher, A New Name for the Dinosaur

Haplocanthus. Biol. Soc. Wash., Proc., vol. xvi, p. 100, 1903.

From the middle beds of the Morrison formation near Canon City,

Colorado. A considerable part of the skeleton is known. The form is

the most primitive of the American Sauropoda (along with H. utter-

backt).

Brachiosaurus altithorax Riges

Brachwosaurus altithoraz Riggs, Brachiosaurus altithorax, the Vargest

Known Dinosaur. Amer. Journ. Sci., 4th ser., vol. xv, p. 299, 1903.

From the McElmo beds in the Grand River Valley, near Fruita, Colo-

rado. This is a remarkable form in which the humerus is longer than

the femur. It is represented by several species in German Hast Africa.

The present species is known from characteristic parts of the skeleton.

Haplocanthosaurus utterbacki Hatcher

Haplocanthosaurus utterbackt Hatcher, Osteology of Haplocantho-

saurus, with Description of a New Species, and Remarks on the Probable

Habits of the Sauropoda and the Age and Origin of the Atlantosaurus

beds. Carn. Mus. Mem., vol. 11, p. 27, 1903.

From the middle beds of the Morrison formation near Caiion City,

Colorado. It is larger than H. priscus, and is known from characteristic

parts of the skeleton.

Apatosaurus louise Holland

Apatosaurus louse Holland, A New Species of Apatosaurus. Carn.

Mus. Ann., vol. x, p. 143, 1915.

A large and well characterized form from the Morrison formation near

Jensen, Utah.

THEROPODA

Dryptosaurus trihedrodon (Cope)

_ Lelaps trihedrodon Cope, U. 8S. Geol. and Geog. Surv. Terr., vol. iii,

art. xxx, p. 805, 1877.

MOOK, STUDY OF THE MORRISON FORMATION 141

Dryptosaurus trihedrodon Marsh, Notice of a new and Gigantic Dino-

saur. Amer. Journ. Sci., 3rd ser., vol. xiv, p. 87, 1877. | Footnote to

p. 88 states Lelaps Cope to be preoccupied by Lelaps Koch. Drypto-

saurus is proposed to replace it. |

Discovered near Canon City, Colorado. Probably from the uppermost

beds of the Morrison formation. Known from fragmentary remains only.

Hypsirophus discurus Cope

Hypsirophus discurus Cope, A New Genus of Dinosauria from Colo-

rado. Amer. Nat., vol. xii, p. 188, 1878.

Probably from the uppermost beds of the Morrison formation near

Canon City, Colorado. Known from part of the skeleton.

Allosaurus fragilis Marsh

Allosaurus fragilis Marsh, Notice of New Dinosaurian Reptiles from

the Jurassic formation. Amer. Journ. Sci., 3rd ser., vol. xiv, p. 514

(ens) 1877.

“Upper Jurassic of Colorado.” Probably the middle beds of the Morri-

son formation near Canon City, Colorado. Known from practically com-

plete skeletons.

Creosaurus atrox Marsh

Creosaurus atrox Marsh, Notice of New Dinosaurian Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xv, p. 241 (243), 1878.

From the “Upper Jurassic of the Rocky Mountains,” probably the

middle beds of the Morrison formation near Cation City, or near Morri-

son, Colorado. Known from representative portions of the skeleton.

Antrodesmus lucaris (Marsh)

Allosaurus lucaris Marsh, Notice of New Dinosaurian Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xv, p. 241 (242), 1878.

Labrosaurus lucaris Marsh, Principal Characters of American Jurassic

Dinosaurs. Amer. Journ. Sci., 3rd ser., vol. xvii, p. 86 (91), 1879.

Antrodesmus lucaris Hay, Bibliography and Catalogue of the Fossil

Vertebrata of North America. U.S. Geol. Surv., Bull. No. 179, p. (489),

1902. }

From the “Upper Jurassic of the Rocky Mountains,” probably from

the middle beds of the Morrison formation near Cafion City, or near

Morrison, Colorado. Small part of the skeleton is known.

142 “ANNALS NEW YORK ACADEMY OF SCIENCES

Antrodesmus valens Leidy

[ Poicilopleuron] (Antrodesmus) paul, Phila. Acad. Nat. Sci., Proc.,

vol. for 1870, p. 3 (4), 1870. |

Labrosaurus feroc Marsh, Principal Characters of American Tar

Dinosaurs. Pt. VIII. The Order Theropoda. Amer. Journ. Sci., 3rd

ser., vol. xxvul, p. 829 (333), 1884.

Antrodesmus valens Hay, Bibliography and Catalogue of the Fossil

Vertebrata of North America. U. 8. Geol. Surv., Bull. No. 179, p.

(490), 1902. :

From Middle Park, Colorado. Small part of skeleton known.

Ceelurus agilis Marsh

Celurus agélis Marsh, Principal Characters of American Jurassic Dino-

saurs. Pt. VIII. The Order Theropoda. Amer. Journ. Sci., 3rd ser.,

vol. xxvii, p. 829 (335), 1884.

“Jurassic, Colorado.” Probably the middle part of the Morrison for-

mation, near Cafion City, or near Morrison, Colorado. Small part of

skeleton known.

Coelurus fragilis Marsh

Celurus fragilis Marsh, Notice of new Jurassic Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xviii, p. 501 (504), 1879.

“Jurassic.” Probably from the Morrison formation. Small part of

skeleton known.

This species was about the size of a wolf, being unusually small for a

dinosaur.

Tichosteus lucasanus Cope

Tichosteus lucasanus Cope, On Reptilian Remains from the Dakota of

Colorado. Amer. Philos. Soc., Proc., vol. xvii, p. 198 (195), 1877.

From near Canon City, Colorado. Probably from the uppermost beds

of the Morrison formation. Only small part of the skeleton is known.

Tichosteus equifacies Cope

Tichosteus equifacies Cope, Descriptions of new Extinct Vertebrata

from the Upper Tertiary and Dakota Formations. U.S. Geol. and Geog.

Surv. Terr., vol. iv, p. 879 (392), 1878.

Probably from the uppermost beds of the Morrison formation near

Canon City, Colorado. Only a small part of the skeleton is known.

MOOK, STUDY OF THE MORRISON FORMATION 143

Ceratosaurus nasicornis Marsh

Ceratosaurus nasicornis Marsh, Principal Characters of American Ju-

rassic Dinosaurs. Pt. VIII. The Order Theropoda. Amer. Journ.

Sci., 3rd ser., vol. xxvu, p. 329 (330), 1884.

Probably from the middle beds of the Morrison formation near Canon

City, Colorado. Most of the skeleton is known.

Ornitholestes hermanni Osborn:

Ornitholestes hermannm Osborn, Ornitholestes Hermanni, a New Comp-

sognathoid Dinosaur from the Upper Jurassic. Amer. Mus. Nat. Hist.,

Bull., vol. xix, art. xu, p. 459, 1903.

From “Bone Cabin Quarry” near Medicine Bow, Wyoming, in the Mor-

rison formation. ‘This form is especially hght and small.

Allosaurus medius Marsh

Allosaurus medius Marsh, Notice of a New Genus of Sauropoda and

other new Dinosaurs from the Potomac Formation. Amer. Journ. Sci.,

ard ser., vol. xxxv, p. 89 (93), 1888.

From the Arundel formation, near Muirkirk, Prince Georges County,

Maryland. Known from teeth only.

Creosaurus potens Lull

Creosaurus potens Lull, [Systematic Paleontology], Reptilia. Md.

Geol. Surv., vol. Low. Cret., p. 183, 1911.

From the Arundel formation in Washington, D. C. Known from frag- .

mentary material only.

Ceelurus gracilis Marsh

Celurus gracilis Marsh, Notice of a New Genus of Sauropoda and other

new Dinosaurs from the Potomac Formation. Amer. Journ. Sci., 3rd

ser., vol. xxxv, p. 89 (94), 1888.

From the Arundel formation, near Muirkirk, Maryland. Small part

of the skeleton is known.

PREDENTATA

Stegosaurus armatus Marsh

Stegosaurus armatus Marsh, A New Order of Extinct Reptilia (Stego-

sauria) from the Jurassic of the Rocky Mountains. Amer. Journ. Sci.,

SnGeser., VOl.. xiv, p. old, 11877.

144 ANNALS NEW YORK ACADEMY OF SCIENCES

According to Marsh, the type was found in the Jurassic of the Rocky

Mountains in Colorado, near the locality of Atlantosaurus montanus.

This means the Morrison formation at Morrison. Most of the skeleton

is known.

Stegosaurus discurus (Cope)

Hypsirophus discurus Cope, A New Genus of Dinosauria from Colo-

Tadoy = Amer. Nat.,.vol: xi p: Ss. 1878.

Stegosaurus discurus Hay, Bibliography and Catalogue of the Fossil

Vertebrata of North America. U. S. Geol. Surv., Bull. No. 179, p.

(496), 1902. . .

Probably from the uppermost beds of the Morrison formation near

Canon City, Colorado. Characteristic portions of the skeleton are known.

Stegosaurus seeleyanus (Cope)

Hypsirophus seeleyanus Cope, New Jurassic Dinosauria. Amer. Nat.,

vol. xiii, p. 402 (404), 1879.

Stegosaurus seelayanus Hay, Bibliography and Catalogue of the Fossil

Vertebrata of North America. U.S. Geol. Surv., Bull. No. 179, p. (496),

1902.

Locality not given. Hay notes it as from the “Jurassic, Colorado.”

Characteristic portions of the skeleton are known.

Stegosaurus ungulatus Marsh

Stegosaurus ungulatus Marsh, Notice of New Jurassic Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xvii, p. 501 (504), 1879.

Locality not given in the original description, but the form is known

to exist in the Morrison formation. ‘The complete skeleton is known.

This is one of the best known members of the Morrison fauna.

Stegosaurus affinis Marsh

Stegosaurus affins Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. IV. Spinal Cord, Pelvis, and Limbs of Stegosaurus.

Amer. Journ. Sci., 3rd ser., vol. xxi, p. 167 (169), 1881.

Locality not given. Parts of the skeleton are known.

Stegosaurus stenops Marsh

Stegosaurus stenops Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. IX. The Skull and Dermal Armor of Stegosaurus.

Amer. Journ. Sci., 3rd ser., vol. xxxiv, p. 413 (414), 1887.

Probably from the middle beds of the Morrison formation near Canon

City, Colorado. Practically the complete skeleton is known.

MOOK, STUDY OF THE MORRISON FORMATION 145

Stegosaurus sulcatus Marsh

- Stegosaurus sulcatus Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. IX. The Skull and Dermal Armor of Stegosaurus.

- Amer. Journ. Sci., 3rd ser., vol. xxxiv, p. 413 (415), 1887.

No locality is given. Part of the skeleton is known.

Stegosaurus duplex Marsh

Stegosaurus duplex Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. IX. The Skull and Dermal Armor of Stegosaurus.

Amer. Journ. Sci., 3rd ser., vol. xxxiv, p. 413 (416), 1887.

Locality not given. Posterior portion of the skeleton known.

Diracodon laticeps Marsh

Diracodon laticeps Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. V. Amer. Journ. Sci., 3rd ser., vol. xxi, p. 417 (421),

1881.

Fiom the Atlantosaurus beds of Wyoming, probably from Como Bluff.

Very little of the skeleton is known.

Stegosaurus longispinus Gilmore

Stegosaurus longispinus Gilmore, Osteology of the Armored Dinosauria

in the United States National Museum, with Special Reference to the

Genus Stegosaurus. U.S. Nat. Mus., Bull. No. 89, 136 pp., 37 pls., 73

figs., 1914.

From the Morrison 114 miles east of Alcova, Natrona County, Wy-

oming. Characteristic portions of the skeleton are known.

Hoplitosaurus marshi Lucas

Hoplitosaurus marshi, from the Lakota beds of the Black Hills region,

may also oceur in the Morrison formation, but has not heen definitely

reported.

Camptosaurus dispar Marsh

Camptonotus dispar Marsh, Notice of New Jurassic Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xviii, p. 501, 1879.

Camptosaurus [dispar] Marsh, Names of Extinct Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xxix, p. 169, 1885.

No locality given. Characteristic portions of the skeleton are known.

146 ANNALS NEW YORK ACADEMY OF SCIENCES

Camptosaurus amplus Marsh

Camptonotus amplus Marsh, Notice of New Jurassic Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xvii, p. 501 (503), 1879. .

Camptosaurus [amplus| Marsh, Names of Extinct Reptiles. Amer. -

Journ. Sci., 3rd ser., vol. xxix, p. 169, 1885.

From a lower horizon than C. dispar. No locality given. A small

part of the skeleton is known.

Camptosaurus medius Marsh

Camptosaurus medius Marsh, The Typical Ornithopoda of the Ameri-

can Jurassic. Amer. Journ. Sci., 3rd ser., vol. xlvil, p. 85, 1894.

No locality given. Parts of the skeleton are known.

Camptosaurus nanus Marsh

Camptosaurus nanus Marsh, The Typical Ornithopoda of the American

Jurassic. Amer. Journ. Sci., 3rd ser., vol. xlvii, p. 85, 1894.

No locality given. Small part of the skeleton is known. This form

is one of the smallest of the dinosaurs, being only about six feet long,

according to Marsh’s estimate.

Laosaurus celer Marsh

Laosaurus celer Marsh, Notice of New Dinosaurian Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xv, p. 241 (244), 1878.

Probably from the middle beds of the Morrison formation near Canon

City, Colorado. Characteristic portions of the skeleton are known. This

form is remarkably bird-like, and is very small, being only about the size

of a fox.

Laosaurus gracilis Marsh

Laosaurus gracilis Marsh, Notice of New Dinosaurian Reptiles. Amer.

Journ. Sci., 3rd ser., vol. xv, p. 241 (244), 1878.

Locality not given. It is known from Como Bluff. Exceedingly

small.

Laosaurus consors Marsh

Laosaurus consors Marsh, The Typical Ornithopoda of the American

Jurassic. Amer. Journ. Sci., 3rd ser., vol. xlviii, p. 85 (87), 1894.

From the Morrison of Wyoming, probably from Como Bluff. Char-

acteristic portions of the skeleton are known.

MOOK, STUDY OF THE MORRISON FORMATION 147

Dryosaurus altus Marsh

Laosaurus altus Marsh, Principal Characters of American Jurassic

Dinosaurs. Pt. J. Amer. Journ. Sci., 3rd ser., vol. xvi, p. 411 (415),

1878.

Dryosaurus altus Marsh, The Typical Ornithopoda of the American

Jurassic. Amer. Journ. Sci., 3rd ser., vol. xlvii, p. 85 (86), 1894.

From the Morrison formation in Colorado and Wyoming. Character-

istic portions of the skeleton are known.

Macelognathus vagans Marsh

Macelognathus vagans Marsh, A New Order of Extinct Jurassic Rep-

tiles (Maceloenatha). Amer. Journ. Sci., 3rd ser., vol. xxvil, p. 341,

1884.

Morrison beds of Wyoming, probably from Como Bluff. Known from

fragmentary remains only. The position of this form is unknown.

Marsh placed it among the turtles and Hay provisionally placed it among

the dinosaurs.

eApatodon mirus Marsh

Apatodon mirus Marsh, Notice of Some New Vertebrate Fossils.

Amer. Journ. Sci., 3rd ser., vol. xiv, p. 249 (255), 1877.

Lower Cretaceous or Jurassic, according to Marsh, no locality being

given. Hragmentary remains only are known. The form is probably a

dinosaur.

Camptosaurus depressus Gilmore

Camptosaurus depressus Gilmore, Osteology of the Jurassic Reptile

Camptosaurus, with a Revision of the Species of the Genus, and Descrip-

tions of Two New Species. U.S. Nat. Mus., Proc., vol. xxxvi, p. 197

(292), 1909.

The type specimen of this species was discovered in the Lakota beds

near Buffalo Gap, South Dakota. A specimen has been found in the

Morrison formation near Como, Wyoming, which probably belongs to this

species. Known from the posterior portion of the skeleton.

Camptosaurus browni Gilmore

Camptosaurus brownt Gilmore, Osteology of the Jurassic Reptile

Camptosaurus, with a Revision of the Species of the Genus, and Descrip-

tions of Two New Species. U. 8. Nat. Mus., Proc., vol. xxxvi, p. 197

(295), 1909.

From the Morrison formation 8 miles east of Como, Wyoming. Known

from a considerable portion of the skeleton.

148 ANNALS NEW YORK ACADEMY OF SCIENCES

Brachyrophus altarkansanus Cope

Brachyrophus altarkansanus Cope, Descriptions of New Extinct Verte-

brates from the Upper Tertiary and Dakota Formations. U. 8. Geol.

and Geog. Surv. Terr., Bull. No. iv, p. 379 (390), 1878

Near Canon City, Colorado, probably from the uppermost beds of the

Morrison formation. Known from several vertebre.

RHYNCHOCEPHALIA

/ Opisthias rarus Gilmore

Opisthias rarus Gilmore, A New Rhynchocephalan Reptile from the

Jurassic of Wyoming, with Notes on the Fauna of Be OFS Uae

Nat. Mus., Proc., vol: xxxvii, p. 35, 1909.

From the Morricon formation at Como Bluff, Wyoming. Known from

dentary bones of several individuals.

CROCODILIA

Goniopholis lucasii (Cope)

Amphicotylus lucasii Cope, Descriptions of New Extinct Vertebrata

from the Upper Tertiary and Dakota Formations. U. 8. Geol. and

Geog. Surv. Terr., Bull. No. iv, p. 379 (391), 1878.

Gomopholis lucasu Zittel, Handbuch der Paleontologie. I. Abth.

Paleozoologie. III Bd., p. 677, 1890.

From the uppermost beds of the Morrison formation near Canon City,

Colorado. Known from vertebre and skull.

Goniopholis felix (Marsh)

Diplosaurus felia Marsh, Notice of Some New Vertebrate Reptiles.

Amer. Journ. Sci., 3rd ser., vol. xiv, p. 249 (254), 1877.

Goniopholis feliz Zittel, Handbuch der Paleontologie. I. Abth.

Paleeozoologie, III Bd., p. 677, 1890.

According to Marsh, from the Lower Cretaceous or Wealden of Colo-

rado. Probably from the middle beds of the Morrison formation near

Canon City, Colorado. This form is known from the skull and a few

vertebre.

Goniopholis gilmorei Holland

Gontopholis gilmorei Holland, A New Crocodile from the Jurassic of

Wyoming. Carn. Mus. Ann., vol: iii, p. 431, 1905.

From the Morrison formation in the Freezeout Hills of Wyoming.

The skull is known.

MOOK, STUDY OF THE MORRISON FORMATION 149

CHELONIA

: Compsemys plicatulus Cope

(Syn. Glyptops ornatus Marsh)

Compsemys plicatulus Cope, On Reptilian Remains from the Dakota

Beds of Colorado. Amer. Philos. Soc., Proc., vol. xvii, p. 193 (196),

ISG

From the uppermost beds of the Morrison formation near Canon City,

Colorado. Known from a considerable portion of the skeleton.

PTHROSAURIA

- Dermodactylus montanus Marsh

Pterodactylus montanus Marsh, New Pterodactyl from the Jurassic of

the Rocky Mountains. Amer. Journ. Sci., 3rd ser., vol. xvi, p. 233, 1878.

Dermodactylus montanus Marsh, Note on American Pterodactyls.

Amer. Journ. Sci., 3rd ser., vol. xxi, p. 842, 1881.

From the Morrison formation in Wyoming, probably from Como Bluff.

Known from various remains of wings, teeth, and vertebre.

PISCES

Ceratodus guntheri Marsh

Ceratodus gunthert Marsh, New Species of Ceratodus, from the Juras-

sic. Amer. Journ. Sci., 3rd ser., vol. xv, p. 76, 1878.

“Jurassic of Colorado.” Probably from the middle beds of the Morri-

son formation near Canon City, Colorado. Known from a left lower

dental plate.

Ceratodus robustus Knight

Ceratodus robustus Knight, Some New Jurassic Vertebrates from Wy-

oming. Amer. Journ. Sci., 4th ser., vol. v, p. 186, 1898.

From the Morrison formation in Albany County, Wyoming, associated

with crocodile and dinosaur bones. Known from part of a tooth.

Ceratodus americanus Knight

Ceratodus americanus Knight, Some New Jurassic Vertebrates from

Wyoming. Amer. Journ. Sci., 4th ser., vol. v, p. 186, 1898.

From the Morrison formation in Carbon County, Wyoming, associated

with bones of a carnivorous dinosaur. Known from part of a left man-

dibular tooth.

150 ANNALS NEW YORK ACADEMY OF SCIENCES

This fauna in its general character seems to require low, or at least

level and aquatic, conditions. Woodworth (1894, 1), in discussing the

relations of peneplanation to organic evolution, states that the reptiles

and in particular the dinosaurs are correlated in development with the

growth of the peneplain. He makes the following remarks regarding the

reptilia:

“Reptilia are characteristic lowland forms. They will endure the cold

of high altitudes and latitudes only by falling into a state of torpidity.

In the development of the peneplaim from the high relief of the Permian,

and again, at the close of the Jura-Trias, the widening out of the lowland,

with plains and jungles near tide-level, followed by depression of the land,

must have highly favored the water-loving reptilia. It is to these geo-

graphic circumstances, I think, that we must look for an explanation of

the remarkable history of this class in Mesozoic times.”

Many of the forms listed above are no doubt synonyms, but their deter-

mination is beyond the scope of the present paper.

AGH OF THE MORRISON FORMATION

The age of the Morrison formation has been the subject of considerable

discussion in the past. The reports of the early surveys refer to the

Morrison beds as “Jurassic beds,” “Lower Dakota” and other terms signi-

fying various ages. Cope (1877, 5; 1878, 8) described typical Morrison

reptiles as coming from beds of the “Dakota Epoch” in Colorado.

Cope (1884, 1) made a faunal comparison of the Morrison and

Wealden formations, but made no definite statement as to their age or

correlation. Osborn (1888, 2) compared the mammals of the Morrison

with those of the Purbeck beds, and considered the former to be of

Jurassic age. Emmons, Cross and Eldridge (1896, 1) stated that from

the point of view of the stratigrapher the assignment of the Morrison beds

to the Lower Cretaceous (Comanchean) was more desirable than assign-

ment to the Upper Jurassic, “not only because it accords better with the

sequence of sedimentation thus far disclosed in the adjoining regions of

Kansas and Texas, but because it places the physical break whose effects

are recognized over the whole continent between these two great time

divisions rather than in the midst of one of them.” Marsh (1896, 5;

1896, 7) vigorously maintained the Jurassic age of the Atlantosaurus

Beds and correlated them with the Wealden of Europe. Scott (1897, 5)

in his Manual of Geology placed the Morrison or Como in the Co-

manchean. Ward (1900, 6) considered the evidence from the ecycads

sufficient to place the formation in the Jurassic. Knight (1900, 2)

‘

MOOK, STUDY OF THE MORRISON FORMATION 151

placed the formation in the upper Jurassic, being closer to the Purbeckian

than to the Oxfordian in age. Logan (1900, 5) correlated the Morrison

of the Freezeout Hills region with the Wealden of England. Riggs

(1901, 4) described the Morrison or McElmo of the Grand River Valley

as Jurassic. Loomis (1901, 6) noted the resemblance of the Morrison

mammalian fauna to the fauna of the Purbeck beds of England, and on

this ground assigned the formation to the Jurassic. Hatcher (1903, 4)

correlated the lower beds of the Morrison at Canon City with the Sun-

dance beds in Wyoming. He considered the cycads as pointing to the

Jurassic age of the deposits, and the dinosaurs as agreeing most closely

with those of the Middle Oolite series of Europe. He concluded that

there is undoubtedly Jurassic represented in the formation, but that it

was quite probable that some of the formation might be of Lower Cre-

taceous age. Williston (1905, 4) gave strong evidence from the verte-

brate fauna for Comanchean age of the Morrison. Lull (1911, 8) dis-

eussed the fauna of the Arundel formation and considered it to be Lower

Cretaceous or Comanchean in age.

In view of the great differences of opinion concerning the age of the

Morrison it is important to review the evidence at present available on

this subject. The principal evidence from the stratigraphic relations is

here summarized.

The youngest beds upon which the Morrison rests are the sandstones

of the Unkpapa formation in the Black Hills area. (It is possible that

the Exeter sandstone in New Mexico may be equivalent in age to the

Unkpapa.) Below the Unkpapa, which is thin, lies the Sundance for-

mation. Over wide areas the Morrison lies on the Sundance directly.

The Sundance, according to Stanton (1909, 9), belongs to the lower part

of the upper Jurassic. The Jurassic sea retreated, therefore, consider-

ably before the close of the Jurassic period, although it is possible that

post-Sundance beds were laid down and eroded before the deposition of

the Morrison. The Morrison over wide areas cannot he older than

middle or late upper Jurassic in age. It is probable that some of the

lower beds in the southwestern areas where the Sundance is absent may

be slightly older than the oldest Morrison beds which directly overlie the

Sundance. In the Black Hills area there is a time interval between the

Sundance and the base of the Morrison which is represented by the

Unkpapa sandstone. There is often a sharp contact between the Morri-

son and Sundance formations in the Wyoming areas. This indicates that

the Morrison in these areas may be considerably younger than the

Sundance.

The oldest beds overlying the Morrison, the age of which is definitely

152 ANNALS NEW YORK ACADEMY OF SCIENCES

known, are the Washita beds near Canon City, Colorado (Stanton, 1905,

11). The upper beds of the Morrison at this locality cannot be later

than Fredericksburg in age, but may be much older. In Montana the

Morrison is overlain by the Kootenie formation, which contaims: Co-

manchean plant remains, some of which are represented in the Patuxent

formation in Maryland. The Kootenie apparently lies conformably on

the Morrison, and it is quite probable that the Morrison and JXootenie

are not distinct formations, but belong to the same deposition cycle.

This question will be taken up again in considering the evidence from

the vertebrate fossils.

In many areas the Morrison is overlain by the Cloverly, Lakota, or

Purgatoive formations, which belong, in whole or in part, to the Co-

manchean period. In western Colorado the Morrison is overlain by the

Dakota sandstone. The contact with the Cloverly and Purgatoire is

often sharp, but there is no evidence of extensive erosion between the

two formations. Hrosion to a slight extent probably did take place, how-

ever. As noted by Lee, the relations of the Morrison to the overlying

formations are much closer than to those beneath.

In Texas and adjoining regions, where the Morrison is absent, there

is a great development of Comanchean marine deposits. Where the

Morrison is present in considerable thickness, the marine Comanchean is

absent or is very thin.

The evidence from the stratigraphic relations indicates, therefore, that

for the eastern areas at least, the age of the Morrison is Comanchean

rather than Jurassic.

The evidence from the flora as to the age of the Morrison is not con-

clusive, a number of species of cycads comprising the entire known flora.

As noted above, Ward placed the age of these as Jurassic. ‘The flora of

the overlying formations has more significance and will be considered in

connection with the discussion of the evidence from the vertebrates.

The invertebrate fauna has no value in determining the age of the

formation. Most of the genera range from Morrison to recent time, a

few being older. The species also have considerable range and are diffi-

cult to determine accurately, owing to poor preservation or lack of dis-

tinguishing characters.

The vertebrate fauna, which is one of the largest and most character-

istic vertebrate faunas in any known geological formation, has often been

appealed to in connection with the age of the Morrison. Marsh (1878,

2) referred the Morrison, or Atlantosaurus Beds, as he called it, to the

Jurassic on the basis of evidence from the reptilian fauna. Just what

this evidence consists in was never published by Marsh. He correlated

MOOK, STUDY OF THE MORRISON FORMATION 153

the beds with the Wealden of Europe, which he considered to be Jurassic

(1895, 1). Im discussing the age of the Wealden he correlated it with

the Morrison on the basis of its reptilian fauna, and considered it, on this

evidence, to be Jurassic. It seems to the present writer that, so far

as the reptilian faunas of the Morrison and Wealden were concerned,

Marsh was arguing inacirele. Marsh (1896, 7; 1896, 4) quoted Seward

as favoring the Jurassic age of the Wealden on the evidence of its fossil

plants, and Smith-Woodward as maintaining the Jurassic age of the

Wealden on the evidence from the fossil fishes. Marsh also considered

the Sauropoda of the Potomac beds to be more primitive than those of

the Morrison, and from this judged the Morrison to*be younger than the

Potomac.

Hatcher (1903, 4) held that the reptilian fauna of the Morrison was

closer to that of the middle Jurassic of Europe than to the Wealden.

Lull (1911, 8), discussing the reptilian fauna of the Arundel] forma-

tion, said: “The character of these dinosaurs, and of the crocodile as well,

correlates the beds wherein they are found absolutely with the Morrison

(Como) of the West. An accurate comparison with European forma-

tions is more difficult, as the faunas have fewer forms in common.

Pleurocelus is reported from the Kimmeridgian as well as from the

Wealden, but that from the former horizon may readily have been an-

cestral to the Arundel type, although the European material is too frag-

mentary to admit of a just comparison. Of the other dinosaurs, the

affinities seem to be entirely with Wealden forms, Calurus being found

therein, while A/losaurus compares in point of size and dentition with

the Wealden Megalosaurus. Dryosaurus has its nearest Huropean ally

in Hypsilophodon, again a Wealden type, and the crocodile, Goniopholis,

is reported from the Wealden and its marine equivalent, the Purbeckian,

not from the older Jurassic levels.

“The weight of this evidence would seem to place this fauna beyond

the Jurassic into the beginning of Cretaceous times.”

The most complete comparison between the Morrison and correspond-

ing vertebrate faunas has been made by Williston (1905, 4), and the

following is extracted from his paper:

“Cetiosaurus longus Owen is from the Great Odlite, or Middle Jura ;

C. glymptonensis Phillips, imperfectly known, is from the same horizon ;

while C. brevis Owen, also imperfectly known, is from the Wealden, but

is referred by Seeley to Ornithopsis, by Lydekker to Morosaurus. Orni-

thopsis Seeley is from the Wealden; O. humerocristatus Hulke, from the

Kimmeridge. Other uncertain forms are from the Wealden of England.

Titanosaurus is referred by Lydekker to probable Upper Greensand.

{54 ANNALS NEW YORK ACADEMY OF SCIENCES

Remains of the Sauropoda are spoken of as ‘frequent’ in the Weaiden,

while from the Middle Jura only a few are known, and all these are of

one, or at most two, species. I certainly cannot see what evidence these

forms present that would lead one to say that the American forms are

clearly Jurassic. The range of this suborder, so far as is known, is from

the Middle Jurassic to the Upper Cretaceous, though there may be doubt

as to the real age of the Indian form. Their known geographic distribu-

tion is Europe, India, Madagascar, Africa, South and North America—

that is, over the whole world. The generalized characters presented by

them are not at all sufficiently well understood to say off-hand that certain

forms are older than others.

“Tt is quite true that the Brachiosauride of Riggs (Brachiosaurus

Riggs and Haplocanthosauwrus Hatcher) have a more generalized structure

in this respect than has Cetiosawrus even, but we have no reason to

assume that all the generalized forms died out with the advent of special-

ized ones, such as are most of the American Sauropoda. Nor do I think

it quite certain that the Brachiosauride are the most generalized, cer-

tainly not if the hypothesis that the Sauropoda have been derived from

primitive ornithopoda is at all probable. Furthermore, the genus Plewro-

celus, originally described from the Potomac beds, has been recognized in

the Atlantosaurus beds by Marsh, and later by Hatcher, and forms from

the Wealden have been referred, provisionally at least, to the same genus.

“For the most part, the carnivorous dinosaurs have little value in the

correlation of the horizons. Megalosaurus is reported from Europe from

the Lias to the Wealden. In America we have three or four genera of

the Megalosauride in the Atlantosaurus beds, Creosaurus, Allosaurus,

Antrodesmus, and Ceratosaurus, and the family survived to the Laramie

Cretaceous. Ca@lurus was described from the Atlantosaurus beds, but is

known to occur in the Potomac beds. In the Wealden of Hngland

Aristosuchus is very closely allied, indeed is supposed to be identical, and

all the other genera referred to the Cceluride are from the Wealden.

In the extensive hollowness of the bones of the skeleton, Celurus is not

only the most specialized of dinosaurs, but of all vertebrate animals.

The evidence then to be derived from the Theropoda is for the con-

temporaneity of the Wealden with the Atlantosaurus beds.

“So far from the evidence of the Iguanodontia being against this

correlation, I believe that it is decidedly for the identity of the two

horizons. Iguanodonts are found in abundance in the Atlantosaurus

beds, and of the largest size and high specialization. . . . And, so

far from the American forms being the most generalized, Liydekker says

that Hypsilophodon is ‘the smallest and least specialized member of the

MOOK, STUDY OF THE MORRISON FORMATION 155

family! Perhaps this opinion is not decisive, but Hypsilophodon cer-

tainly cannot be called the most specialized. uydekker even refers cer-

tain Kimmeridge and Wealden species to the American genus Campto-

SQUTUS:

“Perhaps the best evidence we have for the Jurassic age of the Ameri-

can deposits is that of Stegosaurus, which is so closely allied to Omo-

saurus Owen from the Kimmeridge that Marsh believed the two genera

to be identical. On the other hand, this type of the predentate dinosaurs

seems to range from the Lower Lias in Scelidosawrus to Paleoscincus

from the Laramie, with four or five genera referred to the group from

the Wealden. Its value, then, is slight. .

“Other evidence offered by the reptiles from the American beds is

slight. A genus of crocodiles called by Marsh Diplosawrus seems to

include Hyposaurus vebbuw Cope from the Comanche Cretaceous of

Kansas. Years ago Zittel referred both of these forms to the genus

Gomopholis from evidence communicated by Professor Marsh, and

Goniopholis is said to be ‘a genus very characteristic of the Wealden’

(Lydekker). The recently published figure of the type specimen of

Diplosaurus, when compared with figures of Goniopholis, shows a start-

ling resemblance. Indeed, so far as I can learn, there are no brevirostral

crocodiles known from below the Purbeck or lithographic slates. The

evidence, then, of the crocodiles is decidedly for the uppermost Jurassic

or Wealden age of the American beds.

“Of the Chelonia the single species Compsemys plicatulus Cope

(Glutops ornatus Marsh) is not at all decisive. If the species is correctly

referred to Compsemys, all its related forms are of Cretaceous age.

Nor is there any evidence to be obtained from the pterosaurs or birds.

Of the mammals I will not venture to speak, save that I think that there

are too few forms known from the Wealden to offer any basis of compari-

son. Of the fishes a few species of Ceratodus only are known, and inas-

much as this genus is supposed to range from the Trias to the present

time, these species have no correlating value whatever.

“To sum up: there is no valid vertebrate evidence pointing to an age

greater than the Purbeck for the Atlantosaurus beds, and but very little

for a greater age than that of the Wealden.

Unfortunately, in most of the discussions hitherto the Atlantosaurus

beds have been considered as some brief epoch. The faunas of the upper

and lower parts have never been differentiated, save in some exceptional

eases. Marsh, indeed, rarely ever gave any precise location for his type

specimens, referring them simply to Wyoming, Colorado, etc. The term

‘Upper Jurassic’ has been applied indiscriminately to the whole fauna.

Hatcher was the first to distinctly point out that the uppermost

part of the beds might include a part of the Lower Cretaceous. .

“T am strongly of the opinion that these deposits, nowhere, so far

as known, exceeding a thickness of 500 feet, really represent various

epochs between the Jurassic and the Upper Cretaceous, and that sooner

or later we shall have evidence to distinguish the later from the earlier

faunas. .

“The upper part of the Atlantosaurus beds is, it seems to me, mdis-

putably Cretaceous; the lowermost part is probably not older than the

Wealden, though possibly of Purbeckian age. I therefore strongly pro-

test against the common usage of referring all the fossils from these beds

to the upper Jura. Until more is known of the different faunas con-

tained in it, the only proper designation for the composite faunas in-

cluded in them is Jura-Cretaceous; this assumes that the Wealden is

really Jurassic.”

A sauropodan coracoid was discovered by Larkin (1910, 2) in the

Trinity formation in Oklahoma. There is no Morrison present at this

locality, but it is possible that the bone had been transported some

distance.

Berry (1911, 7) has discussed the three divisions of the Potomac for-

mation and their floras at some length, and has shown that the floras of

the Patuxent and Arundel beds, which have many forms in common, are

closely allied to the flora of the Kootenie formation. “The two floras

[ Patuxent-Arundel and Kootenie] have a great many elements in com- ~

mon, and upon the basis of the floras alone the conclusion would be

reached that the base of the Kootenie was approximately the same age

or slightly older than the base of the Patuxent.” The Patuxent forma-

tion, however, which contains a larger flora than the Arundel, lies below

the Arundel, which contains the Morrison fauna. In the west this con-

dition is reversed ; the Kootenie, which contains a flora very closely allied

to that of the Patuxent-Arundel series, lies above the Morrison with its

fauna. ‘This relation is shown by the following diagram:

156 ANNALS NEW YORK ACADEMY OF SOIENCES

Arundel (plants and bones} Kootenie (plants)

EESSRY hdd,

LIT, SSN

Patuxent (plants) Morrison (bones)

The conclusion seems to be that the Iootenie and Morrison are practi-

cally the same thing, and that the Patuxent and Arundel are very closely

MOOK, STUDY OF THE MORRISON FORMATION 157

related. Berry gives the correlation of Morrison-Kootenie together ap-

proximately equalling the Patuxent-Arundel.

Lee (1915, 2) has recently given strong diastrophic evidence for the

Comanchean age of the formation.

The evidence for Comanchean age of the Morrison seems much str onger

than that for Jurassic age. The interval between the Sundance and the

Washita is a long one, and the Morrison may not occupy the whole of it,

but only the upper portion. It is, probable that the Morrison is not of

exactly the same age throughout the whole area of its occurrence, and it

is very improbable that every particular bed in a given locality necessarily

has a corresponding bed in some other locality. The Morrison is the

product of a slow accumulation process, and therefore may fill a con-

siderable part of the interval between the Sundance and Washita. The

most probable condition is that the greater part of the Morrison is

Comanchean in age, with Jurassic members in its lower portion in some

areas. It is possible also that in the southwestern areas the base of the

Morrison is much lower than in the eastern areas, and may include con-

siderable Jurassic.

ORIGIN AND INTERPRETATION OF THE MORRISON

FORMATION

SUMMARY OF CHARACTERS

In the preceding pages many facts regarding the Morrison formation

have been recorded. A number of these which may have a bearing on

the question of the origin and geologic significance of the Morrison are

here briefly summarized:

1). The Morrison has a very wide distribution. As noted in the sum-

mary of the stratigraphic relations of the formation, the area which is

now underlain by the Morrison probably covers several hundred thousand

square miles, and its original area, before being exposed to the extensive

erosion which occurred in the Rocky Mountain region at the end of Cre-

taceous time, probably amounted to four or five hundred thousand square

miles and perhaps more.

2). Considering the vast area occupied by the formation, it is very

thin. The greatest thickness reported is something like 900 feet, but it

is usually very much less than that.

3). The thickness is variable over large areas, and to a lesser extent

in small areas. In the southwestern areas the thickness varies from 400

to 900 feet; in the northwestern areas the actual thickness and variation

are both somewhat less; in the eastern and central Wyoming areas the

158 ANNALS NEW YORK ACADEMY OF SCIENCES

thickness is usually about 200 feet, but in some cases it is as high as 300

or as low as 150 feet; in the Black Hills area the thickness is never more

than 200 feet, and ranges from that down to zero, averaging about 100

feet; in the southeastern Colorado and New Mexico areas the thickness

varies from 400 to 200 feet. It will be seen from this that while there

is a considerable variation in individual areas, the thickness 1s much

greater in the western areas than in the eastern, and that there 1s a

thinning out eastward, which 1s very gradual considering the distances

involved.

4). The size of grain of the sediments varies to a considerable extent.

Fine-grained material is the most abundant; a considerable amount of

medium-grained material is present, with a smaller amount of coarse-

grained rock. Very coarse sediment does not appear to be present.

Coarse material is more abundant in the western than in the eastern

areas.

5). The succession of beds varies greatly from point to point, but the

kind of succession is practically the same in every locality. Fine joint-

clays or grits usually make up the greater part of the outcrops, especially

toward the top. Sandstone and nodule layers are usually present at

intervals in the section, and often thin limestones or occasionally con-

glomerate beds. ‘These various members are found to be arranged in a

certain order in one, locality, and in another locality not far away the

succession will be different. Sandstone beds that are thick in the first

section may be thin or absent in the second. Limestone beds present in

-a certain position in the first section may be in another position in the

second section, or absent altogether. On studying the various sections

of the formation a constant thinning and thickening or replacement of

individual members is to be seen. An examination of the sections in

the stratigraphic division of this paper will emphasize the prevalence of

the conditions above described. This type of succession in many sections

has been described by Lee as “uniformly variable.”

6). The contacts of the various members with each other is usually

sharp, showing rather rapid changes of conditions of deposition. Beds

of fine grits or clays are often followed directly by beds of medium-

grained sandstone and vice versa.

7). Channeling is often present, certain layers lying in troughs eroded

in the underlying beds. This has been discussed in the section on

structures.

8). Cross-bedding is common in the Morrison. Both the stream and

wind types have been observed. ts

MOOK, STUDY OF THE MORRISON FORMATION 159

9). The principal mineral ingredient in the Morrison sediments is

quartz. Other materials usually or often present are calcite, kaolin, iron

oxides, mixed carbonates, gypsum and feldspar. Mica and volcanic ash

are present in very small amounts.

10). The larger quartz grains are usually well rounded; the smaller

ones are often angular.

11). The iron oxides usually occur as interstitial material between fine

quartz grains, and sometimes as a staining of fine-grained binding matter.

Tn some cases it is uniformly distributed, and in other cases it is scattered

in patches.

12). The limestones are thin, often very pure calcite or dolomite, and

consist almost entirely of very fine-grained material. They are some-

times argillaceous and sandy.

13). The sandstones are often nearly pure quartz; when fine-grained

they sometimes have interstitial materials of iron oxides, kaolin and

mixed carbonates; when coarse they are often extremely calcareous, and

sometimes arkosic.

14). The arkosic sandstones usually occur near the base of the forma-

tion. They are occasionally found in the middle beds, and are rare near

the top.

15). The color of the rocks of the formation varies greatly, often in

short distances, so that the formation was formerly called the “Variegated

Beds.” ‘This variegated character is sometimes present in a hand speci-

men. ‘There is often a pronounced color banding in the formation.

Gray and purplish red are the usual colors, but green, white, blue,

yellow and black are also often present, and all these colors grade into

each other in a complex fashion.

16). The coarse sandstones are usually gray or white. The finer clays

and grits may be either green, gray, white, blue, red or dark brown. The

green clays are often finer than the red or brown grits.

17). The flora of the formation is of such a nature as to indicate a

warm and moist climate at the time of deposition, in some areas at least.

This flora is not especially abundant, however.

18). The invertebrate fauna consists of fresh-water types. They be-

long to genera having a wide geologic range.

19). The vertebrate fauna is composed of aquatic, amphibious, ter-

restrial and aérial forms. The fish were aquatic, of course. The habitat

of the sauropod dinosaurs has been the subject of controversy; some

writers have held that they were exclusively terrestrial, others that they

were exclusively aquatic, and still others that they were amphibious. The

latter theory seems the most probable. They certainly possess aquatic

160 ANNALS NEW YORK ACADEMY OF SCIENCES

adaptations, but they also possess adaptations for walking on land, in

some forms at least. The crocodiles were amphibious and probably the

turtles as well. The theropod and predentate dinosaurs were terrestrial,

and probably the mammals as well. No marine vertebrates have been

found in beds which have been definitely identified as Morrison.

20). The skeletons of the large dinosaurs often indicate, to a certain

extent, by their preservation, some of the physical processes connected

with their burial. In some cases, of which the Bone Cabin Quarry near

Medicine Bow, Wyoming, is an example, the bones of many individuals

and species are found mixed up in an intricate manner, so that anything

like a complete skeleton is rare. In other cases complete or nearly com-

plete skeletons are found in position. In still other cases a skeleton will

be found complete up to a certain point and then end suddenly, with not.

a bone to be found beyond. in any direction.

The mixed-up bones indicate that they were gathered together from

their original resting-places by current action, in a restricted area, such

as one individual stream. The complete skeletons indicate swift burial

in relatively quiet waters or by wind action. The partial skeletons poimt

toward erosion of the beds they were deposited with, after their burial.

21). The Morrison is more closely related to the overlying than to the

underlying formations.

22). The contact with the overlying beds is sharp in places, and indi-

cates a change of depositional conditions. ‘There may have been a small

amount of erosion of Morrison beds prior to the deposition of the oyer-

lying beds in places, but if so it was probably shght.

23). In Texas, where the Morrison is absent, its place in the strati-

graphic column is occupied by great thicknesses of marine Comanchean

beds.

24). In the north the Morrison is overlain conformably by the Ioo-

tenie formation. The Kootenie is similar in character to the Morrison,

and part of it, at least, may belong to the Morrison. The flora of the

KKootenie and Potomac formations have a bearing on this question, which

has been discussed in the section on the age of the Morrison.

25). The formation hes on beds of various ages, from Archean to

upper Jurassic.

26). There is a widespread erosion plane beneath the Morrison over

most of its area. The relation to the Sundance will be discussed later.

27). The formation is present in isolated areas in the Rocky Moun-

tains in Colorado, about midway between the eastern and western Colo-

rado areas.

MOOK, SUUDY OF THE MORRISON FORMATION 161

History OF PREVIOUS OPINIONS AS TO THE ORIGIN OF THE FORMATION

The origin of the Morrison formation has been the subject of consider-

able attention in the past. Some of the more important discussions are

noted at this point. ‘Their merits will be discussed later.

C. A. White (1886, 2) in discussing the Morrison and its invertebrate

fauna came to the following conclusions: “The character of the strata in

which these fresh-water Jurassic fossils were found, both at the Colorado

and at the Wyoming localities, in addition to the character of the fossils

themselves, is such as to indicate for them a lacustrine, and not an

estuary or a fluviatile, origin; that is, the rocks are regularly stratified

and have such an aspect and character as to indicate that they were

deposited in one or more large bodies of water. If the strata of the

Colorado and of the Wyoming localities really contain an identical fauna,

it may be regarded as probable that they were deposited in one and the

same lake. The distance between the Colorado and the Wyoming locali-

ties indicates that the supposed lake was nearly 200 miles across; and,

if the Black Hills fossils also belonged to the same contemporaneous

fauna, the assumed lake was much larger.”

Riggs (1901, 4) described the Morrison of the Grand River Valley,

and gave an interpretation of the history of deposition as follows: “wet

us attempt to trace the history of the Jurassic formation as evidenced by

the nature of the rocks, the stratigraphy and the occurrence of fossils:

Given an arm of the Jurassic sea, fed by rivers and open to the ebb and

flow of tide waters. Under these conditions the sediments washed down

by the river everywhere accumulated slowly, and alternating with them

thin ledges of limestone and gypsum were laid down. Occasional strata

of sand accumulated by the action of the retarded currents about the

estuaries of streams. Later, by some change in levels, the ingress of

seawater was cut off, but the outlet still remained and so ensued the

gradual change from salt to fresh water. ‘Then followed a period of

comparatively uninterrupted deposition in which the green shale was laid

down under still water. Along with it were deposited near the mouths

of streams the occasional homogeneous beds of green sand. As the basin

filled up and its outlet deepened, the lake became shallower until its bed

was invaded by the shifting channels of broad and shallow streams. Its

sand-bars have formed the cross-bedded sandstone ledges which mark the

transition from the lower to the upper clays. With the shallower waters

came the great land and shore reptiles and about the estuaries of streams

their remains were deposited abundantly.

“Again the lake waters invaded the region and the deposition of sand

162 ANNALS NEW YORK ACADEMY OF SCIENCES

in this locality was cut-off. The period following was one of greater

changes and probably of slower deposition than that preceding the river

period. ‘The presence of fine reeds or sedges shows that the water was

shallow, at least in places, and parts of skeletons found on irregular sur-

faces imbedded in these reedy clays suggest mud-bars or islands, on

which they have stranded. In one instance part of a skeleton found

imbedded in a stratum of blue clay which thinned out and was replaced

by sandstone with pebbles at the base, indicates that the carcass was

buried in a mud-bank bordering a stream or water-current. ‘The inter-

ruption of the vertebral column and the displacement of the ribs in one

direction show that the stream was sufficient to carry away the missing

part of the skeleton.

“The tendency toward a more shaly nature and the presence of car-

bonaceous matter in the upper measures indicate the return of shallows

and the greater abundance of vegetable matter. This condition evidently

culminated in the great influx of sand laden with deciduous leaves which

marks the period represented by the Dakota sandstone.” ee

Loomis (1901, 6) discussed the Morrison in the Como Bluff region.

He referred to the beds as “non-marine Jura,” and later in the same

paper stated that the shore line, which was about 30 miles south of Como

Bluff during Shirley or Sundance time, moved 100 miles to the south at

the beginning of Como or Morrison time, and.that the deposits were then

laid down in shallow water; also that “the bones [of dinosaurs] are

clearly floated out to sea by the presence of considerable meat on them.”

There is thus an element of contradiction in Loomis’s interpretation.

Hatcher (1903, 4) discussed the origin of the Morrison at some length.

As his conclusions are closer to those of the present writer than those of

any of the other workers mentioned, the important parts of his discus-

sion will be quoted at this point. f

“T can fully agree with Dr. White as to the necessity of assuming the

existence in Jurassic times of a continental land-mass of the dimensions

intimated in his paper. But it does not seem to me at all necessary to

presuppose the existence of a Jurassic lake of even the smaller or more

moderate dimensions assigned by him. While I do not wish to be under-

stood as denying the possibility of the existence of a great lake in Jurassic

times extending as Dr. White has suggested from the Arkansas River

in Colorado to the Black Hills of South Dakota, it does appear to me that

our present knowledge of the character of the faunas, both terrestrial and

aquatic (fresh-water) as well as of the lthologic and stratigraphic fea-

tures exhibited by the beds themselves is decidedly against such a pre-

sumption. If I properly understand Dr. White he finds nothing in the

MOOK, STUDY OF THE MORRISON FORMATION 163

character of the aquatic mollusea to preclude the possibility of their hav-

ing lived and developed in smaller lakes. After a personal examination

of the localities at Green River, Utah, at Grand River in western Colo-

rado, Canon City and Morrison in eastern Colorado, Como and Sheep

Creek in southern Wyoming, at the Spanish Mines in eastern Wyoming,

along the Bighorn Mountains in central Wyoming, about the Black Hills

in South Dakota and in the country near Billings in southern Montana,

in all of which localities the Atlantosawrus beds are exposed and exhibit

in more or less abundance, the remains of those dinosaurs which are

characteristic of them, I am convinced that neither the character of the

vertebrate fauna nor the facts of stratigraphy at any one of these places

can be taken as affording anything like conclusive evidence of the presence

of a great body of water. At several of these localities, however, the oc-

curence at intervals of sandstones showing frequent examples of cross-

bedding, ripple-marks and even occasionally exhibiting footprints is con-

clusive proof that such sandstones had not their origin in the midst of a

great lake, while the presence almost everywhere of the remains of terres-

trial reptiles and less frequently of mammals tells only too plainly of an

adjacent land-mass. In all this region I know of no locality where any

considerable extent of the Atlantosaurus beds occurs, in which remains of

quadrupedal, terrestrial dinosaurs have not been found. . . . An

hypothesis, which it appears to me is far more reasonable and more nearly

im accordance with the facts as we now know them, is to consider this

region as presenting in late Jurassic and early Cretaceous times the ap-

pearance of a low and comparatively level plain, with numerous lakes,

both large and small, connected by an interlacing system of river chan-

nels.”

Chamberlin and Salisbury (1907, 7) assign a fluviatile origin to the

Morrison formation.

Lee (1915, 2) considers the Morrison to be largely fluviatile in origin.

Discussion oF Previous THEORIES OF THE ORIGIN OF THE FORMATION

The theory of deposition of the Morrison in a great lake, as advanced

by C. A. White, does not seem to be supported by evidence now available.

The following list of characteristics of beds of lacustrine origin has been

given by Johnson (1903, 8):

1). No great variations in texture and composition in vertical section.

2). No beds of conglomerate.

3). No marked and sudden variations in respect to the thickness and

areal extent of the component beds.

164. ANNALS NEW YORK ACADEMY OF SCIENCES

4). Few unconformities of erosion.

5). No extensive cross-bedding at high angles.

6). A lacustrine rather than a land fauna or flora.

The Morrison departs widely from every one of these six characteris

except the last. The fauna might be considered lacustrine in part, but

some of it, if not most of it, is strictly terrestrial, and much of the aquatic

element may be fluviatile as well as lacustrine.

The series of events given by Riggs might fit very well a restricted area

of the Morrison deposits. The Morrison is an extremely widespread for-

mation, however, and this fact must be continually kept in mind in dis-

cussing its origin. There does not appear to be any evidence sufficient

for concluding that the lower beds of the Morrison are marine, and depo-

sition in estuaries is not in accord with the vast distribution of the for-

mation.

There is abundant evidence for alternating lake and river conditions

in restricted areas, however, and no doubt such conditions were common.

The statement by Loomis that the dinosaur bones had floated out to

sea by means of meat on them is not supported by the known facts, as

there is no evidence whatever of marine conditions in the Morrison for-

mation itself.

Hatcher’s theory of a low level plain, with lakes and interlacing

streams, fits the observed conditions much better. The interpretation

given in the present paper 1s in some senses an amplification of this idea.

PRELIMINARY STATEMENT OF PRESENT INTERPRETATION

To the present writer the best explanation of the origin of the Morri-

son formation appears to be that of a number of large streams issuing

from a mountainous area and crossing a very broad flat plain. Such

streams would deposit much of their loads on their flood-plains in the

forms of very flat alluvial fans. Deposition by distributaries, aided by

tributaries and eolian action, would tend to unite these fans into a broad

alluvial plain. The main streams and tributaries consequent on the plain

would gradually extend such alluvial deposits over a very broad area. In

local basins between the principal stream areas and in abandoned stream

valleys lakes would probably form locally. In these lakes fine sediments

would be deposited, with sandstones around the margins. Afolian de-

posits would probably form to a certain extent between the main stream

areas also.

The presence of a Comanchean sea in Texas and other areas east of the

Morrison area, shown by the presence of marine sediments, indicates that

part of the Morrison may be a true delta formation.

MOOK, STUDY OF THE MORRISON FORMATION 165

With conditions such as those above outlined kept in mind as a work-

ing hypothesis, it is desirable to consider the characteristics of large

alluvial fans and river flood-plains of recent and Pleistocene origin.

CHARACTERISTICS OF RecENT ALLUVIAL PLAINS

Davis (1898, 6) describes the fan of the Hoangho River in China as

follows: “One of the largest alluvial fans in the world is that of the

Hoangho, in eastern China. This great river, bearing a heavy load of

fine silt from the basins among the inner mountains, issues from its

inclosed valley 300 miles inland from the present shore-line, and at a

height of about 400 feet above sea-level, and then flows to the sea down

the gentle slope of its extensive fan.” The fan is fertile and is subject

to overflow on a vast scale. A single flood in 1887 covered 50,000 square

miles and drowned at least 1,000,000 people. The course of the river

and its tributaries is constantly shifting.

The fan of the Yangtse-Kiang hes immediately south of that of the

Hoangho and is more or less connected with it. The large rivers leave

the mountains in valleys which resemble estuaries in their form and rela-

tion to the mountains. The mountains may be compared to the land and

the plains and valley to the sea and estuary. The great rivers are bor-

dered on either side by lakes, swamps and other streams, which often

connect with each other in an intricate manner. The lakes vary in size

from small ponds to large lakes 50 miles or so in length. They are

usually situated in tracts alone the borders of the large rivers, but are

sometimes situated far from the latter. They extend from the mountains

to the delta and are not especially characteristic of any one region. These

features are well shown on the German government’s land survey maps of

eastern China (1908, 9, 10; 1904, 9, 10, 11).

Grabau (1914, 6) describes the dry delta of Cooper Creek as extending

over an area of 185 x 170 miles. Grabau describes the great alluvial

plain of the Indo-Gangetic region as follows:

“The Indo-Gangetic alluvial plain is an example of a river plain

formed of many confluent dry deltas and carried forward by the two

great rivers of northern India—the Indus on the west and the Ganges,

with the tributary Brahmaputra, on the east. Numerous small streams

feed these rivers from the south slope of the Himalayas, carrving an

abundance of coarse and fine debris. . . . The great alluvial plain

extends over an area of about 300,000 square miles, and comprises the

richest and most populous portion of India. It varies in width from 90

to nearly 300 miles, and entirely separates the lower peninsula of India

166 ANNALS NEW YORK ACADEMY OF SCIENCES

from the Himalayas to the north. It rises 924 feet above the sea in its

highest portion, and the deepest boring has located these deposits at a

depth of nearly a thousand feet below the present sea-level. . . .. It

abounds in gravels and conglomerates near the sloping borders, but luta-

ceous or clayey deposits, more or less arenaceous, prevail over much of ©

the plain, especially near the center, with only subordinate deposits of

sand, gravel, and conglomerates. Beds of blown sand of great thickness

are found in some regions. . . . Shells of river and marsh molluses

are occasionally found, and caleareous concretions and nodules of irreg-

ular shape, locally known as kankar, are frequent. . . . Calcareous

tufas also form conglomerates in the stream beds by cementing pebbles

derived from the hills. In the clays along the borders and in the shoals

of the Jumna River a great variety of vertebrate remains has been found,

including elephant, hippopotamus, ox, horse, antelope, crocodile and

various fish.” Grabau gives further descriptions of these deposits, much

of which would apply to the Morrison.

Lakes are not especially abundant on these plains, though some are

present. The large rivers are braided in a complicated manner. An in-

teresting feature is shown in the delta portion of the Ganges, where a

large tributary, the Brahmaputra, joins the main river below the poimt

where one of its largest delta distributaries, the Hooghly, is given off.

These features are shown on any large map of India.

Grabau also gives a description of the Nile flood-plain. Extracts from

this description are here quoted. .

“A striking example of a flood-plain is afforded by that of the Nile,

which flows from a well-watered region through a desert country without

receiving a tributary for a thousand miles, except a few small wet weather

streams. Entrenched beneath the desert uplands this flood plain holds

its own for a length of 500 miles, and maintains a width of from 5 to 15

miles, broadening on the delta to over 100 miles. The annual inunda-

tion of the flood plain is caused by the northward movement of the belt

of equatorial rains in summer. The flood begins in June and usually

rises 25 feet or more at Cairo in the late summer or early autumn. The

annual addition of the river silt causes a slow rising of the entire flood

plain estimated to amount to 414 inches a century.

“This region furnishes an instructive example of widely varying con-

temporaneous deposits within the same general area. On the one hand

occur the drifting, cross-bedded, well rounded and pure quartz sands of

the desert, and, on the other, the extremely fine, well-stratified muds of

the river flood plain.”

MOOK, STUDY OF THE MORRISON FORMATION 167

Grabau makes the following statement regarding flood-plain sediments:

_ “From the nature of the deposits on river flood plains, perfect and often

very fine stratification is to be expected. This may be considered as char-

acteristic of typical flood plains.” The Po, Ganges and Hoangho are

given as examples. Davis (1900, 9) states that the proportions of fine

_ to coarse materials in these rivers is very great.

In general, levelness of surface is a characteristic of flood-plains; the

material may vary from coarse to fine, the former usually occurring in

greater abundance near the source and the latter at a distance from the

Fie. 94.—A tributary of the Grand River, near Mack, Colorado.

Streams of this character were probably abundant in the Morrison area during the

: deposition of the formation.

source; and overlap away from the source of supply is characteristic.

The strata deposited will often approach horizontality over considerable

areas. Thinning out and replacement of beds is common. Footprints

and similar structures are often found.

CoLor oF SEDIMENTS

In moist or pluvial climates with moderate vegetation, the soil is apt

to be bluish. Vegetation prevents a high degree of oxidation. “In

seasons of dryness, when the amount of vegetation is small, the iron of

the sediments of deltas and alluvial fans may become thoroughly oxidized.

168 ANNALS NEW YORK ACADEMY OF SCIENCES

Where dryness prevails for most of the year, and where vegetation is as a

result scanty, such oxidation may be especially favored. Thus semiarid

or even desert regions would furnish the best conditions for such oxida-

tion. On river flood plains there is always sufficient moisture to result

in the formation of hydroxides of iron, and hence the colors of such

deposits will range from yellows to ocher and brown. It is only under

conditions of intense heat that dehydration will result with a consequent

change in color toward the reds. Such change of color may, however,

take place as the result of aging of the deposits, as pomted out by Crosby”

(Grabau, 1914, 6). Crosby’s statement is as follows: “. . . the

color of the deposit, so far as it is due to ferric oxide, is, other things

being equal, a function of its geological age. . . . In other words,

the color naturally tends with the lapse of time to change from yellow

to red; and, although this tendency exists independently of the tempera-

ture, it is undoubtedly greatly favored by a warm climate” (1891, 3).

Barrell has also discussed the causes of color combinations in continental

sediments (1912, 10).

_ Without discussing the literature on this subject any further, the fol-

lowing conclusions may be made regarding the origin of beds of various

colors in the Morrison formation. As noted above (p. 159), the coarser

beds are usually gray or white, these beds often being cross-bedded, while

the finer beds are green, gray, white, blue or red. The red and reddish-

brown beds are not extremely fine, however, like the greenish clays.

This is probably due to the prevalence in them of quartz grains, while

the green clays are often composed largely of kaolinic material. ‘There -

is a considerable amount of gradation of color in the finer beds. The

coarser sands were probably deposited in the streams and as deltas in the

lakes. The finer red, brown and gray grits were deposited in both lakes

and streams, and also along river flood-plains. In most cases it would

be difficult to assign one of these brownish-red grits to a precise origin.

As noted above in discussing the petrographic characters of the forma-

tion, the green clays often grade into red and brown, and there is distinct

evidence of the origin of some of the red color, at least, by the alteration

of iron carbonate. It is possible, of course, that some of this oxidation

may have taken place before the burial of the material. It is much more

probable, however, that the process has been going on during a long

period of time subsequent to the burial of the deposits, and in some cases

is still going on. Many beds have been completely oxidized, there being

httle but quartz and red-stained clayey matter in the rock. This material

is usually more abundant in the upper members of the formation than in

the lower. Other beds show the operation to have progressed to a con-

MOOK, STUDY OF THE MORRISON FORMATION 169

siderable extent, but not completed. If the process is not interfered with

by diastrophism, or other violent disturbance, it is probable that oxidation

will continue and red color will be produced more and more, up to the

limits set by the nature of the material. Pure quartz sands or kaolinic

clays without iron cannot be oxidized to hematitic red beds under ordi-

nary conditions. The iron will have to be introduced from outside.

This probably accounts for the absence of red color in many of the very

fine green clays.

INTERPRETATION OF THE Morrison FORMATION

From the foregoing facts recorded concerning the Morrison formation,

from the conditions which are known to prevail on modern flood-plains,

alluvial fans and deltas, and from previous knowledge regarding the dis-

tribution of land and sea in western North America in Mesozoic times,

an attempt will be made to interpret the Morrison formation and to trace

the history of parts of western North America during middle Mesozoic

time.

At the close of the Triassic period certain areas in western North

America were elevated. This is shown by the presence of folding in

Triassic rocks which are overlain unconformably by later beds and by

disconformable contact with Jurassic beds. Large areas near the Pacific

Coast were greatly affected and, as the effects are visible in eastern Colo-

rado and New Mexico, the elevation was probably widespread. Hrosion

progressed over the greater part, at least, of the western United States

until a peneplain was developed. Over this peneplain the sea advanced

in late Jurassic time, as shown by Logan (1900, 10), coming from the

Pacific through Alaska and western Canada, and extending south into

the United States and covering practically the same areas that are occu-

pied by the states of Montana, Wyoming and Utah, with very slight

extensions into other states. The beds deposited at this time, or at any

rate part of them, now constitute the Sundance formation. In areas

where these marine deposits were not laid down, such as most of western

Colorado, continental sediments were laid down. ‘These continental sedi-

ments may be represented by parts of the La Plata sandstone. Beds with

Sundance fossils overlie the La Plata in some areas, however, so it is not

possible to correlate these formations directly.

As the deposits immediately overlying the Sundance are of continental

origin in every area which has been described, possibly excepting the

Unkpapa sandstone of the Black Hills region, and it is probable that this

also is continental, it is evident that the sea withdrew from the Rocky

170 ANNALS NEW YORK ACADEMY OF SCIENCES

Mountain area before the deposition of the Morrison formation, or perhaps

before the deposition of the Morrison formation of certain regions in the

eastern part of its distribution area. Whether this retreat took place im-

mediately after the deposition of the beds now constituting the highest

members of the Sundance formation, or whether post-Sundance marine

beds were deposited and eroded before the deposition of the Morrison, is

a rather difficult question to decide. It is probable that there was a time

interval between the deposition of the highest Sundance beds and lowest

Morrison beds in the eastern area.

In the southwestern Morrison area the McElmo appears to overlie the

La Plata sandstone conformably. In some localities, however, such as

near Green River, Utah, and in northeastern Utah, the McHlmo or its

representative, the continental part of the Flaming Gorge, overlies the

marine Jurassic of Sundance age. It is probable that the continental

sedimentation which produced the larger part of the La Plata sandstone

was interrupted by the invasion of the Sundance sea. If any area where

the La Plata had been deposited was not covered by this sea, and there

appears to be such, and if this area was in connection with the source of

material to the westward, it is probable that continental deposition con-

tinued without any extensive break from La Plata into lower McElmo

time. In areas in Colorado, east of the southern Sundance sea in Utah,

the La Plata sedimentation was suspended for the time being; whether

erosion of the Colorado area took place at this time is difficult to deter-

mine. The Colorado La Plata probably never extended very far to the

east at any time. Possibly shght erosion took place over the Colorado

area, but not enough to make any sharp erosion contact between the

La Plata and McEImo.

From the distribution of the Sundance beds, it appears probable that

the Sundance sea retreated in the direction from which it advanced, ex-

posing the southern areas first. From the nature of the contact between

the Sundance and Morrison formations in the eastern areas, it appears

possible that post-Sundance beds were deposited and eroded before the

deposition of the Morrison. Such an interpretation certainly fits the facts

known in the case, and there does not appear to be any strong evidence

against it.

When the southern Utah area was laid bare by the retreat of the Sun-

dance sea, a broad practically flat plain seems to have been left, and as

the sea retreated farther and farther this plain appears to have become

larger and larger, until it occupied a considerable tract in the western

portion of the United States. Continental sedimentation probably began

immediately after the retreat of the sea. In the southwestern areas the

MOOK, STUDY OF THE MORRISON FORMATION 171

lowest beds of the McEImo formation probably represent this period of

sedimentation. The exact geological age of these lower McElmo beds

depends upon the decision of the question regarding the post-Sundance

deposition and erosion. If these beds were deposited immediately after

the highest Sundance, they are upper Jurassic in age; if they were de-

posited after a post-Sundance-pre-Morrison erosion interval, they may be

upper Jurassic or basal Comanchean. 'T’o which of these two periods the

lower beds of the McEImo really belong is not especially important from

the point of view of the present paper.

From the greater thickness of the Morrison beds to the west, and from

the larger amount of coarse material in the formation in its western

occurrences, conditions which are distinctly shown in the descriptions of

the formation, though there are local variations from them, it seems to

the writer almost certain that the source of the materials comprising the

Morrison came from mountain areas to the west of the present area of

the formation.

After the lower beds of the McElmo phase of the Morrison were de-

posited, the formation was extended to the east, northeast and southeast.

On such a plain as the one above indicated, it would be possible for a

drainage system similar to that now existing in eastern China to develop.

Such a drainage system, with large overloaded rivers, swamps, lakes and

interlacing connecting streams was inaugurated. Afolian sedimentation

no doubt accompanied the stream deposition to a certain extent. As the

_ formation increased in thickness it also spread farther out, the upper beds

overlapping the lower ones. It seems probable that the lower beds of the

Morrison formation in its eastern areas are not to be correlated in age with

the lower beds of the McElmo in the western areas, but are later. This

extension of the formation undoubtedly took a considerable leneth of

time. The section shown in a given locality at present does not usually

represent continuous deposition in that area, but in many cases at least

represents an alternation of erosion and deposition, with deposition pre-

dominating in the long run. A given thickness laid down under such

conditions may represent as long a time interval as a thickness three or

four times as great, or more, deposited under conditions of continuous

deposition.

The Unkpapa sandstone, in the Black Hills region, may represent an

zolian deposit laid down on the Morrison plain after the retreat of the

Sundance sea and before the Morrison sediments had been extended to

_ that point.

Under the conditions of alternating deposition and erosion indicated

above, it would not be necessary for the beds in every section to corre-

172 ANNALS NEW YORK ACADEMY OF SCIENCES

spond, bed for bed, or even generally, with the beds in another section.

It is also reasonable to suppose that some whole sections in certain areas

are slightly younger or older than other whole sections in other areas.

It appears, then, that the Morrison commenced as a continental deposit

in the western areas of its occurrence im early Comanchean twme (or

possibly latest Jurassic), and that it spread outward as it was built up,

the uppermost and easternmost beds being laid down in Comanchean

time. The upper beds are generally fine-grained as compared with the

lower ones. This suggests that the mountain areas to the west were being

worn down and that the streams had only sufficient gradient, on the

average, to carry fine material.

The exact relation of the Morrison to the marine Comanchean is not

definitely known, except that Washita beds are known, in one or two

cases, to overlie the Morrison. If the above interpretation of the Morri-

son be anything like the truth, it seems probable that the Morrison merged

into the marine deposits in the southeastern areas, such as Texas, and

that the Morrison in its southeastern and eastern areas consisted of true

delta deposits.

BiB EO GAY s

1821. 1. James, HE. P.: “Remarks on the sandstone and fioetz trap formation

of the Valley of the Mississippi.” Amer. Philos. Soc., Trans., vol. ii, pp.

191-215, 1821 (read Aug. 17, 1821). [General description of the hog-backs,

ete. ]

1823. 1. Lone, StepHEN H.: Account of an expedition from Pittsburgh to

the Rocky Mountains, performed in the years 1819-20; compiled by Edward

James. Vol. i, 503 pp.; vol. ii, 442 pp.; atlas of 11 sheets, 1823. [Descrip-

tions of sediments at the east base of the Rocky Mountains. ]

1859. 1. Meek, F. B., and Hayprn, F. V.: [Some remarks on the geology of

the Black Hills and portions of the surrounding country.} Phila. Acad.

Sci., Proe., vol. x, pp. 41-49, map, 1859. [Section and description of beds

around the Black Hills. ]

1861. 1. Nerweserry, J. S.: “Geological report.” Colorado Exploring Pxpedi-

tion, Lieut. J. C. Ives in charge, 154 pp., 28 figs., 4 plates, 1861. [Sections

and descriptions of the beds, some of which probably include Morrison. ]

10 All important papers are listed, though the bibliography is not absolutely complete,

especially in regard to very early papers. Works on the principies involved in the dis-

eussions in the present paper are included, as well as works dealing directly with the

Morrison formation. The bibliography of the paleontology of the Morrison is not in-

cluded, as it would add hundreds of titles which are of no value from the point of view

of this work, being anatomical in nature. The original references to the various genera

and species are given in the section on paleontology, with a few of the more important

subsequent references.

MOOK, STUDY OF THE MORRISON FORMATION 173

1868. 1. Hayprn, F. V.: “Remarks on the geological formations along the

eastern margins of the Rocky Mountains.” Amer. Journ. Sci., 2nd ser.,

vol. xlv, pp. 322-326, May, 1868. [Notes the presence of Jurassic beds,

which include what is now known as Morrison. ]

1871. 1. Marsnu, O. C.: “On the geology of the eastern Uintah Mountains.”

Amer. Journ. Sci., 3rd ser., vol. i, pp. 191-198, March, 1871. [Notes the

occurrence of a Megalosaurus tooth south df the mountains. ]

1871. 2. Haynpen, F. V.: “Notes on the geology of Wyoming and Colorado

territories.” No. 2. Amer. Philos. Soc., Proc. N. 8., vol. xi, pp. 25-26, 1871.

[Notes the presence of Jurassic beds in Como Bluff. ]

1873. 1. Comstock, THEO. B.: “On the geology of western Wyoming.” Amer.

Journ. Sci., 3rd ser., vol. vi, pp. 426-432, Dec., 1873. [Jurassic and Creta-

ceous beds of the Owl Creek Mountains described. |

1874. 1. Marvine, A. R.: [Report of Middle Park Division.| U.S. geol. and

geog. Sury. Terr., embracing Colorado, F. V. Hayden in charge, 7th Ann.

Rep. [for 1873], pp. 83-192, 1874. [Many sections and descriptions of

Front Range strata. ]

1874. 2. Enpiicu, F. M.: [Report of the San Luis Division.] U. S. geol.

and geog. Surv. Terr., embracing Colorado, F. V. Hayden in charge, 7th

Ann. Rep. [for 1873], pp. 275-301, 305-361, 1874. [Many sections, including

that at Cafion City, Colorado. ]

1874. 3. Marvine, A. R.: “Gold Hill mining region, its position and general

geology.” U. S. geol. and geog. Surv. Terr., embracing Colorado, F. V.

Hayden in charge, 7th Ann. Rep. [for 1873], pp. 685-687, 1874. [Descrip-

tions of Front Range geology. Triassic, Jurassic and Cretaceous present

in the hog-backs. ]

1874. 4. GiLpert, G. K., Howe tt, W. E., and Lorw, O.: Geolegic Atlas. U.S.

geog. and geol. Hxplorations and Surveys west of the 100th meridian,

G. M. Wheeler in charge, 20 sheets folio, 1874? [Distribution of the.

Jurassic shown. |

1875. 1. Corr, E. D.: “Report on the geology of that part of northwestern

New Mexico examined during the field season of 1874.” U.S. geog. and

geol. Explorations and Surveys west of the 100 meridian, by Wheeler, Ann. .

Rep. in Ann. Rep. of the Chief of Engineers, U. S. A., for 1875. App. LL,

pp. 61-97, 1 pl., 1875. [Descriptions of the Jurassic beds at Colorado City

and northern New Mexico. |

1875. 2. Lonw, Oscar: “Geological and mineralogical report on portions of.

Colorado and New Mexico.” U.S. geog. and geol. Explorations and Sur-

veys west of the 100th meridian, by Wheeler, Ann. Rep., in the Ann. Rep.

of the Chief of Engineers, U. S. A., for 1875, App. LL, pp. 97-116, 1875.

[Description of the Arkansas Valley section. ]

1875. 3. Comstock, THEO. B.: ‘Geological report.’’ Report upon the recon-

naissance of northwestern Wyoming, including Yellowstone National Park,

for 1873, by Jones, pp. 85-259, map, 1875. [Correlation tables, notes on

Jurassic sandstone. ]

1875. 4. Corr, H. D.: “The geology of New Mexico.” Phila. Acad. Sci.,

Proe., vol. x, pp. 152-153, Aug., 1875. [Tooth of Zelaps found.]

1875. 5. Hower, HE. H.: “Report on the geology of portions of Utah, Ne-

vada, Arizona and New Mexico examined in 1872 and 1873.” U.S. geog.

1974 ANNALS NEW YORK ACADEMY OF SCIENCES

and geol. Explorations and Surveys west of the 100th meridian, G. M.

Wheeler in charge, Rep., vol. iii, Geology, pp. 227-301, 1875. [Description

of Jurassic beds in Utah.]

1875. 6. SveEvenson, J. J.: “Geology of a portion of Colorado explored and

surveyed in 1873.” U.S. geog. and geol. Explorations and Surveys west

of the 100th meridian, G. M. Wheeler in charge, Rep., vol. iii, Geology, pp.

303-501, 1875. [Notes on the Canon City beds. ]

1876. 1. Powe tt, J. W.: “Report on the geology of the eastern portion of the

Uintah Mountains and a region of country adjacent thereto.” U.S. geol.

and geog. Sury. Terr., vii + 218 pp., atlas folio, 1876. [Original deserip-

tion of the Flaming Gorge group. |]

1876. 2. Prare, A. C.: Report [as geologist of the middle division]. U. 8S.

geol. and geog. Surv. Terr., embracing Colorado and parts of the adjacent

Territories, F. V. Hayden in charge, 8th Ann. Rep. [for 1874], pp. 73-180,

1876. [Sections and descriptions of Jurassic beds. ]

1876. 3. Nerwperry, J. 8.: “Geological report.” Report of expedition from

Santa Fe, N. Mex., to the junction of the Grand and Green rivers of the

Great Colorado of the West, in 1855, under the command of Capt. J. N.

Macomb, Pp. 9-118, map, plates, 1876. [Descriptions of Jurassic and other

beds. ]

1877. 1. Prare, A. C.: “Notes on the age of the Rocky Mountains in Colo-

rado.” Amer. Journ. Sci., 3rd ser., vol. xiii, pp. 172-181, 1877. [Subsidence

from Archiean to Tertiary, elevation in Tertiary. ]

1877. 2. Pratt, A. C.: [Report as geologist of the Grand River Division,

1875.] U.S. geol. and geog. Sury. Terr., embracing Colorado and parts of

adjacent Territories, F. V. Hayden in charge, 9th Ann. Rep. [for 1875],

pp. 31-101, 1877. [Detailed descriptions of the Grand River representa-

tives of the Morrison. ]

1877. 38. Hotmrs, W. H.: “Geological report on the San Juan district.”

U. S. geol. and geog. Sury. Terr., embracing Colorado, 9th Ann. Rep. [for

1875], pp. 241-276, 18 pls., 1877. [Sections and descriptions of Morrison

and other beds. ]

1877. 4. Hacur, ARNoLD, and Emmons, S. F.: “Descriptive geology.’ U. S.

geol. Exploration of the 40th parallel, Clarence King, geologist in charge,

vol. ii, 890 pp., 25 pls., 1877. [Many sections and descriptions, some of

which include the Morrison. ]

1877. 5. Corn, HE. D.: “On a gigantic saurian from the Dakota epoch of

Colorado.” Paleontological Bulletin No. 25, “published August 23, 1877,”

9 pp. [Original description of Camarasaurus supremus. The Morrison is

here called Dakota. ]

1878. 1. Kine, CLarence: “Systematic geology.” U.S. geol. Exploration of

the 40th Parallel, vol. i, x + 803 pp., 42 pls., frontsp., profile, 1878. [Dis-

eussion of Jurassic strata. ]

1878. 2. Marsu, O. C.: “Principal characters of American Jurassic dino-

saurs. Pt. I.’ Amer. Journ. Sci., 3rd ser., vol. xvi, pp. 411-416, pls. 4-10,

Noy., 1878. [Discussion of the Atlantosaurus beds. ]

1878. 3. Wuuiston, S. W.: “American Jurassic dinosaurs.” Kansas Acad.

Sci., Trans., vol. vi, pp. 42-46, 1878. [Stratigraphic notes and history of .

early work. |

MOOK, STUDY OF THE MORRISON FORMATION 175

1878. 4. Wutitr, C. A.: Report on the geology of a portion of northwestern

Coiorado, F. V. Hayden in charge, 10th Ann. Rep. [for 1876], pp. 1-60, 2

pls., 1878. [Short description of Jurassic beds. ]

1878. 5. Enpiicu, H. M.: “Report on the geology of the White River dis-

trict.” U.S. geol. and geog. Sury. Terr., embracing Colorado and portions

of adjacent Territories, F. V. Hayden in charge, 10th Ann. Rep. [for

1876], pp. 61-159, 1878. [Sections, descriptions and discussions of Jurassic

beds. ]

1878. 6. PeEatE, A. C.: “Geological report on the Grand River district.”

U. S. geol. and geog. Surv. Terr., embracing Colorado, F. V. Hayden in

charge, 10th Ann. Rep. [for 1876], pp. 181-185, 1878. [Notes on Jurassic

beds. ]

1878. 7. Hotmes, W. H.: “Report on the geology of the Sierra Abaja and

west San Miguel Mountains.’ U.S. geol. and geog. Surv. Terr., 10th Ann.

Rep. [for 1876], p. 189, 1878. [Mentions Lower Dakota and Jurassic in

Dolores Canyon. |

1878. 8. Cops, EK. D.: ‘On the yvertebrata of the Dakota epoch of Colorado.”

Paleontological Bulletin No. 28, “printed Jan. 12, 1878;” Amer. Philos.

Soe., Proc., vol. xvii, pp. 233-247, 16 figs., 1878. [The Morrison is called

Dakota. ]

1879. 1. SvEeveNsonN, J. J.: “Report on a special geological party operating

in Colorado and New Mexico from Spanish Peaks south, field season of

1878 (and 1879).” U.S. geog. and geol. Explorations and Surveys west

of the 100th meridian by Wheeler, Ann. Rep., in Ann. Rep. of the Chief of

HWngineers, U. S. A., for 1879, App. OO, pp. 271-281, 1879. [p. 276 men-

tions slight occurrence of Jura-Trias rocks; some of these may be Morri-

son. |

1879. 2. Murer, 8. A.: “North American Mesozoic geology and paleontol-

ogy.” Cincin. Soe. Nat. Hist., Journ., vol. ii, pp. 140-161, 223-244, 1879.

[See also 1880, 1, and 1881, 3.] [Sections and descriptions. ]

1879. 3. Prat, A. C.: “Report on the geology of the Green River district.”

U.S. geol. and geog. Sury. Terr., embracing Wyoming and Idaho and por-

tions of adjacent Territories, F. V. Hayden in charge, 11th Ann. Rep. [for

1877], pp. 509-646, 1879. [Many stratigraphic sections and descriptions,

including Jurassic beds. ]

1879. 4. Mepuicorr, H. B., and BLANrorp, W. T.: A manual of the geology

of India. Vol. ii, pp. 445-817, 21 pls., 1879. [Descriptions of alluvial de-

posits. |

1880. 1. Muirrer, 8. A.: “North American Mesozoic geology and paleontol-

ogy.” Cincin. Soc. Nat. Hist., Journ., vol. iii, pp. 9-32, 79-118, 165-202,

245-288, 1880. [See also 1879, 2, and 1881, 3.] [Sections and descrip-

tions. ]

1880. 2. Newton, HENRY, and JENNEY, WALTER R.: ‘“‘Report on the geology

and resources of the Black Hills, with atlas.” U.S. geol. and geog. Surv.

of the Rocky Mountain Region, J. W. Powell in charge, xv + 333 pp., 28

figs., atlas, 1880. [Many detailed sections, descriptions and discussions. ]

1881. 1. StEvENSON, J. J.: “Report upon geological examinations in south-

ern Colorado and northern New Mexico during the years 1878 and 1879.”

U. S. geog. and geol. Explorations and Surveys west of the 100th meridian,

we 4 a i —"

176 ANNALS NEW YORK ACADEMY OF SCIENCES

G. M. Wheeler in charge, vol. iii, Geology, Supplement, 420 pp., 1 pl., 3

maps and 49 figs. Appendix by C. A. White, 33 pp., 3 pls., 1881. [ Descrip-

tions of beds, some of which are probably Morrison. ]

1881. 2. Haypen, F. V.: Geological and geographical atlas of Colorado. and

portions of adjacent territories. Detailed sheets by F. M. Endlich, W. H.

Holmes, A. C. Peale, A. R. Marvine and C. A. White. To accompany the

10th Ann. Rep. [for 1876] of the U. 8S. geol. and geog. Surv. Terr., F. V.

Hayden in charge, 1881. [Maps showing the distribution of the Jurassic

and “Lower Dakota” of Colorado. ]

1881. 3. Mutter, S. A.: “North American Mesozoic geology and paleontol-

ogy.” Cincin. Soc. Nat. Hist., Journ., vol. iv, pp. 3-46, 93-144, 183-254,

1881. [See also 1879, 2, and 1880, 1.] [Sections and descriptions. ]

1882. 1. Hits, R. C.: “Jura-Trias of southwestern Colorado.” Amer. Journ.

Sci., 3rd ser., vol. xxiii, pp. 234-244, 1882. [General description of beds:

some of these are probably Morrison. |

1884. 1. Corr, H. D.: “Tertiary vertebrata.” U. S. geol. and geog. Surv.

Terr., F. V. Hayden in charge, Report, vol. iii, vii + 1009 pp., 38 figs., 138

pls., 1884. [In the introduction remarks on Mesozoic stratigraphy are

given. The “Camarasaurus Beds” — Wealden. Comparative faunal lists

of Morrison and Wealden. ]

1885. 1. Emmons, 8. F.: “Report of Rocky Mountain division.” U. S. Geol.

Sury., 6th Ann. Rep., pp. 62-67, 1885. [The variegated beds near Gunnison

separated from the Dakota by a non-conformity. |

1885. 2. Marsu, O. C.: “On American Jurassic mammals.” Brit. Assoc. for

the Ady. Sci., Rep., 54th meeting, pp. 734-736, 1 pl., 1885. Geol. Masg.,

decade iii, vol. iv, pp. 241-247, 289-299, pls. 6-9, 1887. [General section of

Mesozoic beds and descriptions of Morrison mammals. |

1886. 1. Iuusene, I. H.: “Report on oil fields of Fremont County.” Colo.

Sch. Mines, Rep., 1885, pp. 75-88, 1886. [Oil present in the Morrison beds

near Canon City.]

1886. 2. Wuuirr, C. A.: “On the fresh-water invertebrates of the North

American Jurassic.” U. 8S. Geol. Surv., Bull. No. 29, 24 pp., 4 pls., 1886.

[Descriptions and illustrations of all Morrison invertebrates known up to.

that time. Discussion of origin of the Morrison. The beds deposited in a

great lake extending from southern Colorado to the Black Hills. ]

1887. 1. Lakers, ArtHuR: “Geology of Colorado ore deposits.” Colo. Sch.

Mines, Rep. 1886, pp. v-xix, xxi-clix, 5 pls., 1887. [Describes strata, in-

cluding the Morrison, in the introduction. |

1887. 2. Lakes, ArtHur: “Geology of the Aspen mining region, Pitkin

County, Colorado.” Colo. Sch. Mines, Rep. 1886, pp. 45-84, 1 pl., 1887.

i [Jurassic beds, probably meaning Morrison, present. ]

1887. 3. Wuitsr, C. A.: “On the Cretaceous formations of Texas and their

relation to those of other portions of North America.” Phila. Acad. Sci..

Proec., vol. xxxix, pp. 39-47, 1887. [The Dakota in the Missouri Valley

rests on Jurassic beds, which are absent in the Texas region. |

1888. 1. Cops, H. D.: “Mesozoic realm.” Int. Cong. Geol. Amer. Comm. Rep.,

1888, FE, pp. 1-15, 1888. Amer. Geol., vol. ii, pp. 261-268, 1888. [Notes of

fauna and stratigraphy of Jurassic (Morrison). ]

MOOK, STUDY OF THE MORRISON FORMATION maiure

1888. 2. Osporn, H. F.: “On the structure and classification of the Mesozoic

mammalia.’ Phila. Acad. Nat. Sci., Journ., vol. ix, pp. 186-265, 30 figs., 2

pls., 1888. [Mammals from the Purbeck and Morrison formations de-

seribed and discussed, the Morrison forms being referred to as Jurassic. ]

1889. 1. Hurts, R. C.: [Address: The field for original work on the Rocky

Mountains.] Colo. Sci. Soc., Proec., vol. iii, pp. 148-164, 1889. [Suggests

collecting in the Atlantosaurus beds. ]

1889. 2. STEVENSON, J. J.: “The Mesozoic rocks of southern Colorado and

northern New Mexico.” Amer. Geol., vol. iii, pp. 391-397, 1889. [Jurassic

in southern Colorado consists of thin limestones; near Cafion City shales.]

1889. 3. Wuure, ©. A.: “The lower Cretaceous of the southwest and its re-

lation to the underlying and overlying formations.” Amer. Journ. Sci.,

3rd ser., vol. xxxviii, pp. 440-445, 1889. [Marine origin of the Dakota

shown by fossils. No Jura or Lower Cretaceous in central New Mexico.

No evidence of Triassic or Jurassic seas. ]

1880. 1. Craern, F. W.: “On the Cheyenne sandstone and Neocomian shales

of Kansas.” Washburn Coll. Lab., Bull., vol. ii, pp. 69-80, 1890. Amer.

Geol., vol. vi, pp. 233-238; vol. vii, pp. 23-33, 1890. [The Cheyenne sand-

stone may be equivalent to the Atlantosaurus beds or to the Trinity series. ]

1890. 2. Hitts, R. C.: “Additional notes on the eruptions of the Spanish

Peaks region.” Colo. Sci. Soc., Proc., vol. iii, pp. 224-227, 1890. [Notes

the occurrence of Jurassic shales. ]

1890. 3. Emmons, S. F.: “Orographic movements in the Rocky Mountains.”

Geol. Soe. Amer., Bull., yol. i, pp. 245-286, 1890. [Atlantosaurus beds may

be Cretaceous. Term “Jura-Dakota” used. The beds are of fresh-water

origin. They were deposited around various “islands” in the Rocky Moun-

tain region. |

1890. 4. Lakes, ArTHUR: “Extinct volcanoes in Colorado.” Amer. Geol.,

vol. v, pp. 38-43, 2 pls., 1890. [Notes cutting of Jurassic strata by vol-

canoes. |

1890. 5. Wut, C. A.: “The North American Mesozoic.” Amer. Assoc. for

the Ady. Sci., Proc., vol. xxxviii, pp. 205-226, 1890. [Atlantic Coast pos-

sesses upper Jurassic. The Potomac formation is divided. In “Interior

Region’ a few hundred feet of Jurassic lie conformably on the Trias; the

upper part is non-marine and lower part marine. Jurassic disappears

north and south, its distribution being less than that of the Trias. ] ‘

1891. 1. CANNON, GroRGE B.: “Notes on the geology of Perry Park.” Colo.

Sei. Soc., Proe., vol. iii, pp. 308-315, 1891. [Note on the Jura-Dakota hog-

back. |

1891. 2. Marsn, O. C.: “Geological horizons as determined by vertebrate

fossils.” Amer. Journ. Sci., 3rd ser., vol. xlii, p. 112, 1891 (abstract of

paper read to the Intern. Geol. Congr.). [The Hallopus beds are Jurassic

and older than the Baptanodon beds. |

1891. 3. Grospy, W. O.: “On the contrast in color of the soils of high and

low latitudes.” Amer. Geol., vol. viii, pp. 72-82, 1891. [Color contrast is

due partly to difference in climate under which deposits were formed and

also to geologic age. ]

1892. 1. WeeEp, W. H.: “Two Montana coal fields.” Geol. Soc. Amer., Bull.,

vol. iii, pp. 301-330, 13 figs., 1892. [Jurassic and Kootenie beds are both

present at Great Falls, Montana. ]

178 ANNALS NEW YORK ACADEMY OF SCIENCES

1893. 1. Cannon, GeorceE L., Jr.: “The geology of Denver and vicinity.”

Colo. Sci. Soc, Proe., vol. iv, pp. 235-270, 1893. [Account of the early

dinosaur collecting and description of the section at Morrison, Colorado. ]

1894. 1. Woopwortn, J. B.: ‘The relation between base-leveling and organic

evolution.” Amer. Geol., vol. xiv, pp. 209-235, 1894. [Review of the

various theories concerning land erosion, discussion of the effect of river

changes on organisms and their distribution, and the relation of the de-

velopment of the Jura-Cretaceous peneplain with the contemporaneous

fauna and flora, and general summary of the facts presented. Reptiles,’

and particularly the dinosaur group, correlated in development with the

- growth of the peneplain. }

1894. 2. Cross, WHITMAN: “Pike’s Peak, Colorado, quadrangie.” U.S. Geol.

Surv., Geol. Atlas, Folio No. 7, 7 pp., 5 maps, 1894. [Descriptions of the

Morrison formation, including the Oil Creek locality. Proposal of the

name Morrison. ]

1894. 3. Evprincr, G. H., and Emmons, 8. F.: ‘“Anthracite-Crested Butte,

Colorado, quadrangle.” U.S. Geol. Surv., Geol. Atlas, Folio No. 9, 10 pp.,

8 maps, 1 section sheet, 1894. [Description of the Gunnison formation

and proposal of the name Gunnison. ]

1895. 1. Marsu, O. C.: “Restoration of some European dinosaurs, with sug-

gestions as to their place among the reptilia.””’ Amer. Journ. Sci., 3rd ser.,

vol. 1, pp. 407-412, 1 fig., 4 pls., 1895. [Morrison equal to Wealden in age,

and both are Jurassic. Restorations of Morrison dinosaurs. ]

1896. 1. Emmons, 8S. F., Cross, WHITMAN, and Hupringr, G. H.: “Geology

of the Denver basin in Colorado.” U.S. Geol. Sury., Monograph, No. 27,

556 pp., 31 pls., 102 figs., 1896. [Morrison formation deposited in a de-

pression following Jurassic movement. The formation is Lower Creta-

ceous in age. |

1896. 2. MarsuH, O. C.: ‘‘Vertebrate Fossils” [of the Denver basin.j U. S.

Geol. Surv., Monograph, No. 27, pp. 473-527, pls. 21-31, figs. 23-102, 1896.

[Notes on the Hallopus, Baptanodon and Atlantosaurus beds. The latter

two are Jurassic in age.]

1896. 3. Warp, L. F.: “Some analogies in the lower Cretaceous of Europe

and America.” U.S. Geol. Sury., 16th Ann. Rep., pt. 1, pp. 452-463, pls.

. 97-107, figs. 67-69, 1896. [Comparison in detail of the Potomac and Weal-

den. Discussion of origin and description of the flora. ]

1896. 4. Woopwarp, ArTHuR S.: “Note on the affinities of the Hnglish

Wealden fish-fauna.” Geol. Mag., decade iii, No. 380, pp. 69-71, 1896.

[The Wealden estuary the last refuge of the Jurassic fish-fauna. ]

1896. 5. Marsu, O. C.: “Age of the Wealden.” Amer. Journ. Sci., 4th ser.,

vol. i, p. 234, 1896. [From the evidence of the fossil fishes the Wealden

is Jurassic. ]

1896. 6. Marsu, O. C.: “The geology of Block Island.” Amer. Journ. Sci.,

4th ser., vol. ii, pp. 295-298, 375-377, 1896. [Jurassic of the Potemae type

present. |

1896. 7. Marsu, O. C.: “The Jurassic formation on the Atlantic Coast.”

Sci., N. S., vol. iv, pp. 805-816, 1896. [Evidence for Jurassic age of the

Potomac deposits. ]

MOOK, STUDY OF THE MORRISON FORMATION 179

1896. 8. MarsH, O. C.: “The Jurassic formation on the Atlantic Coast.”

Amer. Journ. Sci., 4th ser., vol. ii, pp. 433-447, 2 figs., 1896. [Description

of the Baptanodon and Atlantosaurus beds of the west. Description of

the Pleurocelus beds and the Potomac formation. Discussion of the rela-

tive importance of fossils, the age of the Wealden and the position and

character of the Jurassic. |

1896. 9. GipERT, G. K.: “Age of the Potomac formation.” Sci., N. S., vol.

iv, pp. 875-877, 1896. [Discusses the methods of correlation used by Marsh

in his paper on the Jurassic formation of the Atlantic Coast. Slightly

favors Cretaceous age for the Potomac beds. ]

1896. 1@. Hz, R. T.: “A question of classification.” Sci., N. S., vol. iv, pp.

918-922, 1896. [Equivalents of the Potomac extend along the Atlantic

Coast and westward into Texas. Tuscaloosa equals Lower Trinity. The

whole is Cretaceous. Discussion of Marsh’s evidence of the Jurassic age

of these beds. ]

1896. 11. Marcovu, Jutes: “The Jura in the United States.” Sci, N. S.,

vol. iv, pp. 945-947, 1896. [Potomac formation Jurassic in age.]

1897. 1. HawortH, Hrasmus: “Underground waters of southwestern Kan-

sas.” U.S. Geol. Surv., Water Supply Paper, No. 6, 63 pp., 12 pls., 2 figs.,

1897. [Map and discussion of Jura-Trias beds. Red beds were deposited

in ocean water. |

1897. 2. GireEerT, G. K.: “Pueblo, Colorado, quadrangle.” U.S. Geol. Surv.,

Geol. Atlas, Folio No. 36, 7 pp., 16 figs., 6 maps, section sheet, illustration

sheet, 1897. [Discussion and sections of Mesozoic strata, including the

Morrison. ]

1897. 3. CrarK, Wm. B.: “Outline of present knowledge of the physical fea-

tures of Maryland, embracing an account of the physiography, geology

and mineral resources.” Md. Geol. Sury., vol. i, pp. 141-228, pls. 6-13, 1897.

[Upper Jurassic and Lower Cretaceous deposited in brackish water. ]

1897. 4. CLark,, Wm. B., and Biserns, ArTrHur: “The stratigraphy of the

Potomac group in Maryland.” Journ. Geol., vol. v, pp. 479-506, 1897. [De-

Scriptions of the Patuxent, Arundel, Patapsco and Raritan formations.

Discussions of the relations and age of the deposits and the views of other

writers. Patuxent and Arundel are Jurassic? Patapsco is Lower Creta-

ceous. The whole series deposited in brackish water. ]

1897. 5. Scorr, Wm. B.: An introduction to geology. 1st ed., xii + 573 pp.,

169 figs., 18 pls., Macmillan Co., 1897. [Name “Como” given to the Morri-

son in southern Wyoming. The formation is assigned to the Lower Cre-

taceous period. ] .

1898. 1. Purineton, C. W.: “Preliminary report on the mining industry of

the Telluride quadrangle, Colorado.” U.S. Geol. Surv., 18th Ann. Rep.,

pt. 3, pp. 751-848, pls. 103-158, figs. 66-74, 1898. [Notes on the La Plata

and Gunnison formations. ]

1898. 2. Spurr, J. E.: “Geology of the Aspen mining district, Colorado, with

atlas.’ U.S. Geol. Surv., Monograph, No. 31, 260 pp., 48 pls., 11 figs., 30

atlas sheets, 1898. [Description of the Gunnison formation, part of which

is correlated with the Atlantosaurus beds. ]

1898. 3. MarsH, O. C.: “Jurassic formation on the Atlantic Coast.’ Sup-

plement. Amer. Journ. Sci., 4th ser., vol. vi, pp. 105-115, 1 fig. 1898. [Re-

180 ANNALS NEW YORK ACADEMY OF SCIENCES

ply to Gilbert’s criticism and restatement of evidence for Jurassic age of

the Potomac beds. ]

1898. 4. Topp, JAmMeEs E.: “Section along Rapid Creek from Rapid city west-

ward. South Dak. Geol. Sury., Bull., No. 2, pp. 27-40, pls. 2-5,° 1898.

[Notes on the Black Hills Jurassic. ]

1898. 5. Marsu, O. C.: “Cyead horizons in the Rocky Mountains.” Amer.

Journ. Sci., 4th ser., vol. vi, p. 197, 1898. [Notes on the Mesozoic strata

of the Black Hills. ]

1898. 6. Davis, W. M.: ‘Physical geography,’ xviii + 432 pp., 9 pls., 261

figs., frontsp., Ginn & Co., N. Y., 1898. [Discussion of river deposits. De-

scription of the Hoangho alluvial plain. ]

1899. 1. Marsu, O. C.: “Footprints of Jurassic dinosaurs.” Amer. Journ.

Sci., 4th ser., vol. vii, pp. 229-232, 3 figs., 1899. [Footprints found in the

Morrison of the Black Hills region.] Y

1899. 2. Darton, N. H.: “Jurassic formations of the Black Hills of South

Dakota.” Geol. Soc. Amer. Bull., vol. x, pp. 383-396, 3 pls., 1899. [De-

scription and history of the Black Hills Jurassic beds: Beulah shales

equivalent to the Morrison. |

1899. 3. Cross, WHITMAN: “Telluride, Colorado, quadrangle.” U. 8S. Geol.

Surv., Geol. Atlas, Folio No. 57, 18 pp., 4 maps, section sheet, 3 illustra-

tion sheets, 1899. [Sections and descriptions of the La Plata and McElmo

formations. These names are proposed for divisions of the Gunnison for-

mation. |

1899. 4. Cross, WHITMAN, SPENcER, A. C., and Purrneton, C. W.: “La Plata,

Colorado, quadrangle.” U.S. Geol. Surv., Geol. Atlas, Folio No. 60, 14 pp.,

4 maps, 2 illustration sheets, 1899. [La Plata and McK]mo formations

described and discussed. ]

1900. 4. Kwynicut, W. C.: “The Wyoming fossil fields expedition of July,

1899.” Nat. Geog. Mag., vol. xi, pp. 449-465, 8 pls., 1900. [Description of

Como Bluff and other Morrison localities. |

1900. 2. Kwnicut, W. C.: “Jurassic rocks of southeastern Wyoming.” Geol.

Soc. Amer., Bull., vol. xi, pp. 377-388, pl. 23, 1900. [Detailed sections,

map, descriptions and faunal lists. ]

1900. 3. Kwynicut. W. C.: “A preliminary report on the artesian basins of

Wyoming.” Wyo. Exp. Station, Bull. No. 45, pp. 107-251, 14 pls., 15 figs.,

map, June, 1900. [Brief description of the Morrison formation. ]

1900. 4. Cross, WHITMAN, and Spencer, A. C.: “Geology of the Rico Moun-

tains, Colorado.” U.S. Geol. Sury., 21st Ann. Rep., pt. 2, pp. 15-165, pls.

1-22, 1900. [The La Plata is correlated with the lower part of the Gunni-

son, and the McEHlmo with the upper part, and in part with the Morrison. |

1900. 5. Locan, W. N.: “The stratigraphy and invertebrate faunas of the

Jurassic formation in the Freezeout Hills of Wyoming.” Kans. Univ.

Quart., vol. ix, pp. 109-134, pls. 25-31, 5 figs., 1900. [Descriptions, detailed

section and descriptions of new species of invertebrate fossils. ]

190C. 6. Warp, L. F.: “Deseription of a new genus and twenty new species

of fossil cycadean trunks from the Jurassic of Wyoming.’ Wash. Acad.

Sei., Proe., vol. i, pp. 251-300, pls. 14-21, 1900. [Stratigraphic notes and

deseriptions of the eyeads, which form the principal element of the Mor-

rison flora. |

MOOK, STUDY OF THE MORRISON FORMATION 181

1900. 7. Hurts, R. C.: Walsenberg, Colorado, quadrangle. U.S. Geol. Sury.,

Geol. Atlas, Folio No. 68, 6 pp., 3 figs., 6 maps, 2 section sheets, 1900.

[Deseription of the Morrison formation. It varies from 100 to 270 feet. ]

1900. 8. Warp, L. F. (with the collaboration of Wm. Fontaine, Atreus Wan-

ner and F. H. Knowlton): “Status of the Mesozoic floras of the United

States. First paper: Older Mesozoic.” U.S. Geol. Surv., 20th Ann. Rep.,

pt. 2, pp. 211-430, pls. 21-179, 1900. [Description of the occurrence and

character of the strata and plant remains of the Trias and Jura at differ-

ent localities in the United States and the characters of the genera and

species. ]

1900. 9. Davis, W. M.: “The fresh-water Tertiary formations of the Rocky

Mountain region.” Amer. Acad. Arts and Sci., Proc., vol. xxxy, pp. 345-

373, 1900. [Discussion of flood-plain deposits and short description of

Hoangho and Indo-Gangetice flood-plains. ]

190@. 10. Logan, W. N.: “A North American épicontinental sea of Jurassic

age.” Journ. Geol., vol. viii, p. 241, 4 figs., 1900. [Section of the Morrison

and Sundance formations, map of distribution of the Sundance, summary

of sequence of events concerning the advance and retreat of the Sundance

sea. ]

1901. 1. Darton, N. H.: “Preliminary description of the geology and water

resources of the Black Hills and adjacent regions in South Dakota and

Wyoming.” U. S. Geol. Sury., 21st Ann. Rep., pt. 4, pp. 497-599, 55 pls.,

28 figs., 1901. [Sections, descriptions, etc.; Beulah shales equal the Mor-

rison. ]

1901. 2. Darron, N. H.: “Comparison of the stratigraphy of the Black Hills

with that of the Rocky Mountain front range.” Geol. Soc. Amer., Bull.,

vol. xii, p. 478, 1901. [General comparison, Morrison included.]

1901. 3. Wiutiston, 8S. W.: “The Dinosaurian genus Creosawrus Marsh.”

Amer. Journ. Sci., 4th ser., vol. xi, pp. 111-114, 1 fig., 1901. [Name “Atlan-

tosaurus Beds” replaced by “Como.’’]

1901. 4. Ruices, Eimer §8.: “The dinosaur beds of the Grand River Valley of

Colorado.” Field Col. Mus. Pub. 60, Geol. Ser., vol. i, no. 9, pp. 267-275,

6 pls., 1901. [General section and description of beds. They were de-

posited by a combination of stream and lake deposition. |

1901. 5. Harcuer, J. B.: “The Jurassic dinosaur deposits near Canon City,

Colorado.” Carn. Mus., Ann., vol. i, pp. 327-341, 5 figs., 1901. [Descrip-

tion of section, discussion of origin and correlation. |

1901. 6. Loomis, F. B.: “On Jurassic stratigraphy in southeastern Wyo-

ming.” Amer. Mus. Nat. Hist., Bull., vol. xiv, pp. 189-198, 2 pls., 1901.

[Detailed sections and descriptions of the Morrison at Como Bluff and

near-by localities. ]

1901. 7. Ler, W. T.: “The Morrison formation of southeastern Colorado.”

Journ. Geol., vol. ix, pp. 343-352, 4 figs., 1901. [Detailed section and dis-

eussion of correlation of the beds in the canyons in southeastern Colo-

rado. |

1901. 8. Darron, N. H., and Kerry, A.: “Washington, Maryland-Virginia-

District of Columbia, quadrangle.” U.S. Geol. Sury., Geol. Atlas, Folio

No. 70, 7 pp., 8 maps, 1901. [Notes on the Potomac beds. ]

1902. 1. Darton, N. H.: “Norfolk, Virginia-North Carolina, quadrangle.”

U. S. Geol. Sury., Geol. Atlas, Folio No. 80, 4 pp., 4 maps, section sheet,

182 ANNALS NEW YORK ACADEMY OF SCIENCES

illustration sheet, 1902. [The Potomac series Cretaceous in age and

estuarine in origin. |

1902. 2. Darton, N. H.: “Oelrichs, South Dakota-Nebraska quadrangle.”

U. 8S. Geol. Surv., Geol. Atlas, Folio No. 85, 6 pp., 4 maps, 2 figs., section

sheet, illustration sheet, 1902. [The Lakota immediately overlies the

Unkpapa near Hot Springs, South Dakota. The Morrison is absent in this

locality. |

1902. 3. Rices, EK. S., and Farrineron, O. C.: “The dinosaur beds of the

Grand River Valley of Colorado.” Sci. Amer., Supp., vol. liii, pp. 22061-

22062, 2 figs., 1902. [Description and discussion of the Grand River beds.

They were deposited in a system of streams and lakes. ]

1902. 4. Fraas, E.: “Geologische Streifztige durch die Pririen und Felsen-

gebirge Nordamerikas.” Wtirttemberg, Jahreshefte des Vereins ftir vater-

landische Naturkunde, Stuttgart, Jahrg. lviii, pp. 65-68, 1902. [Obseryva-

tions on the Jurassic beds of Wyoming and their invertebrate fossils. ]

1902. 5. Lee, W. T.: “The Morrison shales of southern Colorado and north-

ern New Mexico.” Journ. Geol., vol. x, pp. 36-58, 7 figs., 1902. [Detailed

descriptions of the southern Morrison occurrences. The Morrison extends

eastward into Oklahoma. ]

1902. 6. Len, W. T.: “Canyons of southeastern Colorado.” Journ. Geog.,

vol. i, pp. 357-370, 12 figs., 1902. [Sections, descriptions, etc., of the Morri-

son and adjacent beds. ]

1902. 7. Loomis, F. B.: “On Jurassic stratigraphy on the west side of the

Black Hills.” Second paper on American Jurassic stratigraphy. Amer.

Mus. Nat. Hist., Bull., vol. xvi, pp. 401-407, 1 pl., 1902. [Detailed descrip-

tions and sections. |

1902. 8. Darton, N. H.: “Stratigraphy of the Bighorn Mountains.” Sci,

N. S8., vol. xv, p. 823, 1902. [Brief abstract of fuller paper.]

1902. 9. Hatcuer, J. B.: “Structure of the foreleg and manus of Bronto-

saurus.” Carn. Mus., Ann., vol. i, pp. 356-376, 2 pls., 1902. [Notes on the

levels of different quarries. |

1902. 10. SwHarruck, GrorcE B.: “Development concerning the physical fea-

tures of Cecil County.” Md. Geol. Surv., vol. Cecil Co., pp. 31-62, 2 pls.,

1902. [Extensive bibliography. ]

1902. 11. SwHatruck, GrorGE B.: “The geology of the coastal plain forma-

tions.” Md. Geol. Surv., vol. Cecil Co., pp. 149-194, 5 pls., 2 figs., 1902.

[Patuxent is Jurassic; Patapsco is Cretaceous; Arundel is absent or not

differentiated. ]

1903. 1. Reacan, A. B.: “Geology of the Jennez-Albuquerque region, New

Mexico.” Amer. Geol., vol. xxxi, pp. 67-111, 7 pls., 1903. [Cretaceous rests

directly upon Red Beds; apparently no Morrison present. ]

1903. 2. Ler, W. T.: “The canyons of northeastern New Mexico.” Journ.

Geog., vol. ii, pp. 63-82, 14 figs., 1908. [Sections, descriptions ete. of coun-

try where the Morrison is present. |

1903. 3. -Darton, N. H.: “Preliminary report on the geology and water re-

sources of Nebraska west of the 100th meridian.” U.S. Geol. Sury., Pro-

fessional Paper No. 17, 69 pp., 43 pls., 23 figs., 1903. [Sections, ete. ]

1903. 4. Harcuer, J. B.: “Osteology of Haplocanthosaurus, with descrip-

tion of a new species and remarks on the probable habits of the sauropoda

{

‘

MOOK, STUDY OF THE MORRISON FORMATION 183

and the age and origin of the Atlantosaurus beds.” Carn. Mus. Mem., vol.

li, pp. 1-72, 6 pls., 28 figs., 1903. [The Atlantosaurus beds, or Morrison,

are Jurassic in age. They represent the result of combined erosion and

deposition, the latter process being the dominant one. ]

1903. 5. Smiru, W. S. Tancrier: “Hartville, Wyoming, quadrangle.’ U. 8.

Geol. Surv., Geol. Atlas, Folio No. 91, 6 pp., 2 maps, 2 section sheets, 1

illustration sheet, 1903. [Short description of the Morrison formation.]

1903. 6. Santon, T. W.: “A new fresh-water molluscan faunule from the

Cretaceous of Montana.” Amer. Philos. Soc., Proe., vol. Ixii, pp. 188-189,

1 pl., 1903. [Discussion of the age of the Morrison formation. ]

1903. 7. Warp, lL. F.: “Correlation of the Potomac of Maryland and Vir-

ginia.” Abst., Sci., N. S., vol. xvii, pp. 941-942, 1903. [General discussion. ]

1903. 8. JoHNSON, D. W.: “Geology of the Cerillos Hills, New Mexico. Pt. I.

General Geology.” Sch. Mines Quart., vol. xxiv, pp. 303-350, 7 figs., 7 pls. ;

pp. 456-500, 6 figs., 10 pls., 1903. [Discussion of origin of sediments and

their criteria. ] é

1903. 9. Tsi nan fu Sheet. Kartographische Abtheilung der Konig]. Preuss.

Landes-Aufnahme. Karte von Ost-China, 1901? [Pub. 1903]. [Detailed

map of part of the alluvial plain in eastern China. Shows streams inter-

lacing in a complicated manner, many lakes and swamps on the fan. |

1903. 10. Nanking Sheet. Kartographische Abtheilung der Konigl. Preuss.

Landes-Aufnahme. Karte von Ost-China [Pub. 1903]. [Map of the delta

of the Yangtse Kiang. Many lakes and swamps are on it. Some of the

lakes are 50 miles or more in length. ]

1904. 1. HartcHeEr, J. B.: “An attempt to correlate the marine with the non-

marine formations of the Middle West.” Amer. Philos. Soc., Proe., vol.

xliii, pp. 341-365, 2 figs., 1904. [The Atlantosaurus beds and the Dakota

considered as the possible equivalents of the marine Jurassic and Lower

Cretaceous. | :

1904. 2. JaAccar, THomMAS A.: “Economic resources of the northern Black

Hills, pt. 1, General Geology.” U.S. Geol. Sury., Professional Paper No.

26, pp. 13-41, pl. 1, 1904. [Section and short description of the Morrison. |

1904. 3. PercK, Frep. B.: “The Atlantosaur and Titanotherium beds of Wyo-

ming.” Wyoming Hist. and Geol. Soc., Proc. and Col., vol. viii, pp. 25-41,

5 pls., 1904. [Sections, stratigraphical descriptions and faunal lists.]

1904. 4. Darton, N. H.: “Newcastle, Wyoming-South Dakota, quadrangle.”

U. S. Geol. Surv., Geol. Atlas, Folio No. 107, 9 pp., 4 maps, 6 figs., section

sheet, illustration sheet, 1904. [Description of the Morrison. ]

1904. 5. Darton, N. H., and SmitH, W. S. T.: “Edgemont, South Dakota-

Nebraska, quadrangle.” U.S. Geol. Surv., Geol. Atlas, Folio No. 108, 10

pp., 4 maps, 5 figs., section sheet, illustration sheet, 1904. [Description

and section of Morrison. |

1904. 6. Spencer, A. C.: “The copper deposits of the Encampment district,

Wyoming.” U.S. Geol. Sury., Professional Paper No. 25, 107 pp., 2 pls.,

49 figs., 1904. [Notes 400 feet of fresh-water Jurassic beds with lime-

stones. |

1904. 7. Lee, W. T.: “Age of the Atlantosaurus beds.” Geol. Soc. Amer.,

-Bull., vol. xiv, pp. 531-532, 1904. [These beds can be correlated with the

Lower Cretaceous of Texas. ]

‘i;

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184. ANNALS NEW YORK ACADEMY OF SCIENCES

1904. 8. Darton, N. H.: “Comparison of the stratigraphy of the Black Hills,

Bighorn Mountains and Rocky Mountain front range.” Geol. Soc.,Amer.,

Bull., vol. xv, pp. 379-448, 14 pls., 1904. [Many sections, descriptions and

discussions. The Morrison is considered as Cretaceous in age.)

1904. 9. Peking Sheet. Kartographische Abtheilung der Konigl. Preuss.

Landes-Aufnahme. Karte von Ost-China, 1901 [Pub. 1904]. [Map of part

of the alluvial plain of China. Many lakes are present on it.]

1904. 10. Yi tschang fu Sheet. Kartographische Abtheilung der Konig.

Preuss. Landes-Aufnahme. Karte von Ost-China, 1901? [Pub. 1904]. [Map

of part of the alluvial plain of China near the inland mountains. Lakes

are present on it.]

1904. 11. Hankau Sheet. Kartographische Abtheilung der Konigl. Preuss.

Landes-Aufnahme. Karte von Ost-China, 1902 [Pub. 1904]. [Map of the

portion of the alluvial plain of China which includes the divide between

the Hoangho and Yangtse rivers. Many lakes, from small ponds to lakes

25 miles or more in length, are présent in broad belts each side of the main

rivers. They connect more or less by small streams, | :

1904. 12. Ossporn, HENRY F.: “Fossil wonders of the West, the dinosaurs of

the Bone-Cabin Quarry, being the first description of the greatest ‘find’

of extinct animals ever made.’ Century Mag., vol. Ixviii, pp. 680-694, 18

figs., 1904. [General account of the discovery and description of the oc-

currence of the remains, with some descriptions. Good figures of Morrison

outcrops. ]

1905. 1. Cross, W., and Hows, Ernst: “Red Beds of southwestern Colorado

and their correlation.” Geol. Soc. Amer., Bull., vol. xvi, pp. 447-498, 4 pls.,

4 figs., 1905. [The McEH]lmo, 300 to 900 feet thick, equivalent to the upper

Gunnison or Morrison. ]

1905. 2. Keyes, CHARLES R.: “The Jurassic horizons around the southern

end of the Rocky Mountains.” Amer. Geol., vol. xxxvi, pp. 289-292, 1 fig.,

1905. [Diagram of relations of beds in the southern Rocky Mountain

region. ]

1905. 3. Darton, N. H.: “Preliminary report on the geology and under-

ground water resources of the central great plains.” U. S. Geol. Sury.,

Professional Paper No. 32, 433 pp., 72 pls., 18 figs., 1905. [Extensive dis-

cussion of the Morrison and other Mesozoic formations, with many sec-

tions. ]

1905. 4. Wuuiston, 8S. W.: “The Hallopus, Baptanodon and Atlantosaurus

beds of Marsh.” Journ. Geol., vol. xiii, pp. 338-350, 1905. [Hallopus beds

are Triassic, Baptanodon beds are Jurassic and Atlantosaurus beds prob-

ably Cretaceous. Historical notes. ]

1905. 5. Darton, N. H.: “Sundance, Wyoming-South Dakota, quadrangle.”

U. S. Geol. Surv., Geol. Atlas, Folio No. 127, 12 pp.. 5 maps, 3 figs., 1905.

[Sections and descriptions. The Morrison is Cretaceous. ]

1905. 6. Darton, N. H., and O’Harra, C. C.: “Aladdin, Wyoming-South Da-

kota, Montana, quadrangle.” U.S. Geol. Suryv., Geol. Atlas, Folio No. 128,

8 pp., 4 maps, 1 fig., 1 section sheet, 1905. [Short description of the Mor-

rison formation. ]

1905. 7. Warp, L. F.: “Status of the Mesozoic floras of the United States.”

Second paper. U. S. Geol. Sury., Monograph No. 48, pt. 1, text, 616 pp.;

MOOK, STUDY OF THE MORRISON FORMATION 185

pt. 2, plates, 119 pls., 1905. (Includes papers by Fontaine, Bibbins and

Wieland. Stratigraphic notes by Wieland.) [Complete descriptions of

Mesozoic plants and discussions and descriptions of their occurrence. |

1905. 8. Darton, N. H.: “Discovery of the Comanche fauna in southeastern

Colorado.” Sci., N. S., vol. xxii, p. 120, 1905. [Brief note.]

1905. 9. FENNEMAN, N. M.: “Geology of the Boulder district, Colorado.”

U. S. Geol. Surv., Bull., No. 265, 101 pp., 5 pls., 11 figs., 1905. [Detailed

description of the Morrison at this locality.]

1905. 10. Cross, W.: “Rico, Colorado, quadrangle.” U.S. Geol. Surv., Geol.

Atlas, Folio No. 130, 20 pp., 5 maps, illustration sheet, 1905. [Sections

and descriptions of the La Plata and McE]mo formations. ]

1905. 11. Sranton, T. W.: “The Morrison formation and its relations with

the Comanchic series and the Dakota formation.” Journ. Geol., vol. xiii,

pp. 657-667, 1905. [Statement of existing knowledge of the Morrison in

southern Colorado. Upper Comanchean fossils found above the Morrison

at Cafion City.]

1905. 12. HuNnTINGTON, ELLSworTH : “The basin of eastern Persia and Sis-

tan.” Carn. Inst. Wash., Pub. 26, pp. 217-317, figs. 149-174, 1905. [Obser-

vations on the deposition of shales of various colors. ]

1906. 1. FrRaas, H.: “Vergleichung der amerikanischen und europiischen

Jura-formation.”’ Intern. Amerikanisten Kongress, Tag. 14, pp. 41-45,

| Stuttgart, 1906. [General comparison. ]

1906. 2. Darron, N. H.: “Geology of the Bighorn Mountains.’ U. S. Geol.

Sury., Professional Paper No. 51, 129 pp., 47 pls., 14 figs., 1906. [Many

sections and descriptions, etc. The Morrison is Cretaceous; good distri-

bution map. ]

1906. 3. Darton, N. H.: “Geology and underground waters of the Arkansas

Valley in eastern Colorado.” U. 8S. Geol. Sury., Professional Paper No.

52, 90 pp., 27 pls., 2 figs., 1906. [Section, descriptions and discussion of

the Mesozoic strata.]

1906. 4. I suer, Casstus A.: “Geology and water resources of the Bighorn

basin, Wyoming.” U. S. Geol. Surv., Professional Paper No. 53, 72 pp.,

16 pls., 1 fig., 1906. [Many sections and descriptions; the Morrison is

Cretaceous; good distribution map. ]

1906. 5. Mitrer, Bengamin L.: “Dover, Delaware-Maryland, quadrangle.”

U. S. Geol. Surv., Geol. Atlas, Folio No. 187, 10 pp., 2 maps, 1 fig., 1906.

[Patapsco is present and is Lower Cretaceous in age; Arundel and Patux-

ent may underlie the Patapsco.]

1906. 6. Darton, N. H.: “Bald Mountain and Dayton, Wyoming, quad-

rangles.” U.S. Geol. Surv., Geol.-Atlas, Folio No. 141, 15 pp., 7 maps, 6

figs., 1 cross-section and 2 illustration sheets, 1906. [Sections, maps, de-

seriptions, ete., including the Morrison. ]

2 1906. 7. Darton, N. H.: “Cloud Peak and Fort McKinley, Wyoming, quad-

rangles.” U.S. Geol. Sury., Geol. Atlas, Folio No. 142, 16 pp., 7 maps, 1

cross-section and 2 illustration sheets. [Sections, maps, descriptions, etc.,

including the Morrison. |

1906. 8. CLARK, W. B., and Mittrr, B. L.: “A brief summary of the geology

of the Virginia coastal plain.’ Va. Geol. Surv., Geol. Ser., Bull., No. 2, pp.

11-24, 1906. [Patuxent and Arundel provisionally referred to the Jurassic. ]

186 ANNALS NEW YORK ACADEMY OF SCIENCES |

1906. 9. Darton, N. H.: “Geology of the Owl Creek Mountains, with notes

on resources of adjacent regions in the ceded portion of the Shoshone

Indian reservation.” 59th Cong., Ist Sess., Sen. Doc. no. 219, 48 pp., 19

pls., 1 fig., 1906. [Section, descriptions and distribution map of the Mor-

rison and other formations. |

1906. 10. Darton, N. H.: “The hot springs at Thermopolis, Wyoming.”

Journ. Geol., vol. xiv, pp. 194-200, 4 figs., 1906. [The Morrison is present

at Thermopolis. |

1906. 11. CrLarK, W. B., and MatHews, H. B.: “Repert on the physical fea-

tures of Maryland, together with an account of the exhibits of Maryland

mineral resources made by the Maryland Geological Survey.” Md. Geol.

Sury., vol. vi, pts. 1 and 2, pp. 27-281, 30 pls., 19 figs., map, 1906. [Patux-

ent and Arundel are Jurassic. Both were deposited in Swampy areas. ]

1906. 12. Wrevtanp, G. R.: “American fossil cyeads.” Carn. Inst. Wash.,

Pub. 34, 266 pp., 50 pls., 137 figs., 1906. [Notes on the occurrence of the

cyeads in the Morrison beds, with complete discussion of their morphology

and relationships. | '

1907..1. Cross, W.: “Stratigraphic results of a reconnaissance in western

Colorado and Utah.” Journ. Geol., vol. xv, pp. 634-679, 11 figs., 1907.

[Description of the McElmo formation. Correlation table. McHlmo

equivalent to the Morrison. }

1907. 2. Weexs, F. B.: “Stratigraphy and structure of the Uinta range.”

Geol. Soe. Amer., Bull., vol. xviii, pp. 427-448, 6 pls., 3 figs., 1907. [600—

800 feet of Jurassic present, of which 200-300 feet is limestone. ]

1907. 3. Fisuer, C. A.: “The Great Falls coal field, Montana.” U.S. Geol.

Sury., Bull., No. 316, pp. 161-173, 1 pl., 1907. [Morrison and Kootenie beds

present.] :

1907. 4. Darton, N. H., and O’Harra, C. C.: “Devil’s tower, Wyoming,

quadrangle.” U.S. Geol. Surv., Geol. Atlas, Folio No. 150, 9 pp., 3 maps,

eross-section and structure sheet, 1907. [Sections, maps, descriptions, ete.,

of the Morrison and other beds. ]

1907. 5. Swuarruck, G. B., Mizurr, B. L., and Brppins, ARTHUR: “Patuxent,”

Maryland, quadrangle. U. S. Geol. Sury., Geol. Atlas, Folio No. 152, 12

pp., 8 maps, 2 figs., section sheet, 1907. [Patuxent and Arundel provision-

ally classed as Jurassic and Patapsco as Cretaceous. |

1907. G6. Cross, W., Hower, H., and Irvine, J. D.: “Ouray, Colorado, quad-

rangle.” U. S. Geol. Sury., Geol. Atlas, Folio No. 153, 19 pp., 3 maps, 4

figs., illustration sheet, 1907. [Descriptions and maps, La Plata, MceH]lmo

and other formations. |

1907. 7. CHAMBERLIN, T. C., and SaLispury, R. D.: Geology, Volume III.

624 pp., 269 figs. [Good description of the Morrison formation and fluyia-

tile origin given for it.]

1908. 1. Darron, N. H.: “Paleozoic and Mesozoic of central Wyoming.”

Geol. Soe. Amer., Bull., vol. xix, pp. 403-470, 10 pls., 1908. [Many sections

and descriptions. Morrison is Cretaceous. |

1908. 2. Keyes, Cartes R.: “‘Geotectonics of the Hstancia plains.” Journ.

Geol., vol. xvi, pp. 434-451, 12 figs., 1908. [The Morrison is present in

eastern New Mexico. ]

MOOK, STUDY OF THE MORRISON FORMATION 187

1908. 3. FisHer, C. A.: “Southern extension of the Kootenai and Montana

coal-bearing formations in northern Montana.” Econ. Geol., vol. iii, no. 1,

pp. 77-99, 1908. [The Kootenie lies apparently with perfect conformity on

the Morrison. ]

1908. 4. Barrett, JosEpH: “Relations between climate and terrestrial de-

posits. Pt. If. Relation of sediments to regions of deposition.” Journ.

Geol., vol. xvi, pp. 255-295, 1908. [Discussion of types of sediment de-

posited under various conditions; notes on colors in sediments and discus-

sion of their origin. ]

1909. 1. Martin, G. C.: “The Niobrara limestone as a source of Portland

cement material.’ U.S. Geol. Surv., Bull. No. 380, pp. 314-326, 1 fig., 1909.

[The Morrison is of fresh-water origin. ]

1909. 2. GitmMorE, C. W.: “A new Rhynchocephalian from the Jurassic of

Wyoming, with notes on the fauna of ‘Quarry 9.’” U.S. Nat. Mus., Proc.,

vol. xxxvii, pp. 35-42, 1 pl., 5 figs., 1909. [Lists of the fauna of the Mor-

vison formation. ]

1909. 3. Spurr, J. H.: “Scapolite rocks of America.” Amer. Journ. Sci., 4th

ser., vol. xxv, p. 154, 1909. [Description of the Gunnison formation. ]

1909. 4. Les, W. T.: “The Grand Mesa coal field, Colorado.” U. S. Geol.

Sury., Bull., No. 341, pp. 316-334, 1 pl., 1909. [Section including the Gun-

nison formation. |

1909. 5. Darton, N. H.: “Geology and water resources of the northern part

of the Black Hills and adjacent regions in South Dakota and Wyoming.”

U. 8. Geol. Sury., Professional Paper No. 65, 105 pp., 24 pls., 15 figs., 1909.

[Many sections and descriptions of Sundance, Unkpapa, Morrison and

other beds. ] :

_ 1909. 6. Darton, N. H., and O’Harra, C. C.: “Bellefourche, South Dakota,

quadrangle.” U.S. Geol. Surv., Geol. Atlas, Folio No. 164, 9 pp., 4 maps,

1 fig. (field edition, 67 pp., 5 maps), 1909. [Descriptions, sections, ete. of

Morrison and associated formations. ] ,

1909. 7. Gimore, C. W.: “Osteology of the Jurassic reptile Camptosaurus,

with a review of the species of the genus and descriptions of two new

species.” U. S. Nat. Mus., Proc, vol. xxxvi, pp. 197-332, 15 pls., 47 figs.,

1909. [Deseription of quarry and copies of Loomis’s sections. |

1909. 8. Wuis, Batty: “Paleogeographic maps of North America.” Journ.

Geol., vol. xvii, pp. 203-208; 253-256; 286-288; 342-343; 403-405; 406-409;

424-428; 503-505; 506-508; 600-602; 15 figs., 1909. [Pp. 408-409; 424-425,

Jura-Cretaceous maps and descriptions. ]

1909. 9. Sranron, T. W.: “Succession and distribution of later Mesozoic

invertebrate faunas in North America.” Journ. Geol., vol. xvii, pp. 410-

423, 1909. [Jurassic of the Rocky Mountain region equals Oxfordian and

perhaps Callovian. The Morrison is overlain by the Kootenie at the north

and by the Comanchean at the south. ]

1909. 10. HENDERSON, JuNiUS: “The foothills formations of north central

Colorado.” Colo. Geol. Sury., Ist Ann. Rep. for 1908, pp. 145-188, 6 pls.,

1909. [General descriptions of the Morrison and other formations. ]

1909. 11. FuisHerr, C. A.: “Geology of the Great Falls coal field, Montana.”

U. S. Geol. Sury., Bull., No. 356, 85 pp., 12 pls., 2 figs., 1909. [Correlation

tables. The Morrison is present, overlain by the Kootenie. ]

188 ANNALS NHW YORK ACADEMY OF SCIENCES

1909. 12. Darron, N. H., and SimeentHat, C. E.: “Geology and mineral re-

sources of the Laramie basin, Wyoming.” U.S. Geol. Sury., Bull., No. 364,

81 pp., 8 pls., 1 fig., 1909. [Sections, description and distribution map of

the Morrison and other formations. |

1909. 13. FisHer, C. A.: “Geology and water resources of the Great Falls

region, Montana.” U.S. Geol. Surv., Water Supply Paper, No. 221, 89 pp.,

7 pls., 1909. [Cretaceous, Morrison (60-120 feet thick) and Ellis forma-

tions appear to be conformable throughout. ]

1909. 14. Darton, N. H.: “Geology and underground waters of South Da-

kota.” U.S. Geol. Sury., Water Supply Paper, No. 227, 156 pp., 15 pls.,

7 figs., 1909. [Sections, discussions and illustrations. Sundance and

Unkpapa are Jurassic; Morrison is Cretaceous. ]

1909. 15. Ler, W. T., and Girry, G. H.: “The Manzano group of the Rio

Grande Valley, New Mexico.” U.S. Geol. Sury., Bull., No. 389, 120 pp.,

12 pls., 9 figs., 1909. [The Morrison is probably present. ]

1909. 16. Hennine, Kart I.: “Streifztige in den Rocky Mountains. IY.

Morrison und die Morrisonformation.” Globus, Bd. xcvi, pp. 344-349, 5

figs., 1909. [Description of the Morrison formation, with discussion as to

its age. |

1910. 1. Lut, R. S.: “Dinosaurian distribution.’ Amer. Journ. Sci., 4th

ser., vol. xxix, pp. 1-39, 10 figs., 1910. [Correlation tables and discussion

of the Morrison and other faunas. ]

1910. 2. Larkin, Pierce: “The occurrence of a sauropod dinosaur in the

Trinity Cretaceous of Oklahoma, with an introductory note by S. W. Wil-

liston.” Journ. Geol., vol. xviii, pp. 93-98, 4 figs., 1910. [A morosauroid

coracoid found in the Trinity sands. ]

1910. 3. ScHuUCcHERT, CHARLES: ‘Paleogeography of North America.” Geol.

Soc. Amer., Bull., vol. xx, pp. 427-606, 56 pls., 1910. [Paleogeographie

maps and discussions. |

1910. 4. Cross, Wuitman: “Hngineer Mountain, Colorado, quadrangle.”

U.S. Geol. Sury., Geol. Atlas, Folio No. 171, 13 pp., 3 maps, 1 section sheet,

2 illustration sheets, 1910. [La Plata is lower Jurassic and equivalent to

the lower part of the Gunnison. The McEI]mo is in general equivalent to

the Morrison. ]

1910. 5. Darton, N. H., BLAcKWELDER, HLioT, and SIEBENTHAL, ©. E.:

“Laramie and Sherman, Wyoming, quadrangles.” U.S. Geol. Surv., Geol.

Atlas, Folio No. 173, 17 pp., 7 maps, 1 section sheet, 1 illustration sheet,

1910. [Sections of Sundance and Morrison formations. ]

1910. 6. Gar, Hoyt S.: “Coal fields of northwest Colorado and northeast

Utah.” U.S. Geol. Sury., Bull., No. 415, 265 pp., 22 pls. and figs., 1910.

[Description of the Flaming Gorge formation. ]

1910. 7. ©O’HarraA, CreopuHas: ‘The Badland formations of the Black Hills

region.” S. D. Sch. Mines, Dept. Geol., Bull., No. 9, 152 pp., 50 pls., 20

figs., Noy., 1910. [Sections and descriptions of the Jurassic. ]

1910. 8. CrarK, W. B.: “Results of a recent investigation of the coastal

plain formations in the area between Massachusetts and North Carolina.”

Abst., Geol. Soc. Amer., Bull., vol. xx, pp. 646-654, 1 pl., 1910. [Patuxent,

Arundel and Patapsco are all Lower Cretaceous. ]

1911. 1. Wooprurr, Kimer G.: “The Lander oil field, Wyoming.” U. S.

Geol. Sury., Bull., No. 452, pp. 7-36, 6 pls., 1 fig., 1911. [Section of Sun-

dance, Morrison and Cloverly formations. ]

MOOK, STUDY OF THE MORRISON FORMATION 189

1911. 2. Stons, R. W.: “Geological relations of ore deposits in the Elkhorn

Mountains, Montana.” U. S. Geol. Sury., Bull., No. 470, pp. 75-98, 1 pl.,

1911. [Geologic section and map. Morrison is present at this locality. ]

1911. 3. von Huerns, F.: “Kurze Mitteilung tiber Perm, Trias, und Jura in

New Mexico.” Neues Jahrb., Beilage-Bd. xxxii, H. 3, pp. 730-739, 1 pl., 2

figs., 1911. [Sections at Morrison, Colorado, and Mesa Prieta. ]

1911. 4. Jamison, C. H.: “Geology and mineral resources of a portion, of

Fremont County, Wyoming.” Wyoming [Geol. Surv.] ser. B, Bull. No. 2,

$0 pp., 14 pls., map, 1911. [Section and description of the Morrison. ]

1911. 5. CrarK, W. B., Bresins, A., and Berry, H. W.: “The lower Creta-

ceous of Maryland.’ Md. Geol. Surv., vol. Lower Cretaceous, pp. 23-98,

10 pls., 1911. ['The lower portion of the Potomac is Lower Cretaceous in

age. Descriptions and sections of the members of the Potomae forma-

tion. ]

1911. 6. Brrry, Epwarp W.: “The lower Cretaceous floras of the world.”

Md. Geol. Sury., vol. Lower Cretaceous, pp. 99-151, 1 fig., 1911. [Discus-

sion of Lower Cretaceous floras and map of their distribution. ]

1911. 7. Berry, Epwarp W.: “Correlation of the Potomac formation.” Md.

Geol. Sury., vol. Lower Cretaceous, pp. 153-172, 1911. [Correlation table.

Patuxent-Arundel .equal to the Morrison-Kootenie and in part to the

Wealden. |

1911. 8. Lut, R. S.: “The reptilia of the Arundel formation.” Md. Geol.

Surv., vol. Lower Cretaceous, pp. 173-187, 1911. [The Arundel fauna is

Lower Cretaceous rather than Jurassic in age.]

1911. 9. Mirtier, B. L.: “Development of knowledge concerning the physical

features of Prince George County.” Md. Geol. Surv., vol. Prince George

Co., pp. 24-33, 1911. [Note on the Lower Cretaceous, and extensive bibli-

ography. |

1911. 10. Mitier, B. L.: “Geology of Prince George County.” Md. Geol.

Sury., vol. Prince George Co., pp. 83-136, 7 pls., 1911. [Descriptions of the

various members of the Potomac formation. They are all considered as

Lower Cretaceous in age. ]

1912. 1. WeeErmann, C. H.: “The Powder River oil field, Wyoming.” U. S.

Geol. Surv., Bull., No. 471, pp. 56-75, 1 pl., 1 fig., 1912. [Short description

of the Morrison formation. |

1912. 2. Catvert, W. R.: “The Electric coal field, Park County, Montana.”

U. S. Geol. Sury., Bull., No. 471, pp. 406-422, 1 map, 1912. [Description of

Ellis, Morrison and Kootenie formations. Detailed section.]

1912. 3. Ler, W. T.: “The Tijeras coal field, Bernalillo County, New Mex-

ico.” U.S. Geol. Surv., Bull., No. 471, pp. 574-578, 1 pl., 1912. [Notes the

presence of the Morrison formation. ]

1912. 4. Stoner, R. W.: “Coal near the Black Hills, Wyoming-South Da-

kota.” U.S. Geol. Sury., Bull., No. 499, 66 pp., 7 pls., 8 figs., 1912. [Short

description of the Morrison formation. ]

1912. 5. Wiis, Baitey, and Srosr, G. W.: “Index to the stratigraphy of

North America,” accompanied by a geologic map of North America, com-

piled by the United States Geological Survey, in codperation with the

Geological Survey of Canada and the Instituto Geologico de Mexico, under

the supervision of Bailey Willis and George W. Stose. U. 8S. Geol. Surv.,

190 ANNALS NEW YORK ACADEMY OF SCIENCES

Professional Paper, No. 71, 894 pp., 19 figs., large map in sections, 1912.

[Descriptions and bibliographies of all important North American geo-

logical formations; correlation tables ete. |

1912. 6. Ler, W. T.: “Coal fields of Grand Mesa and the West Elk Moun-

tains, Colorado.” U.S. Geol. Surv., Bull., No. 510, 287 pp., 21 pls., 37 figs.,

1912. [Map of the Grand Mesa region, with description and section of the:

Gunnison formation in that region. ]

1912. 7. Srose, G. W.: “Apishapa, Colorado, quadrangle.” U.S. Geol. Sury.,

Geol. Atlas, Folio No. 186, 12 pp., 3 maps, 1 illustration sheet, 1912. [De-

scription of the Morrison formation. ]

1912. 8. Jamison, C. E.: “The Douglas oil field, Converse County, Wyo-

ming.” Wyoming [Geol. Sury.], Bull., No. 3, ser. B, 50 pp., 8 pls., 1912.

[Notes the presence of the Morrison formation. |

1912. 9. Jamison, C. E.: “The Salt Creek oil field, Natrona County, Wyo-

ming.” Wyoming [Geol. Sury.], Bull., No. 4, ser. B, 75 pp., 16 pls., 1 map,

1912. [Notes the presence of the Morrison formation. ]

1912. 10. BarreLL, Josepy: “Criteria for the recognition of ancient delta

deposits.”” Geol. Soc. Amer., Bull., vol. xxiii, pp. 377-446, 4 figs., 1912.

[Discussion of deltas and criteria for recognizing their origin and criteria

for the determination of the marine, lacustrine and fluviatile origin of

sedimentary deposits. |

1913. 1. Grout, F. F., Worcester, P. G., and HENDERSON, JUNIUS: “Recon-

naissance of the geology of the Rabbit Ears region.” Colo. Geol. Sury.,

Bull., No. 5, pt. 1, pp. 1-57, 1 pl., 1 fig., 1913. [Brief description of the

Morrison formation. ]

1913. 2. Burters, R. M.: ‘“ ‘Permian’ or ‘Permo-Carboniferous’ of the east-

ern foothills of the Rocky Mountains in Colorado.” Colo. Geol. Surv., Bull...

No. 5, pt. 2, pp. 61-94, 1915. [Discussion of the Morrison formation.] _

1914. 1. Barnett, V. H.: “The Douglas oil and gas field, Converse County,

Wyoming.” U.S. Geol. Surv., Bull., No. 541-C, pp. 3-42, 1 pl, 1 fig., 1914.

[Brief discussion of the Morrison formation and section. |

1914. 2. WHewetr, D. F.: “The Shoshone River section, Wyoming.” U. S.

Geol. Surv., Bull., No. 541-C, pp. 48-67, 1 pl., 1 fig., 1914. [Deseription and

discussion of the Morrison formation. It is 580 feet thick, which is very

unusual in the northern areas. |

1914. 3. Lupron, CHARLES T.: “Oil and gas near Green River, Grand County,

Utah.” U. S. Geol. Surv., Bull., No. 541, pp. 115-133, 1 pl., 1 fig., 1914.

[The McEImo formation is over 1,000 feet thick near Green River.]

1914. 4. ScuHucneErt, CHaries: “Climates of geologic time.” Carn. Inst.

Wash., Pub. 192, pp. 263-298, figs. 87-90, 1914. [Discussion of the prevail-

ing climates of the various geologic periods. Morrison dinosaurs lived in

a warm and moist climate. |

1914. 5. TRowBRIDGE, ARTHUR C.: “A classification of common sediments and

some criteria for identification of the various classes.” Journ. Geol., vol.

Xxii, pp. 420-436, 12 figs., 1914. [Descriptions of modern sediments of vari-

ous modes of origin and criteria for recognizing the same in older de-

posits. ] ; :

1914. G6. Grapavu, A. W.: Principles of stratigraphy. 1185 pp., 264 ills.,

A. G. Seiler and Co., N. Y., 1914. [Extensive discussion of sedimentary

processes. |

MOOK, STUDY OF THE MORRISON FORMATION 191

1914. 7. Cross, WHITMAN, and LARSEN, HE. 8.: “Contributions to the stratig-

raphy of southwestern Colorado.” U.S. Geol. Surv., Professional Paper

90-H, pp. 37-50, figs. 2, 3, pl. viii, 1914. [Description of McHIlmo formation

and discussion of geological history of region concerned. ]

1914. 8. Barnett, V. H.: “The Moorcroft oil field, Crook County, Wyoming.”

U. 8S. Geol. Surv., Bull., No. 581-C, pp. 83-104, 1 fig., 1 plate (map), 1914.

[Separates only; bulletin not yet issued, Mar. 4, 1915.] [Section of the

Morrison formation in this locality, with brief description. ]

1914. 9. Barnett, V. H.: “Possibilities of oil in the Big Muddy Dome, Con-

verse and Natrona counties, Wyoming.” U. S. Geol. Sury., Bull., No.

581-C, pp. 105-117, 1 plate (map). [Separates only; bulletin not yet

issued, Mar. 4, 1915.] [Note on the Morrison. |

1914. 10. Cross, WHITMAN, and Larsen, Psper §.: “The stratigraphic break

below the Jurassic sandstone in southwestern Colorado.” Abstract. Wash.

Acad. Sci., Journ., vol. iv, p. 237, 1914. [The Dakota does not overlap the

McElmo in Gunnison Canyon, as indicated by Peale’s map of Colorado.]

1915. 1. Berry, Epwarp W.: “Paleobotanic evidence of the age of the Mor-

rison formation.” Geol. Soc. Amer., Bull., vol. xxvi, pp. 335-842, 1915

(read before the Paleontological Society December 30, 1914). [Discussion

of the floras of the Potomac, Wealden and Kootenie formations and the

relation of these to the Morrison. Favors Lower Cretaceous (Coman-

chean) age for the Morrison. ]

1915. 2. Ler, Wituis T.: “Reasons for regarding the Morrison as an intro-

ductory Cretaceous formation.’ Geol. Soc. Amer., Bull., vol. xxvi, pp. 303-

314, 1915 (read before the Paleontological Society December 30, 1914).

[Diastrophic criteria applied to the study of the Morrison. The formation

is considered as the non-marine forerunner of the marine Cretaceous de-

posits. ]

1915. 3. Lui, RicHarp S.: “Sauropoda and Stegosauria of the Morrison of

North America compared with those of Europe and eastern Africa.” Geol.

Soc. Amer., Bull., vol. xxvi, pp. 323-334, 1915 (read before the Paleonto-

logical Society December 30, 1914). [The Morrison partly at least homo-

taxial with the Tendaguru dinosaur beds. The latter are not older than

uppermost Jurassic and probably are early Comanchean. |

1915. 4. Moox, CHartes C.: “Origin and distribution of the Morrison for-

mation.” Geol. Soc. Amer., Bull., vol. xxvi, pp. 315-522, 4 figs., 1915 -(read

before the Paleontological Society December 30, 1914). [The Morrison

the product of alternate deposition and erosion; it may be both Jurassic

and Comanchean in different parts. |

1915. 5. Osporn, H. F.: “Close of Jurassic and opening -of Cretaceous time

in North America.” Geol. Soc. Amer., Bull., vol. xxvi, pp. 295-302, 1915

(read before the Paleontological Society, December 30, 1914). [Paleon-

tologic evidence considered as of greater value than diastrophic in corre-

lation; the Morrison probably both Jurassic and Lower Cretaceous. ]

1915. 6. Stanton, T. W.: “Invertebrate fauna of the Morrison formation.”

Geol. Soc. Amer., Bull., vol. xxvi, pp. 3438-348, 1915 (read before the Pale-

* ontological Society December 30, 1914). [Evidence of the invertebrates is

not conclusive, but seems to indicate Jurassic age for the Morrison. ]

ELATH VI

MAP SHOWING THE DISTRIBUTION OF THE MORRISON FORMATION

Heavy black lines indicate actual outcrops. Cross-hatching indicate areas

where the Morrison probably lies buried beneath younger beds. Dashes indi-

cate areas where the Morrison may or may not underlie younger beds.

Norr.—Since the preparation of this map, Dr. W. T. Lee has informed the writer of

additional outcrops in New Mexico.

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PRELIMINARY REPORT ON FOSSIL MAMMALS FROM PORTO

RICO, WITH DESCRIPTIONS OF A NEW GENUS OF

GROUND SLOTH AND TWO NEW GENERA

OF HYSTRICOMORPH RODENTS?

CONTENTS

Te EROOUCIIOME ss cece ess cee ss eres ee a Poeaceravsuamiaieaie a eee eee Z

SH SUCMNUCe EMEA I CM ee rele cceiie seis elesel eles oie ayav eiercgeta ie smlesi@aieeh Lue e nw bu ok

eNew ceuus of sround sloth................-...- ROR Seay hae ao Aa 195

Deseription of Acratocnus Odontrigonus......0.ccccessccscccccee 195

AS Upto Rete aiden ere a APOC r age as eri te A Aho tes a Anne enc ae 195

MEASUFEMENTS | Olen CLAMMUM eens esi areal ae eee eke 196

Mitaima Chilly nleae sac MU Sine co -ay rare seve) cies Lele ese hace siete eaccre cs a Sckla Meee 196

IMEGASUneMmEMES = Ofe RAMUS cies 2 cis. c anes soo oc) s cue srousinie ov Si ave whl oe les 196

AETULTAT ETS eape re ees eae vanes Sha ers eee aha tee cc ee coat anaiesaee? os sual aus Sumi We Gn eee 196

RUN CUUUI SP eee cee reat nate Ri stops terstcs Sdene meet oars tei ak or ets HAM ois w ob oem e te 197

UMS TDINGVIETIS oc coe gsc bdaaesgosdaucumenoedusen saeuB en 5) LUN

Femur...... aden Garo Ee ORES I SST EH eT OO Or an Ron eee ees 197

UPI eARe ae Meee yaar creachsuavarin aia iaiceedc eae whbeie a ahs ws fe nye oh nia eee a Be 197

DpH La iU1IUaepeeees totes aspera tens SN steno eanctisc ti Mire nm 5c RNR Mat pub aar ier ahah 197

Gallic Guinean retesaes rats Navan atone ora gid ioten v aetranseaiacdn eit eae ee 198

AVGiglie Ise Neman enc teats erie eer a tien Open mes ee le tld 198

VERITAS VE Se ee leh im Gres cise etch eee CEM at Gee Be) are Pe rea ae Be tee we tae ae 198

New genus of hystricomorph................. At eee nts by pce me 199

Description of Hlasmodontomys obliquus....1................... 200

Scour lll eee terrence eae renin et eeu smn mast tn Mine ait sMkos <5 -< teaavbbeet ors 200:

ID CHIEU O Meera eee eine oe eee aes seen SRN AC Get Mase Rone wee 200:

IMIG ASTECTINGIS eterna ee neni on Mr Van ners Niele cvs eons pan 201

Limb bones and trunk skeleton............................ 201

JEVENIT ATES Mets Ses romeo eacmeec neat Riana ag cel le cide en laltn se” sua i¥s Sues arent Skinners 201.

Second new genus of hystricomorph.....................-.....--0-. 202

Description of Heteropsomys insulans...... 00... eee ee ee eee 202

ScUilllenem mrs enctcwe cae ees eat rtate on eyelids ec reget caaurtrs Se Ueto soca 202

ID XSL IRON Gaticeca acre a okra ee koe aoe ee eee ee Perea eae c aiSieners cidiote 203

IMG ASUMEMIEINESE es sec licialcoinis sists oie ea tsloe nels ORL R aS pea en OSS

TRGTTITEES SS aie dec eee ro Enact e oT Bia EC fee Nene eRe tS DUM OAM Imani hs 203

1 Manuscript received by the Hditor, 6 June, 1916.

(193)

194. ANNALS NEW YORK ACADEMY OF SCIENCES

’

INTRODUCTION

The material that forms the basis of this paper came to the American

Museum of Natural History through Dr. Franz Boas, who conducted

archeological investigations in Porto Rico in 1915 as part of the natural

history survey of the island, undertaken by the New York Academy of

Sciences with the codperation of the Insular government. From a cave,

the Cueva de la Ceiba, between Utuado and Arecibo, a number of human

bones were taken and more or less intermingled with them were remains

of several species of mammals. From the upper layers of the cave floor,

largely a heavy deposit of ashes, came a number of bones of a new rodent

genus described recently by Dr. J. A. Allen as Isolobodon portoricensis.?

This part of the deposit Dr. Boas regards as artificial. From deeper in

the cave floor came the material under present discussion, and this for-

mation appears to be of stalactite origin, dark red in color and of a depth

of from 18 to 24 inches.

Before more extended search for additional material is made, it has

‘ seemed best to make a preliminary report on this material, leaving the

finer details of the question of affinities to be discussed in a later paper.

The present paper is part of the author’s plan to report on the mammals

of Porto Rico as his assignment in the natural history survey mentioned

above.

The author wishes to acknowledge indebtedness to Mr. Gerrit Miller,

Curator of Mammals in the United States National Museum, for the

privilege of comparing the rodent material with the collections of fossil

rodents now at Washington; and to Dr. J. A. Allen, Curator of Mam-

malogy and Ornithology, and to Dr. W. D. Matthew, Curator of Verte-

brate Paleontology, both in the American Museum, thanks are due for

valued advice and suggestions.

A list of the material is as follows:

Rostrum with one tooth, fragments of mandibular rami, part of a

humerus, end of a radius, three vertebre, one femur and part of the

other, two tibize, portions of two fibule and a calcaneum, all seemingly of

one individual, an unknown ground sloth.

Two fragmentary rami of different sizes, of an unknown insectivore ?

or bat?

A fragmentary mandibular ramus, too incomplete for present determi-

nation, of a large hystricomorph rodent.

2J. A. Antpn: Annals N. Y. Acad. Sci., Vol. XXVII, pp. 17-22. 25 January, 1916.

8 J, A. ALLEN, 1. c., p. 18.

ANTHONY, FOSSIL MAMMALS FROM PORTO RICO 195

A partially complete cranium with all but one of the teeth, fragments

of crania and rami and fragments of humeri, ulne, radii, femora, all

affording more or less characters, of a large hystricomorph rodent of a

genus seemingly distinct from the above.

A quite complete cranium with one mandibular ramus of a smaller

hystricomorph rodent.

The anterior rostral portion of a canid skull, unquestionably an intru-

sion.

In addition to the above there is a small amount of uncorrelated ma-

terial of fragmentary nature and also skulls and limb bones of Artibeus

jamaacensis.

SYSTEMATIC TREATMENT

New GENUS OF GROUND SLOTH

The type of Megalocnus came from Cuba and consequently it is not so

surprising to discover remains of a ground sloth on Porto Rico. The

feature that is remarkable, however, is that the Porto Rico animal should

be such a widely different type of animal. With this fact in mind, 2. ¢.,

that Megalocnus was a massive bulky animal, while the Porto Rico sloth

was a much more active, less ponderous creature, I have incorporated the

contrast in the following name which I offer for the new form:

Acratocnus odontrigonus* gen. et sp. nov.

Type, No. 14170, Dept. Vert. Pal., from Cueva de la Ceiba, near Utuado,

Porto Rico, 1915; collector, Dr. Kranz Boas. The skull is selected as the type.

DESCRIPTION

Skull (Plate X, Figs. 1-6; Plate XI, Fig. 1).—The skull is incomplete

and shows only the rostrum back to the zygomatic process of the maxil-

laries, one upper tooth and several pieces, somewhat fragmentary, of the

mandibular ramus.

The rostrum is elongate, rather wider anteriorly and is evenly convex

from side to side above. There are no apparent premaxillaries. The

canine is large, slightly curved, of decided triangular cross-section and

with the worn surface seemingly much as in Cholepus. The alveolus of

the canine is very long and curved, reaching the plane of the posterior

border of the zygomatic process on the maxillary, at which point it has

attained a horizontal direction. A pair of very deep preorbital fosse is

* Acratocnus: a, without; «partys, robust, heavy; “ocnus”—meaning ground sloth

without great weight. Odontrigonus: 66wv = ddovs, tooth; Tprywvos, triangular—in al-

lusion to the triagonal canine.

196 ANNALS NEW YORK ACADEMY OF SCIENCES

present, which reduce the palatal width at the first of the molar alveoli to

less than half the width anteriorly. The palatal border of the preorbital

fossa is a regularly curved line. When the skull is viewed in profile, the

palate slopes rather abruptly downward posteriorly, making the rostrum

much deeper at the first tooth of the molar series than it is at the canine.

Measurements of cranium: Width of rostrum just anterior to zygo-

matic roots, 31.5 mm.; greatest width of rostrum, at outside of canine

alveoh, 36 mm.; width of palate between preorbital fossee, 13 mm. ; width

of palate between canines, 13 mm.; length of palate back to first molar

alveolus, 28 mm.; greatest antero-posterior extent of preorbital fossa, 23

mm. ; greatest vertical depth of fossa, 16 mm.; width of canine just below

worn surface, 11 mm. ; thickness of canine, antero-posteriorly, same point,

9 mm.

Mandibular ramus.—The rami are fragmentary, pieces of both sides

and the symphysial junction being found, but give the following charac-

ters (see Plate X, Figs. 3-6) : )

The ramus is deep with a wide ascending portion. The molar alveoh

are deep and of large size. The canine alveolus is three sided to match

the condition found in the maxillary. The canines are large, apparently

of nearly the same size as the upper canines, flaring apart externally but

meeting at the roots. There is no space for a very wide median sym-

phlysial tongue, but a shallow interior concavity or groove is present.. The

diastema between the canine and pm, is very short. Pm, and m, are

larger than m, and m,, m, appearing to be the largest of the series. The

molars are subrectangular to roughly cylindrical in cross-section. The

inferior dental foramen is large.

Measurements of ramus: Depth at anterior edge of ascending portion

(approximate), 25 mm.; depth at pm,, 21 mm.; antero-posterior width

of alveolus of pm,, 8 mm.; width of alveolus of m,, 7 mm.; width of

alveolus of m,, 10 mm.

ITumerus (Plate IX, Figs. 1-2).—Only the middle portion of a hu-

merus (the left) was saved, but this part is sufficient to show that the bone

is rather slender and much ridged for muscle attachment. The deltoid

ridge is large and prominent, giving to the anterior face of the limb a

very flat aspect, while there is a long sharp ridge paralleling the deltoid

developed along the internal side of the humerus for attachment of the

pectoralis muscle. This ridge is deep and terminates distally in a notice-

able knob-like projection. A cross-section of the humerus through these

two ridges would be quite rectangular in outline. There is a noticeable

ridge on the inner posterior aspect of the humerus, extending downward

nearly as far as the deltoid ridge, for the attachment of the latissimus

ANTHONY, FOSSIL MAMMALS FROM PORTO RICO 197

and the teres major. A very large entepicondylar foramen is present.

The small portion of the distal region represented in the bone indicates

a thin expanded condylar region. Greatest width from deltoid to pec-

toral ridge, 14.5 mm.; greatest thickness of bone antero-posteriorly, at

distal end of pectoral ridge, 13.5 mm.; diameter of entepicondylar fora-

men, 6 mm.

Radius (Plate IX, Fig. 3).—Only an end of a radius, the proximal

half, was in the collection of bones. This seems to indicate a fairly

straight flat element not specialized to any marked extent. Width at

about the middle of the bone, 11.5 mm.: thickness at same point, 5.5 mm.

Unguinal phalanx (Plate VIII, Fig. 6).—This phalanx, of which two

from the fore limbs were secured, is of a strong, compressed and moder-

ately curved type. On the articulating surface there is a strong medial

keel. Width of phalanx at a mid point, 5 mm.; depth just anterior to

osseous basal knobs, 8 mm.

Femur (Plate VII, Figs. 1-4; Plate VIII, Fig. 1).—Both femurs are

represented, one complete, except for a small corner of the internal con-

dyle, the other being the distal half only. The femur is fairly robust but

is not at all massive as in most of the Megalonychide. The shaft is not

expanded but has a width considerably less throughout the mid portion

than at the extremities. No great specializations are shown in the muscle

attachment areas. The great trochanter does not rise above the head of

the femur and there is no trochanteric fossa. There is a well developed

lesser trochanter and also a quite prominent crest extending about 30 mm.

along the external aspect of the femur about midway of the shaft. The

condyles are large with marked tuberosities and a deep intercondylar

fossa. Length, 138 mm.; greatest width across condylar portion, 39

mm.:; mean antero-posterior thickness of shaft, 14 mm.; greatest width

across head and great trochanter, 40 mm.; least width of shaft, about

one third of distance from condyles to head, 18 mm.; head of femur, 22

mm. in diameter.

Tibia (Plate VIII, Figs. 2-4).—Both the tibie are complete. The tibia

is but shghtly curved and has a quite smooth, normal shaft. All of the .

facets on the two condyles are well developed. Length, 111 mm.; width

across proximal head, 34 mm.; width across distal head, 26 mm.; shaft

at mid portion, 13 mm. wide X 10 mm. thick.

Fibula (Plate VIII, Fig. 5)—The one nearly complete fibula, the ex-

treme proximal end being broken off, is a slender but strong bone. It has

a large articulating surface distally and proximally as well, as is shown

by the well-marked facet for the proximal head of the fibula on the tibia.

Length, 106 mm.; cross-section of mid portion, 5 & 7 mm.

198 ANNALS NEW YORK ACADEMY OF SCIENCES

Calcaneum (Plate IX, Fig. 4).—The well preserved caleaneum is

quite large with a widely expanded free portion. The border is exten-

sively roughened for tendon attachment.. The facet for the astragulus is

about 5 mm. posterior to the cuboid facet, showing that the astraculus

must be of a long-necked type (no astragulus was obtained). Greatest

length, 41 mm.; width of expanded portion, 30 mm.; thickness of ex-

panded portion, 4.5 mm.; transverse width of cuboid articulation, 15

mm. ; greatest width of calcaneum at anterior end, 19.5 mm.

Vertebre (Plate IX, Figs. 5-7)—Three vertebre were obtained—the

axis, a dorsal and a caudal vertebra.

The axis has a fairly high, wide, keel-shaped neural spine and a short

thick odontoid process. The neural canal is very large. Height from

bottom of centrum to top of neural spine, 34 mm.; length of centrum

from end of odontoid, 24 mm.; height of neural spine from roof of neural

canal, 13 mm.

The dorsal vertebra bears a long spinous process set at a low angle with

the vertebral column. The transverse processes are short; the ribs articu-

late, the tubercle with the transverse process, the head, partly with the

centrum of the anterior vertebra, but to a greater extent with a facet on

the wall of the neural canal of the posterior vertebra. The centrum is

subtriangular im cross-section. Length of spinous process from plane of

anterior margin of transverse processes, 27 mm.; height of spinous process

above roof of neural canal, 12 mm.; length of centrum, 14 mm.

The caudal vertebra is peculiar in having a depressed, flattened appear-

ance with wide transverse processes. ‘The spimous process is low (dis-

torted?) and the neural canal very small. There are no other noticeable

projections from the body of the vertebra. This is a condition very

closely approximating that found in Cholepus of the Bradypodide.

Width across transverse processes, 38 mm.; vertical thickness of centrum,

posteriorly, 8 mm.; lateral width of centrum (articulating surface),

posteriorly, 17 mm.

REMARKS

Acratocnus presents characters that sharply mark it off from any hith-

erto described forms. It seems to have no close direct affinities with any

of the Megalonychide, but relationship, somewhat removed, is shown to

several genera. Compared with the Hapalops-Hucholeops group of the

Santa Cruz formation of Patagonia, a distant relationship may be as-

sumed on the basis of the comparative lightness of limb bones of the

Hapalops-Eucholeops type. Acratocnus is even more slender limbed

than the Santa Cruz sloths, the femur of this genus, for example, being

almost as long as that of Hapalops rutimeyert but of less than half its

breadth. However, the Santa Cruz animals are the hghtest hmbed, most

ANTHONY, FOSSIL MAMMALS FROM PORTO RICO 199

generalized members known among the Megalonychide and it is among

them that the nearest affinities to Acratocnus are found. The calcaneum

of Acratocnus resembles very much that of Hapalops, and the triangular

canine, characteristic of this new genus, is approximated rather closely in

some species of Hapalops. Acratocnus seems to have no very apparent

affinities with Megalocnus from Cuba, the former being at one extreme of

the series, the lighter limbed end, the latter being at the massive hmbed

end of the series.

To summarize, Acratocnus is a form widely differmg from other ground

sloths in such a significant collection of characters as slender limb bones

(relatively speaking), deep anteorbital fossa, triagonal canines, large

molars, short diastema between c and pm,, no pronounced median, sym-

physial tongue, low-spined dorsal vertebree and depressed, expanded

caudal vertebre that its distinctness is readily apparent. Such sugges-

tive structures as the wide caudal and the low dorsal vertebre, the facets

on the calcaneum calling for a long-necked astragulus, and the limb

bones, relatively long for their width, call for a consideration of the tree

sloths, the Bradypodidx, in this connection. It is not the purpose of this

paper to go deeply into such a question and the material might well be

deemed inadequate for such conclusions; but it appears well within the

limits of possibility that some such form as Acratocnus may be used

eventually to throw the two families, the Bradypodide and the Megalony-

chide into one family. Certainly the Porto Rico sloth was not so re-

stricted in its habitat as most of the members of the Megalonychide and

if not in part, at least, arboreal, might readily become so.

Regarding the age of Acratocnus, the indications point to its being a

contemporary of the Pleistocene or late Pleistocene period, quite certainly

not of a much earlier time.

New GeENts or HystricoMoRPH

The large hystricomorph rodent represented by the nearly complete

skull and the skeletal portions of several individuals proves upon exami-

nation and comparison with considerable material to be worthy of a new

genus and the following name is therefore proposed for it:

Elasmodontomys obliquus’® gen. et sp. noy.

Type, No. 14171, Dept. Vert. Pal., from the Cueva de la Ceiba, near Utuado,

Porto Rico, 1915; collector, Dr. Franz Boas. The type is a skull having all

5 Blasmodontomys: éXacpwos, a thin plate; ddwy = dédovs, tooth; uvs, mouse—referring

to the thin plates of enamel that are found in the molars; and obliqwus = oblique, these

plates being not at right angles to the tooth row, as might be expected, but decidedly

oblique to it.

200 ANNALS NEW YORK ACADEMY OF SCIENCES

the teeth but m* (right), and with the nasals and the posterior right side of

the cranium broken away.

DESCRIPTION

Skull (Plate XIII, Figs. 1-3; Plate XIV, Figs. 1-4).—The skull is

essentially hystricomorph in general outlines with eight molar teeth and

large anteorbital fenestra or passages for the masseter. The outline of

the skull above is somewhat similar to that of Myocastor, flat-topped, with

nasals widening anteriorly, the greatest width of the skull just posterior

to the zygomatic process of the maxillary, a short sagittal crest, and a

pinched-in occipital region. The incisive foramina are small and set in a

deep narrow excavation in the palate. The tooth rows are divergent an-

teriorly and the post-palatal notch reaches to about the middle of the last

molar. The bulle are large and compressed laterally. An anterior por-

tion of a lower jaw, probably to be associated with the type skull, indi-

cates a deep ramus, an extensive symphysis and mandibles flaring pos-

teriorly from the symphysis.

Dentition (Plate XIV, Fig. 2).—The teeth present the most striking

characters. The incisors, two in the upper and two in the lower jaw, are

‘long, curved and rather slender in proportion to the size of the skull.

The upper incisors show no striations, but the lower incisor has two well

defined grooves running the full length of the tooth and showing on the

cutting edge. The incisors are deeper antero-posteriorly than broad lat-

erally, and in the lower jaw are noticeably flattened on the inner side

where each tooth meets its fellow of the opposing mandible.

The molar teeth, four in each jaw and all of nearly equal size, are made

up of a succession of thin enamel plates, some of which are slightly

curved, alternating with bands of dentine. The enamel plates run com-

pletely through the tooth from side to side and their edges may be seen

laterally, as there is no encircling wall of enamel. There are five of these

plates in all of the upper molars and in addition the last two molars have

a vestige of a sixth plate. The only lower tooth in position, the first of

the molar series, has five plates, and this condition prevails in a number

of uncorrelated teeth, leading me to expect the lower teeth to closely re-

semble the upper in respect to the number of plates. The upper pre-

molar is subtriangular in section, the three molars are quadrangular. In

all the molars, both upper and lower, the plates are set at a pronounced

angle to the line of the tooth row. The upper molars are set into their

alveoli at an angle that makes each row of teeth flare outward from the

other. Loose teeth show that this is due to a progressive curve in each

molar, beginning with the premolar. The curve to m® is quite extreme,

ANTHONY, FOSSIL MAMMALS FROM PORTO RICO 201

the convexity bemg pointed inward and forward. The molars probably

grew throughout life, as they are rootless and of practically the same

cross-section at the bottom as the top.

Measurements: Total length (approximate), 125 mm.; width, back of

zygomatic process of maxillary (approximate), 46 mm.; length of nasals

(estimate), 40 mm.; length of maxillary tooth row, 32 mm.; length dias-

tema, 30 mm.; dimensions of m*, 8 X 8 mm.; length diastema of lower

jaw, 19 mm.; dimensions of pm,, 6 X 8 mm. long.

Limb bones and trunk skeleton.—The skull of Hlasmodontomys suffi-

ciently establishes the distinctness of this type, and a description of the

other bones found must be deferred to a later paper, making mention,

howeyer, of the fact that the limb bones are in a normal proportion to

the size of the skull and are in most respects very similar to those of any

hystricomorph of this size, Myocastor for example.

REMARKS

EHlasmodontomys seems to occupy a position of its own among the hys-

tricomorphs. At the present writing none of the accepted families of

this section appear to have very strong claims upon it, and this conclu-

sion is not a hasty one, but the result of a careful comparison with many

fossil types and all of the recent forms. The molars of Hlasmodontomys

may be matched approximately in several families and among the sciuro-

morphs as well as the hystricomorphs, showing that to this character

undue importance may not be attached, as it is a parallel evolution in

these different groups. But when we couple this character, the laminate

structure of the molars, to such others as are recognized hystricomorph

characters, the presence of anteorbital fenestree and four molars, for

example, the search for an including family must be restricted to the

following families,® the Cavide, the Chinchillide, the Dasyproctide, the

Hrethizontide and the Octodontide, excluding for obvious reasons the

Old World hystricomorphs, and troublesome characters arise in the case

of each family. Examination of the accompanying plates will demon-

strate these points better than a written statement. It is not unlikely

that more extended comparisons and reflections and additional material

may warrant the erection of a separate family for this most interesting

rodent.

As the bones of this animal were found quite well bedded in the red

stalactite formation, the deeper layers of the cave deposit, its age may be

assumed as at least as old as the late Pleistocene, and it is plausible to

consider Elasmodontomys as a contemporary of Acratocnus.

6 Palmer’s classification: N. Amer. Fauna, No. 238, p. 782. 1904.

902 ANNALS NEW YORK ACADEMY OF SCIENCES

Sreconp New Genus or Hystricomorrrt

From a layer evidently higher than that which preserved Elasmo-

dontomys came the skull and mandible of a smaller hystricomorph which

proves equally as interesting as its larger tomb fellow and is, like it,

apparently unknown to science. As it presents characters widely differ-

ent from the hystricomorphs of the Antilles and the mainland of Central

and South America, I propose for it the following name:

Heteropsomys'‘ insulans gen. et sp. nov.

Type, No. 14172, Dept. Vert. Pal., from Cueva de la Ceiba, near Utuado,

Porto Rico, 1915; collector, Dr. Franz Boas. The type skull is a partially

complete cranium lacking the nasals, the left zygomatic arch and the left

auditory region, but with one incisor and the first two molars in each row and

the right mandible with four teeth, the incisor and three molars.

DESCRIPTION

Skull (Plate XI, Figs. 2-3; Plate XII, Figs. 1-5).—The skull has the

superior outline slightly curved from nasals to parietals, abruptly curved

downward in occipital region. From the opening between the- premaxil-

laries it may be seen that the nasals are narrow posteriorly, widening

noticeably anteriorly. The frontals carry a peg-like postorbital process.

There is a short, shallow, sagittal crest along the downward-bent portion

of the cranium. Fairly large anteorbital fenestrae are present and the

zygomatic process of the maxillary is broad and shelf-like. The jugal is

heavy and wide, especially posteriorly, where it bears a prominent process

continued posteriorly from the lower margin of the jugal. There is also

a low postorbital projection at the suture of the jugal with th squamosal.

A shallow excavation, surrounded by a border raised from the surface of

the palate, is present partly in the premaxillaries, partly in the maxil-

laries, and contains the small incisive foramina at its anterior end. The

foramina are not median but are widely separated. The interpterygoid

fossa is carried forward into the palatines almost as far as the anterior

border of the third tooth of the molar series, thus forming a very exten-

sive V-shaped post-palatal notch. The bulle are of moderate size, evenly

rounded but slightly compressed laterally. Short parapophyses are borne

by the exoccipitals. The foramen magnum is very large proportionally.

The mandible is very similar in shape to that of Prechimys. The

coronoid is low and narrow, there is a broad shelf-like masseteric ridge

7 Heteropsomys: €érepos, different; dy, aspect; mus, mouse—i. e., mouse of a different

aspect.

’ =

ANTHONY, FOSSIL MAMMALS FROM PORTO RICO 203

and the posterior portion of the ramus is expanded and deep with a con-

eave border.

Dentition (Plate XI, Figs. 2-3).—The teeth of Heteropsomys are of a

highly specialized type. They are considerably worn and the primary

pattern is, on this account, lost, but the crown surfaces are none the less

distinctive. The incisors are small and of the ordinary curved rodent

type. The molars, four in number in each jaw, are all nearly equal in

size and have a prominent median lateral indentation or infolding down

the side of the tooth, the fold being on the inside of the tooth above, on

the outside of the tooth in the lower jaw. Within the crown surface of

each tooth and more or less isolated from one another by the dentine are

little hollow, flattened tubes of enamel; three in number in the upper

molars (only pm* and m* present to be examined), two in the lower

molars. The molars are two rooted, the roots being short truncated cones

im appearance.

Measurements: Total length, 69 mm.; zygomatic width (approxi-

mate), 40 mm.; width of brain case, back of zygomatic root of squamosal,

27 mm.; interorbital width, anterior to postorbital processes, 18.5 mm. :

alveolar length of maxillary tooth row, 14.5 mm.: length of diastema, 17

mm.; dimensions of m’, 3.5 & 4 mm.; greatest leneth mandible, without

incisor, 44 mm.; alveolar length of mandibular molar series, 15.5 mm.

REMARKS

Heteropsomys apparently requires no lengthy comparison with any

known genus. Its distinctness when compared with any of the mainland

hystricomorphs is immediately evident, and because of this fact it is not

advisable in this paper to attempt to place it in any particular family.

A possible later discovery of more material® in Porto Rico and a better

understanding than that prevailing now of the relationships of the di-

verse families of the hystricomorphs is necessary in the case of Heterop-

somys as well as in that of Hlasmodontomys.

This rodent is doubtless of a later age than either Acratocnus or Hlas-

modontomys, judging from its position in the cave deposits and from the

appearance of the bone itself. While one may not be justified in consider-

ing it a contemporary of Isolobodon, considered by Allen® as exterminated

by the natives in recent times, at least it could scarcely have been earlier

than late post-Pleistocene.

8 Specimens with unworn teeth may reyeal points on the evolution of the molars now

impossible to surmise with accuracy.

9 ALLDN, J. ¢c., p. 22.

PLATE Vile ga ons

FEMUR or Acratocnns odontrigonus

WY ATAIT

almogiitnobo annootsivA To cM THOU:

VOLUME XXVIII, PLATT VIL

Scr.

ANNALS N. Y. ACAD.

Fie.

Fic.

We.

Fic.

Fie.

PLATE VIII

LIMB BONES OF Acratocnus odontrigonus

1.—Internal aspect of femur (nat. size).

2.—Posterior aspect of tibia (11/11 X nat. size).

3.—View of distal end of tibia (12/13 xX nat. size).

4.—View of proximal end of tibia (nat. size).

5.—Posterior aspect of fibula (nat. size).

6.—Unguinal phalanx of fore limb (nat. size).

ad ny APAIT

ahs ‘ . i

4 as

ssnstogrrtiobo euanotsioA 10. eanon cient

“!

ANNALS N. Y. ACAD.

Sci.

VoLumMp XXVU, Phare VIII

Fic.

' Fie.

Fic.

- Fic.

Fig.

Fie.

PLATE IX

IIMB BONES AND VERTEBRA OF Acratocnus odontrigonus

1— Anterior aspect of left humerus (approximately nat. size).

2.—Internal aspect of left humerus (approximately nat. size).

3.—Proximal half of radius (nat. size).

4—Calcaneum, showing articulating surface (1% X nat. size).

5.—Dorsal aspect of caudal vertebra (114 X nat. size).

6.—Lateral aspect of dorsal vertebra (1 1/7 X nat. size).

7.—Lateral aspect of axis (11/12 X nat. size).

toake dent viotamsixongan): earvosieartt tel to wou

Conte Jan vioisaixerqgs) amrosiund Stel to fooqan.

~ .(9xia tem) apibat to Heel Caer

aa ea x ME) sostine, gatiainoits soiwode AU SEB

.(98i2: dea NE) sidgtt97 isbuss to joogan:

ania Jen x ney e sidediey ieetob to —

ANNALS N. Y. ACAD. SCI.

VoLUuUME XXVII, Prare TX

Fie.

Wie.

Fic.

Wie.

Fe.

Fic.

PLATH X

SKULL Or Acratocnus odontrigonus

1.—Lateral aspect of rostral portion (11/3 x nat. size).

2.—Dorsal aspect of rostral portion (11/3 X nat. size).

3.—Internal aspect of left mandible (approximately nat. size).

4.—External aspect of left mandible (approximately nat. size).

5.—Internal view of broken anterior portion of right mandible (approxi-

mately nat. size).

6.—Median symphysial portion of mandible, showing alveoli of canines

nearly meeting at base (approximately nat. size).

i Honky ta iloayis sniwode Aa idibaraneto. toidtog isieydqars

FORTH REX hE fy aahina PES +0 ages

ie oNie na TistnnG Zine? ibis ar Stal To tadas: betyie!

a BeOS. AEG cy Mircinie cet gt eldibtigar Jtaf to Joos. fr

Ixia } eliberbdt iter te hale ten 1obetis. aotord to: welt

Raettc NAT eit ‘lsteat

= ‘ a asia tect piemieoiaa sy seal te. gutioout

VOLUMD XXVII, Puatre X .

PLATE XI

SKULLS or Acratocnus odontrigonus anp Heteropsomys insulans

Fie. 1.—Palatal view of rostral region of Acratocnus (11/3 X nat. size).

Fic. 2.—Palatal view of Heteropsomys, showing pattern of molar crowns (2

nat. size).

Fig. 3.—Crown view of mandibular molar series of Heteropsomys (2 X nat.

size).

xB nwo st ioe eroteg ‘Sustworle 2 aosggrete to woiv at

ANNALS N. Y. AcAD. SCr. VOLUME XXVII, PuatE XI

PLATE XII

. SKULL oF Heteropsomys insulins

Fig. 1.—Skull viewed from above (11/13 X nat. size).

Fic. 2.—Lateral aspect of skull (11/14 X nat. size).

Fic. 3.—Palatal aspect of skull (11/14 X nat. size).

Fic. 4.--Dxternal lateral aspect of right mandible (1144 x nat. size).

Fic. 5.—Internal lateral aspect of right mandible (1% X nat. size).

HI OPATE — ¢

ettiestt aumoagoteteHt 1G 1I0HA -

tgsia tan < SE\E 1). 9vods-mott f

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Lag ) feeie ee x Wt) sldibaent dst: to joaqen fetotat i

: (o8ia thax At) -oldibseer tigit to tooges ts: sinl de

fi; ANNALS N. Y. Acap. Sct. VoLUME XXVIII, Puatn XIT

2 4

2 5)

_ So OE ee

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le basta dat 3EY tarde a6 Ieee

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Annaus N. Y. Acap. Sct. VoLUME XXVIII, PuatE XIII

1 2

Fie.

Fic.

Fie.

% Fic.

PLATE XIV

SKULL OF Elasmodontomys obliquus

1.— Skull viewed from above (1% X nat. size).

2.—Crown view of maxillary tooth row (approximately 2 X nat. size).

3.—Skull viewed from in front (14% x nat. size).

4.—Crown view of mandibular tooth row (approximately nat. size).

Vik aT ATT ee

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gee tha x BER) taort rh mont

i oaie tie “dotnmizorges) wenn digod Talat 1G)

“ANNALS N. Y. Acap. Scr.

VOLUME XXYVII,

)

“4

PLATE XIV

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; Editor, Epmunp Orts Hovey

_PHYSIOGRAPHY OF THE SKYKOMISH

Ne BASIN, WASHINGTON

GB ar wy AT WaRREN S. SmitH

Eau! need |

Nw ORR. oe

PUBLISHED BY THE ACADEMY

See oy al JaNvanY, 191%

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{Anwats N. Y. Acap. Scr, Vol. XXVII, pp. 205-214. 31 January, 1917]

PHYSIOGRAPHY OF THE SKYKOMISH BASIN, _

WASHINGTON? An

By Warren S. Surru

(Presented before the Academy 5 April, 191

CONTENTS

~— Titec ST can 2S eae or ee niet ree eras ena era water De ALY

COE NTER CLSHE! OIE: Un NUTT ea Mea cee tes ok he PR Se sree ne to

EMT ent OMe emet ater ioe soicy ay cu karte ay trays uae. araecre el escuela eres REC Here nots 207

HIB) IEMA Ctrmeeencwegspehs eats aeiee inc hlai ore eoees era AraBAN Cosco 5 Staavia Aa er laedenen es Sasa ale mae tere 210

Relation of topography and geology............ 00.00 cece ccec wesc seen 242

SS EDD TAN AI Ve aera AR cee VN acre i7saoh UTR ont suede As eer ayeec cactioeh gt od a Bieta a elena Rg est aise eee 213

INTRODUCTION

The area whose physiography is considered in the present chapter is in

the Cascade Mountains of Washington, latitude 47° 40’ N., longitude

121° 40’ W., about 40 miles east of Seattle. The surface is extremely

rugged and is clothed with a dense, almost impenetrable growth of under-

brush or forest. But the difficulties of traversing the wooded valleys or

climbing the steep mountain sides are amply repaid by the everchanging

grandeurs of these alpine mountains. The valleys, too, have a wondrous

charm, with their swift dashing streams and lovely lakes of cliff-inclosed

water. lew trails, a single railroad and the recently constructed Cascade

Highway furnish ingress to this little known part of the State. Three or

four small lumbering towns in the main valley give shelter to a small

population. But in summer there is an ever growing number of recrea-

tion seekers who pass a care free week or two in this mountaih wonder-

land. The writer’s home is in one of the small towns and the facts for

this chapter haye been accumulated during the summer months of the

past few years.

CHARACTER OF THE UPLIFT

Standing on any of the needles that rise to an altitude of 5500 feet or

more, one has an unobstructed view in every direction. Hundreds of -

1 Manuscript received by the Editor 21 June, 1916.

(205)

206 ANNALS NEW YORK ACADEMY OF SCIENCES

peaks of about the same elevation rise in the distance, but none high

enough to cut off the vista of still more distant peaks. More than 100

mules to the north the volcanic cone of Mt. Baker and an equal distance

to the south Mt. Rainier loom up into the field of one’s vision as the eyes

rest on the mountainous landscape. The enchanted mountaineer is im-

pressed with the nearness of these majestic, pure white cones, and the

idea occurs to him that if only one could fill the depressions between

peaks, the surface. would be practically level. If such a thing were

actually done, the result would be what physiographers call an upraised

peneplain (Fig. 1).

The existence of this peneplain is generally admitted. Russell? called

it the “Cascade Plateau” and various subsequent writers have used the

first half of the term, replacing the second with such equivalent terms as

“uplift? (Willis). This uplifted peneplain will be called the Cascade

-peneplain for the purposes of this paper.

The character of the deformation resulting in the plateau must be

worked out from a study of the range as a whole, 300 square miles being

too small an area in which to do more than apply such principles. These

principles are two in number:

1.4 The cause of uplift of the Cascade peneplain is to be found in com-

pressive stress acting on materials below the outer crust, the surface

‘deformations being incidental results of such deep-seated strains.

2.° The slow and gradual uplift of the peneplain was accompanied by

local warpings whose parallel axes le at an angle to the principal axis of

the uplift.

Granting the first of these principles, the second needs no further

proof, since any irregularity in the surface, in the competency of the rock

structure or in the direction from which the pressure of deformation was

applied, would result in such warpings of the surface.

The northernmost warping in the Snoqualmie quadrangle is called the

Wenatchee Uplift. Trending west of north, this uplift meluded all of

the mountains south of the Skykomish River lying in the Skykomish

quadrangle. The mountains north of the Skykomish River seem to be-

long to a separate uplift. Weaver has called them the Skykomish Moun-

tains (Fig. 2) and they will here be called the Skykomish Uplift. The

presence of the well defined Skykomish Basin, with its gentle slopes rising

southward and its steeper slopes rising northward, seems sufficient ey1-

27. C. Russevu: 20th Ann. Report, U. 8. G. S., pt. 2, p. 144.

3 BAILEY WiLLIs: U. S. G. S. Prof. Paper 19, p. 85. 1203.

47dem:; Prof. Paper 19, 1903, p. 97.

> JTdem: Prof. Paper 19, 1903, p. 97.

6¢. EH. Weaver: Bull. 7, Wash. Geol. Sury., p. 31. 1911.

Fig. 1.— Cascade peneplain. From head of Miller River Basin.

‘kykomish Mountains at Berlin.

Skykemish River in foregreund.

a ‘lice

cit

eae)

Hic. 3.—Skykomish Valley at Berlin.

Fie. 4.—Glacial lake. La Bohn Mountain in distance. On Foss River trail.

ail

Wo a eee tr er ee

SMITH, PHYSIOGRAPHY OF SKYKOMISH BASIN OX a

dence to identify the Skykomish Uplift as a separate warping of the ™

Cascade peneplain (Fig. 3). :

Willis has shown mathematically’ that the cause of uplift of the Cas-

cade peneplain, of whatever nature it may be, was the result of deep-seated —

strain. The strain was due to a disturbance of isostatic equilibrium.

This disturbance may have been due to the transfer of material eroded in

the formation of the peneplain, thus decreasing the load on the pene-

plaimed block and increasing it on the adjacent block. Another possible

cause of the disturbance might be found in magmatic movements result-

ing in the vuleanism and batholithic intrusion of the Miocene. Both of

these may have acted. In the Skykomish Basin, Miocene igneous rocks

are affected by the planation and are included in the uplift. Therefore

the upward movement must be post-Miocene. On the other hand, the

movement was pre-Pleistocene because the latter is the period of glacial

occupancy. Thus by delimitation the age of the peneplain dates to the

Pliocene. The fact that the plateau is maturely dissected by valleys

reaching 5000 feet in depth is evidence that a considerable part of the

Pliocene must have elapsed since the orogenic process began. The begin-

ning of the uplift may then be confidently stated as early Phocene, pos-

sibly extending to, or even into, Pleistocene.

The nature of the uphft was a regional warping of a block of the

earth’s crust by deep-seated forces acting principally in Pliocene time.

GLACIATION

The efficacy of glaciers as agents of erosion seems too well established

to need comment. Jor one interested in the forms due to such erosion

few localities in the United States are more favorable to their study than

the Skykomish Basin. Hight small glaciers in the area, lying in two

eroups of four each, are lone descendants of mighty alpine glaciers that

formerly crowded the valleys with slow-moving ice. These may be classi-

fied as transitional between cliff glaciers* and alpine glaciers. The lowest

elevation to which they extend is at present about 5000 feet.

Comparatively straight, glaciated or “U” shaped-valley troughs with

hanging valleys, from which water falls in cascades and which are often

occupied by deep, narrow bodies of water are typical features of the

Skykomish Basin. Truncated spurs are seen on either side of these val-

leys and till is found on the valley walls of the largest streams. Cirques,

often with tarn lakes, abound. Serrate ridges or arétes lead to alpine

peaks of the Matterhorn type and only a little rolling, pre-glacial upland ©

7 BaiLpy WILLIS: Prof. Paper 19, p. 97. 1903.

8 CHAMBERLAIN & SALISBURY: Geology, Vol. 1, p. 256. 1904.

908 ANNALS NEW YORK ACADEMY OF SCIENCES

is to be seen. All these topographical features are characteristic of an

area in which alpine glaciation has been active.

The valley of the Hast Fork of Foss River may serve as an example of

a glaciated valley (Fig. 4) ; one is particularly impressed with the steep-

ness of the valley walls. In one place the valley wall rises 3000 feet in a

horizontal distance of 2500 feet. The valley floor is half a mile wide and

beyond this the opposite wall rises steeply again. Another excellent

trough valley is the one occupied by Deception Creek. Trough lakes are

numerous. The largest of the lakes of the Skykomish Basin, Lake

Dorothy, is probably the best example. It lies in a hanging trough valley

whose sides rise precipitately about 1500 feet on either shore of the lake.

Passage along the lake shore is hazardous or impossible because of this

steepness. The lake is deep and pours its waters over a solid granodiorite

barrier through a narrow gorge which has apparently been cut since

glacial retreat.

There are innumerable examples of cirques, such as those occupied by

Malachite’ Lake and by Crystal Lake. The walls of these cirques rise

precipitously for 1000 feet, and the sight of a score of cascades tumbling

into the horseshoe-shaped basins with a mingled roar and hiss as they

fall into the pools which their energy has hewn is one that once seen is

forever retained as one of the magnificent memories of mountaineering.

These cirques are more often than otherwise occupied by tarns, or shal-

low, circular bodies of water, scores of which are mapped, besides other

scores which escaped the cartographer’s-attention.

Hanging valleys are frequent, but perhaps the finest and most pictur-

esque example is the one occupied by Lake Katharine (Fig. 5). It hangs

1200 feet above the West Fork of Foss River. The valley is exceedingly

steep-walled, and the vista opened before one standing on a commanding

height at the lower end displays the whole length of the box-like valley

with its extraordinarily lovely sheet of water, reflecting the snowy moun-

tains at its head. Turning down stream one can see a narrow spillway

along which the foaming water plunges to a second lake several hundred

feet below, and beyond this a similar chute that gives outlet to Foss

_ River more than 1000 feet below.

Serrate ridges and alpine peaks will be considered later. Possibly the

best occurrence is the southeast trending ridge that forms the apex of

the angle between the Skykomish and Beckler Rivers. Truncated spurs

are well shown at S in the block diagram (Fig. 6).

Till-covered valley walls occur along the Skykomish, Beckler, Tye and

Snoqualmie Rivers. Near the confluence of Martin Creek and the Tye

River, this boulder clay extends 250 feet above the stream level. Its

Fic. 5.—Lake Katharine. Glacial trough lake on Foss River drainage.

Je 1982

Jy GOT

Aug, / 44

Sept 7.29

Gap (Rey

Nov. 3775

LEG,

Jan 9-70

Feb, 8.26

.. liar = 284

April 6.47

/hy 21-39

133.59 jr ches

19-12

Fig. 7.—Run off at Berlin from Miller River drainage basin. Area, 14.2 square miles.

Fig. 6 BIOCK DIAGRAM OF A PORTION OF THE SKYKOMISH BASIN.

SMITH, PHYSIOGRAPHY OF SKYKOMISH BASIN 209

thickness measured perpendicular to the valley wall is variable but never

great. Five miles farther west, near the confluence of Tye and Foss

Rivers, glacial till occurs to an estimated height of 350 feet above the

water. It is filled with boulders from the size of an ege up to great,

rounded individuals weighing a ton or more. This till shows little sign

of weathering and probably belongs to the last glacial advance. Bretz

has described similar valley till on the Middle Fork of the Snoqualmie.®

There is no evidence of any earlier till to be seen in the Skykomish Basin,

it probably having been entirely removed by the last glacier (Vashon)

that occupied the valley. At Berlin, ten miles below Martin Creek, there

is blue glacial clay which occurs in lenses in the glacial till on the valley

sides to a height of 500 feet above water level. Bretz has estimated the

thickness of the Puget Sound Glacier, which was of the Piedmont type,

originating in ice coming not alone from the Cascade Alpine glaciers,

but also southward from British Columbia, at 4000 feet.t° My own ob-

servations tend to show that the surface of the ice was about 2500 feet

above sea level at Berlhn. About 1000 feet of the Puget Sound ice was

below present sea level. Inasmuch as considerable gradient would be

necessary for ice to flow down to a confluence with the Piedmont Glacier,

only something less than 3500 feet could be allowed for the thickness of

this Piedmont tongue, an amount in discrepancy with Bretz’s figure.

The drainage modifications due to glacial moraines were not specially

studied. From observations near Berlin, however, it would appear that

material deposited from the Miller River Glacier has crowded the Sky-

komish River to the north wall of the latter stream’s valley. There are

many other minor modifications, but they are of little importance.

We have seen thus far the forms of topography due to glacial erosion.

Let us now consider the remnants of the mountain ridges between which

the valley glacier so effectively worked. These may be considered under

three divisions: first, serrate ridges; second, alpme peaks; third, pre-

elacial uplands.

With few exceptions all the ridges are serrated. A serrate ridge or

aréte is produced by headward development of cirques*t or’? by trough

widening. These leave the “fishbone” edges so characteristic of the

northern Cascades. The best example in the Skykomish Basin is prob-

ably the ridge separating the West Fork of Foss River and the Hast Fork

9J. H. Brerz: “Glaciation of the Puget Sound Region,’ Wash. G. 8. Bull. No. 8, p. 224.

1913.

10 J. H. Brevz: “Glaciation of the Puget Sound Region,’ Wash. G. 8. Bull. 8, p. 36.

1913.

11 \. H. Hopgs: Characteristics of Existing Glaciers, p. 33 et seq.

12273. pp MARTONNE: Traité de Géographie Physique, p. 622.

210 ANNALS NEW YORK ACADEMY OF SCIENCES

of Miller River. One is immediately impressed—first, with the narrow-

ness of the ridge; second, with the roughly triangular shape of the teeth

of the comb (aréte), and third, with the abundance of cirques, many of

them occupied by tarns, on either side. This ridge is not serrated more

than normal in the district, for nearly every crest line is a narrow, jagged

series of cliffs always difficult to traverse.

The trigonal pyramidal teeth, which are referred to above, are not

irregularities characteristic of the ridge crest. Nearly every culminating

peak of sufficient prominence to have attracted a name to itself is a pyra-

mid terminating upward in an apex, so sharp that not more than a dozen

men could occupy it at once. These points have been called “horns” in

the Alps, e. g., Matterhorn, Dreieckhorn, ete. Locally they are called

“hay-stacks.” Usually they are accessible only from the southern slopes

because the northern face is precipitous and presents from a few hundred

to a thousand feet of almost vertical cliff face. It is at the foot of this

northern face that the small cliff glacier exists, largely because it is there

protected from the sun’s heat throughout most of the day. Standing on

one of these “horns” one can count a dozen others at varying distances in |

every direction. Certain areas at an elevation of 6000 feet are character-

ized by rolling surfaces which are comparatively smooth (P in Fig. 6).

These are interpreted as parts of the peneplain not affected by glaciation.

DRAINAGE

The chmate of the northern Cascades is temperate. In the larger

valley bottoms the temperature never falls below 0° Fahrenheit, nor rises

above 100° Fahrenheit, and the daily variation for weeks at a time will

not be*more than 10° above or below 40° Fahrenheit. The area lies in

the belt of prevailing westerlies and for a preponderant portion of the

seasons the air moves inland from the Pacific Ocean, after being warmed

by the Japanese current. In the winter, this warm wind blowing from

the southwest will melt snow with surprising rapidity and the great

floods of the year result. They immediately follow the lowest stage in

the river run-off—that is to say, about November 15, following the

minimum run-off period of late October. In the spring, the melting of

the winter’s snowfall sustains the run-off well into the summer, and it is

not until about July 15 that the streams begin to lose volume markedly.

The months of January, February and March are those of least run-off.

Such a régime has been called “alpine” 1* in Europe to describe streams

rising in the high Alps and fed until midsummer by melting snows

(RissG).

13H). pE MARTONNE: Traité de Géographie Phy., p. 356. 1909.

SMITH, PHYSIOGRAPHY OF SKYKOMISH BASIN 211

The southwest winds, heavily saturated with warm waters from the

Japan current, are compelled to rise 7000 feet or more in crossing the

Cascades. As a result of this rise the pressure of the overlying atmos-

phere is reduced so that the air loses density and the temperature drops.

This tends to cause heavy precipitation, and in fact the moisture is so

completely taken from the atmospheric currents that eastern Washington

has a semi-arid climate.

Precipitation comes chiefly in the months of minimum temperature

and a very large proportion of this precipitation is in the form of snow.

At Cascade, a little way down the eastern slope of the Cascade Moun-

tains, and just east of Scenic, D. C. Shafer says 110 feet of snow fell in

one year.**

Willis tells us that the canyons of the Cascades were cut to advanced

youth in the Twisp or pre-glacial stage. The canyons were over-deepened

to an unknown amount by glaciation in the Chelan stage and he gives the

name Stehekin to the stage succeeding glacial occupancy.*”

Little can be said of the Twisp stage; there are but few unglaciated,

elevated areas and all valley sides have been affected by glaciation. A

majority of them present the straightened courses and the nearly vertical

walls which are characteristic of alpine glaciation. These vertical walls

rise to a height of hundreds of feet, but the pre-glacial slope beginning at

the upper limit of the vertical wall has been so modified by extremely

active geologic processes of ice, water and insolation that no accurate data

of over-deepening are ventured in this paper, though it is probable that if

the extent of such modifications could be determined more or less reliable

information could be obtained.

The amount of Stehekin cutting varies with varying factors; the depth

-of the stream gorge of Dorothy Creek is about 40 feet and this has ap-

parently been cut by swiftly running, but sediment free, water. Maloney

Creek runs in a gorge about 80 feet deep, but here the erosion has been

chiefly in Eocene sediments and by swiftly running water abundantly

provided with cutting tools. The Great Falls of Miller River seem to

have retreated in resistant granodiorite a distance of some 60 feet. Many

other examples could be cited, but they would only show that Stehekin

cutting has been comparatively slight and therefore the stage is not very

far progressed. This means that at a comparatively recent time the

tributary valleys of the Skykomish and Snoqualmie Rivers were occupied

by glaciers.

4D). C. SHarer: A Waterfall to Haul Mountain Trains, World’s Work, Vol. 17, p. 10,

982. 1908-1909. ;

6B. Wits: Contributions to Geology cf Washington, Prof. Paper 19, pp. 80-83.

1903.

212 ANNALS NEW YORK ACADEMY OF SCIENCES

The type of drainage in the Skykomish Basin is medium textured and

its pattern is dendritic. Of the 300 square miles included, very few have

no stream of mapable size, while many have as many as six. The master

streams have a course oblique to the trend of the mountains. The sec-

ondary streams are parallel to the axial trend and those of lesser order

are dendritic. The South Fork of the Skykomish and the Middle Fork

of the Snoqualmie are the master streams.

Hrosion of the Cascade Mountains had reached a mature stage before

their occupancy by glaciers. These glaciers continued their work long

enough to destroy nearly all the pre-glacial upland (Fig. 6) and so reach

a stage of maturity. Present day drainage is largely through glacial

troughs which are characterized by precipitous canyon walls, hanging

valleys and some undrained swamps and numerous lakes.

RELATION OF TOPOGRAPHY TO GEOLOGY

We have seen that the major Cascade peneplain had warpings whose

axes were oblique to the principal Cascade axial trend. Two of these

warpings, which seem to be identifiable in the area under discussion, we

have called the Wenatchee and the Cascade Mountains. We have seen

that these warpings have a gentler slope toward the north. The possi-

bility that the steeper slopes might be fault escarpments has been pointed

out by Weaver,’® but neither he nor any other writer have found any

direct evidence of faulting and at present the unsymmetrical fold hy-

pothesis seems more defensible.

It seems possible that some relation exists between the present drainage

system and the original structure of these folds. Some future work may

explain this relation, but at present insufficient information is at hand to

justify any genetic classification of the rather complex drainage system.

Streams and glacial corrosion have produced many sharp peaks. The

highest of these is 7986 feet in elevation and lies on the divide between

the Columbia and the Puget Sound watersheds. A few other elevations

reach 7000 feet or over and many lesser peaks approach this height. All

those above 7000 feet are on the Cascade Divide, a condition which is

not in accord with Smith’s observations in the Snoqualmie Quadrangle.

The relation between kind of rock and type of topography must be -

stated cautiously. It is notable that the higher mountains, such as Big

Snow, Index and others, are in plutonic igneous rocks. But on the other

hand, White Horse Mountain is in Eocene sandstone. The high peaks on

16C, ©. Wraver: Index Mining District, Bull. 7, Wash. Geol. Surv.. p. 32. 1912.

m7 Gro. O. Syrrrit: Contributions to the Geology of Washington, Prof. Paper 19, pp. 35

et seq. 1903.

SMITH, PHYSIOGRAPHY OF SKYNKOMISH BASIN 213

the divide above mentioned are carved from the granodiorite batholith,

with the possible exception of the very highest of all, which was unex-

plored by the writer.

There are apparently stronger grounds for stating a relation between

drainage and rock type. The long, nearly straight, north and south valley,

occupied in turn by Beckler River and by the Foss, is developed in Hocene

sedimentaries and was very probably determined by the lesser resistance

to corrosion offered by these terranes. The trend of the valley corre-

sponds with the strike of the rock strata. It will be seen at a glance that

a stream like Miller River, which is quite analogous in nearness to base

level and in size of drainage basin and hence in volume, has succeeded

far less strikingly in cutting its valley. The position of the master

streams has no known relation to rock type.

SUMMARY

The Cascade peneplain was up-arched in Pliocene time with a north-

south axial trend. Orogenic processes resulted in unsymmetrical surface

warping with an axial trend oblique to that of the main Cascade uplift.

In the pre-glacial stage this was maturely dissected and in the Pleisto-

cene, due to changed climatic conditions, was burdened with alpine gla-

ciers. ‘These produced a mature topography characterized by splendid

examples of peak, cirque and valley glacial corrasion, leaving the surface

excessively rugged. The post-glacial stage has been of short duration.

The local climate favors rapid destruction of land forms. Precipita-

tion, largely in the form of snow, is unusually high, due to the rising of

warm, moisture laden southwest winds in passing the high Cascades.

This is accompanied by a high run-off, with the result that streams of

mapable size and continuous flow are very numerous. The drainage pat-

tern is dendritic and the land surface is maturely dissected by both

streams and glaciers.

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[Anwats N. Y. Acap. Scr., Vol. XXVII, pp. 215-243. 2 August, 1917]

OPERATING FEATURES OF THE AUDI AS

meee

Gansonian ing?; me

By E. H. Armstrone ™ SEP 131 4

CONTENTS Bon ot muses ee

PART I OES eae

EXPLANATION OF THE ACTION OF THE AUDION AS AN AMPLIFIER AND AS

A DETECTOR OF HIGH-FREQUENCY OSCILLATIONS...................-. 215

PART II

Some RECENT DEVELOPMENTS OF THE AUDION RECEIVER..... ........ 223

REENFORCEMENT OF RADIO FREQUENCY OSCILLATIONS BY THE

PANUIDD LO INtetsteeeieen te mewe cetera reece th alco aie a8, cian iale ear ee aelamee em eee aie 224

ATWDIO) HREQURNCY “AMPEIFIG@ATION: ooo. 2. osc osc sl. sete one 228

THE AUDION AS A GENERATOR AND BEAT RECEIVER.......... ea 229

PECULIAR HEATURES OF OSCILWATION.:......-.....--22:eenecee: 231

FA DIOR MRE OWE ING Yas INWIN TINGS. crlere eile: a lo alata RNS wien thls ce tile eee 233

CUNSKOVNITD SSN OGY IS) A eSB BG sees Oe STORY a Ree a en 235

EFFECTS OF ATMOSPHERIC DISTURBANCES................eeeee0ee 238

SST UM LANTERN Ge 8 I aS al Ts et ae ay 242

PART I

EXPLANATION-OF THE ACTION OF THE AUDION AS AN AMPLIFIER AND

AS A DETECTOR OF HIGH-FREQUENCY OSCILLATIONS

Although the audion has been in use for several years as an amplifier

and a detector of high-frequency oscillations, the explanations advanced

to account for its action do not appear to be satisfactory. With the idea

of pointing out some features of operation which heretofore do not seem

to have been appreciated, the following explanation and oscillograms are

given.

The audion is essentially an electron relay; that is, the exhaustion is

carried to such a point that the amount of gas present is exceedingly

small, and the current between the hot and cold electrodes is entirely

thermionic, the absence of gas making impossible the presence of posi-

tive ions. The operating characteristic of such a relay is shown in Fig. 1.

This characteristic was obtained in the manner indicated in Fig. 2. The

1 The material for the present article appeared in part in the Hlectrical World De-

cember 12, 1914, and in part in the Proceedings of the Institute of Radio Engineers,

September, 1915. It has been combined, revised, and partly rewritten for the present

publication.

(215)

916 ANNALS NEW YORK ACADIUMY OF SCIENCES

potential of the grid with respect to the filament was varied in step be-

tween —10 and +10 volts, by means of the potentiometer P, correspond-

ing readings of the grid voltage and wing current being taken in order

to plot the curve of Fig. 1. The characteristic shows that, starting with

the grid and filament at zero potential difference, a negative charge im-

parted to the grid produces a decrease in the wing current and a positive

WING CURRENT

=/0 4) +/0

GRID POTENTIAL

Fie. 1

charge imparted to the grid produces an increase in the wing current.

This is the fundamental action of the audion when used either as an

amplifier or a detector. The reason for this action will appear upon ex-

amination of the behavior of an audion of the type shown in Fig. 3.

The wings of the audion were placed symmetrically with respect to the

hte tt Hut

Wing Current = 5 ees Current

4Milliamperes = 08 Milliamperes

Fig. 2 Fig. 3

filament, but only one grid was employed. It was found that, under

similar conditions of filament temperature and voltage of the battery 5,,

a considerably smaller current was obtained between the filament and

plate on the side in which the grid was inserted. In both measurements

the grid was left entirely free of any connection with the rest of the ap-

paratus. Obviously the grid obstructed the flow of the thermionic cur-

Poleniial of

Grid with 0

ARMSTRONG, OPERATING FEATURES OF THE AUDION O17

rent. Investigation showed that this was due to the charge accumulating

on the grid when exposed to bombardment by the electrons passing from’

the filament to the wing. The electrons pass readily enough into the

erid but cannot easily escape from it, and as a consequence of this, nega-

tive electricity piles up on the grid. The potential assumed by the grid:

respect fo

Filament =

wing

Current

Fic. 4

To Oscillograph™ ~

when exposed to this bombardment may be several volts: negative with .

respect to the negative terminal of the filament, it may be the same as

the negative terminal, or it may be positive with respect to the negative

terminal, but it will always be negative with respect to the potential of

the field im the plane of the grid which would exist if the erid were Te-

.moved from the bulb. The negative charge on the grid, therefore,

Gud poolential

Wing current

Fic. 6

impedes the flow of electrons from filament to plate, causing the decrease

in the wing current. ‘The placing of a positive charge on the grid from

an external source tends to neutralize the negative charge on the grid,

thereby permitting an increase in the wing current. The addition of a

negative charge to the grid increases the deflection of the electrons and

produces a further decrease in the wing current.

918 ANNALS NEW YORK ACADEMY OF SCIENCES

‘An alternating E. M. F. impressed between the grid and the filament

causes variations in the wing current in the manner indicated in Fig. 4,

the positive alternation producing an increase and the negative alterna-

tion a decrease in the wing current. This is the action involved im the

audion when it is used as an amplifier.

Incomin

Osea Wi Wile

Potential of *

; Grid with ¢

respect to

Filament - |

Wing

Currént

me Telephone

Current

Fic. 8

To substantiate the above and other actions, the writer, working in

conjunction with Prof. J. H. Morecroft, of Columbia University, has

secured oscillograms which substantiate the idea just presented. Fig. 5

shows the arrangements with which the test was carried out.

Incomin. j

Oscillations W\\fJWu~ wi

Potential

of Gr. id 0

with

respect fo\_

Filament

Wing

Current

Telephone

Current

BiGaed

The potentiometer P was used to adjust the grid to a potential corre-

sponding to point P at the center of the operating part of the curve

shown in Fig. 1. The audion is capable of handling the greatest amount

ARMSTRONG, OPERATING FEATURES OF THE AUDION ) 919

of energy as an amplifier when the grid potential is adjusted to this

point. Fig. 6 shows the oscillogram of the action as an amplifier. The

result bears out the explanation already given.

The action of the audion as a detector of high-frequency oscillations

is quite different from its action as an amplifier. Since the incoming

To Oscillograph

Fic. 10

oscillations are of too high a frequency to affect directly the telephone

receiver, the audion must be so connected and adjusted that the cumula-

tive effect of a group of oscillations in the grid circuit is translated into

a single low-frequency pulse or variation in the telephone current. This

may be done in two ways, one depending on the non-linear form of the

Grid potential

_ Wing, current

Grid on pelentiomeler

NE Grid Condenser

: Tefephone oxrrernt

Fig. 11

operating characteristic of the audion and the other depending on the so-

called “valve” action between hot and cold electrodes at low pressures.

Fig. 7 shows the connection used for operating in the first-named man-

ner. The potentiometer P is employed for the purpose of adjusting the

potential of the grid to point M on the characteristic curve of Fig. 1.

The action is much the same as in one of Professor Fleming’s methods

2290 |: ANNALS NEW. YORK: ACADEMY OF SCIENCES

of using his valve. <A group of high-frequency oscillations impressed on

the grid causes corresponding high-frequency variations in the continuous

current in the wing current, but owing to the fixing of the grid potential

at the lower bend of the curve by adjustment of the potentiometer in the

grid circuit, the amplitude of the positive part of the high-frequency cur-

rent in the wing circuit exceeds the amplitude of the negative part. As

the positive half-waves are greater than the negative half-waves, more

electricity flows in one direction than the other, and the condenser C,,

through which the high-frequency current in the wing circuit flows, be-

comes charged, the side connected to the battery B, having the positive

charge. This charge accumulates in (, in a relatively short time, ap-

proximately that of the duration of a wave train. (', then discharges

tea grid Candgpser

heleehone currert

Fig. 12

through the telephone 7’, the rate of this discharge being determined by

the constants of the telephones and the condenser. It is probable that

this discharge is aperiodic or nearly so. In any case the main part of the

discharge through the telephones is in the same direction as the current

due to the battery B, and constitutes an increase in the current in the

telephones. As this action is repeated for each group of oscillations, a

series of wave trains causes what might be regarded (in its action on the

telephones) as an alternating current in the telephones superposed on

the continuous current and having a fundamental frequency equal to the

number of wave trains per second. The action is shown diagram-

matically in Fig. 8. |

Tf the potential of the grid is adjusted to the upper bend in the curve

of Fig. 1, as at point V, the fundamental action will be the same, but the

ARMSTRONG, OPERATING FEATURES OF THE AUDION 294

effect of high-frequency oscillations in the grid circuit on the wing cur-

rent will be reversed. The amplitude of the negative part of the high-

frequency oscillations in the wing circuit will exceed the amplitude of

the positive part and the condenser C’, will become charged, but in the

opposite sense, the side connected to the battery B, becoming negative.

The discharge of the condenser through the telephones will therefore be

in the opposite direction to the flow of the continuous current of the wing

circuit, and will constitute a decrease in the telephone current. Dia-

grammatically the action is as indicated in Fig. 9.

Oscillograms bearing on these actions were obtained in the matter indi-

cated in Fig. 10. Oscillations were set up by the discharge of the con-

denser C’ through the inductance L’, which was coupled with the in-

Fig. 13

ductance L of the tuned grid cireuit. ‘To permit the use of an ordinary

General Electric oscillograph, an oscillation frequency of about fifty

cycles per second and a group frequency of two or three cycles were em-

ployed. ‘The action of the audion is the same, regardless of frequency,

provided that the circuit constants are suitably modified to fit the fre-

quency employed. In this case the oscillation frequency of the circuit

CYL’ was fifty cycles and the circuit UC was accordingly tuned to the

same frequency. The capacity of C, was selected to correspond to the

‘low frequency employed. Figs. 11 and 12 show oscillograms taken as

indicated in Fig. 10, with the grid potential adjusted respectively to the

lower and the upper bends of the operating characteristic. It will be

observed that the telephone current reaches in Fig. 11 its maximum

value, and in Fig. 12 its minimum value, when the oscillating current

has almost died away. This effect would be shown more plainly with a

higher oscillation frequency, but even at the frequency used it is quite

evident. Sb

922 ANNALS NEW YORK ACADEMY OF SCIENCES

To make use of the “valve” action between hot and cold electrodes for

the detection of high-frequency oscillations a connection as shown in Fig.

13 is used. In this case a condenser C’, is inserted somewhere in the

circuit between the grid and filament to prevent the flow of a continuous

current between them, and the grid is therefore left free to assume a

potential determined by its position with respect to the filament and

wing. Usually this will be somewhere near the center of the operating

part of the curve in Fig. 1; that is, near point P. Now the action for

incoming oscillations, as far as the closed oscillating circuit, filament,

grid and condenser (, are concerned, is identical with the rectifying

action of the Fleming valve. An incoming wave train sets up oscilla-

Potential of

Grid WAL

Flare

C urrent

Tele, cai

Ci THE

Fig. 14

tions in the closed circuit ZC which are rectified by the “valve” action of

the filament and grid, and the rectified current is used to charge the con-

denser (,. Electrons pass readily enough into the grid, but cannot easily

escape therefrom, and a negative charge is built up on the side of the

condenser connected to the grid. The negative charge thus imparted to

the grid cuts down the flow of electrons from the filament to the wing,

producing a decrease in the wing and telephone currents. At the end of

a wave train the charge in (, gradually leaks off and the wing current

returns to its normal value. The charge and discharge of this condenser

take place in the manner indicated in Fig. 14.

One group of oscillations produces a single low-frequency variation

(decrease) in the telephone current and a series of wave trains produces

a corresponding series of low-frequency variations in the telephone cur-

rent. In Fig. 15 is shown an oscillogram of the behavior of the audion

when the “valve” action is employed for the detection of oscillations.

ARMSTRONG, OPERATING FEATURES OF THE AUDION 992

With the means at hand it was impossible to obtain the variations of

grid potential directly, as the leak introduced by connecting the oscillo-

graph to the grid would destroy the cumulative action. The grid poten-

tial, however, varies in exactly the same manner as the wing current.

The fundamental detecting action is, therefore, that of a valve, the high-

frequency oscillations being rectified between the filament and the grid

to charge the grid and the grid condenser. The charged grid then. ex-

erts a relay or trigger action on the wing current, so that the audion

is at once a rectifier and an amplifier. A somewhat similar combination

Wing current

Condenser “sed in

Grad circewif

Rikyshone current

of rectifying and amplifying actions occurs in the arrangement shown in

Fig. 7. The action of the audion is being further studied by Professor

Morecroft and the writer in the Hartley Research Laboratory, Columbia

University, and the results of these investigations will soon be published.

PART II

Some Recent DEVELOPMENTS OF THE AUDION RECEIVER 2

Tt will be observed from the oscillogram of Fig. 15 that in addition to

the regular detecting phenomena the audion is simultaneously acting as

a repeater of the radio frequencies ; so that oscillations of the grid circuit

set up oscillations of similar character in the wing circuit of the audion.

In the ordinary detector system no use is made of the repeating action,

2 Paper read before the Institute of Radio Engineers, New York, March 3, 1915, and

before the Boston Section, April 29, 1915.

RR ANNALS NEW YORK ACADEMY OF SCIENCES

and it is the purpose of the present paper to show that it may be turned

to account to produce improvements in the reception of signals which

completely overshadow any of the particular advantages of the audion

when used as a simple detector. The ordinary detector circuit is illus-

trated by Fig. 13 and the phenomena present therein may be summed up.

diagrammatically by the curves of Fig. 14. It will be seen from these

that the radio frequency oscillations present in the wing circuit of Fig.

13 with the ordinary audion are necessarily small, and also that they are

of no value in producing a response in the telephones; but by providing

means for increasing their amplitude and means for utilizing them to ©

reénforce the oscillations in the grid circuit, it becomes possible to pro-

duce some very remarkable results.

REENFORCEMENT OF Rapio FREQUENCY OSCILLATIONS BY THE AUDION

There are two ways of reénforcing the oscillations of the grid cireuit

by means of those in the wing circuit. The simplest way perhaps is to

Fic. 16

couple the two circuits together in the manner shown in Fig. 16. This

is essentially the same as Fig. 13, but modified by the introduction of the

inductively coupled coils L, and LZ, in the grid and wing circuits re-

spectively and by the condenser C,, which forms a path of low impe-

dance across the telephones for the radio frequencies. In such a system,

incoming signals set up oscillations in the grid circuit which repeat into

the wing current producing variations in the continuous current, the

energy of which is supplied by the battery B,. By means of the coupling

M,, some of this energy of the wing oscillations is transferred back to

the grid circuit, and the amplitude of the grid oscillations thereby im+

ARMSTRONG, OPERATING FEATURES OF THH AUDION 99.5

creased. The amplified grid oscillations then react on the wing circuit

by means of the grid to produce larger variations in the wing current,

thus still further reénforcing the oscillations of the system. Simul-

taneously with this procedure the regular detecting action goes on; the

condenser C’, is charged in the usual way, but accumulates a charge which

is proportional, not to the original signal strength, but to the final am-

plitude of the oscillations in the grid circuit. The result is an increased

response in the telephone proportional to the energy amplification of the

original oscillations in the grid circuit. It will be observed from the

operating characteristic (the relation between the grid potential and

wing current) that the amplitude of the variation in the wing current

is directly dependent on the variation of the grid potential. This indi-

ib G

a. ie,

(ili —

BIiGs Le Fie. 18

cates that the grid circuit should be made up of large inductance and

small capacity to obtain the maximum voltage which it is possible to im-

press on the grid. For moderate wave lengths the tuning condenser U

of the grid circuit may be omitted altogether and the capacity of the

audion alone used to tune the circuit. For long wave lengths the dis-

tributed capacity of the grid circuit inductance becomes so high with

respect to the capacity of the audion that better results are obtained by

the use of a tuning condenser to fix definitely the points of maximum

potential difference across the grid and filament of the audion.

In the second method of reénforcing the oscillations of the grid circuit

the wing circuit of the audion is tuned by means of an inductance in-

troduced as shown by Fig. 17. This differs from the ordinary detector

cireuit of Fig. 13 by the addition of the coil LZ, and the condenser C,.

The manner in which the grid oscillations are amplified may best be

understood by the following analysis. With no oscillations in the system,

the potential difference between filament and wing will be approxi-

mately the voltage of the battery B',, but when oscillations are set up in

226 ANNALS NEW YORK ACADEMY OF SCIENCES

the grid circuit, causing radio frequency variations of the wing current,

the potential of the wing with respect to the filament varies as the react-

ance voltage of the wing inductance alternately adds to and subtracts

from the voltage of the battery. When a negative capacity charge is

placed on the grid, the wing current will be reduced and the direction of

the reactance voltage of the wing inductance will therefore be the same as

the voltage of battery B,. The reactance voltage will therefore add to

the battery voltage, and the difference of potential between wing and fila-

ment and also between wing and grid will be increased. Similarly, when

a positive charge is placed on the grid the wing current is increased

and the reactance voltage of the wing inductance opposes the battery

voltage, producing a decrease in the potential difference between grid and

Fic. 19 Fic. 20

wing. Hence, supposing a negative capacity charge is placed on the

grid, the tendency of the corresponding increase in the potential of the

wing with respect to the grid will be to draw more electrons out of the

grid, thereby increasing the charge in the condenser formed by the wing

and grid, the energy for supplying this charge being drawn from the

wing inductance as the wing current decreases. The increased negative

charge on the grid tends to produce a still further decrease in the wing

current and a further discharge of energy from the wing inductance into

the grid circuit. On the other hand, when a positive charge is placed on

the grid, the potential difference between grid and wing is reduced and

some of the energy stored in the capacity formed by them is given back to

the wing inductance. During this part of the cycle, electrons are being

drawn into the grid from the surrounding space to charge the grid con-

denser in accordance with the well known valve action, and this, in effect,

is a conduction current, so that a withdrawal of energy from the circuit

takes place. In spite of this withdrawal of energy, however, a well

defined resonance phenomena between the audion capacity and the wing

inductance is to be expected, and in the reception of signals such is found

;

ARMSTRONG, OPERATING FEATURES OF THE AUDION 99017

to be the case. When the wing inductance is properly adjusted at the

resonance frequency, energy from the wing circuit is transferred freely

to the grid circuit, and the oscillations build up therein and are rectified

in the usual way.

A curve showing the general relation between the signal strength and

value of wing inductance is shown in Fig. 18, the circuits used being

those of Fig. 17. As the capacity of the audion is the main means of

transferring energy from the wing to the grid circuit, best results are

obtained when the condenser C' is very small. On account of the very

small capacity of the audion, the effectiveness of this method of tuning

is more pronounced at the higher frequencies, but by’ the use of a shunt

Bie. 21

condenser across the inductance of the wing circuit very good amplifica-

tion is secured on frequencies as low as 30,000 cycles (10,000 meters

wave length). The best results, however, are obtained with some combi-

nation of coupling and wing circuit tuning, as illustrated in Fig. 19.

Other methods of coupling may be employed between the grid and wing

cireuits, electrostatic and direct magnetic couplings being illustrated in

Figs. 20 and 21. The arrangement of Fig. 21 operates in the same way

as the system with the two-coil coupling; but the electrostatic coupling

of Fig. 20 works in an odd way. It is necessary, in this connection, to

complete the wing circuit for the continuous current of the battery, and

this is done by shunting the coupling condenser C’, by a coil of high in-

ductance. The continuous current of the wing circuit flows through this

coil and C, provides a path of low impedance around this coil for the

radio frequency oscillations of both the grid and wing circuits. When

228 ANNALS NEW YORK ACADEMY OF SCIENCES

a positive charge is placed on the grid, an increase in the wing current

results, the alternating component of the wing current charging the con-

denser C’, and the sum of the currents passing through C', and L, equal-

ing the current through the audion. When a negative charge is placed

on the grid the current through the audion is reduced and the inductance

L; discharged into the condenser shunted across it, chargimg it in the

opposite way to that caused by the increase in the wing current. In both _

cases, C’, then discharges through the grid circuit, reénforcing the oscil-

lations therein.

Aupio FREQUENCY AMPLIFICATION

It is possible to combine with any of these systems a system of audio

frequency circuits which amplify the telephone current in exactly the

P0080 0000

; Ly

— G

= Sy ll

Llyey O Ch a a)

M; arth

me C3 C4

Fig, 22

same manner as the radio frequency oscillations are amplified, and such.

a system is shown in Fig. 22. Here M, represents the coupling of the

radio frequencies, and the coils are of relatively small inductance. M,

is the coupling for the audio frequencies, and the transformer is made up

of coils having an inductance of the order of a henry or more. The con-

densers C, and C, having the double purpose of tuning M, to the audio

frequency, and of by-passing the radio frequencies. The total amplifica-

tion of weak signals by this combination is about 100 times, with the

ordinary audion bulb. On stronger signals, the amplification becomes

smaller as the limit of the audion’s response is reached.

ARMSTRONG, OPERATING FEATURES OF THE AUDION 999

THE AUDION AS A GENERATOR AND BEAT RECEIVER

Any repeater, which is also an energy amplifier, may be used to pro-

duce continuous oscillations by transferring part of the energy in the

circuit containing the battery back to the controlling circuit to keep the

latter continuously excited. By providing a close enough coupling be-

tween the grid and wing circuits, sufficient energy is supphed to the grid

eireuit to keep it in continuous oscillation, and as a consequence thereof

oscillations of similar frequency exist in all parts of the system. The

GRID CIRCUIT

CURRENT

GRID

POTENTIAL

WING

oie ane

TELEPHONE

CURRENT

Fic. 23

frequency of these oscillations is approximately that. of the closed grid

circuit if the tuning condenser of that circuit is large with respect to the

capacity of the audion. If this capacity is small, then the wing circuit

will exert a greater influence on the frequency of the system, and it will

not approach that of the grid circuit so closely. When such a system of

circuits is in oscillation, it has been found possible not only to receive

continuous waves by means of the beat method, but also very greatly to-

amplify them as well.

The phenomena involved may best be understood by reference to Figs.

-23 and 24, which show the relation between wing current and time at the

230) ANNALS NEW YORK ACADEMY OF SCIENCES

beginning of oscillation. When the audion begins generating, the grid

oscillations are continuously rectified to charge the grid condenser, and

this charge continuously leaks off either by way of the grid or by means —

of a special high resistance placed in shunt with the condenser. As the

negative charge builds up in the grid condenser, it decreases the average:

value of the continuous current component of the wing current, and

therefore limits the amplitude of the oscillations of the grid circuit until

a point is finally reached where the rate at which electricity is supplied

to the grid condenser is just equal to the rate at which it leaks off. Con-

GRID

CIRCUIT

CURRENT

GRID Ia

POTENTIAL

WING

CURRENT

TELEPHONE

CURRENT

Fig. 24

sider now the effect on the system of an incoming continuous wave hav—

ing a frequency slightly different from the frequency of the local oscil-

lations. ‘The presence ofthe local oscillations will not in any way inter-

: fere with the amplifying powers of the system, and the incoming oscilla-

tions will build up in exactly the same manner as for the non-oscillating:

state, but to a greater degree, because of the closer grid and wing coup-.

ling. Simultaneously with the amplifying of the incoming wave, beats

are produced between the local and the signaling currents, the effect being:

alternately to increase and decrease the amplitude of the oscillations im:

the system. From Fig. 23 it will be apparent that when this steady:

- ARMSTRONG, OPERATING FEATURES OF THE AUDION 931

state is reached an increase in the amplitude of the grid oscillations by

any means whatever will increase the negative charge in the grid con-

denser, producing a decrease in the average value of the wing current,

and hence a, decrease in the telephone current. On the other hand, a

decrease in the amplitude of the oscillations will allow some of the nega- -

tive charge in the grid condenser to leak off and thereby permit an in-

crease in the telephone current. Hence, when incoming and local oscil-

lations add up, the negative charge in the grid condenser is increased

and a decrease in the telephone current results. When the two frequen-

cles are opposed, some of the charge in the grid condenser leaks off and

an increase in the telephone current occurs. The result is the production

in the telephones of an alternating current having a frequency equal to

the difference in the frequencies of the local and incoming oscillations

and having the very important property of being almost simple harmonic.

Fig. 24 illustrates the characteristics of this method of reception. The

complete phenomena may be summed up as follows. Incoming oscilla-

tions are simultaneously amplified and combined in the system to pro-

duce beats with a local oscillation continuously maintained by the audion.

The radio frequency beats are then rectified by the audion to charge the

grid and the grid condenser, and this charge varies the electron current

to produce an amplifying action on the current in the telephones.

When the grid condenser is omitted, the beat phenomenon is slightly

modified, and the audio frequency variation of the telephone current is

produced according to the asymmetric action outlined in a previous pub-

lication dealing with the operating features of the audion. The system

1s more sensitive with the grid condenser, but the same general result is

obtained by either method of reception.

PECULIAR FEATURES OF OSCILLATION

Some very interesting features of operation accompany the production

of oscillations in the system. Suppose the audion is not oscillating, and

the grid and wing coupling is fairly weak. As this coupling is increased,

the point at which oscillations begin is indicated by a faint click in the

telephones accompanied by a slight change in the character of the static.

The oscillations produced are usually so high in frequency and constant

in amplitude that they are entirely inaudible. As the coupling is still

further increased, a rough note is heard in the telephones, the pitch de-

creasing with increase of coupling. This note is produced by the break-

ing up of the oscillations into groups, and it occurs whenever electricity

is supplied to the grid condenser at a greater rate than that at which it

Bs.

232 ANNALS NEW YORK ACADEMY OF SCIENCES

can leak off. The result is that the grid is periodically charged to a.

negative potential sufficient to cut off entirely the wing current, causing

a stoppage of the local oscillations until the grid charge leaks off and the

wing current reéstablishes itself. The frequency of this interruption

depends largely on the capacity of the grid condenser, the resistance of

its leakage path, and the amplitude of the local oscillations; it may be

varied from several hundred down to one or less per second. This effect

is sometimes troublesome in the reception of signals, especially with high

vacuum tubes. It may be eliminated, however, by increasing the leak of

the grid condenser by means of a high resistance shunt. The best coup-

ling for receiving continuous waves lies somewhere between the point at

which oscillations start and the point at which interruption begins, and

aa = C

Be) Saget

LEE,

= = |

Gi lee 2 ll )

Ci {i||_

Fig. 25

can only be determined by trial. In this region, trouble is sometimes

experienced by the appearance of a smooth musical note in the telephone.

This occurs under certain critical conditions of coupling with the an-

tenna when the grid circuit oscillates with two degrees of freedom. Two

slightly different frequencies are therefore set up, producing beats which

are rectified by the audion in the usual way. This effect is quite critical,

and when it causes interference with signals, a slight readjustment of the

circuit will usually make it disappear. It may, however, be made per-

fectly steady and reproduced at will by the system shown in Fig. 25,

where two grid circuits of different periods are provided. ‘Two frequen-

cies are therefore generated, one having the frequency of the cireuit

LCL, and the other the frequency of the circuit L’C’L,C. This arrange-

ment may replace to advantage the ordinary buzzer for producing groups

of oscillations. The foregoing explanations refer to the audion only

ARMSTRONG, OPERATING FEATURES OF THE AUDION 933

when vt 1s used as an electron relay.2 When there is an appreciable

amount of gas in the tube in the ronized state, disturbances of an entirely

different character occur.

Aupio FREQUENCY TUNING

One of the very important advantages of the receiver when used for

continuous waves is that the alternating current produced in the tele-

phones is almost a pure sine wave. Only when the audio frequency is

simple harmonic can selectivity be obtained by tuning the telephone cir-

cuit. A distorted wave such as that produced by spark signals possesses

many harmonics, and as each may be picked out by the tuned telephone

circuit there is little chance of separating two spark signals by audio

1Sy;

Wee ee

Fie. 26

STATI —#£—

frequency tuning. With continuous waves, however, the pure wave pro-

duced by the beat method of reception makes it possible to obtain selec-

tivity by the audio frequency tuning, resonance being fully as sharp as in

radio frequency circuits. Two methods of audio frequency tuning are

shown in Figs. 26 and 27. In Fig. 26, the telephone is inductively con-

nected to the wing circuit of the audion by means of a transformer, the

secondary of which includes besides the telephone a tuning condenser.

In this connection, the telephone, with a resistance of many thousand

ohms, is placed directly in the tuned audio frequency circuit, and hence

2 Hlectrical World, December 12, 1914; and also discussion in London Electrician, be-

tween Reisz and de Forest on the difference between electron and gas relays. (Hebruary

6, 1914, page 726; March 13, 1914, page 956; June 12, 1914, page 402; July 3, 1914,

page 538; July 31, 1914, page 702.)

234 . ANNALS NEW YORK ACADEMY OF SCIENCES

for good tuning the inductance of the coil L, must be made extremely

large to secure the necessary ratio of the reactance of L, to the resistance

of the circuit. This disadvantage is overcome in the system of Fig, 27

by removing the telephones from the audio frequency circuit, and using

the latter to operate a second audion. The telephones may then be

placed in the wing circuit of this audion without adding appreciably to

the damping of the circuit. The tuning of the circuit L,C, may there-

fore be made very sharp with reasonable values of inductance simply by

keeping the resistance low. In this case considerable amplification is

obtained by the use of resonance in the transformer M, to increase the

voltage impressed on the grid of the second audion. The great advan-

tage of this kind of tuning is shown by the followimg example. Suppose

Fig, 27

the incoming signal has a frequency of 50,000 cycles, and the local fre-

quency is 49,000 cycles. The differential frequency is 1,000, and the

audio frequency circuit is tuned accordingly. An interfering wave 1 per

cent shorter than the signaling wave, of 49,500 cycles, will produce an

audio frequency of 500 cycles per second, which will not appear at all in

the wing circuit of the second audion unless it is many times stronger

than the 1,000 cycle signal. This combination of radio and audio fre-

quency tuning is too selective for use at the present time, even when the

sending station is equipped with an alternator, as the slight changes in

frequency of the radiated wave produce changes in the beat frequency -

of the receiver which carry it out of range for the sharply tuned audio

frequency circuit. A disadvantage of this method of tuning is that at-

ARMSTRONG, OPERATING FEATURES OF THE AUDION 935

mospheric disturbances produce a musical note due to shock excitation

of the audio frequency system. Very loose coupling with the wing cir-

cuit of the first audion is a partial remedy for this. There are times,

however, when interference is ‘more troublesome than static, and in such

cases the method may be used to great advantages. If desired, both

radio and audio frequency tuning can be carried out in the same audion

as indicated in Fig. 22. This combination is apt to be somewhat trou-

blesome to operate as a cumulative amplification is obtained in the audio

frequency as well as in the radio frequency system.

CASCADE SYSTEMS

Where a greater amplification than can be obtained with one audion

is required, cascade working of the radio frequency systems may be’ re-

Gi Bez

Fie. 2

sorted to by coupling together two or more audion systems, each con-

nected as already described, in. the manner indicated in Fig. 28. The

incoming oscillations in the first audion system are amplified in the usual

manner and set up oscillations in the second system by means of the

coupling M,. The oscillations initially set up in the second system are

again amplified, and then rectified in the second audion to produce audi-

ble response in the telephones. For the reception of ‘spark signals, con-

siderable adjustment is required to get the best results without causing

one or the other, or both, of the systems to generate oscillations. It will

be found that after the first circuit is adjusted to the point of oscillation

and the second is coupled with it, the strength of signal in the first sys-

tem will be reduced owing to the withdrawal of energy from it by the

second system. The signals may then be again brought up in strength |

by increasing the coupling between the grid and wing circuits of the first

936. ANNALS NEW YORK ACADEMY OF SCIENCES

‘audion until the appearance of the local oscillations indicates that the

limit of amplification has been reached. By careful adjustment about a

thousand times amplification and very sharp tuning can be obtained with

two steps. ;

For continuous wave reception, there are several methods of operating

cascade systems. It is possible to have either system generate oscilla-

tions, the other system acting simply as an amplifier or both systems may

be made to generate in synchronism. It will generally be found that

when both systems produce oscillations, beats will be produced, so that a

continuous note is heard in the telephones; but by adjusting the fre-

quency of one of the systems the pitch of this note will be reduced as the

two systems approach synchronism, until finally at one or two hundred

beats per second the two systems pull ato step in much the same way as

two alternators. The ability of the two systems to keep in step depends

mainly on the value of the coupling between them, and the closer this is

the better the two hold together. There is still another way of working

this combination, and that is asynchronously. In this case beats are

continuously produced in the system so that a continuous note is heard

in the telephone, but the circuits may be so adjusted that the note is not

loud enough to be troublesome, or it may be tuned out of the telephone

in the manner previously described. Incoming oscillations are combined

im the system to produce beats with the beats already present, so that a

rather curious note is heard. Very good amplification is secured by this

method, though naturally the system is troublesome to operate.

It may be noted here that whenever a signal is too weak to read with

one audion system, and cascade operation becomes necessary, it is always

better practice to use the cascade circuits for the radio frequencies, even

if the regenerative circuits are not employed with each individual audion

000000

= C6 C)

== all O

ARMSTRONG, OPERATING FEATURES OF THE AUDION 937

system. The frequency of the oscillations set up in the circuits by static

are, under normal conditions, the same as those of the incoming signal,

and the static is therefore never amplified more than the signal. Usually

it is amplified to a somewhat lesser extent, especially if regenerative cir-

cuits are employed. In the cascade system used for audio frequencies,

a different condition exists. It is ordinary practice to connect the dif-

ferent stages by means of transformers, and this leads to conditions

which cause the system to produce greater amplifications of the higher

frequencies. The rate of change of the wing current of the detecting

audion produced by static corresponds to a very high frequency, and as

such is invariably amplified to a greater extent than the signal.

There is a second method of receiving continuous oscillations which

INCOMING

SIGNAL Va

CURRENT

IN L,C,

Fie. 30

makes use of the generating feature of the audion, but does not employ

the beat phenomena. The amplifying ratio of the audion depends more

or less directly on the value of the wing current, and by varying this

current periodically there will be a corresponding periodic change in the

amplifying power of the audion. Hence an audion arranged to repeat a

continuous wave under such conditions will produce in its wing circuit

oscillations which vary periodically in amplitude, and which may there-

fore be received by a simple audion system. The first audion may be

arranged to produce the necessary variation in its amplifying power in

the manner indicated in Fig. 29, which also shows the complete circuit

for carrying out this method of reception. Here C,L,L,C, is an audio

frequency system designed to produce audio-frequency oscillations; and

P isa potentiometer for adjusting the potential of the grid so that on the

negative part of the oscillation in the circuit, the wing current is reduced

practically to zero. The radio frequency cireuit C’LCC, is tuned to

the oscillation frequency of the incoming wave. The radio frequency

oscillations cannot be detected in the first audion system, as the strong

audio frequency current circulating in this system would produce a con-

tinuous note in the telephone receivers of such strength as to render in-

938 ANNALS NEW YORK ACADEMY OF SCIENCES

audible all save very strong signals. By arranging to detect the oscil-

lations in a second audion system coupled to the wing circuit of the first,

interference of this sort is avoided, as the circuit L,C, has a very high

impedance for the audio frequency currents and the effect produced

through the magnetic coupling of Z, and L, on the second system is neg-

ligible. The capacity current between these two coils through the tele-

phones to ground is, however, appreciable; and to avoid this it is ad-

visable to ground their two adjacent ends as shown. ‘The action of the

system may be summed up as follows. The first audion system varies

the amplitude of the incoming radio frequency oscillations at an audio -

frequency, and the second audion system amplifies and detects the radio

frequency oscillations supplied to it by the first system. Diagram-

matically, the phenomena occurring are as illustrated in Fig. 30. The

system gives about the same response as can be obtained with a single

audion working with the beat method of reception. The advantages

derived from the heterodyne method of amplification and the dependence

of the audio frequency note in the receivers on the wave length are, of

course, lacking; but for the reception of waves having a frequency higher

than that at which beat reception is practicable, this method is of value.

EFFEects oF ATMOSPHERIC DISTURBANCES

A very interesting feature of these receiving systems is their behavior

under conditions of severe atmospheric disturbances, particularly when

used for receiving continuous waves. Their success under such condi-

tions is due to the fact that they combine, in addition to their inherent

property of responding more readily to a sustained wave than a strongly

damped one, the characteristics of the two most effective static elimina-

tors known, the balanced valve and the heterodyne receiver. The func-

tion of the balanced valve is a physiological one, as it simply provides

a means to shield the ear from the loud crashes which temporarily 1m-

pair its sensitiveness for the relatively weak signals. In effect, it puts

a limit on the noise which can be produced in the telephone by a stray,

regardless of its amplitude. Now the effect of the static on an audion —

is to build up a negative charge on the grid, reducing the wing current,

and the limit of the response which can be produced in the telephones is

reached when the wing current is reduced to zero. Under ordinary con-

ditions, this limit is too great to do much good; but when the audion

is generating, it is possible by proper adjustment of the amplitude of

the local oscillations to reduce the wing current to a point just above the

lower bend in the operating characteristic so that the audion is rendered

ARMSTRONG, OPERATING FEATURES OF THE AUDION 939

insensitive to a further increase in the negative charge on the grid. The

strays which cause serious interference are of a much greater amplitude

than the local frequency, so that no appreciable interaction between the

two takes place, and the wing current is invariably decreased. Since the

- decrease in the wing current is not in proportion to the change in the

grid potential, the response in the telephone and the effect on the ear of

the operator are correspondingly reduced. Static of smaller amplitude

than the local oscillations may interact with them to produce either an

increase or a decrease in amplitude of the oscillation in the grid circuit,

and may therefore cause either a decrease or an increase in the wing cur-

rent. The wing current can, of course, increase to a relatively large

value, but as it is impossible for the wing current to increase faster than

the charge in the grid condenser can leak off, the rate of increase is nec-

essarily slow. The response in the telephones is therefore not so dis-

turbing as would be caused by a decrease of similar value where the rate

of change of current is usually large.

When the system is operated without an auxiliary leak around the

erid condenser, a peculiar paralysis of the audion is frequently caused

by heavy static, no sound of any kind being heard in the telephone for

a considerable length of time. If the apparatus is not touched, the

paralysis may last for many minutes, and then suddenly disappear and

the former sensitiveness be restored. The effect is primarily caused by

the charging of the grid condenser to a sufficient potential to cut off en-

tirely the flow of electrons to the wing, thereby decreasing the wing cur-

rent to zero. Now, the way in which the negative charge in the grid con-

denser leaks off is chiefly by means of the positive ions in the tube, which

are drawn into contact with the grid when it becomes negatively charged.

These positive ions are the result of ionization by impact, and when the

voltage of the wing battery is properly adjusted, they can be produced

only in the region between the grid and the wing, since the velocity at-

tained by the electrons between the filament and grid is very low. When

the grid is charged to a high negative potential it keeps all the electrons

between the grid and filament, thereby barring them from the region be-

tween grid and wing. Hence the production of positive ions must cease,

and the usual means of removing the negative charge from the grid van-

ishes. The resistance of the leakage path of the grid condenser must

then be almost infinite, as is shown by the very long time taken for the

charge to leak from a condenser of approximately 0.0001 microfarads

capacity. The effect is naturally the more pronounced the higher the

vacuum, as the number of positive ions present is correspondingly re-

‘duced. A resistance of several hundred thousand ohms placed across the

240 ANNALS NEW YORK ACADEMY OF SCIENCES

grid condenser gives a leak which is independent of the value of the wing

current and which effectually prevents trouble of this kind. With the

very high vacua now obtainable by the use of a molecular pump, there

are practically no positive ions present, so that the auxiliary leak is

always necessary. Under these conditions, it not only prevents paralysis

by the static, but it also removes from the grid condenser the excess of

negative electricity which accumulates in it, thereby increasing the sensi-

tiveness of the audion and the sharpness of the signals in the telephones.

The very high potentials to which the grid condenser may be charged by

the static are surprising. These potentials may be measured in a very

simple and accurate way, here described. After a stray has cut off the

wing current, if we continuously increase the capacity of the grid con-

denser, the potential across it and hence the potential of the grid with

respect to the filament will be decreased inversely as the capacity. A

point will finally be reached where the grid potential is sufficiently re-

duced to allow the wing current to flow. When this occurs it indicates

that the potential of the grid condenser is slightly less than that shown

by the operating characteristic as necessary to reduce the wing current to

zero. The potential to which the grid condenser was originally charged

is equal to this voltage times the ratio of the capacity of the condenser at

which the wing current began to flow to the original capacity. Voltages:

of over a hundred are not uncommonly reached by the grid and as one

volt represents a very strong signal, the difficulties of the static problem

are very forcibly presented.

The fact that static of large amplitude produces almost invariably

a decrease in the wing current, while a signal (with beat reception) pro-

duces alternately an increase and decrease in the wing current, is a cir-

cumstance of which it should be possible to take advantage. The circuits

can be arranged to rectify the wing current in such a way that only the

increases in this current are available to produce a response in the tele-

phones, but in carrying this method out, trouble is experienced from a

shifting zero. A better way of making use of the difference in response

is the following one. Suppose that we arrange two complete receiving

systems oscillating in step with each other, but so related to the antenna

that the beat currents in the two systems are 180 degrees apart. The

result of this will be that at the instant when the incoming signal is pro-

ducing an increase of current through the telephones in one receiver, it

will be producing a decrease of current through the telephones of the

other receiver ; so that the two telephone currents are 180 degrees out of

phase. Static of large amplitude does not interact with the local fre-

quencies, and will produce simultaneously in each receiver a decrease in

ARMSTRONG, OPERATING FEATURES OF THE AUDION DAT

the telephone current. These, two currents are therefore in phase with

each other. On replacing each telephone by the primary of a trans-

former, and. connecting their secondaries through a telephone in the

proper phase, it is possible to balance out the static and at the same time

secure an additive response of the signals from each receiver.

An arrangement of circuits by means of which this method can be ©

carried out is shown in Fig. 31. Here two oscillating receiving systems

Fig. 31

are kept in step by means of the circuits £,0,C,/L,’.. £,C, and L,’C,’

are identical, and each is tuned separately to the frequency to be received.

When both audions are oscillating in step, the flow of current in these

circuits, as indicated by the vectors of Fig. 31, will be alternately up on

one side and down on the other. The point between the condenser C,

and C,’ will be a node; and the antenna may be connected to this point

without disturbing the conditions appreciably if a resistance R, placed

as indicated, is included in the antenna. This resistance need not be

large enough to interfere seriously with the signal strength ; it need only

be large with respect to the resistance of the circuit L,C,C,/L,’, which

circuit has a very low resistance.

Incoming oscillations pass through the divided circuit as indicated in

the diagram, and therefore are in phase with the local oscillations of one

949 ANNALS NEW YORK ACADEMY OF SCIENCES —

receiver and 180 degrees out of phase with the local oscillations of the

other. This produces the desired result in the currents through the

transformers of the circuit 7’, which act in the manner already described.

It is found in practice that the oscillations set up in each system by

the incoming signals tend to neutralize each other through the circuit

' [,0,0,'L,'. This effect is avoided by introducing in the wing circuits

a differential coupling arranged to neutralize the coupling between the

two grid circuits. It is possible to do this, as it does not affect the coup-

ling of either receiver with the antenna, and does not interfere with the

local operation until the effective coupling between the two systems is

reduced to a point below which they will no longer remain in step. There

are other ways of securing the same result, but ‘the system shown wiil

illustrate the general procedure in carrying out this method of balancing.

The practical results obtainable with these receivers may perhaps be

of interest. At the present time, signals from all high-power stations

from Hilvese (Germany) to Honolulu are heard day and night at Colum-

bia University with a single audion receiver. Cascade systems give cor- |

respondingly better results, two stages being sufficient to make the night

signals of Honolulu audible throughout the operating room. Inter-

ference with the signals from Nauen by the arc station at Newcastle,

New Brunswick (Canada), is very easily eliminated by means of an

audio frequency tuning circuit; and this is the most severe interference

we have yet experienced, the two frequencies sometimes differing by less

than 1 per cent and the arc signals being much the stronger.

These receivers have been developed in the Hartley Research Labo-

ratory, Columbia University, and are mainly the result of a proper un-

derstanding and interpretation of the key to the action of the audion—-

the grid potential-wing current curve. In conclusion, I want to point

out that none of the methods of producing amplification or oscillation

depend on a critical gas action; they depend solely on the relay action of

the tube employed (electron or gas relay) and the proper arrangement

of its controlling circuits.

SUMMARY

The action of the audion as a detector and simple amplifier is ex-

plained, with the method of verification of the theory by means of oscil-

lograms. To reénforce the oscillations in the grid circuit two methods

are employed. First, to couple the grid circuit to the wing circuit and

arrange the latter to permit radio frequency currents to pass freely in

ARMSTRONG, OPERATING FEATURES OF THE AUDION 2.43

it; and, second, to use a large inductance in the wing circuit, thereby

_ tuning it to the incoming frequency (in conjunction with the capacity

between the filament and wing in the audion itself). Both methods may

be used together. Various methods of coupling grid and wing circuits

are shown. Methods of combined audio and radio frequency caer

tion are described.

The audion, being a generator of alternating current of any desired

frequency, can be used as a beat receiver. A steady audion generator of

regular groups of radio frequency oscillations is illustrated. Various

methods of audio frequency tuning permitting high selectivity are pos-

sible. By the use of two audions in cascade, amplifications as high as

1,000 are attainable. The cascade systems can be arranged so as to

operate both audions either synchronously or non-synchronously.

As an alternative to beat reception of sustained wave signals, an ar-

rangement is explained, wherein the amplifying ‘ratio of a repeating

audion is varied periodically at an audio frequency. Coupled to this

system is a simple audion detector. Musical signals of any desired pitch

are thus obtained.

It is found that static of large amplitude nearly always decreases the

wing current, while a signal (with beat reception) alternately increases

and decreases it. A system of circuits is described whereby this fact is

taken advantage of in balancing out static while retaining the additive

response to signals, thus effecting an elimination of static to a consider-

able extent.

Finally, instances of Tare distance stations received and interference

overcome in practice are given.

shal I dal i a aah i a Ga he Bie ala ta ae ee

= a ne a ees Cees E :

: % Me OF 4 as ¥

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Se ss a ae

PUBLICATIONS

OF THE |

NEW YORK ACADEMY OF SCIENCES

(Lyceum or Natura History, 1817-1876)

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PRESS OF JODD & OBTWEILER. INC.. WASHINGTON. D.C.

- Editor, Ratpn W. Tower

RECORDS OF MEETINGS

. _ MEMBERSHIP IN 1916.

Or THE

NEW YORK ACADEMY OF SCIENCES

WITH INDEX TO VOLUME XXVII

NEW YORK

PUBLISHED BY THE ACADEMY

- 80 NovEeMBER, 1917

‘THE NEW YORK ACADEMY OF SCIENCES —

(Lyceum or NaTuRAL History, 1817-1876)

Guaeus: AQ Oo ee

Pee eee Ipvorsky PuPIN, ‘Columbia University

Vice-Presidents—Ernest E. Surry, J. McKeen Carrett,

Corresponding Secretary—-HENRY E. Crampton, American Mensur s

Recording Secretary—RALPu W. Tower, American Museum ~

Treasurer—HENRY J. Cocuran, Bankers’ Trust Co., 5th Avenue and

- 42d Street

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Editor—Ratru W. TowEr, American Museum

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

Lee ere E, SMITH, 50 East 41st Scat

Secretary—Victor E. Levine, 70 Jefferson Street.

SECTION OF BIOLOGY

Chairman—HerMANN VON Ww. SCHULTE, College of f Physicians: and

Surgeons ;

Secretary—WitL1am K. GrecoRY, American dineer ue

SECTION OF GHOLOGY AND MINERALOGY

Chairman—Dovucias W. Jounson, Cohunbia University

Douenas W. Jounson, Hermann von W. apaneen E 2

Secretary—Oneste A. REEDs, aneviers Musehm >> S75 eee)

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

Chariton, MoKren cNanne Columbia University — aoe 6 a

Secretary—RoBert 13e Lowi, American Museum ~

The sessions of the See are held on Monday evenings at 8: 1b

- o'clock from October to May, inclusive, at the American Museum ‘of -

Natural ESO T7th Street and Central Park, West.

[Annas N. Y. Acap. Scr, Vol. X XVII, pp. 245-336. 30 November, 1917]

RECORDS OF MEETINGS

OF THE

NEW YORK ACADEMY OF SCIENCES

January to December, 1916

By Raueu W. Tower, Recording Secretary

BUSINESS MEETING

3 JANUARY, 1916

The Academy met at 8:15 Pp. m. at the American Museum of Natural

History, Vice-President Douglas W. Johnson presiding.

The minutes of the last meeting were read and approved.

The following candidate for active membership in the Academy, recom-

mended by the Council, was duly elected:

Leo Wallerstein, 171 Madison Avenue.

The Secretary reported the following death:

Sir Henry Enfield Roscoe, Honorary Member since 1887, died 18

December, 1915. .

The Academy then adjourned.

Henry EH. Crampton,

Acting Recording Secretary.

SECTION OF GHOLOGY AND MINERALOGY

3 JANUARY, 1916

Section met at 8:20 Pp. m., Vice-President Douglas W. Johnson pre-

siding.

The following program was presented :

(245)

24G ANNALS NEW YORK ACADEMY OF SCIENCES

Douglas W. Johnson, THe Strarecic VALUE OF LANDFORMS IN THE

GREAT Russtan RETREAT.

A. W. Grabau, SoME PARALLELISMS IN THE GEOLOGY OF West-

ERN HUROPE AND AMERICA.

SUMMARY OF PAPERS

Dr. Johnson described and illustrated by specially prepared maps how

the detailed movements in the Russian retreats of 1915 were influenced

to a remarkable degree by the surface features of the country over which

the contending armies moved.

Professor Grabau, with the aid of charts and lantern slides, contrasted

the topographic, sedimentary and faunal relations of the British Isles

and western Hurope, particularly the Baltic region during the Tremadoc,

Areing and Landeillo stages with the Potsdam, Beckmantown and St.

Peters stages in the United States and southeastern Canada. Special

reference was made, on the one hand, to the Caledonian and American

lands and on the other to the Ceratopyge, Phyllograptus and Tetra-

graptus faunas of the Areing beds and to the trilobites, Megelapsis lim-

bata and M. plantilimbata of the Landeillo beds. In the Baltic region

the Dictyonema fauna thins outward to the east and is superseded by the

Ceratopyge forficula forms. The possible routes of migration of marine

forms at these stages in our geologic history between Europe and America

was explained.

The Section then adjourned.

Curster A. REEDs,

Secretary.

SECTION OF BIOLOGY

10 January, 1916

Section met at 8:15 p. m., Vice-President H. von W. Schulte pre-

siding.

The following program was presented :

Henry Fairfield Osborn, Dinosaurs wHicH Mimic THE OSTRICHES

AND OTHER StRUTHIOUS Brrps.

Roy C. Andrews, THe Ser WuHate (Balenoptera borealis).

Irs History, Hairs, ExrernaL ANAT-

OMY, OsTEOLOGY AND RELATIONSHIP.

(Read by Title.)

RECORDS OF MEETINGS 24%

H. von W. Schulte, ON THE ANATOMY OF A FHTAL Balenoptera

; borealis.

John D, Kernan, Jr., REMARKS ON THE Ear or Balenoptera

borealis.

SUMMARY oF PAPERS

Professor Osborn described and illustrated the remarkably complete

skeleton of a bird-like dinosaur allied to Ornithomimus, recently mounted

in the American Museum. He showed its general resemblance to

struthious birds in the form of the skull and hind limbs and discussed

the various hypotheses which had been advanced concerning the life

habits of this animal. He then contrasted it with Tyrannosaurus, a giant

carnivorous dinosaur, and showed the wide adaptive divergence between

these two branches of the carnivorous dinosaur stock. The paper was dis-

cussed by Dr. Gregory.

Professor Schulte stated that the following results are based upon the

dissection of a foetus measuring 37.5 cm. in length, collected by Mr. Roy

C. Andrews at Rikusen, Japan. The complete details of the examination

will appear in the Monograph of the Pacific Cetacea, to be published by

the American Museum of Natural History.

The panniculus carnosus formed a very complete investment of the

venter and sides throughout the region corresponding to the body cavities

and neck. Over the dorsal muscles and pedicle it was replaced by

aponeurosis. From this arrangement it was thought that it might serve

by its contraction to maintain pressure upon the contents of the thorax

and abdomen as the animal rose to the surface. It may further subserve

an expirator function. In its disposition it closely resembles the cuta-

neous muscle of Phocaena except that in front of the shoulder its dorsal

division overlies the ventral instead of forming with it a continuous

sheet, which may, however, show a tendinous inscription.

Throat furrows were not yet present. The integuments of the inter-

mandibular region, throat and thorax, well down upon the abdomen,

were, however, redundant and rendered easily movable upon the deeper

parts by the interposition of a layer of very loose areolar tissue. Between

this and the skin was a complex muscle intimately bound to the integu-

ments. From without inward was a thin layer of scattered fasciles of the

dorsal panniculus, then the ventral panniculus, then mylohyoid, and

finally a longitudinal stratum of hypoglossal cervical mnervation, extend-

ing from mandibles to abdomen. The throat furrows, to which this

redundency of the integumentary complex is plainly antecedent. have

948 ANNALS NEW YORK ACADEMY OF SCIENCES

been explained as a provision for enlarging the capacity of the mouth

(Kiikenthal) ; but their presence on the thorax can hardly be so ac-

counted for. Andrews has suggested that they may be a provision for

great expansion of the thorax, taken in connection with the fact that in

Balenoptera the sternum is greatly reduced, is jomed by only the first

pair of ribs and costo-central articulations are present only from the

second to the fourth or fifth rib. Dr. J. Vaughan has suggested that

this extreme expansion of the thorax may be passive and would seem to

be called for if it can be assumed that the diaphragm relaxes during the

period of apnoea, when the animal is submerged.

The heart was practically unrotated, its long axis nearly dorso-ventral

and not appreciably deviated to the left. Its chief mternal peculiarity

was the form of the valve of the fossa ovalis, like a perforated thimble

attached all around to its base. There was, further, no Eustachian and

no Thebesian valve. These conditions have been previously described

by Knox and by Turner. :

The trachea was wide, short and covered as far as its bifurcation by a

thick walled muscular laryngeal sac. The structure of this is such as to

preclude the possibility of its acting as a reservoir. It may possibly

serve by its contraction to set up a current in the air within the capacious

bronchial tree, so aiding in the diffusion and utilization of the con-

tained air.

The liver was massive and of simple contours; the stomach showed

four compartments; the intestine had undergone rotation and an ascend-

ing colon, splenic flexure and descending colon—in a word, the left colic

loop of Bardeen was present and fixed; the caecum was of moderate size,

bluntly rounded at the apex. The chief peculiarity of the situs viscerum

was the collacation of almost all of the intestine together with liver,

spleen, pancreas and stomach in the preumbilical portion of the abdomen.

There was no foramen epiploicum, a condition recorded by Hunter of

certain whales.

The genito-urinary tract resembles closely the description of Daudt

except that there is certainly no mesentery for the kidneys, nor was it

evident that there was any real asymmetry of the internal or the external

organs—the individual being a female—other than could properly be

ascribed to the curvature of the fcetus.

The skull was remarkable for its rounded cranium, wide exposure of

the supra-occipital, enormous auditory bulle, straight axis and small

development of rostrum, orbital process and squamosal.

There were thirteen pairs of ribs. The first rib was two headed on

Pe.

ms)

;

RECORDS OF MEETINGS 949

both sides. The ventral bar of the transverse process of the 7th cervical

vertebra was lacking, that of the sixth was retarded in development and

moveable upon the centrum. The pelvis showed no sign of an acetabu-

‘lum. ‘There was no trace of a femur.

The nasal fossa, larynx and ear were studied by Dr. John D. Kernan,

Jr., of Columbia University, whom I have asked to present his results as

a continuation of this communication.

Dr. Kernan stated that the important thing to note in connection with

the ear of this animal is that it is of high mammalia type made over for

life in the water. The external ear has disappeared, and neither muscle

nor cartilages were observed in this fcetus, although both have been re-

corded by other observers. The external auditory meatus is a very small,

tortuous passage capable of valve-like closure. In the foetus there is no

trace of the ceruminous mass found in the adult. The tympanic mem-

brane is of the ordinary mammalian type. attached by its margins to the

tympanic ring, concave externally, and attached to the manubrium

mallei by a triangular fold which appears to be a protrusion of the mem-

brane itself. The ossicles present no peculiarities. There is a well de-

veloped tensor tympani present, a fact which has not before been noted.

The cavum tympani is filled by a mass of cavernous tissue which is

thought to have the function of regulating pressure in the middle ear

during submersion of the animal. The internal ear shows a well de-

veloped semicircular -canal system and a cochlea of nearly three turns.

In considering these structures as an apparatus for hearing we see

at once that all possibility of hearing’ by air conduction is shut off. It

seems as if rather elaborate precautions had been taken to prevent this.

In this connection it is interesting to recall that in diseased conditions

of the conducting apparatus in human beings the hearing by bone con-

duction is increased and prolonged. It may well be said that in whales

the closing off of the external auditory meatus increases the possibility

by bone conduction, on which they must depend for hearing water-borne

sounds. These are probably conveyed to the cochlea through the promi-

nent mastoid process which occupies a considerable extent of surface

between the squamosal and exoccipital bones.

The Section then adjourned.

WititiaAm K. Greicory,

Secretary.

ANNALS NEW YORK ACADEMY OF SCIENCES

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

24+ JANUARY, 1916

The Section met at 8:30 P. M., in conjunction with the American Hth-

nological Society, whose president, Dr. P. E. Goddard, presided.

The following program was presented :

Franz Boas, GreNERAL EruHnotocicaAL Norss rrom Porto Rico

Robert T. Aiken, Porro Rican Burran Cavzs.

H. K. Haeberlin, ArcHnoLocicaL Work IN Porto Rico.

SUMMARY OF PAPERS

Mr. Aiken stated that the archeological work done during the past

summer was in two sections, the first being the excavation of a cave

and adjacent village site, the second the excavation of a much larger

site. The following data refer only to the former undertaking, which

was carried through with the cooperation of Dr. J. H. Mason and under

the general direction of Professor Franz Boas. The cave in question is

one of the innumerable hollows in the limestone formation which com-

poses a large portion of the island. It lies in a ridge about ten miles

from Utuado, at an elevation of about two hundred feet above the adja-

cent valley. The entrance is large and faces east. The floor was en-

tirely excavated. It was composed of alternate layers of disintegrated

limestone and crystalline calcite with a thick underlying stratum of

clay. ‘The upper forty inches of the stratified formation yielded no less

than twenty fairly complete human skeletons, all evidently imterred in

contracted position. All the remains were quite fragile but hardened on

exposure to the air. Only three intact skulls were found. A few scat-

tered bits of potsherd were found, as well as a few fragments of stone

and shells. The village at the foot of the hill yielded nothing but a few

similar sherds, a single hammer stone and a few pebbles. However, the

fact of there being a site here was proved by the presence of prehistoric

walls.

The conclusions to be drawn from the material are that the Porto

Ricans practised cave burial, but did not use such caves for habitation

and did not place offerings with the dead.

Dr. Haeberlin stated that a ball-court near Utuado was studied as —

part of the same expedition of which Mr. Aitken was a member. On the

north and south the court was bordered by a continuous row of flat

RECORDS OF MEETINGS 251

stones from one to three feet; on the east and west no stones were found.

Red pottery with incised scroll work occurred. In a cave excavated by

the speaker enormous quantities of snail shells, rodent and crab bones

were found, together with many potsherds of a type different from the

ball-court variety in texture, in the absence of incised decoration, and in

the presence of inside handles. A baby burial was unearthed.

The Section then adjourned.

R. Hi. Lowte,

Secretary.

BUSINESS MEETING

7 FEBRUARY, 1916

The Academy met at 8:15 Pp. m. at the American Museum of Natural

History, Vice-President Ernest E. Smith presiding.

The minutes of the last meeting were read and approved.

The following candidates for membership in the Academy, recom-

mended by the Council, were duly elected:

ActivE MEMBERS

Miss Mary C. Dickerson, American Museum of Natural History,

‘Pierre A. Bernard, 662 West End Avenue,

Howard L. Clark, North Farm, Bristol, R. I.,

Howard Notman, 136 Joralemon Street, Brooklyn.

Associate MEMBERS

C. L. Camp, Columbia University,

A. M. Brown, Columbia University.

The Secretary reported the following death :

Mr. Tgnaz Matausch, Active Member since 1914, died 14 December,

1915. ihe

The Acting Recording Secretary presented an informal statement re-

garding plans for the Centennial Celebration of the foundation of the

Academy, to be held in May, 1917. The Council has been organized

into committees, which are to deal with different parts of this celebra-

tion. It is intended that a fund of at least $100,000 shall be raised, the

income of which is to be employed for scientific investigations. As

959, ANNALS NEW YORK ACADEMY OF SCIENCES .

an initial gift, Professor N. L. Britton has generously promised $5,000.

The Academy then adjourned. | }

Henry EK. CRAMPTON, _

Acting Recording Secretary. -

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

¢ February, 1916

Section met at 8:20, Vice-President Ernest E. Smith presiding.

The following program was presented :

A.J. Goldfarb, CurmicaL AnD PHysicaL CHANGES oF EGGs AND

THEIR SIGNIFICANCE IN GRAFTING.

Arthur E. Hill, Report on THE ABsoRBING PowER oF CERTAIN

CotLoms.

SUMMARY OF PAPERS

Professor Goldfarb stated that when eggs of sea-urchins (Toxopneustes

varvegatus) are removed from the ovaries and placed in sea water at

room temperature (84° F.) a series of changes take place that affect the

character of the fertilization membrane, the rate of fertilization membrane

formation, the viscosity of the egg protoplasm, and the rate of cleavage.

These changes are approximately in proportion to the time factor, reach-

ing a maximum just before death. These changes permit of ready fusion

of separately fertilized eggs, whose further development into fused larvae

was elsewhere described.

Professor Hill stated that absorption occurs when chromium, iron or

aluminum are precipitated by ammonium chloride and ammonium

hydroxide in the presence of salts of cobalt, nickel, manganese or zinc.

Using 100 mg. of the absorbing metal, it was found that as much as

40 mg. of nickel would be so completely absorbed as to be undetectable

in the filtrate. The order of absorbents, from greater to less, is as

follows: chromium, aluminum, iron; and the metals absorbed are in the

order nickel, zinc, manganese and cobalt. It was found that the absorp-

tion is roughly proportional to the alkalinity. Moderate excess of am-

monia will increase absorption so greatly that chromium hydroxide will

carry down more than its own weight of nickel or zinc salts. In keeping

with this generalization, it was found that separation of the two groups

of metals by use of solid barium carbonate reduces the absorption greatly

and the separation by sodium acetate in slightly acid solution reduces

the absorption to an almost undetectable amount. A precise study of

RECORDS OF MEETINGS 953

absorption of cobalt salts by pure chromium oxide suspensions was also

made and followed the usual absorption isotherm, the equilibria being

reached both from the side of excess in solution and that of deficiency

in solution.

Dr. Mutscheller, in discussing Professor Hill’s paper, found the re-

sults in full agreement with his own conclusion. The question whether

the results given have been substituted in the exponential absorption

equation was answered in the negative. Dr. Mutscheller believes that if

these substitutions had been made in this equation, different values for

the constant of equation for each one of the three colloids would have been

obtained. This constant is known to depend on the temperature, the

nature of the dispersion medium, and the dispersoid. This fact would

preclude that each one of the three colloidal hydroxides possesses a dif-

ferent absorption potential or affinity, by reason of which an increase or

decrease of the [OH—]| concentration would produce proportional results.

This seems to be the case in the data given by Professor Hill, for the

values given in the columns show all proportional changes.

Dr. Mutscheller in his work on reversible colloids found by conductiv-

ity measurements that they absorb ions. Moreover, by means of poten-

tiometric determination of the ionic concentrations, he found that they

absorb specifically oppositely charged ions and leave the other ion free so

long as certain limits of low concentration are not surpassed. Professor

Hill’s data seems to demonstrate the same fact. An increase of acidity

and consequently hydrogen ion concentration, therefore, neutralizes the

absorption affinity of the colloids so that other cations, namely, the metal

salt in solution, are no longer absorbed by the colloid. «

The Section then adjourned.

VY. HK. LEVINE,

Secretary.

SECTION OF BIOLOGY

14 Fepruary, 1916

Section met at 8:15 p. m., Vice-President H. von W. Schulte presid-

ing.

The following program was presented:

R. W. Shufeldt, Tur Canovu snp ortHeR Extinct Prrrets. (Pre-

sented by Dr. F. A. Lucas.) -

J.D. Kernan, Jr.. THE CiHoNnpDROCRANIUM OF A 20 MM. HUMAN

EmMpryo.

254 _ ANNALS NEW YORK ACADEMY OF SCIENCES

A. J. Brown, THE DEVELOPMENT OF THE SPINE IN THE Cat.

J. T. Nichols, On PRIMARILY UNADAPTIVE VARIANTS AMONG

VERTEBRATES. .

SuMMARY OF PAPERS

Dr. Kernan stated that the chondrocranium presents at this stage

fairly complete development of the base of the skull in the region of the

posterior and middle fosse. There is no skull floor to the anterior fossa.

The lateral occipital regions are united to the basal region by two roots

which embrace the hypoglossal foramen. On the left side this foramen

is partially subdivided. There is some evidence in this embryo for the

view that the vertebre entering into the formation of the occipital region

are of the atlas type. By this hypothesis is best explained the subchordal

position of the basioccipital, and the relations of the suboccipital nerve

and the costal and transverse processes of the occipital vertebra to the

condyle. The paraoccipital process and the lamina alaris of the lateral

region may be analyzed on the evidence found in this fcetus into the

costal and transverse process of the occipital vertebree.

The otic capsules are well developed and they form with the parietal

plates which surmount them a considerable part of the side wall of the

skull, which contrasts markedly with their basal position in the adult.

In the orbito-temporal region the sphenoid body is a solid mass of carti-

lage. There is a well developed dorsum sell, and sella turcica. he

lamina hyochiasmatica, which in earlier embryos is on a level with the

floor of the sella turcica, is elevated. The optic foramina are not yet

surrounded by cartilage, the ale orbitalis being unconnected with the

presphenoid. There are well developed ale hyochiasmatica free from

both preesphenoid and ale orbitales.

The alee temporales show separation into two parts, the processus alaris

related to the basisphenoid, and an independent processus ascendens.

The processus alaris is extended to the cochlea by a commissura ali-

cochlearis. The foramen rotundum is complete, the foramen ovale only

indicated.

In the ethmoidal region the septum nasi is well developed. The nasal

walls, however, are merely small plates of cartilage with only slight in-

rolling of the ventral.edges to indicate the maxillo-turbinals. There is

no nasal roof or floor.

Ossification has begun in two Bones only, the maxilla and mandible.

Meckel’s cartilage is a massive structure, continuous dorsally with the

malleus which shows manubrium and caput. The incus shows all its

RECORDS OF MEETINGS OBR

Lo)

processus. The stapes is of younger tissue than the other ossicles, and is

still connected by an “‘interhyale” to the dorsal end of the hyoid cartilage.

Mr. Nichols stated that his paper deals with vertebrate variants

(forms or species of animals more or less related but differing from one

another) which, although geographical, are not direct or obvious re-

sponses to the environment.

Several types of variant are defined. Representative forms occupy-

ing adjacent: regions are designated as adjacent races or species; forms

intermediate in structure between adjacent forms and occupying terri-

tory remote from them as foreign intermediates; related forms occupy-

ing the same territory and contrasted in superficial characters as com-

plements; forms separated geographically and showing greater resem-

blance (not induced by environmental adaptation) than their degree of

relationship would presuppose, as outcrops.

The hypothesis was advanced that, probably on account of competition,

closely related forms are antagonistic. That is when in touch geograph-

ically they tend to force one another apart in superficial characters. If

this hypothesis, which seems to fit into certain known facts extremely

well, be accepted, it involves a centrifugal force in evolution opposed to

the centripetal tendencies of blood relationship.

Tt is the main theme of the paper to advance the concept of these two

forces as the fundamental framework of evolutionary control, the helm

which is swayed by natural selection or other forces.

The Section then adjourned.

WiLtitiAmM K. Gregory,

Secretary.

SECTION OF GHOLOGY AND MINERALOGY

21 FrBruary, 1916

Section met at 8:20 p. m., Vice-President Douglas W. Johnson pre-

siding.

The minutes of the last meeting of the Section were read and ap-

proved.

The following program was presented :

S. H. Knight, CLIMATIC CONDITIONS IN SOUTHERN WYOMING

Durineé DEPOSITION OF THE “RED BeEpDs.”

Charles P. Berkey, UNstTasLn ConDITIONS EXHIBITED BY SOME OF THE

° Rock FouUNDATIONS OF THE Htupson VALLEY.

256 ANNALS NEW YORK ACADEMY OF SCIENCES

SUMMARY OF PAPERS

Mr. Knight stated that the “red beds” consist principally of sand-

stone, arkoses and conglomerates, with smaller amounts of limestone and

gypsum. They outcrop over hundreds of thousands of square miles in

the territory embraced by Wyoming, Colorado, New Mexico, Kansas,

Oklahoma, and Texas. They are late Pennsylvanian in age. Mr.

Knight attempted to prove that the “red beds” are for the most part

continental in origin, and that the climate was arid to semi-arid. By

means of type geological sections A and B some fifty miles apart, by

three block diagrams illustrating the relief at various stages in the his-

tory of the region, and by ten lantern slides the speaker proved his con-

tentions. In summing up, Mr. Knight stated that heretofore the “red

beds” had been regarded as of marine origin, rather than of continental.

His presentation of the subject argues for the torrential, fluvial, and

eolian origin of the greater part of the deposite instead of the marine

one. The Upper Pennsylvanian age of the lower 800 feet of the “red

beds” was determined from a pelecypod fauna found in the thin lime-

stone member of Section A. The paper was discussed by Doctors Gra-

bau, Finlay, Johnson and Reeds.

Dr. Berkey stated that the rock formations penetrated by the various

tunnels of the Aqueduct were at many places not at all stable. The

causes of instability are chiefly of two kinds. First: The excessive

rock decay, represented both by badly fractured crush zones through

which water has circulated to considerable depth, and also a few places

where superficial decay matters of pre-glacial origin are still preserved

beneath the drift. Very many crush zones with weakened material were

encountered. The most extensive development of weathered rock of

superficial relations was in the vicinity of Garrison in the Highlands,

where the tunnel extended for several hundred feet through such ma-

terial. Second: A type of instability of very different character is rep- _

resented by rock which is under strain and which tends to relieve itself

when the support is removed, as happens in the case of tunneling or shaft

construction, allowing slabs to break off from the walls sometimes with

considerable suddenness and noise. This is called “popping-rock” by

the workmen and has been a source of considerable danger. It has been —

observed in several different formations, most prominently in the Hsopus

shales, the Storm King granite, and the Ravenswood granodiorite. The

author undertook to explain in some detail the condition exhibited at one

of these places in the vicinity of Cornwall on the Hudson, where it was

RECORDS OF MEETINGS Rot

found that there was movement in the rock through which the tunnel

passed, after the concrete was placed and put under test. Various ex-

planations have been suggested for this movement, and consequent leak-

age from the tunnel. Dr. Berkey’s explanation involved the question

_ of the movement dependent upon this known tendency of the rock to

relieve the strain under which it is subjected. It is thought that the

bursting pressure of the water when the test was made tended to add to

the natural tendency of the rock, and the result was a movement which,

except for this help, would probably not have taken place. ~ Movement

to the extent of jostling the blocks in the complexly fractured granite

was aided by the escaping water, which tended to wash out the soft clay-

lke gouge which normally fills many of the crevices or joimts. ‘The

chance of being able to stop the leakage under these circumstances

seemed so remote that it was finally decided to construct a new section

of tunnel at this point at a lower level, to avoid the unstable condition

that had been encountered. The interesting phenomenon from a geo-

logical standpoint is the fact that the rock had the appearance at all

times during construction of being one of the most substantial and

stable sections in the whole Aqueduct line.

The Section then adjourned.

Custer A. REEDS,

Secretary.

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

28 Fupruary, 1916

The Section met at 8 p. m., Prof. R. S. Woodworth presiding.

The minutes of the last meeting of the Section were read and ap-

proved. :

The following program was presented :

Russel L. Gould, Trsts or Manuan Accuracy oF PRE-VOCATIONAL

ScHoor Boys. :

G. C. Myers, — ASSOCIATION AND CLASSIFICATION.

Edith F, Mulhall, Tests or THE Memory oF ScHooL CHILDREN.

J. L. Stenquist, Tests or MECHANICAL ABILITY.

SUMMARY oF PAPERS

Mr. Gould stated that the tests were undertaken for the purpose of

offering some possible data on the efficacy of the newly established Ht-

258 ANNALS NEW YORK ACADEMY OF SOIENCES

tinger Pre-vocational Schools of New York City, in improving the gen-

eral manual accuracy of the boys. The problem resolved itself into a

new aspect of the old question of transfer from practiced abilities to un-

practiced ones.

The plan was to test at the beginning of the school year two groups

of boys; one group of those just beginning the pre-vocational shop work,

and the other a control group of academic boys of the same grade and

school. At the end of the year the tests are to be repeated. In so far

as they are a reliable index of general motor ability, they are expected to

indicate some effect of the shop work.

The necessity for large groups and for moderate haste prevented the

use of more than three tests on each boy. Those used were the Thrust-

ing, the Hammering and the common 3-hole test. The first two were

designed for this work.

The Thrusting test required a full arm movement ; to hit with a pencil

the middle target of a row of three varying targets, thirty rows appear-

ing from behind a screen at a constant speed. Four groups of thirty

were used at four speeds, such that each row was in sight for 1.0 sec.,

1.2 sec., 1.6 sec., and 2.0 sec. Hach hit was separate and distinct, as one

row only was in sight ata time. The number of hits ranged from 0 to 21.

In the Hammering tests the subject used a specially prepared ham-

mer, to hit three points, distant from each other by 50 cm. ‘Time was

constant, measured by the beats of a metronome, at the average rate

preferred by ten boys. An improvement in the apparatus records each

hit electrically on a kymograph. There were very marked differences

in the abilities of the boys, the hits ranging from 0 to 20 in 50 shots.

The 3-Hole test was too well known to be described. ‘Time was taken

for 50 contacts.

Mr. Myers stated that the purpose of this study is to investigate the

natural tendency of classification as shown by the superior speed in nam-

ing (within certain limits) successive individuals of a single class over

the speed of naming single individuals of successive classes.

In the preliminary test each of 71 normal school girls was supplied

with a copy of 2 series, each of 10 class names of familiar things (Group

I). These two series interchanged reappeared on the opposite side of

the page (Group IT). About half the subjects were given 18 seconds to

write the names of things falling under each of the 10 class names of

the first series. Then for the second series they were given a total of

180 seconds. to write successively under each of the 10 class names, one

name at a time, as many individual names as possible. For the other

half of the subjects the procedure throughout was reversed.

2 es se

Sees. eee we

RECORDS OF MEETINGS 259

The successive association under single class names may be called less

controlled, the other more controlled associates. In the 3 minutes the

average total number of words given for group I as less controlled asso-

ciated is 56.4, M. V. 5.8, with a range of from 34-80 words. For more

controlled associates the respective figures are 46.1, 4.9 and 20-60. For

group II the less controlled associates give 60.4, M. V. 6.5, and a range

of from 39-77 words; the more controlled 42.5, 4.0 and 32-58 respectively.

This test is unfair to the less controlled records because of time lost in

writing.

In a second experiment on 56 more girls the subjects were divided into

pairs, each member of the pair serving as subject and experimenter 1n

turn.

The writer read 20 class names pausing 8 seconds for each name while

one of each pair named as many individuals of that class as possible.

Number two recorded the number of individual names given. Then

number one was provided with a list of these 20 class names and on

signal she named an individual of each class name, repeating the opera-

tion until interrupted by writer at the end of 2 min. 40 sec. Number

two recorded the number of responses as before. Then number two pro-

ceeded in reverse order with number one as recorder.

In the 2 min. 40 sec. the average total number of individual names

given is for less controlled associates 123.7 M. V. 13.8, range 89-182;

more controlled associates 66.9, M. V. 9.7 and 53-106. Four subjects

studied practice effect by repeating the test 9 times, over a period of

several days. Three found an increase in the total number of associates

of each type and the superiority of the less controlled associates increased

with time. For the other subject both decreased with time.

These facts emphasize a fundamental difference between the two

types of associates and the rather obvious inference that classification is

a very natural process. The study is still in progress.

Miss Mulhall stated that an attempt was made to determine whether

or not there are any characteristic differences between the two memory

processes known as recall or reproduction and recognition. Answers

were sought to the five following questions: 1—Does the person who

recalls one kind of material well also recall another kind of material well ;

or what is the correlation between the recall of different materials? 2—

Does the person who recognizes one material well also recognize another

kind as well; or what is the correlation between the recognition of dif-

ferent materials? 38—Does the person who recalls one material well

recognize that material well; or what is the correlation between the

260 ANNALS NEW YORK ACADEMY OF SCIENCES

recall and recognition of the same material? 4—Are the recall records

of girls better than those of boys as earlier literature states? Is there

any sex difference in recognition memory? 5—TIs there any difference

in the sex variability in recall or in recognition? .

The subjects were 192 children, 71 in grade 5 B, 62 in 6 A and 59 in 6

B in a city school. The materials used were two series each of 25 words,

25 forms, 25 syllables. Memory was tested half the time by requiring

the subjects to write down what they remembered (reproduction) and

half the time by asking them to select from another set the items which

they had and had not seen (recognition).

The conclusions were: 1—A person who can reproduce a great many

items of one material cannot necessarily reproduce many of another ma-

terial. 2—The person who can recognize one material well cannot neces-

sarily recognize another material well. 3—-A person who secures a high

seore for recalling words, forms, syllables may not necessarily receive a

high score for recognizing words, forms, syllables respectively. (In no

case was the average of the coefficients of correlation as high as .30.)

4—There is found no superiority of the girls over the boys for recall, but

a confirmation of the work of Chamberlain. There are no sex diiferenves

for recognition. 5—There is no consistent difference in sex variability

in recall or in recognition.

Mr. Stenquist stated that his report consists chiefly of a description

and exhibition of a series of mechanical tests which have been deyised

by the author under the direction of Professor Thorndike. The first i

of these is called Construction Test, Series I, and is described in detail

in “The Intellectual Status of Children who are Public Charges,”

Archives of Psychology No. 33, Columbia University. Construction

Test, Series II, is similar to Series I, but more difficult. These tests

consist of a series of mechanical models to be assembled under standard-

ized conditions by the subjects, the original idea being to provide a test

that did not depend upon the subject’s ability to read and write, and to

deal with heard words. In the case of Construction Test, Series I, age-

grade standards have been built up and the child can be scored as over

or under a standard “Construction-age”, as determined by the scores of

' 432 public school children of New York City.

The second type of test reported upon has been named “Recognition

of Mechanical Devices,” and consists of 55 mechanical devices, ranging

from a common nail to a spark plug and its parts, all numbered and

fastened to a card about 8 by 18 inches, placed in a suitable box. A com-

plete list of the names of all the devices is given the subject and his task

RECORDS OF MEETINGS 261

consists in identifying each device known to him, which he does by writ-

ing the appropriate number before each name.

Both of these tests have only been begun and the data thus far gath-

ered does not warrant any further conclusions than those reported in the

monograph referred to above.

Section then adjourned. R. H. Lowiz,

Secretary.

BUSINESS MEETING

6 Marcu, 1916

The Academy met at 8:15 Pp. m. at the American Museum of Natural

History, Vice-President Ernest E. Smith presiding.

The minutes of the last meeting were read and approved.

The following candidate for Associate Membership, recommended by

the Council, was duly elected:

Adolph Elwyn, Hoagland Laboratory, Brooklyn.

The Secretary reported the following death:

Nathaniel C. Nash, Life Member since 1910, died 10 October, 1915. |

The Academy then adjourned.

Henry E. Crampron,

Acting Recording Secretary.

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY |

6 MarcuH, 1916

Section met at 8:20 Pp. M., Vice-President Ernest E. Smith ae

The following program was offered :

Victor C.Myers, Tur Curmican CoMPosITION OF THE BOD IN

DISEASES OF THE KIDNEY.

James P. Atkinson, Foop Poisons. :

G. A. Reichling, Unusuat Mereoronocican Conprrrons OB-

SERVED Durine A WINTER-FLIGHT IN A TR ACTOR

BIPLANE.

SUMMARY OF PAPERS

Dr. Myers stated that normally the non-protein nitrogen of the blood.

in the human subjects amounts to 25-30 mg., the urea nitrogen to 12-15

mg.. the uric acid to 2-3 mg.. the creatinine to 1-2.5 mg. and creatine to

962 ANNALS NEW YORK ACADEMY OF SCIENCES

5-10 mg., all calculated per 100 cc. of blood. The ease of excretion of

the three most important nitrogenous waste products—creatinine, urea

and uric acid—seems to fall in the order just named, possibly owing to

purely physical laws of concentration and solubility. In gout, where the

permeability or activity of the kidney is only slightly lowered, we en-

‘counter an increase only in the uric acid concentration of the blood (4-9

mg. per 100 cc.). In the early states of chronic interstitial nephritis

a similar retention of urea is observed. Here, however, we begin to find

a retention of urea as well (urea nitrogen figures from 15-35 mg. per

100 cc.), although, as yet, there is very little influence upon the cre-

atinine. As the disease becomes more severe, the retention of urea in-

creases (60-80 mg.), although, with improvement, it falls. Creatinine,

however, is normally excreted with such great ease that it is apparently

only in the last stages of the disease that a notable retention occurs,

figures over 5 mg. per 100 ce. indicating, as a rule, an early fatal termi-

nation. The blood creatine has been found increased in only a few

cases, viz., terminal cases of interstitial nephritis with very high figures

for uric aed (13-27 mg.).

The retention of the nitrogenous waste products is . frequently of less

immediate concern than the retention of acid substances. As an indica-

tion of the actual severity of an acidosis, we recently found Van Slyke’s

method of ascertaining the oo combining power of the blood plasma of

very great value.

In the early cases of diabetes the glucosuria is a very reliable guide

as to the hyperglucemia, although quite the reverse may be true in cases

of long standing with nephritic complications. Here one may encounter

very high figures for blood sugar with a very small amount, or even no

sugar in the urine. In one case the blood sugar of 1.10 per cent., ten

times the normal, was observed with only 0.5 per cent. of sugar in the

urine. In such cases the estimation of blood sugar is of greater value

than the urine sugar.

--Mr. Atkinson outlined his paper as follows: 1. Definition of Foods

and Poisons. In general, Foods comprise those substances which taken

into the body go to or assist in building up the body cells and furnish

energy. Poisons are those substances which taken into the cells interfere

with its normal metabolism.

Foods Poisons

Animal Animal

Vegetable Vegetable

Mineral Mineral

Synthetic Organic Compounds Synthetic Organic Compounds

RECORDS OF MEETINGS 263

Foods may become poisons under certain conditions and, vice versa,

poisons may become foods. Certain foods (protein) may predispose

(sensitize) for subsequent poisoning by the same food. Certain generally

accepted food substances may possibly become the source of serious or

fatal illness through refinement in manufacture—that is, by the removal.

of some necessary constituent, as the removal of the pericarp in polishing

rice (so-called deficiency diseases).

2. A brief enumeration of food poisons, including preservatives and

heavy metals.

3. Discussion of the action of heavy metals as poisoning agents and

demonstration with guinea pig showing that the normally toxic dose of

mercury (as an example) is very much diminished if first treated with

protein—that is, protein first fixing the metal prevents its action. A

brief summary of the fixing power of heavy metals by protein with the

conclusion from experimental data that the toxicity of certain heavy

metals appear to be functions of their combining powers with protein—

that is, the firmer the combining power the more toxic is the metal.

4. Deficiency diseases—The demonstration of polineuritis in a pigeon

fed exclusively on polished rice.

5. A brief discussion of idiosyncrasy of foods; the theory of anaphy-

laxis for idiosyncrasy to protein foods with a demonstration of anaphy-

lactic shock in the guinea pig sensitized to horse serum.

Mr. Reichling stated that a flight was made about 2:30 P. M. January

15, 1916, in a Huntington military tractor at the hangars of the Hunt-

ington Air Craft Co., Garden City, L. I. The pilot was P. C. Millman

of the Areo Club of America. Mr. Lacey, Mr. Vincent Armor and

several mechanics were witnesses. The afternoon was quite cold and

slightly cloudy. Ground temperature perhaps 15° F. The time of

flight was ten minutes. Distance covered about 12 miles. Maximum

altitude about 1600 feet. They passed through mist and some low

hanging clouds and could see a considerable portion of the island at

maximum altitude spread out in contour style. The air was quite clear

above 1,000 feet. ‘The speed of the ascent was about 800 feet per minute

(perpendicular). No difficulties were caused by air conditions. Mr.

Reichling found street clothes adequate with exception of cap, and it

would have been easy to make various scientific observations just as

readily as on the ground. The author believes that it will be possible

to. make observations throughout the year in this way, to test the feasi-

bility of wireless apparatus, to study solar spots or prominences during

total eclipses, etc. Air-samples at different altitudes, studies in ioniza-

964 ANNALS NEW YORK ACADEMY OF SCIENCES

tion, cosmic dust and map-making show how various the possibilities of

these flights might be, with the proper instruments.

The Section then adjourned.

VY. EH. LEVINE,

Secretary.

SECTION OF BIOLOGY

13 Marcu, 1916

Section met ‘at 8:15 Pp. m., Vice-President H. von W. Schulte pre-~

siding.

The following program was presented :

W.W.Browne, THE BAcTERIOLOGY oF AIR.

George G. Scott, Oxyemn UTILIzaTIon IN FIsHEs.

F. H. Pike, THE SIGNIFICANCE OF CERTAIN INTERNAL FACTORS

IN OrGANnICc EvoLuTIon.

SUMMARY OF PAPERS

Dr. Browne stated that determinations of the microbic content of the

atmosphere were made under the direction of Prof. C-E. A. Winslow,

Chairman of the New York State Commission of Ventilation. A total

of 385 samples of air were examined during the first six months of 1914,

obtained from four different groups of sources: country (85 in number),

city (135), office (87), factories (47). The samples of air were collected

and examined by the methods prescribed by the Committee on Standard

Methods for the Examination of Air of the American Public Health

Association.

SUMMARY

Source. Number. pensnobes FEE Seo Strepiocces

Outdoor :

Country, see eke 85 56 30 12

City ee aa ee acres 134 72 32 11

Indoor

OM CO eis ne ieee 87 94” 80 22

TOBVOUNEIES Gasacocacouc 47 113 63 43

The microbes include both molds and bacteria.

Conclusions.—The number of bacteria developing at 20° C. from out-

door air is generally under 50 per cubic foot and rarely over 100.

RECORDS OF MEETINGS 265

The count at 37° C. for such air is about half that of 20° C. and

rarely over 50 per cubic foot.

The air of occupied spaces shows larger average numbers of micro-

organisms and greater fluctuations. The 20° C. count may average over

100 per cubic foot and may reach 700 or more. The 37° C. count aver-

aged over 50 in the factories and offices. Mouth streptococci are more

abundant in the indoor air, ranging from 20 to 40 per 100 cubic foot

of air.

Dr. Scott stated: A. Lowering of the temperature causes a reduction

- in the rate of oxygen consumption. B. Oxygen was consumed more rap-

idly in tall, narrow vessels of water than in broad, shallow ones. C.

Fishes kept in dark vessels apparently consume oxygen at a less rapid

rate than those exposed to ight. D. Some forms show more resistance

to low oxygen supply than others. This is particularly true of inverte-

brates. Respiration ceases altogether, and commences again if the speci-

men is returned within certain time limits to aérated water. The toad

fish and killifish live in water with low oxygen content, while a butter-

fish and menhaden quickly succumb to reduction of oxygen supply. Z£.

Most marine invertebrates consume oxygen at a very low rate; fishes at a

much higher rate; with amphibia the rate is between that of inverte-

brates and fishes; the rate with mammals and birds is relatively high,

that of birds being extremely high as compared with anatomically lower

forms.

Professor Pike stated that the changes which occur in animals and

plants may be divided as follows:

1. Changes of form—growth and development, ontogenetic and phylo-

genetic. .

2. Changes of position—the phenomena of movement.

3. Changes of material and energy.

There are many contributions to the study of evolution from the stand-

point of changes in form and changes in position and but few from the

point of view of changes in matter and energy. The effect of environ-

ment upon the organism is manifested through the changes in matter

and energy. Injurious substances in the environment may slow down

or stop the processes occurring in living matter. The failure of moisture

may mean death or encystment. A low temperature means a slowing

down of life processes, a suspension of activity or death. Distribution of

an organism is restricted to a region in which a given set of conditions

exists. Herbert Spencer pointed out the fact that some organisms have

acquired a certain degree of independence of the environment. My own

266 ANNALS NEW YORK ACADEMY OF SCIENCES

interest in the subject relates to the mechanisms by means of which this

independence of the environment is secured. The study of the effects

of the environment may be taken up in terms of the changes in internal

conditions. If the environment really does affect these internal con-

ditions, we have the possibility that the environment is one cause of

variations. The questions of adaptation, the struggle for existence, the

survival of the fittest and geographical distribution may all be approached

from this point of view.

The paper was discussed by Dr. E. L. Scott.

The Section then adjourned.

WILLIAM K. GREGORY,

Secretary.

SECTION OF GEOLOGY AND MINERALOGY

20 Marcu, 1916

Section met at 8:15 p. m., Vice-President Douglas W. Johnson pre-

siding. The minutes of the last meeting of.the Section were read and

approved.

The following program was presented :

Willis T. Lee, ApPLicaTIoN oF PHyYstoGRAPHIC METHODS TO THE

CoRRELATION OF NON-MARINE FORMATIONS IN THE

Rocky MowunrtvatIns.

SUMMARY OF PAPER

Dr. Lee described his attempt to work out the sequence of events dur-

ing the physiographic evolution which resulted in the stratigraphic and

structural relations now observed in the rocks of the Mesozoic age in the

mountain region. ‘The ancestors of the present Rocky Mountains were

eroded during Triassic and Jurassic time and late in the Jurassic period

they were reduced to a peneplain. On this plain were spread out the

continental deposits which constitute the La Plata sandstone and its age

equivalents. The lower parts of the plains were covered with sea water

in the later part of the Jurassic period. In the sea, where the water

was suitable for marine organisms, there accumulated the fossiliferous

beds which now are called Sundance. However, the sea water found its

way landward over the nearly level plain far beyond the places favorable

for the life of marine organisms and gathered in shallow bays where, by

evaporation, it became unsuitable for habitation. There are beds of

267

limestone and gypsum within the La Plata group which seem to have

been classed by some geologists with the underlying red beds and by

others with the overlying Morrison, and may be due to the spreading of

the Jurassic sea over the peneplain. coe a eta Pes

The Section then adjourned. oer aetna

RECORDS OF MEETINGS

CHESTER A. REEDS,

. 8 ecretary.

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY _

27 Maron, 1916

Section met at 8:15 P. M., in conjunction with the American Ethno-

logical Society, Dr. P. E. Goddard presiding.

The following program was presented :

Brandl dblls oli gimnunly

A. A. Goldenweiser, NotrEs on MELANESIAN ORGANIZATION.*

The Section then adjourned.

R. H. Lowiz,

Secretary.

BUSINESS MEETING

3 APRIL, 1916

The Academy met at 8:20 Pp. m. at the American Museum of Natural

History, President Michael I. Pupin presiding. > NY ean

The minutes of the last meeting were read and approved.

The following candidate for Active Membership in the Academy, rec-

ommended by the Council, was duly elected :

Lucius P. Brown, City Health Repeats

The Academy then adjourned.

HENRY E. CRAMPTON, | :

Acting Recording Secretary,

SECTION OF ASTRONOMY, PHYSICS AND capetetee ?

3 Aprin, 1916

Section met at 8:20 P. M., Wise Paectilan) Emest E. Smith presiding,

The following program was presented :

* Science, Vol. XLIV, 1916, pp. 824-828.

268 ANNALS NEW YORK ACADEMY OF SCIENCES

George B. Pegram, Are THERE Atoms or Licur?—THE QUANTUM

THEORY.

SUMMARY OF PAPER

Dr. Pegram discussed the several experimental facts that have led to

the determination of a certain universal constant, usually referred to as

Planck’s “h’’, and the attempts that are being made to work this constant

into physical theory ; how the fact of this constant means that the atomic

mechanism of radiation and absorption of light or other electromagnetic

radiation involves the transfer of elementary discrete quanta of energy,

the magnitudes of these quanta being directly proportionate to the fre-

quency of the vibration; the irreconcilability of the quantum theory with

the formerly accepted theory of the equi-partition of energy; the quantum

theory as apparently incompatible with the accepted laws of mechanics.

The Section then adjourned.

V. E. Levine,

Secretary.

SECTION OF BIOLOGY

10 Aprin, 1916

Section met at 8:15 Pp. m., Vice-President H. von W. Schulte pre-

siding. :

The following program was presented :

H. B. Williams, Aw ELEctricaL THEORY OF NERVE IMPULSE.

H. von W. Schulte, THE MorpHoLocy oF tHE AzyGos VEINS.

SUMMARY OF PAPER

Professor Schulte stated that the azygos veins, contrary to the imph-

cation of their name, are originally paired channels developed in the

plexus about the anlages of the vertebre and constituting when fully

formed. a series of anastomoses between segmental veins which extend

from the head to the root of the tail. These serial anastomoses make

‘their first appearance in embryos of sauropsids where they develop as a

collateral channel for the drainage of the body segments as the regression.

of the mesonephros entails a reduction of the posterior cardinal vein.

Coincidentally a second longitudinal vessel on each side emerges from the

abundant plexus about the neuraxis within the spinal canal, and this too

receives blood from the segmental veins. These two sets of channels,

RECORDS OF MEETINGS 269

intravertebral or spinous, juxtavertebral or azygos, agree in drainage

area, in the rationale of their development and in having connection with

the districts both of precava and of postcava, between which they so

extend as to be able to serve as an equilibratory anastomosis tending to

equalize conditions of flow in the two great drainage areas of the systemic

veins. Both have numerous connections across the vertebre with their

antimeres. In the case of the azygos the enlargement of some of these

connections permits of the development of asymmetry and the ultimate

preponderance of the vein of one side. This, as might be expected from

the normal dextral position of single pre- and postcave, is usually the

right and presumably the factor common to all three cases in the early

shift of the venous end of the heart to the right. While appearing first

in embryo sauropsids in many and perhaps the majority of adult forms

the azygos is reduced and this seems to depend in general upon the selec-

tion of the spinous channels as the favored line for segmental drainage ;

a more variable factor exists in the establishment of connections between

the right azygos and portal tributaries first in the caval lobe of the liver,

later very generally in the extent of the foregut.

The locus classicus for the history of the azygos is Rathke’s study of

the development of Tropidonotus natriz. He also investigated the con-

ditions in birds. Later Hochstetter examined the subject in several

lacertilans. In all it appears that the cervical portion of the system

becomes included in the costo-transverse space giving rise to the anterior

vertebral vein. ‘The same position may be occupied by the posterior ver-

tebral vein where the costocentral articulations are present as in birds

and for three segments in saurians (Rathke). This position is secondary

and depends upon the interruption of the plexus about the vertebre by

the developing capitela with the persistence of the portion of the plexus

included between rib and transverse process. Chelonians stand apart

from other sauropsids in that they develop a homodynamous vessel dorsal

to the transverse processes.

In mammals essentially similar conditions obtain, as Rathke pointed

out in 1837. A series of anastomoses extends on each side of the spine

from occiput to tail connected across the vertebree by numerous anas-

tomoses. ‘The whole system has been termed the supracardinal veins

by Huntington and McClure, to whom we owe the recognition of its par-

ticipation in the formation of the postrenal segment of the post-

cava in placentals. It was later termed prevertebral plexus by Hunting-

ton. From this plexus the azygos developes in a manner. analogous to its

formation in reptiles. This was recognized by Rathke, who interpreted

270 ANNALS NEW YORK ACADEMY OF SCIENCES

the azygos as a new or secondary vein retaining only the termination of

the postcardinal as its point of debouchment. Unfortunately in the fol-

lowing year Rathke modified his view and considered that the azygos was

of postcardinal origin to the 8th or 10th intercostal space and only beyond

that was what:we should now term supracardinal. This error taken up

by Huntington has obtained wide currency, though it has been corrected

by Zumstein (1897) in the guinea-pig, by McClure in the opossum

(1902) and by Sabin (1915) in the pig.

Among adult mammals the azygos may be bilateral as in monotremes

and many diprotodont marsupials. It may be absent as in cetacea (vy.

Baer), in Cholcepus and Bradypus (Hochstetter). It is usually right-

sided, but may be left, with or without the persistence of a left cava.

Marshall and more recently Beddard have listed its conditions in many

species. It is right-sided in Primates, Carnivora, Perissodactyla, Xenar-

thra except the sloths, in Hyrax and in Tragulus. It is left-sided in

many polyprotodont marsupials, in Suide, in Moschine and in hollow-

horned ruminants. Among rodents the right azygos is the rule; it is

associated with a smaller left azygos in Hystrix, while in the beaver the

vein of the left side alone persists. A specimen of this animal re-

cently dissected at Columbia confirms Beddard’s interesting observation.

In general, bilaterality of the azygos is associated with low position

(Beddard).

Dollinger, v. Baer and the earlier students of the vascular system gen

erally were familiar with the plexiform character of the embryonic blood

vessels and appreciated the réle of hydrodynamic factors in formation of

trunks by the selection of certain lines of flow from the multiplicity of

possible channels afforded by the plexuses. Since Roux and Thoma the

appreciation of the mechanical factor has become general and the impor-

tance of the drainage area in determining the proximal channel has been

recognized. he peripheral plexus increases with the size of the part

in which it lies, and with the differentiation of the part tends to acquire

independence from the general plexus. The venous trunks become the

indexes of the development and growth of their drainage areas and the

pattern of the great veins is, as it were, the expression and integration

of the specialization and relative growth rates of the various parts of

the body, and is relative to the embryonic condition, a reduction and sim-

plification, serving to promote mechanical efficiency by the diminution

of surface friction by the substitution of a few large trunks for the

numerous plexiform channels.. As this is. accomplished the general

venous plexus becomes resolved into independent districts connected ulti-

RECORDS OF MEETINGS 271

mately by feeble and variable anastomoses, e. g., pulmonary, portal, porto-

renal, systemic, the latter subdividing into precaval and postcaval areas.

Between these the spinous and azygos vessels act as equilibrating anas-

tomoses (v. Baer), and are therefore brought into competition, a com-

petition which in sauropsids results unfavorably to the azygos as a gen-

eral rule, for here portal connections also tell against the azygos. Such

connections in mammals are formed between the postcardinal and portal

(Zumstein, Brown, Davis), but they are evanescent and antecede the ap-

pearance of the azygos, which maintains itself as a moderate sized and

rather variable channel except in cetaceans and sloths. In these forms

the spinal channels are of great size.

The Section then adjourned.

Witiiam K. GREGORY,

Secretary.

SECTION OF GEOLOGY AND MINERALOGY

17 Aprit, 1916

Section met at 8:15 Pp. m., Vice-President Douglas W. Johnson pre-

siding.

The minutes of the last meeting of the Section were read and ap-

proved.

The following program was presented :

George F. Kunz, REMARKS ON A PSEUDO-METEORITE, IRON

PYRITE CRYSTALS, AND A Buack Dta-

MOND.

George I. Finlay, THE GEoLoGy oF NortH PARK, CoLORADO.

A. W. Grabau, GEOLOGY OF THE ISLAND OF GOTLAND IN

THE Rawric SBA.

Miss Marjorie O’Connell, Norrs oN tHE GEOLOGY OF OESEL IN THE

GULF OF. RIGA.

SUMMARY OF PAPERS

Dr. Kunz stated that a pseudo-meteorite was sent to him for examina-

tion by Mr. Robert A. Creager, of Mount Orab, Ohio. It weighs four

pounds and two ounces and is about the size and shape of a double hand.

Ii is not a meteorite, but a piece of cast iron scorao. As it had been in

the ground for some time it was thoroughly rusted.

942 ANNALS NEW YORK ACADEMY OF SCIENCES

A new locality for pyrite was found in the past few months at the Ibex

Mines, Colorado. The crystals are of special interest because of their

magnificent character and their frequently hemamorphic shape, two of the

four faces being entirely cubic (a) and the plan of the crystals pentagonal

dodecahedrons (¢). The crystals are unusually compact of type cut into

small jewelry and sold under the name of “marcusite” in the early part

of the eighteenth century. One of the crystals weighed more than two

pounds.

An irregular, cubic crystal of black diamond, weighing 138.75 carats

and measuring 22.5 millimeters on each face, 11 millimeters in width and

6 millimeters in depth was found at the Jagersfontein mine. Although

of cubic form, it is built up of rounded octahedral conglomerations.

Professor Finlay stated that North Park is located near the boundary

line of Colorado and Wyoming. The rocks are of sedimentary and vol-

ceanic origin. The platform upon which the sediments rest is largely

made of granite, and there are considerable amounts of gneiss and schist,

and then comes the Farrell limestone, which is about 30 feet thick.

Above it one finds about 1,500 feet of red sandstone. Next comes the

Morrison, about 260 feet in thickness, and above this the Glen Cairen

shales. ‘Then comes the true Dakota, about 100 feet thick, and above is

a rather complete series of Cretaceous beds, closing with the Pierre shales,

2,500 feet thick. ‘The chief economic deposit found here is coal, which

is quite phenomenal, having a thickness of 50 feet in some places in the

Coalmont formation. Very little of it is mined, however, since it is too

soft for commercial purposes.

The paper was discussed by Dr. Johnson and Mr. Knight.

Professor Grabau stated that the-structure of the island of Gotland is

very simple, being composed of slightly tilted limestone and shale beds

with no faults in evidence. It is very rich in fossils. The Cambrie,

Ordovicic, and Siluric beds were deposited in this region in normal

sequence. Subsequently the region was submerged beneath the water of

the Baltic, except for the island of Gotland. Here two series of forma-

tions are in evidence, a lower in the north and an upper.in the south.

These two series, however, do not correlate one with the other, as some

Kuropean geologists have tried to prove. Professor Grabau believes that

the higher series in the south correlate with the Lower Ludlow of the

English section. There is a break between the Upper and Lower Ludlow

in Europe which is represented in America by the Salina. The Upper

Ludlow is the equivalent of the Monroe of Michigan. The Lower Lud-

low, Wenlock and Llandovery correspond to the American Niagara and

- RECORDS OF MEETINGS 973

Medina. The Lower Ludlow is present in the south of Gotland and

overlies the beds found in the north. It is perfectly evident if this inter-

pretation is correct that the sea withdrew here, and that there was a

period of exposure sufficiently long to permit of the removal of the beds,

which are now absent in the northern part of Gotland. This is proved

by the paleontology of the region, as well as by the physical character of

the rocks, especially the sandstone, which is a sandstone of purely conti-

nental origin, and was in large part worked by the wind and corresponds

to our Salina beds.

Miss O’Connell stated that in Pre-paleozoic time the Oesel region was

composed of crystallines and was worn down to a peneplain. Upon this

surface the sea advanced from the south and southeast. This peneplain

was not perfect, it being a little irregular and slightly tilted. First

came the Cambrian, then the Ordovician, then the Silurian, and at the

end of the Silurian period the sea retreated; some of the continental

deposits were spread out over the area. Then the region was peneplained.

Hrosion was caused by rivers flowing in a radial direction, which wore

off a deal of the surface. Finally only two islands were left, Dago and

Oesel, the rest of the region being submerged.

The most important fossils found here are eurypterids, which are world

famous on account of their almost perfect preservation. Nothing has

been changed in the preservation of these animals; even the hairs on the

outer shell are intact. This horizon is only a foot or two in thickness,

yet thousands of organisms compose the mass. These eurypterids were

carried there by the rivers of that time. It is interesting to note that

their nearest relatives are found in western New York, which are the

second best preserved fossils in the world. This may be explained by

the fact that in Paleozoic time there was a continent extending from

North America to western Europe, which was drained by rivers inter-

lacing with one another; this enabled the animals to migrate from

one river to another. The New York formation is similar to the one of

Oesel. There is a thin layer of limestone, which contains eurypterids,

followed by a conglomerate of about one foot in thickness, which marks

the break between the limestone beds of the lower and upper Ludlow.

The two latter papers were discussed by Doctors Grabau, Johnson,

Knight and Reeds.

The Section then adjourned.

. Cuester A. REEDS,

Secretary.

274. ANNALS NEW YORK ACADEMY OF SCIENCES

BUSINESS MEETING

1 May, 1916

The Academy met at 8:23 P. m., at the American Museum of Natural

History, Vice-President Ernest E. Smith presiding.

The minutes of the last meeting were read and approved.

The Acting Secretary read the following minute prepared by Pro-

fessor E. B. Wilson relative to the death of Theodor Boveri:

Theodor Boveri, professor at the University of Wtirzburg and one of

the most eminent honorary members of this Academy, died in Wurzburg

October 15, 1915, at the age of fifty-three years. A native of Bamberg,

Germany, he studied at the University of Munich under Kupffer and

Richard Hertwig and subsequently became privat-docent at that Univer-

sity. In 1893 he was called to the University of Wiirzburg, succeeding

Semper as Professor of Zodlogy and Comparative Anatomy and Director

of the Zoological Laboratory. Four years ago he was offered the chair of

Zodlogy at Freiburg as successor to August Weismann and later was called

to the directorship of the newly established research laboratory of the

Kaiser-Wilhelms-Institute at Berlin; but both these offers he declined,

remaining loyal to the laboratory which under the direction of Semper

and himself had become one of the leading centers of biological research

in the world.

Boveri’s place among the illustrious leaders of biology is already

assured, though his name is still not widely known outside scientific

circles because of the abstruse and unfamiliar character of the researches

to which his life was devoted. No investigator of our times has accom-

plished more to elucidate the intricate problems involved in the physical

basis of heredity and the mechanism of development. His remark-

able series of Zellen-Studien, beginning in 1887 and extending through

more than twenty years, illuminated the whole field of cell-division, fer-

tilization and maturation of the germ cells. He was the main founder

of the theory of the individuality and genetic continuity of the chro-

mosomes ; and to his memorable researches on dispermic eggs is due the

experimental demonstration of the qualitative differences of the chro-

mosomes and their significance as primary factors in heredity. These

researches, more than any others, opened the way to a cytological ex-

planation of Mendel’s law of heredity, and led him in the last year of

his life to advance a highly suggestive new theory concerning the origin

and nature of tumors. His work was as masterly in experimental em-

RECORDS OF MEETINGS 275

bryology as in cytology, and will constitute an enduring landmark of

progress on the history of investigations upon the organization of the

egg, the role of protoplasm and nucleus, and in the modern controversies

relating to vitalistic and mechanistic conception of development.

Boveri's name will stand with those of Schwann, Kolliker, Remak,

Van Beneden, Flemming and the few other great leaders of microscopical

research; and it may be doubted whether he has had an equal in respect —

to’ the keenness of his scientific insight or the fruitfulness of his labors

in the difficult and fundamental field of inquiry. .The more carefully

we study his works the more is our admiration stirred by his qualities

as an.investigator. He was endowed with a mind fertile in ideas, of

great logical acuteness, of perfect clarity; he was an observer of unsur-

passed accuracy and resourcefulness; and beyond all this his work is

everywhere permeated by that indefinable artistic quality which often

characterizes scientific research of the highest type. With this rare com-

bination of qualities he naturally and inevitably took his place among

the foremost investigators of our time, and his work will endure as a

classical model of creative insight, of fruitful scientific method and of

lucid presentation.

With a deep sense of the loss that science has sustained through

Boveri’s untimely death the New York Academy of Sciences renders its

tribute to his rare and lofty qualities as a man and records its apprecia-

tion of his brilliant original contributions to knowledge. .

The Academy then adjourned.

Henry E. Crampton,

Acting Recording Secretary. .

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

1 May, 1916

Section met at 8:30 p. m., Vice-President Ernest EK. Smith presiding.

The following program was presented :

J.H.Morecroft, THe Erectron Steam AMPLIFIER—AN ELECTRICAL

ULTRAMTICROSCOPE.

The Section then adjourned.

V. HK. LEVINE,

Secretary.

ANNALS NEW YORK ACADEMY OF SCIENCES

=n)

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

: VTA SOG

The Section met in conjunction with the New York Branch of the

American Psychological Association at Columbia University.

The following program was presented :

Herbert W. Rogers, Some Emprrican. Tests IN VOCATIONAL

GUIDANCE AND SELECTION.*

Christine Ladd-Franklin, THE VisrpiLiry oF THE NERVE CURRENT.

T. T. Lew, TABOOS IN CHINA.*

Samuel A. Tannenbaum, How PsycHoaNnatysis CurRES NERVOUS-

NESS.*

The Section then adjourned.

R. H. Lowiz,

Secretary.

SECTION OF BIOLOGY

8 May, 1916

Section met at 8:15 Pp. m., Vice-President H. von W. Schulte presid-

ing.

The following program was presented :

George H. Huntington, THe Ration or THE LYMPHATIC AND

HaMaLt CHANNELS IN THE VASCULAR SYS-

TEM OF THE VERTEBRATES.

W. C. Clark, SomE Puasres oF BoNE GROWTH IN THE

ANDOU:

SUMMARY OF PAPER

Professor Huntington stated that the development of the thoracic

ducts in all three amniote classes follows precisely the same main funda-

mental principle, viz., the formation of lymphatic channels by confluence

of numerous originally separate intercellular mesenchymal clefts and

spaces.

The reptile presents this genetic process in its simplest form, in a region

in which systemic venous development is reduced to a minimum. In

* Abstracts published in Journal of Philosophy, Vol. XIII, 1916, pp. 662-665.

RECORDS OF MEETINGS are.

both the bird and the mammal the development of the thoracic duct

becomes complicated by a direct or indirect relation of the lymphatic

anlages to the adjacent elements of the hemal (venous) vascular system:

In the bird the relation of the lymphatic anlages to the hamopoetie

axial mesenchyme is direct, the avian thoracic ducts beceming for a time

functionally hemophoric.

In the mammalian embryo the relation of the developing thoracic ducts

to the axial venous system is indirect, ‘the lymphatic anlages replacing.

the temporary ventro-medial hemophoric azygos tributaries topograph-

ically, but never themselves assuming the hemophoric function.

Tn all three classes of amniote embryos the final results of the genetic

processes outlined above is the same, viz., the establishment of a peri-

aortic, or para-aortic, lymphatic channel, the amniote thoracic duct. In.

a wider interpretation it becomes evident that all the diversified phenom-

ena of vascular ontogeny, hemal as well as lymphatic, are focussed in

the small field which any extra-embryonic vascular area presents.

The Section then adjourned.

W. K. Grecory,

Secretary.

SECTION OF GEOLOGY AND MINERALOGY

15 May, 1916

Section met at 8:15 Pp. m., Vice-President Douglas W. Johnson pre-

siding.

The minutes of the last meeting were read and approved.

The following program was presented :

H. E. Anthony, PRELIMINARY Report ON Fosstz MAMMALS OF

Porto Rico. (Read by Title.)

E. T. Hodge, GEOLOGY OF THE CoAmMo-GuAYAMA Recion, Porto

Rico.

D. R. Semmes, GEOLOGY OF THE SAN JUAN District, Porro Rico.

Chester A. Reeds, Fossiz Faunas or Porto Rico.

Charles P. Berkey, PLans ror FreELD work IN Porto Rico DURING

1916.

SUMMARY OF PAPERS

Mr. Hedge stated that the Coamo-Guayama district is located in the

east central portion of southern Porto Rico. The rocks of this area are

278 ANNALS NEW YORK ACADEMY OF SCIENCES

complex. The stratigraphic series is made up of thousands of inter-

fingering alluvial fans, deltas, estuarine and littoral deposits, which have

been intruded by innumerable individual igneous bodies, all more or pa

metamorphosed, faulted and folded.

.. Across the northeastern ‘portion of the area is a broad belt of rock be-

lieved to be Comanchic. The presence of Cladophyllia furcifera in a bed

-of limestone and of fossil leaves in an adjacent hematite bed point, ac-

cording to Dr. Edward W. Berry and Dr. Frank H. Knowlton, to the

Comanchic age of these beds. ‘he basal portion consists mostly of

tuffs; the upper portion, of shales and a few limestones. Between this

belt of rock and the adjacent higher one there is a good evidence of a

period of folding and erosion.

A conglomerate occurs at the base of the overlying belt of rocks. It

forms the backbone of the Sierra de Cayey, the principal mountain

range of Porto Rico. It is followed by alternating beds of shale and

limestone with a few beds of tuff and conglomerates. No fossils were

found in these beds, and it is assumed that they belong either to the

Cretacic or the Lower Hocenic system. They occur in a belt which curves

southward and eastward from the northwest corner to the southeast

corner.

This is followed by a third belt, which is composed of a thick con-

glomerate at the base, followed by shales with several thick lmestone

members. In these beds was found a pelecypod, Venericardia alticostata.

which is the typical index fossil for the upper Hocenic of the Gulf States.

A period of considerable uplift and prolonged erosion followed the de-

posit of these sediments. Upon the peneplained surface of the under-

lying complexly folded series of rocks thick limestone beds were laid

down. From this limestone Prof. Charles P. Berkey and Mr. D. R.

. Semmes gathered fossils, which Dr. W. I. Dall pronounced to be Upper

Oligocene in age. In the Coamo-Guayama district this limestone is rep-

resented by one small remnant of erosion. Its former great extent is

suggested by the superimposed drainage, which is now rapidly attaining

structural adjustment. Additional uplift in very recent time is shown

by river terrace deposits bearing fossils of. recent age at elevations of 350

feet. above the. sea. The volcanic centers which broke through the

Cretacic and Eocenic rocks are rather common features. All of these

have been worn down to their roots and are represented at present by

vents clogged with volcanic debris and’ surrounded by numerous in-

trusives and aureoles of hydrothermal alteration. It is thought that the .

hot springs of this area are the dying out phases of volcanic activity.

The paper was discussed by.Dr. Reeds.

RECORDS OF MEETINGS 279

Mr. Semmes stated that the San Juan district lies on the northern

side of the island of Porto Rico. It extends from the city of San Juan

on the east to a point about two miles east of Manati and southward as

far as Barranquitas—an area approximately 500 square miles in extent.

The San Juan district is a typical N-S section through the northern

half of the island, the geological history of which may be regarded as

essentially the same as that of the whole island. The physiographic

history of the San Juan district is that of a complex mountainous old-

land, which has been peneplained, partially submerged, overlapped by a

coastal plain, uplifted, maturely dissected, again slightly submerged and

partially uplifted; erosion continued in the interior from the time of

the first uplift. The formation of the district may be divided into a

younger and an older series. The younger formation consists of a coastal

deposit of indurated lime dune sand of presumably Pleistocene age

which overlies unconformably a limestone series. ‘This limestone series,

termed the Arecibo formation, rests almost horizontal (dip, 6° N.)

and is now maturely dissected, giving rise to the typical pepino or hay-

stack topography of the island. The Arecibo formation is regarded as

probably wholly Upper Oligocene in age. In the northwestern portion

of the island, but not appearing in the San Juan district, is a lignitic

shale member (the San Sebastian shale) which underlies the Arecibo

formation. The age of this shale member is uncertain, but in all proba-

bility it is of Lower Oligocene age. The coastal plain has been carved

out of the younger series. The older series consists of marine and vol-

canic sediments with numerous intrusives. It is highly tilted and locally

folded, resting unconformably below the younger series. The sedi-

mentary types represented are limestones, shales, sandstones, conglom-

erates, tuffs and ashes. All of these sediments are derived almost wholly

from volcanic sources. Even the limestones show brecciated structure

and are, with few exceptions, mere accumulations of limestone frag-

ments derived from older beds shattered by volcanic outbursts. The

foraminiferal content of certain shale and limestone beds in the upper

part of the older series indicates that the beds are Upper Cretaceous

and Eocene in age. ‘The lower part of the series is no doubt Comanchic.

The peneplaination of the older series, prior to the deposition of the

coastal plain, culminated therefore in late Eocene time. The older

series is everywhere intruded by igneous rocks of many varieties. The

predominant type is an andesitic porphyry. The tuffs and other sedi-

ments directly derived from volcanic sources are also of this general com-

position. The igneous rocks occur as extrusive sheets, sills, dikes and

280 ANNALS NEW YORK ACADEMY OF SCIENCES

small and moderate sized stocklike intrusives. The mineral resources of

the district are not large. About 100 ounces of gold are panned

annually from the rivers in the vicinity of Corozal. Gold quartz veins

have been worked in the hills south of Corozal, but without success. In

the barrio Pasto, southwest of Morovia, several copper prospects have been

shghtly explored.

Dr. Reeds stated that his report was one of progress; that he was pre-

pared at this time to make only a preliminary statement concerning the

fossil faunas of Porto Rico, and that his remarks this evening would be

confined to the specimens which he and Mr. P. B. Hill had collected in

1915 from the younger series. A report on the fossil faunas from the

older series, together with a more complete statement of the fossils from

the younger series, would appear at a later date. The many hundred

of specimens collected have been washed, sorted and grouped as to classes,

and with the assistance of Dr. Anna I. Jonas preliminary identifications

of the specimens have been made. The most common groups of fossils

in the collection are Foraminifera, Echinodermata, Pelecypoda and Gas-

tropoda. Of the forty-one species listed twenty-one are Hocene and

twenty Oligocene. The Eocene forms are as follows:

Foraminifera, no species

Hehinodermata—KHocene

LTinthia alabamensis Clark, Midwayan.

Scutella mississippiensis Twitchell, Claibornian

Hemipata subrostratus Clark............. )

Macropneustes mortoni Conrad............ \Jacksonian

Schizaster arminger Clark................

Pelecypods—Hocene

Crasatellites aquianus Clark, Chichasawan

Lucina pandata Conrad................... )

Ostrea alabamensis Lea................... |

Ostrea compresirostra Say......ce-cecccee \Claibornian

Ostrea divaricata Lea................-..- |

Ostrea selleformis Conrad................

Lucme whiter Clarks... 2 2.202228. ++5 += ! :

Jacksonian

ACL OC ISS] Obi name te ee Chei icine 8a clo. Chore eonecNeaearr (

Gastropods—WHocene

Fasciolaria hercules Whitfield............. a

Fasciolaria elevatd.......0-.eceeeer scenes | :

Jacksonian

RAG UES es a ee eee eo eros aslete eegre (

Odostomia turriculd...... 0... ee cee eee e ee }

”

RECORDS OF MEETINGS 281

Caricella subangulata Conrad............. |

Cyprea lapidosa Conrad.................. paar .

IPUCUTOLOMOTIG SD? o.oo. ccc cee cece ccccuc. f Claibornian

Turritella mortoni Conrad................. J

Foraminifera—Oligocene

Cycloceypens sp? Carpenter............... |

Nodosaria cf. bacillum de France.......... [ ‘ :

Orbitoides mantelli ..........0000000.0005. oe

Polystomella crispa.............0.0000005. J

Echinodermata—Oligocene

Amphidetus ruspatangus...............2-- |

Cassidulus raveneli Twitchell.............. [jae ;

Clypeaster rogeri Morton.................. ( Vicksburgian

Echinolampus aldrichi Twitchell.......... ]

Pelecypods—Oligocene

WOGOUUNTE NSD?” er cicca siecs cit creo esses aie Goa ralerate cae

Cardium eversum Conrad................. \Vicksburgian

Chama lyelli Dall. ...... 0... c cece cee ec ee J

; Arca umbonata Lamarck.................. }

Chama chipolana Dall................0058.

Chama tampensis Dall...................

Cardita shepardi Dall.................... \Appalachicolan

Cardium delphicum Dall.................. |

Pecten chipolanus Dall...................

Tellina chipolana Dall.................... J

Gastropods—Oligocene

Ampullina fischeri Dall...............0000.

Conus suridens Conrad................... |

Phasionella ammicoloides................. p :

Strompus aldricht Dall..................-. bvieksburgian

SEG ONUOIES HI) SP aon de eiciclehe crordionie eee a sisi elaea< |

Turritella mississippiensis Conrad.......... J

Cerithium plectrum Dall............eceeee.

Murex cf. mississippiensis Conrad.......... i Appalachicolan

Turritella mediocoustriata Dall............

From this list it will be noticed that except for the echinoderm Lin-

thia alabamensis Clark, which is Midwayan, basal Eocene, all of the

other forms are Upper Hocene and Lower Oligocene. The Arecibo lime-

stone, the rocks from which the specimens were collected, is thus both

Upper Eocene and basal Oligocene in age. The Collazo shale which un-

derlies the Arecibo limestone is Upper Eocene in age.

989 ANNALS NEW YORK ACADEMY OF SCIENCES

The paper was discussed by Dr. Berkey, Dr. Johnson and Mr. Hodge.

The Section then adjourned.

CHESTER A. REEDS,

Secretary.

BUSINESS MEETING

2 Octoper, 1916

The Academy met at 8:20 pv. M., at the American Museum of Natural

History, Vice-President Ernest E. Smith presiding.

The minutes of the last meeting were read and approved. _

The following candidates for Membership in the Academy, recom-

mended by the Council, were duly elected :

John B. Anderson

William M. Baldwin

F. Ambrose Clark

F. Gray Griswold

James H. Hyde

Lire MEMBERS

Francis Kleinberger

Mrs. V. Everitt Macy

J. P. Morgan

Arthur Ryie

Emil M. Sperling

ANNUAL ACTIVE MEMBERS

Carl -E. Akeley

Saverio Agnelli

C. P. Ahlstrom

Rey. Arthur H. Allen

Victor I. Altshul

Emile P. Angot

James C. Ayer

Miss Anna Baller

Charles D. Barry

Llewellyn Barry

George F. Bateman

_ Hdwin de T. Bechtel

Frank Begrisch, Jr.

Mrs. A. Fred. Behre

_ William N. Best

_., EH. R. T. Berggren

Miss Susan F. Bissell

Fred. S. Blackall

Hugo Blumenthal

Jtsush, Jesenllll

Mrs. J. Hull Browning

J. A. Buda

James Byrne

E. T. Caldwell

Henry lL. Calman

Rev. Thomas E. Calvert

Henry ©. Carr

John J. Carty

Fred. G. Clapp

Joseph K. Choate

William Clausen

James B. Clemens

Miss Elizabeth Cogswell

Rufus Cole

RECORDS OF MEETINGS

David S. Collins

George W. Collins

Frederick Coykendal

W. R. Craig

George W. Crary

James W. Cromwell

R. Fulton Cutting

Benjamin G. Demarest

Rey. Herbert McK. Denslow

William P. Deppe

William T. Donnelly

Henry Doscher

Mrs. Charles Douglass

Robert Dunn Douglass

Mr. Charles Drew

William B. Dunning

William G. Eckstein

Harrington Emerson

Miss Mary Pinchot Eno

Abram Erlanger

K. George Falk

Percival Farquhar

Charles A. 8. Ferguson

John A. Frothingham

Frank W. Frueauff

Albert Gallatin

Mrs. Albert Gallatin

Francis P. Garvan

Miss Annie C. Goddard

Morrill Goddard

’ Charles B. Going

L. Goldmerstein

W. A. Gramer

Frank L. Grant, Jr.

’ Simon Guggenheim

Henry Gulick

Robert Halsey

Clarence R. Halter

Mrs. Bertha Hardinge

O. A. Havill

Alfred BP: Hess: 2 710-4

Selmar Hess- ie

Samuel Hoffman

Russell Hopkins

Miss Caroline: Howe

M. D. Howell

Benjamin A. Howes

Ernest V. Hubbard

Cary T. Hutchinson

Henry James, Jr.

’ Reynold Janney

Mrs. Helen Hanae Jenkins

Ludwig Kast

William de Y. Kay -

- Mrs. Hamilton Fish Kean

N. C. Kingsbury

Charles M. Koplik

Adolph Lewisohn

H. T. Liang

Henry- Lorsch

Christopher M. Lowther

James G. Manchester

Edgar L. Marston

Walton Martin

Herbert M.-Metzger

Mrs. Eugene Meyer, Jr.. :.

Gustav’ M. Meyer; Jr.

A. Cressy Morrison

Dwight W. Morrow

Louis L. Mowbray

Mrs. S. Neustadt —

Henry B. Newhall, Jr.

Alwin M. Pappenheimer . .

James C. Parrish

Mrs. Elsie Clews Parsons

283°

984 AJNALS NEW YORK ACADEMY OF SCIENCES

George E. Perkins

Mrs. von R. Phelps

M. Bernard Philipp

Edward Plaut

Miss Florence L. Pond

Roger M. Poor

Frederick J. Powell

H. 8. Putnam

Walter Rautenstrauch

Howard 8. Raymond

Rk. M. Raymond

John King Reckendorf

Mrs. George Stuart Ring

H. B. Roelker

John Roger

Julius Rudisch

Adolphe Rusch, Jr.

Julius Sachs

Thomas B. Scott

Tsaac N. Seligman

H. W. Schoemaker

Mrs. William F. Sheehan

Miss Mary Shoonmaker

William Siegel

Thomas Smidt

Mrs. R. L. Spotts

Phinehas V. Stephens

Chauncey Stillman

Marcus Stine

Willard Straight

Joseph Stroock

Moses J. Stroock

Mrs. J. Andrews Swan

Mrs. Arthur W. Swann

Jokichi Takamine

Malcolm H. Tallman

B. B. Thayer

George W. Thomson

Samuel Thorne, Jr.

J. G. Timolat

Mrs. Alice B. Tweedy

Charles A. Tyrrell

Howard S. Warren

Walter C. Webster

Harold Eastman Weeks

John EK. Weeks

Richard Weil

Bernard W. Weinberger

William West, Jr.

William Y. Westervelt

L. W. Williams

Charles Wimpfheimer

Jonathan Wright

EK. C. Zimmerman

The Secretary reported the following deaths:

James G. Cannon, Active Member since 1910, died 5 July, 1916,

Seth Low, Active Member since 1876, Life Member and Fellow

since 1888, died 10 September, 1916.

The Secretary stated that the Council had appointed a Committee to

formulate a resolution relative to the death of the Honorable Seth Low, to

be spread upon the minutes of the Academy.

The Secretary reported the resignation of

William H. Bliss, Active Member since 1914.

The Academy then adjourned.

Henry E. Crampton, —

Acting Recording Secretary.

a i

RECORDS OF MEETINGS 285

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

2 OcroBErR, 1916

Section met at 8:30 P. m., Vice-President Ernest E. Smith presiding.

The following program was presented :

Lucius P.Brownand A Promisinc CHart FoR DeEtTEcTING ADUL-

C. V. Ekroth, TERATED SAMPLES OF MILK.

Charles Baskerville, ComLomps in THeErR RELATION TO ANIMAL

AND VEGETABLE OILS.

SUMMARY OF PAPERS

Mr. Brown and Mr. Ekroth stated that as the result of investigations

of published analyses of over 200,000 samples of milk a chart has been

devised which appears to show the approximate limits of the chemical

composition of normal cows’ milk as concerns the fat and solids-not-fat

and the inter-relation of these two. This chart should be capable of use

as an indicator of adulteration in milk if the fat and total solids only

are known. The inter-relation of the fat and solids-not-fat appears to

indicate that almost all the milk standards as made by law in the several

states of the Union, as well as that adopted by the Federal Government,

are unbalanced and not based on the actual enforcement. Further, in

legislating on this subject, that fat and total solids should be specified,

because the figure for the total solids necessarily includes the fat and

the very considerable range of limits in the fat percentage corresponding

to any given figure for the solids-not-fat would allow of the abstraction

of a considerable proportion of the fat without placing the milk in the

adulterated class.

The accuracy of this chart has been shown by testing it against the

experience of New York City for the past 10 years. A plotting of the

composition of milk, as shown by analysis for this period, indicates an

agreement between the percentage of fat and solids-not-fat, which is in

accordance with expectations as shown by this chart.

Dr. Baskerville stated that animal and vegetable oils extracted from

selected and perfectly clean parts are usually neutral and “sweet”. Com-

mercial exigencies result in the actual production of oils usually acid

and always contaminated. It is therefore necessary to refine the oils,

especially if they are to be used for edible purposes. The kinds of. im-

purities, various but classifiable, and the favorable conditions of their

286 ANNALS NEW YORK ACADEMY OF SCIENCES

production and development are given to show the principles to be con-

sidered in dealing with the problems of refining. —

The impurities are, roughly stated, (1) acid in character, (2) ae

minoids, (3) gums, (4) coloring matters, (5) metallic soaps, ete. The

character of the crude oil depends upon not only the kind and part of the

vegetable (wood, nut, seed, etc.) and animal (fish, whale, liver, etc.)

used, but the quality of the raw material at the time of expressage or

extraction ‘(rusting, rotting, fermentation, sprouting, heating, etc.), the

method followed, the care exercised in the process, and the conditions to

which the oil is subjected prior to its refining.

The general methods developed during the past 125 years are ex-

plained. These methods usually involve more or less chemical treatment

with heat and sedimentation. The latter is always time-consuming

and the sediment carried with it more or less of the desired refined oil.

Also oil remaining above the sediment acts as a solvent or menstruum for

coloring matter and colloidal material. .

The problem was to coagulate the sediment in such a manner that it

might be filtered out shortly after being produced and thus remove not |

only the colloids, but much absorbed coloring matter, and then squeeze

the mass, thereby increasing the yield of refined oil. i

The problem was solved, after many thousands of trials, by adding an

organic absorbent (cellulose in various forms) along with a suitable

amount of caustic alkali solution, heating to the “break” and then add-

ing a dehydrating agent (soda ash or salt cake), which would and does

agglomerate the small particles and dehydrate the soap, followed by filter-

ing while hot. The oil flows from the filter brilliant and neutral.

While the shrinkage in the process of refining usually follows the per-

centage of free fatty acid in the crude oil, this is not always the case.

Oils very high in acid frequently do not yield to the older processes for

refining, but in every case such oils have been successfully refined by the

method here given.

The Section then adjourned.

ze V. E. LEVINE,

Secretary.

SECTION OF BIOLOGY

9 OctopER, 1916

Section met at 8:15 p. m., Vice-President H. von W. Schulte ‘pier

‘The following program was presented : :

RECORDS OF MEETINGS 287

Herbert Lang, FAUNAL RELATIONS OF CENTRAL AFRICA.

James P. Chapin, DistrisuTIoN AND MIGRATIONS OF CENTRAL AFRI-

_ CAN Birbs.

SUMMARY OF PAPERS

‘Mr. Lang stated that the mammalian fauna of the tropical rain forests

of the Congo and Amazon basins were contrasted. The more arboreal

adaptation of the latter fauna and the relative lack of larger terrestrial

mammals seem to suggest more inundated conditions in the Brazilian

forests. ‘The ranges of gorilla and chimpanzee were discussed. ‘The

ranges of Rhinocerotide, Giraffide, Tragulide and Manide in Africa

were compared with their occurrence in the Oriental region. The con-

nection of the African continent with Eurasia in Miocene times and the

origin and center of dispersal of these forms from somewhere in central

Asia was demonstrated by the Giraffide on a map indicating the region

from which paleontological evidence is available. As a conclusion it

was stated that the ranges of practically all these groups of Ethiopian

mammals are chiefly dependent on the vegetation, though distinct spe-

cific forms may develop everywhere under suitable conditions. Moun-

tains as a whole exercise very little effect, as they are too isolated in posi-

tion to form effective barriers. The relative uniformity of the tropical

and subtropical climate, as well as the satisfactory physiographic condi-

tions in this region, are considered as extremely favorable for the dis-

persal of terrestrial Mammalia. The great West African forest, however,

is an obstacle for many forms; consequently those avoiding it are found

only to the northeast and south. Those species formerly believed peculiar

to the South African subregion have now been recorded not only as far

north as Abyssinia, but even to the northwest in Senegambia, where

later Orycteropus and Taurotragus have been recorded. The intimate

relationship of the fauna and flora was illustrated by a series of typical

landscapes from East and West Africa.. The forms peculiar to the Ethi-

opian region and its subregion were reviewed and snown to be especially

characteristic.

Mr. Chapin stated. that the mountains of Africa have comparatively

little influence on the distribution of birds over the continent as a.whole.

Of far greater importance is the vegetation, and we may say that the two

greatest barriers are the Desert of Sahara and the rain forest stretching

from the West Coast to Uganda. Different kinds of birds have marked

preference for certain plant formations; to the true forest birds the

savannas and plains are a barrier, while the equatorial forest shuts off

288 ANNALS NEW YORK ACADEMY OF SCIENCES

the species of open country. Thus the range of the genus Malimbus

coincides almost exactly with the equatorial forest, while that of Colws

covers the whole of Africa excepting the deserts and the West African

forest. Many other examples could be shown. Even among water birds

forest-loving forms can often be distinguished from those of the more

open districts. On the other hand Heterotrogon vittatus is found only

on the higher mountains of eastern Africa and again on Mt. Kamerun

in the West Coast, and Mt. St. Isabel, on the Island of Fernando Po.

In the study of bird distribution in Africa the importance of a general

knowledge of the extent of forest, savanna and plains cannot be too

strongly emphasized.

Our long stay in Africa gave us an exceptional opportunity to observe

the migration of birds. W. L. Sclater found that of the 814 species

known from South Africa 72 were migrants from Europe and Asia, while

21 were African species that come to spend the summer. In the north-

eastern corner of the Congo we found about 33 species of African birds

that had regular migrations and many of them were studied for three or

four successive years. Since then a careful study of records with dates

in books have enabled us to understand some of these movements. The

Pennant-winged Nightjar (Cosmetornis veaxillarwus), breeding south of

the equator, migrates northward regularly every year; whereas the Stork

(Abdimia abdimw) nests in the north, from Nigeria to Abyssinia, and

migrates to South Africa. Batastur rufipennis, breeding on the White

Nile and Bahr-el-Ghazel, moves in the dry season up to the northern

edge of the forest. This same region is visited in the dry season by a,

great many birds of the Sudan. Almost no forest birds are truly migra-

tory. ‘These few examples show that migration is characteristic of a

considerable number of Central African birds, that these are movements

in different directions, and that they offer an interesting subject for in-

vestigation.

The Section then adjourned. Wituiam K. Grecory,

Secretary.

SECTION OF GEOLOGY AND MINERALOGY

16 OcrozErR, 1916

Section met at 8:15 p. m., Vice-President Douglas W. Johnson pre-

siding.

The minutes of the last meeting of the Section were read and aperCree

The following program was presented :

re eae

- pais

RECORDS OF MEETINGS 289

B. L. Miller, GreoLoGicaL OBSERVATIONS IN THE ANDES OF PERU AND

Boutvia.

SUMMARY OF PAPER

Professor Miller stated that the South American Continent contains

three great areas of highlands known as the Highlands of Guiana, the

Brazilian Highlands,-and the Andes Mountains. The first two corre-

spond in a general way to the highlands of eastern Canada and the

eastern United States, in that they consist largely of metamorphic rocks

of Pre-cambrian or Early Paleozoic age, and represent mainly the roots

of once high mountains now reduced by erosion to hills and mountains

of moderate height, while the Andes are to be compared with the Cor-

dillera of the western North America in that they are composed, for the

greater part, of sedimentary rocks of Cretaceous and Tertiary age, into

which have been intruded great masses of andesites, trachytes, rhyolites,

and other igneous rocks, while active or recently extinct volcanoes con-

stitute some of the greatest elevations. A more careful comparison of

the Cordillera of North and South America brings out several distine-

tions. In the northern continent the western mountains form several

discontinuous ranges which extend from east to west over a wide range

of territory from central Colorado to the Pacific Ocean, while the Cor-

dillera of South America extend uninterruptedly from Colombia to Tierra

del Fuego, and are so concentrated that nowhere is the entire width more

than a few hundred miles, and in many places it is scarcely more than a

hundred miles from the shores of the Pacific Ocean to the eastern flank

of the Andes mountains, where the great interior plains begin. Not-

withstanding the compactness and continuity of the Cordillera of South

America they are by no means a unit, but in the character of the rocks

of which they are composed and in the uplifts to which they have been

subjected they exhibit much variety and complexity. The topographic

features of western South America consist of the following divisions,

' named in order from the Pacific Ocean eastward: (1) the Coastal Range,

(2) the Longitudinal Valley, (8) the Maritime Andes or the Cordillera

Occidental, (4) the Interior Plateau, Altiplanicie, or Bolivian Plateau,

(5) the Eastern Andes, Cordillera Oriental, or Cordillera Real, and

(6) the great Interior Plains.

All of the different ranges of the Andes are of primary euros

on account of the mineral resources which they contain. In the coast

Tanges are numerous deposits of gold, silver and iron; in the Longitudi-

nal Valley are the great deposits of sodium nitrate and considerable

mi haees

= =

290 ANNALS NEW YORK ACADEMY OF SCIENCES

copper ; in the Cordillera Occidental are rich deposits of sulphur, copper,

gold, silver, vanadium and some coal; in the Interior Plateau are de-

posits of borax and salt; while in the Gormley Real are numerous de-

posits of lime, gold, iver antimony, and copper.

The Section then adjourned.

CHeEstEeR A. REEDS,

Secretary.

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

23 OcToBER, 1916

Section met at 8:15 P. M., in conjunction with the American Eth-

nological Society, Dr. A. A. Goldenweiser presiding.

The following program was presented :

P. EB. Goddard, THE Socrat ORGANIZATION OF THE ARIZONA APACHE.

R.H. Lowie, THe Hori Cuan.

Dr. Goddard discussed the local bands and more particularly the social

division of the White Mountain Apache, who are grouped into four

exagamous, matrilineal units. Special stress was laid on the functional

aspects of these clans. With the aid of diagrams an exposition was given

of the Apache Kinship terminology.

Dr. Lowie dealt briefly with the relations of the clan to the maternal

family, the phenomenon of linked clans, the descent of ceremonial offices,

household groups, and the kinship terminology.

The Section then adjourned. R. H. Lowi,

Secretary.

BUSINESS MEETING

6 NovEMBER, 1916

The Academy met at 8:15 Pp. M., at the American Museum of Natural

History, Vice-President Ernest E. Smith presiding.

The minutes of the last meeting were read and approved.

The following candidates for Active Membership in the Academy, rec- -

ommended by the Council, were duly elected :

Richard J. Baker Pliny E. Goddard

Clarence Carson Ferdinand Howald

Everett L. De Golyer Benjamin Lawrence

RECORDS OF MEETINGS 291

Alfred McEwen ‘ Marion L. Thomas

- Walter Mendelson Samuel G. Tibbals

S.. BR. Montcalm EK. B. Treat

Arthur Mutscheller Ludwig Vogelstein

Hideyo Noguchi Guy B. Waite

A. E. Olmsted H. Vincent Wallace

George B. Pegram H. R. Wheeler

L, A. Stoiber Rood Pope Yeatman

Mr. John Roger, upon recommendation of the Council, was elected a

Life Member. :

The Acting Secretary reported the following deaths:

George Murray, Corresponding Member since 1898,

G. Langmann, Active Member and Fellow since 1899, died March,

1916.

The Council presented the following memorial to Seth Low, to be in-

corporated in the minutes of the Academy:

The Council and Members of the New York Academy of Sciences

desire to render their tribute of honor and appreciation of the life and

works of Seth Low, and especially of the services whivh he rendered,

directly and indirectly, to the advancement of science in the city of

New York and throughout the United States.

Mindful of the time, thought and liberality with which he devoted

himself to the cause of good government in the city and State, to religion

and philanthropy, to college and university education, few are aware of

the enthusiasm, as well as wisdom, with which he guided the scientific

development of Columbia University from the moment when he assumed

the Presidency until the close of his tenure of office. He started with

a very high ideal in the selection of the men whom he invited to the

University, not only to sustain the enviable reputation which the city

has gained in applied science and in certain branches of pure sciences,

but also to extend the activities in pure sciences, especially along the

lines of research and through the hfe and work of men of national and

international reputation. ‘To signalize this effort he established a special:

Faculty of Pure Science. In every manner, through encouragement,

advice, and personal henefaction, he promoted the cause of research and

publication. Taking a very broad view of the relations of the University

to the community, he promoted the cause of friendly union and codpera-

tion between the University, the New York Academy of Sciences, the

American Museum of Natural History, the Botanical Garden and the

292 ANNALS NEW YORK ACADEMY OF SCIENCES

Zoological Park, and thus he helped to create the almost unique extension

of opportunity in every field of science which New York City at present

affords. His greatest desire was to see young men attracted to New York

from every State in the Union to enjoy these rare opportunities, and

this desire was more than fulfilled long before the close of his great and

useful career. Thus we may truly say that the present union of so many

scientific forces in our community is in no small degree due to the ideal-

ism, the wisdom, the energy, and the generosity of Seth Low.

The Academy then adjourned.

Henry E. Crampton,

Acting Recording Secretary.

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

6 November, 1916

The Section met at 8:15 Pp. m., Vice-President Ernest E. Smith pre-

siding.

The following program was presented :

J. M. Nelson, CHEMICAL VALENCE.

George Falk, Tur PRoDUCTION OF AN ENZYME-LIKE SUBSTANCE

BY THE ACTION OF ALKALI ON PROTEIN.

George B. Pegram, INpUceD ELEcrromMotTivE ForcE AND THE RELA-

TIVITY THHoRY.

SUMMARY OF PAPERS

Professor Nelson stated that simple compounds add a definite number —

of molecules of other simple compounds, as in ammoniates, hydrates,

double and complex salts. The formation of definite addition compounds

shows definite combining capacity, and therefore like valence. ‘This

molecular valence is effected by external physical conditions in the same

way as ordinary atomic valence. A rise in temperature decreases the

combining capacity for compounds, just as in the case of elements. The

dissociation of molecular compounds obeys the mass law; thus vapor

tension of hydrates and ammoniates has mass equilibrium, just as the

dissociation of simple compounds. The molecular valence is a function

of the two combining compounds, just as the atomic valence is a function

of the two combining elements. Note the relative stability of ammonium

chloride and the hydrate of hydrochloric acid, also the relative stability

of cupric chloride and cupric iodide.

RECORDS OF MEETINGS 293

It has been found that in a series of addition compounds like the

ammoniates of PtCl, that the diammoniate forms no ions, the tri-

ammoniate furnished one Cl-ion, the tetra-ammoniate two Cl-ions and

the hexa-ammoniate four Cl-ions. By examining the composition of

_these various complex ions it becomes apparent that for each additional

NH, beyond (NH,), one Cl is displaced. It also becomes evident that

there is a constant grouping of six about the central Pt-atom. The co-

ordination number is therefore independent of whether the groups are

held by molecular or atomic valences. Many other complex addition

compounds show this same codrdination value of six, others show coordi-

nation number of eight. Basicity of an acid seems to be the difference

between the coordination number and the atomic valence of the central

atom.

Molecular valence manifests itself in addition compounds which are

electrolytes as equivalent to two atomic valences. This is well illus-

trated in the constitution of ammonium chloride H—NH,—Cl, in which

the NH, enters in between the H and the Cl of the HCl. It therefore

becomes evident that the molecular valence holding the ammonia and

the HCl together manifests itself as equivalent to two atomic valences.

The coordination number seems to be a function of the room or space

about the central atom. Thus (NH,) PtCl, exists in two isomeric

forms and the double pyramid configuration proposed by Werner accounts

for the two possible isomers of a disubstituted complex of this kind.

Dr. Falk stated that he had studied the different ways in which the

ester hydrolyzing enzyme, lipase, may be inactivated, including the action

of acids, bases, neutral salts, alcohols, acetone, esters and heat. A con-

sideration of these results led to the hypothesis that the active group-

ing of lipase molecule might be due to a tautomeric form of the peptide

linking, which rearranged to the ordinary form on inactivation. This

view was tested by means of the action of alkal on inactivated lipase

material, casein, and gelatine. Lipolytically active substances were ob-

tained from all three.

Professor Pegram gave a simple proof from the standpoint of the

electron theory, that the seat of the E. M. F. in a unipolar induction

apparatus is in the moving conductor, not in any stationary part of the

circuit; the facts of unipolar induction are shown to be entirely con-

sistent with the Hinstein relativity theory.

The Section then adjourned.

. V. EK. Levine,

Secretary.

294 . ANNALS NEW YORK ACADEMY OF SCIENCES

SECTION OF BIOLOGY

13 November, 1916 |

The Section met at 8:15 Pp. m., Vice-President H. von W. Schulte pre-

siding. :

The section made the following nominations for officers for 1917:

Chairman of the Section and Vice-President of the Academy, Pro-

fessor H. von W. Schulte, Department of Anatomy, Columbia University.

Secretary, Professor W. K. Gregory, American Museum of Natural

History.

The Secretary was instructed to transmit these nominations to the

Council. ;

Upon request of the Secretary the Chair appointed a Committee of

two, consisting of Professor Pike and the Chairman, to examine and

correct the minutes of the meetings of the past year, for publication in

the Records.

The following program was presented :

J.D. Kernan and On THE ARCHITECTURE OF Two CETACEAN SKULLS,

H. von W.Schulte, Xipuius anp Koeta.

W. D. Matthew, SomE Resutts or AMERICAN Musrum ExXPLora-

TIONS FoR Fossir Mammats DuriIneé THE PAst

SUMMER.

SUMMARY OF PAPER

_ Dr. Kernan and Professor Schulte stated that the material for the

following comparison of a skull of Kogia was from an individual about

two-thirds grown, partially disarticulated, and a cranium of a full-term —

fetus of Ziphius cavirostris, both in the collection of the American

Museum of Natural History. In Ziphis the robust pterygoid was

found to’ be composed of two synostosed and overlapping elements, one

mesal and rostral, the other cuadal and lateral. The former bears the

hamular process and forms the rostral half of the contour of the tubal

notch. It also sends a process across the palate to articulate with the

maxilla. The caudal element overlaps the rostral laterally forming

the caudal half of the tubal notch and extends to the basioccipital with

the otocranial flange of which it articulates. Indications of this division

were found also in the adult Ziphius, in Berardius and in Mesoplodon.

In Kogia only a faint furrow in the tubal notch remained in the calf.

These pterygoids articulate with the alisphenoid, but in the immature

RECORDS.OF MEETINGS |. 295

skull are not synostotic with it. There was no obvious pterygoid apophy-

sis of the greater wing. Until younger and even embryonic material is

“available for study the interpretation of this complex must remain prob-

‘Jematic. In both genera a lachrymal separate from the malar was found

‘in Ziphius caudal, in Kogia mesal to the expanded portion of the latter

‘element. In Kogia the frontal process of the maxilla enters extensively

into the wall of the cardinal cavity, ‘the frontal bone itself bemmg com-

pressed to a narrow plate between the maxilla and supraoccipital. In

this character Kogia departs widely from Physeter and the Ziphoids.

Kogia also has no falciform process of the squamosal, in which again it

differs from Physeter and the Ziphoids. The tympanic expands laterad

into a massive process which occupied the position usually taken by the

mastoid region of the periotic. In this character all the Physeterine

agree.

The architecture of the mandible in Physeterine is characteristic and

differs from that of the other odontocetes. The margins of the ramus:

are thickened and proximad are connected with a crescent of thick bone

which bears the condyle. The intervening region is reduced to a papy-

raceous lamella. In other odontocetes, including the Ziphoids, there

is a thickened axial portion of the ramus extending from the condyle to

the dentigerous body of the bone. This character of the mandible and

the peculiar massive pterygoid would seem to be peculiar to ue

Physeterine.

~ The Section then adjourned. WitiiamM K. Grecory,

Secretary.

SECTION OF GEOLOGY AND MINERALOGY

20 NoveMBER, 1916

Section met at 8:15 Pp. m., Secretary Chester A. Reeds presiding.

The minutes of the last preenine of the Section were read and approved.

The following program was presented :

E.de Martonne, THr LimesToNE PLATEAUS OF THE CAUSsES, SOUTH-

ERN FRANCE.

Anna I. Jonas, Pre-CAMBRIAN AND TRIAssic DIABASE IN Basan

PENNSYLVANIA.

A.W.Grabau, SrrarigrAPHic RELATIONS OF THE OIL- Emaswense

TO THE OIL-BEARING SHALES IN THE PALBOZOIC OF

NortH AMERICA; INVOLVING A New Trnony OF

Orn DISTRIBUTION.

996 ANNALS NEW YORK ACADEMY OF SCIENCES

SUMMARY OF PAPERS

Professor de Martonne stated that the Causses are high limestone

plateaus extending on the southern border of the highlands of central

France. It is one of the rare examples of a natural region with a popular

“name, extending exactly as far as the geological formations which control

its physical aspects. Nobody can fail to notice the change in topography

when entering the limestone area. Water has disappeared from the sur-

face, all valleys have become dry, many are changed into completely

closed depressions called “sotch.” ‘These depressions are the only places

where you can find some red soil, and, in the spring, some water; for

this reason they are the only inhabited places on the plateaus. Sink

holes, called “avens,” are frequent; they lead to very extensive caverns,

showing alternation of domes and narrow galleries, streams with cascades,

lakes, splendid stalactites and stalagmites. There are not more than three

valleys with water (Tarn, Jonte, Dourbie). Their depths range from

500 to 700 meters. Like the Canyon of the Colorado, they are cut in

-horizontal layers, showing benches in the weak beds (marls of the Laas

and Middle Jurassic) and cliffs in the strong beds (more or less dolo-

mitic limestone of the Jurassic). The cross-section and the width of the

‘valley depends on the height at which the weak beds appear above the

-bottom. The total thickness of the Jurassic beds which built the Causses

is much greater than the depth of the valleys. They have been dis-

located by faults which can be very easily seen on the stony sides of the

valleys, but do not ordinarily appear in the topography of the plateau,

although the displacement can amount to over several hundred meters.

The rugged but nearly level surface of the plateau may be considered as

a peneplane? slightly modified by underground erosion and dissolution.

From some well-selected points the continuity of the plateau of the

Causses with the rolling surface of the highest summits of the Cévennes

(Aigoual, Lozére) appears very clearly. At one point (Col de Perjuret)

‘you can walk across a great fault separating the Jurassic area from the

crystalline massif on a nearly level plain, while to the north and to the

-south you see subsequent valleys and cuestas developed by recent erosion.

At some points on the surface of the limestone plateaus old gravels com-

ing from crystalline massif may be found. The plateaus of the Causses

seem to be a part of the highest and oldest of the three peneplane surfaces

shown by Briquet and Demangeon in the central massif of France.* One

1] agree entirely with the proposal of Prof. D. W. Johnson concerning the substitu-

tion of “‘peneplane’”’ for ‘‘peneplain.’”-—E. de M.

2A. Demangeon, Le relief du Limousin. Ann. de Geographie, 1910, p. 120. A. Bri-

quet, Sur la morphologie de la partie médiane et orientale du Massif Central. Ann. de

Geographie, 1912, p. 30, et 122. :

RECORDS OF MEETINGS 297

may wonder why only one cycle of erosion seems to have been developed _

in the limestone region since the late Miocene, while two are shown in

. the erystalline area. The cutting of the main valley must have been

very rapid, while all secondary valleys became dry and many were

changed into closed depressions; so that the surface of the limestone.

plateau suffered only slight changes by underground erosion. The great-

est changes certainly did occur in the caverns, and it would be possible

to trace the shifting of the base level by the study of some of them. ‘The

fact that the main valleys carry water shows that they have reached the

level at which torrential circulation in the caverns is relayed by a com-

plete filling up of all hollows, some impermeable layers preventing a

deeper infiltration of water.

It may be proposed to use the word Causses in speaking of lime-

stone plateaus similar to these described here, when the surface is dry.

and very few valleys carry water. One can distinguish between Low. |

Causses, High Causses and the Alpine Causses, referring to the depth of.

the valleys, the surface of the plateau being more rugged on account of

stronger undermining by underground erosion, when the valleys are

deeper. We have described High Causses. The Dordogne and Lot

cross the lower Causses of Quercy. Alpine Causses are frequent in the

limestone Alps of France (Vercors) and Austria (Steinernes Meer,

Todtes Gebirge, etc.). :

Dr. Jonas stated that the region discussed occupies part of the Boner

town and Quakertown quadrangles, eastern Pennsylvania. ‘The area lies

in the Appalachian mountains, locally called the Boyertown hills, and the

Piedmont plateau. The rocks of the Boyertown hills are a series of Pre-'

cambrian gneisses, mainly of igneous origin. The sedimentary gneisses

are remnants of the Precambrian floor into which are intruded an

igneous complex of granite, diorite, and gabbro. Narrow diabase dikes

cut all the Precambrian rocks. The diabase is a fine grained, dark

rock with ophitic texture, composed of plagioclase, augite, pyrite and

biotite. Alteration of feldspar and augite has produced a dark green

schist. The rocks of the Piedmont plateau, lying southeast of the Boyer-

town hills, are sediments and diabasic intrusions of the Triassic age.

The sediments are the Brunswick conglomerate and shale, the upper

member of the Trias. Into them is intruded a diabase sheet, about 1,000

feet thick, locally called the Haycock Mountain sheet. It underlies a

prominent “ridge” composed of rough hills which traverse the Quaker-

town quadrangle. The diabase is for the most part a light-colored,

coarse-grained rock, with ophitic texture, whose constituents are feld-

298 ANNALS NEW YORK ACADEMY OF SCIENCES

spar (acid labradorite), augite, magnetite and biotite. Pyrite and olivine

are absent. A fine-grained type occurs on the ‘edge of the sheet. The

shale adjacent to the diabase has undergone induration, crystallization,

and change of color. There are developed in the round nodules of chlorite

pseudomorphs after cordierite. In addition to the difference in grain’

between the diabase of the Haycock sheet and the dikes of the Boyertown

hills, a difference owing to the greater size of the former intrusive mass,

the Haycock diabase possesses certain characteristics by which it is dis-

tinguished from the diabase of the Boyertown region. The most promi-

nent characteristic is the freshness of the constituents of the diabase of

the Haycock sheet; the diabase of the Boyertown hills has undergone

marked alteration by suassuritization and chloritization, which has ob-

scured the ophitic texture and dulled the rock and changed the color.

Pyrite is absent in Haycock diabase, but is abundant in the diabase of ~

the Boyertown hills. Stratigraphic relations point to a difference in age

of the two diabases. Field relations prove the Triassic age of the Hay-

cock sheet which has invaded Upper Triassic sediments. The diabase

of the Boyertown hills nowhere penetrates to a horizon younger than the

Precambrian. ‘Therefore the alteration prevalent in the diabase of the

Boyertown hills may be explained by their Precambrian age and the

greater metamorphism they have undergone.

Professor Grabau stated that the three important oil-bearing forma-

tions which he has studied in detail are the Trenton limestone, the

Onondaga (Corniferous) limestone, and the Upper Devonie oil sands

of Pennsylvania. In all cases it is shown that these formations grade

laterally into black shales of sapropeltic origin, these shales being the

source of the oil. Lateral migration along the bedding planes has re-

sulted in the accumulation of the oil in the more porous limestones or

sandstones in which they are found today. The beds which have pro-

duced the oils are the Utica shale (in its broadest sense), the Marcellus,

and the Ohio shales. The relation of the Utica-Trenton and of the Ohio-

Portage relation is an interfingering one. The lower two shales are

sapropelites; the upper more nearly a humulith, though having some

sapropelitic admixtures. The significance of this Ce in the

determination of oil-bearing horizons is apparent.

The Section then adjourned.

or Cuester A. REEDS, ~

Secretary.

RECORDS OF MEETINGS 299

SECTION OF ANTHROPOLOGY AND PSYCHOLOGY

27 NovEeMBER, 1916

‘The Section met in conjunction with the New York Branch of the

Aimerican Psychological Association at Columbia University.

The following program was presented :

L. S. Hollingworth, Ecronaria in Iniors: Its MEANING For MopERN

THEORIES OF IMITATION.

G. C. Myers, SHRINKING OF IMAGEs.

J.C. Bell, A COMPARISON OF THE BINET-SiIMON TESTS OF

INTELLIGENCE AND THE SQUIRE GRADED MENTAL

TESTS.

SUMMARY OF PAPERS

Dr. Hollingworth stated that echolalia (which is a curious tendency

found in aments and in certain insane patients to echo or repeat what-

ever is said to them or in their hearing) has occasionally been described

in the literature of pathological psychology, notably by Barr. 'The pres-

ent paper describes three cases of echolalia in idiots, one case being a

child of five years, the second a child of eleven years, and the third a

man of about thirty years. These patients showed marked ability and

tendency to repeat automatically whatever was said to them, revealing no

understanding of the question-response situation. Instead of replying

to questions, they simply repeat them mechanically. Such cases are of

great interest in connection with modern controversies about the nature

of imitation in man. Professor Thorndike has recently called into ques-

tion former ideas about imitation, anc has debated the propriety of its

inclusion, as a general tendency, among the instinctive tendencies of man.

Professor Montague has made persuasive objection to Professor Thorn-

dike’s discussion and final conclusion, holding that the potency of be-

havior to produce similar behavior in witnessing human beings cannot

be satisfactorily explained on the ground of a few specific inherited ten-

dencies plus the laws of habit formation in general. Does the behavior

of our three idiots furnish any new light to the controversy? It would

be desirable to have much more information about the development and

modifiability of the echolalia which they showed. However, it is very

difficult to see how their tendency to duplicate behavior experienced is to

be explained except on the basis of instinctive imitation. The patients

were idiots, incapable of adapting themselves independently to even very’

simple situations, or of understanding the significance of what was said

300 ANNALS NEW YORK ACADEMY OF SCIENCES

to them. Their “echoing” would seem to be inexplicable by the laws of.

habit formation in general, or on the basis of any specific inherited ten-

dencies. If we explain the behavior of such patients as due to an instinct-

ive tendency to imitate, shall we assume that they suffer from some char-

acteristic lesion, which sets them apart as a separate species? Or does

their reaction indicate the presence of an instinct which is an element in

the original nature of man, and is distributed according to the curves of

probability ?

Professor Myers stated that eight students of Columbia University,

under certain standardized conditions, cut threads which represented

one of two dimensions of some familiar object, voluntarily selected,

which could not be seen during the experiment. These threads were

placed between the pages of a magazine where the date and introspections

were recorded. One subject first imaged tactually, then visually; the

rest, as a rule, imaged visually. Some imaged once a day, some twice

and some three times, until they each had about fifty records. Later

these threads were measured in millimeters by the writer.

Four other subjects thus imaged ten familiar objects successively for

six continuous hours, of whom two later selected an arbitrary thread

length and repeatedly cut threads for one hour to equal the memory

length of that thread. Five more did the same for one-half hour.

Twelve subjects, for one hour each, also imaged an object which had

been presented before the experiment began. Its dimensions were 228 by

44 mm. ‘These dimensions, which were voluntarily selected, ranged from

34 inches to about one inch.

Curves were presented of individuals and of the group of twelve.

Although there were considerable individual differences there were no

exceptions to the rule that the general trend of the curve was downward.

Most resembled the learning curve. The curves for length and width

were remarkably parallel. The sizes of the object imaged, as a rule, were

ereatly underestimated. This was only a preliminary report.

Mr. Bell stated that the Binet tests have been criticized because of the

trivial nature of some of the tests, the arrangement of the tests, anid the

mental age of the pupil. The Squire tests were constructed with greater

regard to psychological analysis, but have been used as a graded series

only by Mrs. Squire herself. It was proposed to investigate the rélative’

values of the two series of tests for school purposes. Both were given

to twenty-three elementary pupils in grades four to seven, inclusive;

three from each half grade except the high seventh, where only two were

available. No retarded pupils were included. By the Binet tests the

mental age of the pupils ranged from one year below their chronological

RECORDS OF MEETINGS 301

age to four years above. To reduce the results of the Squire tests to a —

single expression for each pupil the highest score in each test was placed

equal to 100, the lowest equal to 0, and the other scores were reduced to

corresponding values. ‘The results for each individual in the eighteen

tests were then averaged for a final score. The Pearson coefficient of cor-

relation between these scores and the Binet mental ages was .70. The

Binet tests were found superior, because they could be given in one-

fourth the time required for the Squire tests, because the interest of the

pupil was maintained at a higher pitch and because the results were more

easily interpreted.

The Section then adjourned. R. H. Lowiz,

Secretary.

BUSINESS MEETING

18 DrcrEMBER, 1916

The Academy met at 8:15 Pp. M., at the American Museum of Natural

History, Secretary V. HE. Levine, Section of Astronomy, Physics and

Chemistry, presiding.

The minutes of the last meeting were read and approved.

The following candidates for Active Membership in the Academy, rec-

ommended by the Council, were duly elected:

H. H. Anthony Georges Crozel

Charles D. Atkins Otto H. Klein

Morton L. Byers John De Witt Sterry

The Secretary reported the following death:

Prof. F. J. H. Merrill, Active Member since 1886, Life Member

since 1915, died 1 December, 1916.

The Academy then adjourned. Henry EH. Crampton,

Acting Recording Secretary.

SECTION OF ASTRONOMY, PHYSICS AND CHEMISTRY

4 DrcemMBER, 1916

Section met at 8:25 Pp. M., Secretary V. E. Levine presiding.

The following program was presented :

Victor E. Levine, CHEMICAL REDUCTIONS IN THE LIVING ORGANISM.

Clement S. Brainin, Comparative INTENSITIES OF X-RAYS FROM

Various METALS.

302 ANNALS NEW YORK ACADEMY OF SCIENCES

SUMMARY OF PAPER

Dr. Brainin stated that X-radiation is a by-product of the collision

between atoms and fast-moving electrons. X-rays are electromagnetic.

ether waves like light waves, differing from them only in wave-length

and frequency, the wave-length of light being about .00005 em. and that

of X-rays of the order of .00000001 cm.

We distinguish two classes of X-rays:

1. Characteristic or homogeneous rays, which are emitted by a metal

when hit by electrons of proper velocity for that particular metal, which

in turn is determined only by the atomic weight (or number) of the

metal. These.rays are all of the same wave-length.

2. General radiation, which consists of rays of many different lengths,

hike a spectrum from an incandescent solid. The voltage impressed on

the tube determines both the intensity of emission of any particular wave-

length and the length of the shortest wave present in the X-ray spectrum.

This can be determined from the formula (potential) (electronic

charge) == (Planck’s constant) (frequency of wave).

-In these experiments the anode was a hexagon, on each side of which

a different metal was attached, and which could be magnetically rotated

to bring the different metals under the electron stream. The X-rays

passed out of the tube through a mica window .001 cm. thick into an

ionization chamber, which completely absorbed the rays for all potentials

used. ‘The intensity was measured by the usual ionization method.

The following table shows metals used and critical voltages for pro-

ducing characteristic rays of each:

Platinum (atomic weight, 195), about 100,000 volts.

Tungsten He oe 184 95,000 **

Silver a es 103 ce 25,500 **

Molybdenum ‘‘ - 96 nt 19,500 *‘

Copper ° i " 64 ie 12,000 “*

Cobalt Ae mt 59 ue 10,000 ‘

The following table shows relative emissivity of these metals at differ-

ent voltages in descending order:

0,790 8,200 10,000 10,700 12,800 14,200 17,500 up to 40,000

Pt Pte: Pt Pt Pt Pt Pt

Ag eNom Ag Ag ang WV -W Ww

W WwW W Ww Aye Co Co

Mo Mo Mo Co Co Ag Cu

,Cu ‘Cu Co Mo Mo Cu Ag

Coma Co Cu Cu Ch Mo Mo.

V. HE. Levine,

Secretary.

RHCORDS OF MEETINGS 3083

SECTION OF BIOLOGY

11 DrecEMBER, 1916

Section met at 8:15 Pp. m., Vice-President H. von W. Schulte pre-

siding.

The following program was presented :

H. D. Senior, THE DEVELOPMENT OF THE EXTERNAL ILIAC ARTERY

| IN Man.

Halsey J. Bagg, THe GENETICS oF CrRTAIN TyprEs or ANIMAL BE-

, HAVIOR.

John T. Nichols, DEVELOPMENT AND DiIsTRIBUTION oF FRESH-WATER

FIsHES IN AFRICA.

SUMMARY OF PAPERS

Professor Senior stated that in man and pig the femoral artery is not

developed directly from the hypogastric, as described by Hochstetter in

eat and rabbit,’ but that the femoral and inferior epigastric arise from

a common stem (the external iliac), which antedates them both consid-

erably in development.

The external iliac arises from the lateral side of the hypogastric and

is quite independent of the segmental arterial system. It takes a longi-

tudinal course, crossing medial to the root of the obturator nerve in the

cephalic direction. During the considerable period of development which

precedes the origin of the femoral and inferior epigastric from it, its

walls become progressively thickened by condensation of the adjacent

mesenchyme.

The femoral artery, when it has once appeared, very rapidly extends to

the popliteal fossa and there taps the ischiadic. The external iliac, on

the contrary, scarcely alters in appearance between the human stages of

°8.5 and 12 mm., and between the stages in pig of 10 and 12 mm. or

somewhat later. :

Reconstructions are shown of this vessel in human embryos of 8.5 and

12 mm. (crown-rump measurement), and in pig embryo of 12 mm.

(greatest'total length). In none of these stages is the femoral present.

In a reconstruction of a human embryo of 13.6 (greatest total length)

the femoral and inferior epigastric arteries are well developed, and the

1 Ueber die urspriingliche. Hauptschlagader der hinteren Gliedmasse des Menschen und

der Saiigerthiere, u. s. w., Morpholog. Jahrb., Bd. 16, S. 300, 1890.

304 ANNALS NHW YORK ACADEMY OF SCIENCES

former has already tapped the ischiadic in the popliteal fossa. Whether

the femoral arise before the inferior epigastric from the external iliac, or

vice versa, or whether they arise simultaneously, has not been ascertained

from lack of suitable material. Should the femoral arise prior to the

inferior epigastric, it would by no means invalidate the fact that the

external iliac is not merely the root of the femoral; but a separate vessel

having a developmental history quite peculiar to itself. The external

iliac is the second branch (in time of development) of the hypogastric,

the ischiadic (inferior gluteal) being the first. Before the femoral arises

from the external ilac there are four branches of the hypogastric, viz.,

ischiadic, external iliac, internal pudenal, and superior gluteal.

Mr. Bagg stated that the plan of the experiment is to measure indi-

vidual differences in behavior in various strains of mice; to determine

the extent to which an animal which departs from the average in one

direction will depart in others; to measure the resemblance in families

and in lines of descent, and to determine the degree to which kinds of

conduct can. be established in family lines by selection. Results have

been so far obtained for over two hundred mice that were tested in two

types of mazes. Striking mmdividual differences have been noted for

various tasks, and an apparent resemblance between mice belonging to

the same litter was found to be nearly twice as great as between un-

related individuals. There appears to be a considerable difference among

strains of mice, and the sex differences, if any, are slight.

Hight generations of mice have been so far obtained, and the genetics

of the problem has resolved itself into a study of the offspring obtained.

from mating animals that are quick to learn with those slow to learn,

those that are quick with quick ones, and slow with slow ones. The

effects of inbreeding and outbreeding are also being tested.

Mr. Nichols stated that the comparative development of the groups of

Ostariophysous fishes in Africa and related families indicates that the

Mormyrids are a remnant of an earlier ichthyfauna, and that of the more

modern groups the Catfishes came first, then the Characine; the in-

vasion of Carps is very recent and still in progress. ; .

In comparing the condition found in South America the absence of

Carps is accounted for by recent isolation of that continent by sea, the

development of the Gymarchids by absence of similar Mormyrids, and the

diversified development of Catfishes by supposing them to have been the

first fresh-water family in the field.

The Section then adjourned.

WiL~LiAM K. GREGORY,

Secretary.

- RECORDS OF MEETINGS 305

ANNUAL MEETING

28 DrEcEMBER, 1916

The Academy met in Annual Meeting on Monday, 18 December, 1916,

at the Hotel Manhattan, at the close of the Annual Dinner, President

Michael I. Pupin presiding. ;

The minutes of the last Annual Meeting, 20 December, 1915, were

-read and approved.

President Dr. Michael I. Pupin delivered the annual address, en-

titled “The University and Industrial Research.”

Reports were presented by the Corresponding Secretary, the Acting

Recording Secretary, the Librarian, and the Acting Editor, all of which

were received and ordered placed on file.

The Treasurer’s report showed a net cash balance of $1,770.58 on

hand 30 November, 1916. On motion, this report was received and re-

ferred to the Finance Committee for auditing.

The Acting Secretary presented an informal report of the activities

of the Committees on the Centennial Celebration. It was stated that

the membership of the Academy was to be increased to one thousand, that

a history of the work during the past century was to be prepared, that

meetings and a general exhibition showing the progress of science would

be held during the second week in May, 1917, and that a fund of one

hundred thousand dollars was being raised for the support of scientific

activities, lke the Porto Rico Survey. Contributions of $5,000 each

by Professor N. L. Britton and President M. I. Pupin had already been

promised.

The following members of the Academy were elected Fellows, the Sec-

retary being authorized to cast a single affirmative ballot for the list as

presented :

Carl E. Akeley, American Museum of Natural History,

H. E. Anthony, American Museum of Natural History,

John J. Carty, 15 Dey Street, City,

Mary C. Dickerson, American Museum of Natural History,

Pliny E. Goddard, American Museum of Natural History,

Charles B. Going, 140 Nassau Street, City,

Otto H. Klein, 127 Worth Street, City,

Hideyo Noguchi, Rockefeller Institute,

George B. Pegram, Columbia University,

Walter Rautenstrauch, Columbia University,

Phinehas V. Stephens, 1258 Morris Avenue, City.

306 ANNALS NEW YORK ACADEMY OF SCIENCES

The Academy then proceeded to election of officers for 1917. The

ballots prepared by the Council in accordance with the By-Laws were

distributed. On motion, the Secretary was authorized to cast a single

affirmative ballot for the list of nominees as presented :

President: MicuarL Ipvorsky PuPin.

Vice-Presidents: Dovctas W. Jounson (Section of Geology and

Mineralogy), HprMann von W. ScHuLTE (Section of Biology),

Ernest E. Surru (Section of Astronomy, Physics and Chem-

istry), J. McKean Carreny (Section of Anthropology and Psy-

chology).

Corresponding Secretary: Henry E. Crampron.

Treasurer: Henry J. COCHRAN.

Librarian: RatpH W. Tower.

Editor: Rate W. Tower.

Councilors (to serve three years): JoHN H. BARNHART, GEORGE

B. PEGRAM. 3

Finance Committee: JoHN TATLOCK, BasHFORD DEAN, FREDERIC

S. Len. |

On motion, the appointing of a Recording Secretary was referred to the

Council for action. Subsequently, by the authority of the Hxecutive

Committee, Ralph W. Tower was elected to this office.

A report on the work of the Porto Rico Survey was read by Professor

N. L. Britton, Chairman of the Porto Rico Committee. It was voted

that this report be received and placed on file.

The following illustrated accounts of recent scientific activities were

then presented before the Academy :

Pror. Cuartes P. Berxey, “The Geological History of Porto Rico. es

Dr. HERBERT SPINDEN, “Ethnic Relations Between Porto Rico and

Venezuela.”

Me. C. Winu1am Besse, “Zodlogical Studies of British Guiana.”

The Academy then adjourned. Hrnry E. Crampton,

Acting Recording Secretary.

REPORT OF THE CORRESPONDING SECRETARY

We have lost by death during the past year the following ae

Members :

George W. Hill, elected 1898,

Sir Henry Enfield Roscoe, elected 1887, died 18 December, 1915,

and one Corresponding Member:

George Murray, elected 1898.

RECORDS OF MEETINGS 307

There are at present upon the rolls 40 Honorary Members and 111

Corresponding Members.

Respectfully submitted, bak i

Henry E. Crampton,

Corresponding Secretary.

REPORT OF THE RECORDING SECRETARY

During the year 1916 the Academy held 8 business meetings and 28

sectional meetings, at which 73 stated papers were presented, as follows:

Section of Astronomy, Physics and Chemistry, 15 papers; Section of

Biology, 21 papers; Section of Geology and Mineralogy, 17 papers; Sec-

tion of Anthropology and Psychology, 20 papers.

At the present time the membership of the Academy is 687, which

includes 6661 Active Members (of whom 23 are Associate Members, 132?

Fellows, 108 Life Members and 11 Patrons) and 21 Non-Resident Mem-

bers. ‘There have been 6 deaths during the year, 13 resignations have

become effective and one name has been dropped from the roll. Two

names have been transferred to Non-Resident Membership. Two hun-

dred sixteen new members have been elected during the year and eleven

have commuted their annual dues by a single payment of $100 each.

One name has been transferred to the Life Membership list on account

of the payment of Annual Dues for a period of twenty-five years. One

Associate Member has taken up Active Membership. As the member-

ship of the Academy a year ago was 491, there has been a net gain of 196

during the year of 1916. Record is made with regret of the loss by

death of the following Active Members:

James G. Cannon, Active Member since 1910,

G. Langman, Active Member since 1899,

Hon. Seth Low, Active Member since 1876,

F. J. H. Merrill, Active Member since 1886,

Nathaniel C. Nash, Active Member since 1910,

Tgnaz Matausch, Active Member since 1914.

Respectfully submitted,

Henry H. CRAMPTON,

Acting Recording Secretary.

1 including 22 members elect and one Associate made Active to begin 1917.

2To this number must be added the eleven Fellows elected at the Annual Meeting, 18

December, 1916.

308 ANNALS NEW YORK ACADEMY OF SCIENCES

REPORT OF THE LIBRARIAN

It is doubtful if in the history of the New York Academy of Sciences

the library has been so much used by scientists and naturalists in’ the

vicinity as during the year just past. The files, in conjunction with

those of the American Museum of Natural History, now form a remark-

ably complete library in the subject of Natural History, as well as in

the proceedings of the Learned Societies of the world.

The uncertainty of the foreign mails and the disturbed political situa-

tion in Europe have caused an almost complete cessation of exchanges

with that part of the world; on the other hand, opportunity has thus

been afforded for promoting a more intimate affiliation with our sister

societies in South America.

Respectfully submitted, RaupH W. Tower,

Librarian.

REPORT OF THE EDITOR

The parts of the Annals which have been published this year are as

follows :

VOLUME XXV

Pages

L. E. W. Benedict—A Study of Bagobo Ceremonial, Magic and Myth... 1-808

VOLUME XXVI

EK. O. Hovey—Records of Meetings of the Academy.................. 395462

Membership of the Academy......................008. 463474

J Bro 0 feb: tae ane NN ta EO ee ea iene Ua bs! hue Ins ao 475-486

VOLUME XXVII

T. Barbour—Some Remarks upon Matthew’s “Climate and Evolution.” ;

with Supplemental Note by W. D. Matthew........... 1-15

J. A. Allen—An Hxtinct Octodont from the Island of Porto Rico....... 17-22

W. D. Matthew—New Sirenian from the Tertiary of Porto Rico....... 23-29

C. C. Mook—A Study of the Morrison Formation..................... 31-38

H. E. Anthony—Preliminary Report of Fossil Mammals from Porto

TES KEG HS At Anca eat re Nt eee SIH SCmtRen mia SuGUa IS G:G'G 0 39-191

There are likewise in press two papers, one by Warren 8. Smith, en-

titled “Physiography of the Skykomish Basin, Washington,” and the other

by J. Alden Mason, entitled ‘““T'epecano, a Piman Language of Western

Mexico.” The Publication Committee has accepted for publication a

paper by H. E. Armstrong, entitled “Operating Features of the Audion.”

Respectfully submitted,

Henry E. Crampron,

Acting Editor.

RECORDS OF MEETINGS 309

REPORT OF THE TREASURER

MEMBERSHIP

Paid up, Active Members (174 of these were elected after 1 May and paid

So MRL Tem) recy alyseanaiuye se. seco this chess one. Sue, eiesal co eeasiee acaleratesscer say agents, ola 304

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RECEIPTS 666

DECEMBER 1, 1915—NovEMBER 30, 1916

Cash on hand, December 1, 1915.......... 0.0... ccc ce eee eee eee $488.17

Mites Membership MCCS... < .cjcce ee ce tees cewwe se eieeeagcveevsetacens 1,100.00

Income from investments :

Interest on mortgages on New York real estate...... $851.82

Interest on railroad and other bonds................ 1,350.00

2,201 .82

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Active membership dues, 1908..................-.000005 $10.00

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Hh sf SeeH NO Ate oeee), rere i. lituch 50 seme ver aa oaetaw 50.00

4 iS ef aL OED ete ones ie a tekivess ae 6) eeuene oie ie sae 215.00

“f ef esate OMG eaerer a Nea. cteyrete ns oy c- anahe eacryeneoor aie 3,810.00

* mens Seren OIL eseet cern one ieeens 2 ae wae nae ai 195.00

——_——— 4,350.00

Associate membership dues, 1915....................... 6.00 .

_ oe i Seed NOG. 5 See eeteves a aiie/iscats Suntcuatates 54.00

—_—_—_ 60.00

SSO ten MOM CALTOMS ey steracoscs cso cle cine retiree lel cteueyoiolaoetesoncsuoiorens eioenciaee soho 209 .33

Contribution to cost of publication............... 00-0220 eee eee ee 250.00

Subscription to annual dinner (1915).................0. eee e eevee 302.50

Porto Rico Survey (subscription) ............. 5c cece eee e cece tenes 1,000.00

Porto Rico Government (refund of advances made on account of

METUMEXPCTISES)) asics Mistene tars: sci ice eva.er odie 8 laye eile: Guay anatanepaiehreniaus ne) auokoeam enone eich 1,600.74

Washam mote nay DAMS i515 Sees Sika axe Ha eeyec tudiele es Gucigeeys Sutaie om wis. oe ee 000200

Uy BLOKE hs erotics Pecnetaees Cae CRT Dee ac REPORT EE RCIA CACHE DROS ey ero coae $12,593.18

DISBURSEMENTS

DECEMBER 1, 1915—NovEMBER 30, 1916

Publications on account of AnnalS.............ccc cece cee ces ceces $1,887 .63

Publication Of BuUyletiiacs cok ccs cs cas cess s cee scuahed te WERE eemeNs cae 680.55

‘310 ANNALS NEW YORK ACADEMY OF SCIENCES

Recording Secretary’S CXPeNSeS....... ccc cece cee eee eee eet eens

Recording Secretary’s and Wditor’s allowance.....................

Esther Herrman Research Fund (grants)...............-+e0eeeeee

John Strong Newberry Fund (grants)..............ccceencecceees

General SXMENSES) so sare ose cc gcd Ledee oko eeieds os sahacs ig eles tenes CONRT ASIC ee

‘Annual meeting and dinner (1915).......... 00. ccc cece cere ewes ees

‘Porto Rico Survey (advances on field expenses)................-+.. 3,383.80

‘Section of Geology and Mineralogy............ 16 Bante ieered ye eee 28.90

Centennial Celebration—Membership Campaign.................... 1,002.69

Payment of notevin bank 32.5. eec Chas ioe emer eee oe 1,000.00

hiterest on note in: banks. oj fs ac. auseeaar are wote ents aise eel eee 13.45

Gash? Om: Wan desing ereene-s. Sew. rors ee eae ee eee oe 1,770.58

hs agers SD OCA ehees ad itteeutvelanas ao cyeltabees io vakecutenerteiee ie Teed cA Peg wh Oe a a $12,593.18

BALANCE SHEET, NOVEMBER 30, 1916

Investments (cost) ....... $42,332.92 Permanent Fund ......... $24,754.66

Gash on hand............. 1,770.58 Publication Fund ......... 3,000.00

Audubon Fund ........... 2,500.00

e Esther Herrman Research

UNG 3 o SeiSeteie ce eueeetens 10,000.00

- John Strong Newberry

1 td 0 ameter eer eo hy GlniG-G'd 2 1,000.00

Income Audubon Fund..... 885.08

Income Newberry Fund.... 194.49

Income Hsther Herrman

IRIN. se- as seo tte eS 1,769.27

$44,103 .50 $44,103 .50

PROPERTY : Cost

EaiiperiMorteage cs, oa i eaters ice tate eae on td a at 5 per cent. . $12,000.00

Deane-Brennan Mortgage...............0cceeeeceeee at5 percent... 4,036.67

4 Detroit City Gas Co. bonds...................2005- at5 percent... 4,000.00:

3 Grand Rapids Gas Light Co. bonds................ at5 percent.. 2,880.00

20 Madison Gas and Plectric Co. bonds.............. at6 percent.. 10,400.00

1 Binghamton Gas and Electric Co. bond............. at5 per cent.. 995 . 06

1 Quebec-Jacques Cartier Hlectric Co. bond.......... at5 percent... 965 .50

1 San Antonio Traction Co. bond................... at5 per cent.. 487.50

1 San Antonio Gas and Electric Co. bond............. at5 per cent.. 487 .50

5 U. S. Steel Corporation bonds..................06- at5 percent.. 5,081.25

Participation bond of Lawyers’ Mortgage Co......... at5 percent.. 1,000.00

Respectfully submitted, $42,332.92

Henry J. CocHRAN,

15 FEeBRuARY, 1917. Treasurer.

Hxamined and found to be correct.

JOHN TATLOCK,

BASHFORD DEAN,

Auditing Committee.

RECORDS OF MEETINGS 311

REPORT OF THE PORTO RICO COMMITTEE

Under the direction of the Committee of the Academy appointed in

1913 work on the scientific survey of Porto Rico has been continued

during the year in many branches of the subject, both in the field and

in the laboratory and in the preparation of preliminary papers and of

the final reports.

' Areal geological surveys have been carried out by Mr. Bela Hubbard

in the northwestern part of the island, which included, among other

points of special interest, the study of a stratum at the base of the Ter-

tiary series of the island previously detected by Dr. C. A. Reeds, con-

taining large numbers of fossil plants; this discovery, being the first indi-

cation of the occurrence of Tertiary fossil plants in the West Indies, is

of great interest, and the study of the fossil leaves may give us our

first knowledge of the ancestors of some tropical plants; the collections

have been referred to Dr. Arthur Hollick for study. Dr. Charles R.

Fettke carried out an areal survey of the southwestern districts, which

included a detailed study of the large areas of eruptive rocks in that part

of the island. Mr. A. K. Lobeck studied the physiographic geology of

the whole island. The reports of Mr. Douglas R. Semmes on the areal

survey of the San Juan District, and that of Mr. Edwin T. Hodge on

the Coamo-Guayama district, based on their field work of the previous

season, are completed and ready for publication. Progress has also been

made in the study of the paleontological collections made by the several

field expeditions, and data relative to economic geology are being assem-

bled.

In botany the most important field work accomplished was the expe-

dition of Professor H. H. Whetzel, of Cornell University, and Dr. E. W.

Olive, of the Brooklyn Botanic Garden, for the study and collection of

parasitic fungi, which was prolific in results, their collections including

several hundred specimens, which are under investigation by a number of

different experts. The Uredinee (rusts) of this large collection, taken

together with the specimens of this family previously collected, have

enabled Professor J. C. Arthur to prepare a noteworthy paper on this

group for early publication. Professor F. L. Stevens has published

during the year his monograph on the Porto Rican species of the genus

Meliwola. Additional general collections by Mr. John A. Stcvenson, of

the Insular Experiment Station at Rio Piedras, have added to our knowl-

edge of a number of plants. Work on the manuscript for the final re-

ports has been continued by several botanists, and a large number of

312 ANNALS NEW YORK ACADEMY OF SCIENCES

specimens have been returned to Porto Rico and are deposited in the

herbarium of the Insular Experiment Station.

In zodlogy study has been continued by several investigators from the

collections already made; they plan codrdinating the results already

reached, and thus ascertaining where the gaps exist which need to be filled

by further field operations. A large collection of mollusks has been

returned to Porto Rico for installation in the new museum room in the

. =

—

papers on the fossil mammals obtained by our collectors from the floors

of caves have been published in the Annals of the Academy by Dr. J. A.

Allen, Dr. W. D. Matthew and Mr. H. E. Anthony, including the de-

scription of an apparently new family, a new genus, and several new

species, results which were entirely unexpected. The study of the rich

entomological collections, by several experts, has yielded scientific in-

formation of high importance and several preliminary papers are in

course of preparation.

The study of the anthropological collections made during 1915 has

yielded proofs of the use of some of the caves as burial places by the

aborigines, and the great quantities of one of the few species of extinct

mammals found in the caves indicate this animal was extensively used

by them for food. Further progress was also made on the survey of the

ancient settlement of Capa, the most important of all archeological local-

ities thus far examined in Porto Rico. The reduction of the anthropo-

metric data obtained has been continued; these are as yet incomplete,

requiring additional field observation; their completion would give us

information regarding the differences in the rate of physiological and

mental development of children here and in the temperate zone, which

would be of highly educational importance in arranging school curricu-

lums in Porto Rico. The voluminous folk-lore records accumulated in

1915 by Mr. J. A. Mason have been referred to Professor Aurelio M.

Espinosa, of Leland Stanford University, who reports that this material

is more extensive than all hitherto published Spanish folk-lore literature,,

and that it gives us for the first time the means of a careful comparison

of Spanish and other European folk-lore. Dr. Herbert J. Spinden prose-

cuted ethnological observations in several parts of the island during the

season, and made extensive additional collections.

At the request of the Committee, the Council of the Academy has

set aside volumes of the Annals, commencing with Volume 33, for the

final Porto Rican reports to be published in the sequence: (1) Geology

and Invertebrate Paleontology, (2) Botany, (3) Zodlogy and Vertebrate

RECORDS OF MEETINGS 313

Paleontology, (4) Anthropology, and, pursuant to another request of

the Committee, the Council voted to reserve as much of the income of

the Herrman Fund as may be practicable for the next few years for the

use of the Committee in preparing final reports through the aid of stu-

dents not immediately connected with the codperating institutions. Fur-

ther field work will be mainly dependent upon additional appropriations

being made by the Porto Rico Government.

The Committee gratefully acknowledges the continued financial aid

generously given by ex-President Hmerson McMillin and the codperation

of the many experts from other institutions.

Respectfully submitted,

N. L. Britton,

Chairman of the Committee.

December 18, 1916.

Chere

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”

EXLECTED.

1912.

1889.

nO:

1901.

1904.

1876.

OMS:

1902.

1901.

1876.

1909.

1889.

TOO?

1894.

1912.

T3992

1896.

1909.

1876.

1898.

1880.

alae

1898.

1908.

1898.

1900.

Oia

1913.

1899.

NEW YORK ACADEMY OF SCIENCES’

HONORARY MEMBERS >

31 DrcEemBErR, 1916

Frank D. Adams, Montreal, Canadas

CHARLES Barrors, Lille, France. | ae

WILLIAM Bateson, Cambridge, Desiead

Cuartes Vernon Boys, London, ae

W. C. Bréceer, Christiania, Norway, .,

W. Boyp Dawkins, Manchester, England,

CHARLES DéprrEt, Lyons, France. _..,

Sir James Dewar, Cambridge, England.

Emin Fischer, Berlin, Germany.

Sir ARCHIBALD GEIKIE, Haslemere, os England.

K. F. G6spezt, Munich, Germany.

GEORGE LINCOLN GOODALE, Cambridge, Mass.

Patt von GrotH, Munich, Germany.

ERNst HACKEL, Jena, Germany. _—

GeEorRGE EK. Hane, Mt. Wilson, Calif...

JuLtius Hann, Vienna, Austria. ,

Fevix Kisrn, Gottingen, Germany. - oe oe

ALFRED LAcRorx, Paris, France.

Vixtor von Lane, Vienna, Austria.

H. Ray Lanxester, London, England,

Sir Norman Lockyer, London, England.

Ernst Macu, Munich, Germany.

Inrya MercHnrkor, Paris, France. , a

Friptyor Nansen, Christiania, Norway.

WiLHELM OstwaLp, Gross-Bothen,. Germany,

ALBRECHT PENCE, Berlin, Germany. . aes

WILHELM PFEFFER, Leipzig, Germany,

EDWARD CHARLES PICKERING, Cambridge, Mass.

EDWARD BAGNALL POULTON, Oxford, England...

Sir Davin Prain, Kew, England. a

Lord RAYLEIGH, Witham, Essex, England. i |

316

ELECTED.

1898.

US ey

1904.

1896.

1900.

1904.

1907.

1904.

1883.

1891.

1890.

1899.

1876.

1899:

1898.

1878.

1867.

1897.

1899.

1874.

1884.

1894.

1874.

1898.

1876.

1891.

1868.

1876.

1880.

1877.

1895.

1879.

1870.

1885.

1898.

ANNALS NEW YORK ACADEMY OF SCIENCES

Hans H. Reuscu, Christiania, Norway.

SHo Wartassk, Tokyo, Japan.

KARL VON DEN STEINEN, Berlin, Germany.

JOSEPH JOHN THomson, Cambridge, England.

EpwarpD Burnett Taytor, Oxford, England.

Hugo DE Vries, Amsterdam, Holland.

JAMES WarD, Cambridge, England.

WiLHELM Wownpt, Leipzig, Germany.

CORRESPONDING MEMBERS

31 DrcEmMBER, 1916

Cuartes Conrap Agzorr, Trenton, N. J.

Josr& G. AcurLtERA, Mexico City, Mexico.

Witi1am Dr Wirt ALEXANDER, Honolulu, Hawaii.

C. W. AnDrEws, London, England.

JOHN Howarp APPLETON, Providence, R. I.

J. G. Barker, Kew, England.

Isaac Bacrtey Batrour, Edinburgh, Scotland.

ALEXANDER GRAHAM Buti, Washington, D. C.

Epwarp lL. BertHoup, Golden, Colo.

HERBERT Bouton, Bristol, England.

G. A. Boutencer, London, England.

T. S. BranpDEGEE, Berkeley, Calif.

JoHN C. Branner, Stanford University, Calif.

Bonustay Brauner, Prague, Bohemia.

Witir1AmM Brewster, Cambridge, Mass.

T. C. CoamBeruin, Chicago, Ill.

FRANK WIGGLESWORTH CLARKE, Washington, D. C.

L. Cierc, Ekaterinburg, Russia.

M. C. Cooxs, London, England.

H. B. Cornwatu, Princeton, N. J.

CuHarteEs B. Cory, Boston, Mass.

JosEPH CrawForD, Philadelphia, Pa.

Henry P. CusHine, Cleveland, O.

T. Netson Date, Pittsfield, Mass.

Witi14mM Hearty Dart, Washington, D. C.

EDWARD SALISBURY Dana, New Haven, Conn.

Wiii1am M. Davis, Cambridge, Mass.

EXLECTED.

1894.

1899.

1876.

1880.

1869.

1879.

TRS

1885.

1899.

£379:

1870.

1865.

1888.

1868.

1883.

1869.

1882.

1867.

1900.

1890.

1896.

1875.

1899.

1876.

1888.

1876.

1894.

1899.

1876.

SOI

1867.

1874.

1892.

1874.

1898.

MEMBERSHIP 317

RutHveN Drane, Chicago, IIl.

Louis Dotto, Brussels, Belgium.

Henry W. Evuiott, Lakewood, O.

JoHN B. Evviort, Tulane Univ., La.

Francis E. ENGELHARDT, Syracuse, N. Y.

HerMAN Le Roy Farrcuitp, Rochester, N. Y.

FRIEDRICH BERNHARD Frrrica, Marburg, Germany.

Lazarus Fiercuer, London, England.

EBERHARD Fraas, Stuttgart, Germany.

REINHOLD FRITZGARTNER, Tegucigalpa, Honduras.

GrovE K. GinBert, Washington, D. C.

CHarLEs A. GorssMAN, Amherst, Mass.

Frank Austin Goocu, New Haven, Conn.

C. R. Greenuear, San Francisco, Calif.

Marquis ANTONIO DE GreGoriIo, Palermo, Sicily.

R. J. LecHMERE Guppy, Trinidad, B. W. I.

Baron Ernst von Hesse-WartEGG, Lucerne, Switzerland

C. H. Hircucocxk, Honolulu, H. I.

Witt1am Henry Hotmes, Washington, D. C.

H. D. Hosxotp, Buenos Ayres, Argentine Republic.

J. P. Ippines, Brinklow, Md.

Matvern W. Ixzs, Dubuque, Ia.

Orto JAKEL, Greifswald, Germany.

Davip Starr JoRDAN, Stanford University, Calif.

GrorcE A. Kornic, Houghton, Mich.

Baron R. Kuxi, Tokyo, Japan.

JoHN W. LANGLEY, Cleveland, O.

S. A. Larrimore, Rochester, N. Y.

Witi1Am Lipsey, Princeton, N. J.

ARCHIBALD LiversipGE, London, England.

GrorGE MaActLoskiz, Princeton, N. J.

JOHN WILLIAM MALLET, Charlottesville, Va.

CuartEs Rrporc Mann, Chicago, III.

GrorGE F. MatrHew, St. John, N. B., Canada.

CHARLES JOHNSON Maynarp, West Newton, Mass.

THEODORE LuquEER Mrap, Oviedo, Fla.

J. DE MENDIZABAL-T'AMBORREL, Mexico City, Mexico.

Crinton Hart Merriam, Washington, D. C.

MANSFIELD MrrrtAm, South Bethlehem, Pa.

318

EXLECTED.

1876.

1890.

1895.

1864.

1866.

1897.

1882.

1880.

1876.

1900.

1876.

USI i

1868.

1876.

1874.

1886.

USO:

1899.

1898.

1894.

1876.

1883.

1895.

1896.

1890.

1876.

1885.

1893.

USS.

USE

1876.

1871.

1900.

1867.

1890.

1898.

1876.

ANNALS NEW YORK ACADEMY OF SCIENCES

WILLIAM GILBERT Mrx'rer, New Haven, Conn.

RicHAarD MouLpENKE, Watchung, N. J.

C. Liuoyp Morean, Bristol, England.

Epwarp S. Morss, Salem, Mass.

Kucen Nerro, Giessen, Germany.

ALFRED Newton, Cambridge, England.

Francis C. Nicuonas, New York, N. Y.

‘Henry Atrrep Atrorp NicHonts, Dominica, B. W. L

Epwarp J. Nouan, Philadelphia, Pa.

JOHN M. Orpway, New Orleans, La.

GEORGE Howarp Parker, Cambridge, Mass.

STEPHEN F. PEckHAM, New York, N. Y.

Freperick Prime, Philadelphia, Pa.

RapHarL Pumpetty, Newport, R. I.

B. AuEx. Ranpaut, Philadelphia, Pa.

Ira Remsen, Baltimore, Md. -

Ropert Ripeway, Washington, D. oul

Witu14am L. Rog, Troy, N. Y.

SAMUEL P. SapruER, Philadelphia, Pa.

D. Max Scuuosser, Munich, Germany.

We Ba Scorm Primeetons aN ead:

W. T. Sepewicx, Boston, Mass.

ANDREW SHERWOOD, Portland, Ore.

J. Warp SmitH, Newark, N. J. .

CHarLEs H. SmytuH, Jr., Princeton, N. J.

Ropert STEARNS, Los Angeles, Calif.

Water Le Contr Stevens, Lexington, Va.

Francis H. Srorpr, Boston, Mass.

Rajah Sourrnpro Monun Tagore, Calcutta, -India.

J. P. THomson, Brisbane, Queensland, Australia.

Rk. H. Traquair, Colinton, Scotland.

JOHN TROWBRIDGE, Cambridge, Mass.

D. K. Turrin, Philadelphia, Pa.

Henri Van Hevurcx, Antwerp, Belgium.

Cuartes. R. Van Hisz, Madison, Wis.

AppisoN Emupry Verritt, New Haven, Conn.

ANTHONY Wayne Voepus, San Diego, Calif.

CHarLes Dootrrrrn Watcorr, Washington, D. C.. -

Lronarp: Watpo, New York; N. Y.

- ELECTED.

1897.

1874.

1898.

1866.

1899.

1876.

MEMBERSHIP 319

Sruart WeLLER, Chicago, III.

J. C. Wuite, Morgantown, W. Va.

Henry SHALER WiuiiAMs, Ithaca, N. Y.

Horatio C. Woop, Philadelphia, Pa.

A. SmitH Woopwarp, London, Eng.

Harry Cricy Yarrow, Washington, D. C.

ACTIVE MEMBERS

1916

Fellowship is indicated by an asterisk (*) before the name; Life Mem-

bership, by a dagger (+) ; Patronship, by a section mark (§).

*Abbe, Dr. Cleveland : Arnold, James Loring

Abercrombie, David T.. Ashby, George E.

+Adams, Edward D. Atkins, Charles D.

*Adams, L. A. Avery, Samuel P.

Agnelli, Saverio, M.D. Ayer, James C., M.D.

Ahlstrom, C. F. + Bailey, James M.

*Akeley, Carl H. Baird, Charles

+Alexander, Chas. B. Baker, Hugh Potter

Allen, Arthur Huntington. Baker, Richard J.

*tAllen, J. A., Ph.D. tBaldwin, William M.

*tAllis, Edward Phelps, Jr., Ph.D. Baller, Miss Anna R.

Altshul, Victor I. t*Barnhart, John Hendley

*Ames, Oakes Barron, George D.

Anderson, A. A. . Barry, Charles D.

Anderson, A. J, C. Barry, Llewellyn

+Anderson, John B. “Baskerville, Prof. Charles

*+ Andrews, Roy C. Bateman, George F.

Angot, Emile P. . Baugh, Miss M. L.

eAunthony., | le Bechtel, Edwin de Turck

+Anthony, R. A. *+Beck, Fanning C. T.

Archer-Shee, Mrs. M. *Beebe, C. William

Arctowski, Dr. Henryk Begrisch, Frank, Jr.

Arend, Francis J. Behre, Mrs. A. Frederick

+Armour, Allison V. Behrend, Otto F., Ph.D.

tArmstrong, 8. T., M.D.

Beller, A. ee

320 ANNALS NEW YORK ACADEMY OF SCIENCES

Beller, William F.

Berggren, HE. R. T.

tBergstresser, Charles M.

*Berkey, Charles P., Ph.D.

Bernard, Pierre A.

Bernstein, 8. 8.

Best, William Newton

Betts, Samuel R.

van Beuren, F. T.

Bigelow, William 8.

Bijur, Moses

tBillings, Miss Elizabeth

Bird, Henry

Bishop, Heber R.

Bishop, Miss Mary C.

Bissell, Miss Susan F.

Blackall, Frederick S.

Blake, Mrs. Catherine K.

Blake, Joseph A., Jr.

*+ Bliss, Prof. Charles B.

+Blumenthal, George

Blumenthal, Hugo

*Boas, Prof. Franz

Bohler, Richard F.

+Bourn, W. B.

*Bowman, Prof. Isaiah

Boyd, James

+Brackenridge, George W.

Brill, A. A., M.D.

Brinsmade, Charles Lyman

*Bristol, Prof. Charles L.

Bristol, Jno. I. D.

“Britton, Prof. N. L., Ph.D.

Brown, Edwin H.

Brown, Lucius P.

Brown, T. C.

*Brownell, Silas B., LL.D.

Browning, Mrs. J. Hull

Buda, J. A., M.D.

1 Member elect.

Burr, Prof. Freeman F.

Burr, Winthrop

*Bush, Wendell T.

Byers, Morton L.

Byrne, James

*Byrnes, Miss Esther F., Ph. Ey

Caldwell, EH. T.

Calman, Henry L.

Calvert, Rev. Thomas Elliot

Camp, Frederick A.

*Campbell, Prof. William, Ph.D.

*Campbell, Prof. William M.

Carlebach, Walter Maxwell

Carr, Henry Clay

*Carty, John J.

*SCasey, Col. T. L., U. 8. A.

Cassard, eines Jl

Cassebeer, H. A., Jr.

*“+Cattell, Prof. J. McKeen, Ph.D.

*+Chandler, Prof. C. F., Ph.D.

§Chapin, Chester W.

*Chapman, Frank M.

+tChaves, José H.

*Cheesman, Timothy M., M.D.

Choate, Joseph K.

Chubb, Percy

Clapp, Frederick G.

~ ¢Clark, F. Ambrose

Clark, Howard L.

Clarkson, Banyer

Clausen, William

Clayburgh, A. .

Clemens, James B., M.D.

Clendenin, Wm. W.

+Clyde, Wm. P.

+Cochran, Henry J.

Cogswell, Elizabeth N

Cohn, Julius M.

Cole, Rufus

MEMBERSHIP 321

Colfelt, Mrs. Rebecca MeM. . Donald, James M.

Collier, Robert J. Donnelly, Wm. T.

Collins, David S. *+Doremus, Prof. Charles A., Ph.D.

Collins, George W., M.D. - Doscher, Henry

+Collord, George W. *t Douglas, James

Combe, Mrs. William Douglass, Alfred

+Constant, S. Victor Douglass, Mrs. Charles

de Coppet, E. J. Douglass, Robert Dunn

Corning, Christopher R. Drew, Charles V.

Coykendal, Frederick Drummond, Isaac W., M.D.

Craig, W. R. “Dudley rei ahem):

*Crampton, Prof. Henry E., Ph.D. *“Dunham, Edward K., M. D.

+Crane, Zenas +Dunn, Gano

Crary, George W., M.D. Dunning, Wm. Bailey, M. D.

Cromwell, James W. +Dunscombe, George Elsworth

Crozel, Georges _ *Dwight, Jonathan, M.D.

*Curtis, Carlton C. Dwight, Mrs. M. E.

Curtis, G. Warrington *Harle, R. B.

Cutting, R. Fulton *Hastman, Prof. Charles R.

*Dahlgren, B. H., D.M.D. Eccles, R. G.

Davies, J. Clarence Eekstein, Wm. G.

Davis, David T. Sploilioiie, Jers vk. Jel, 12lm.!D),

*+ Davis, William T. Emmet, C. Temple

*+Dean, Prof. Bashford, Ph.D. Emerson, Harrington

De Golyer, Everett L. Eno Miss Mary Pinchot

+ Delafield, Maturin L., Jr. Eno, William Phelps

Delano, Warren, Jr. Eppley, Marion

Demarest, Benjamin G. Erlanger, Abraham

Denslow, Rev. Herbert McK. Estabrook, A. F.

Deppe, William P. _Evarts, Allen W.

Deschere, Harvey *“Hyerman, John

Devereux, W. B. Fairchild, Charles S.

De Witt, William G. Falk, K. George

Dickerson, Edward N. Farquhar, Percival

*Dickerson, Mary C. Farrington, Wm. H.

Dimock, George BE. Fearing, D. B.

*Ditmars, Raymond L. Ferguson, Charles A. S.

Dodge, Francis P. §Field, C. de Peyster

*Dodge, Prof. Richard E., A.M: Field, William B. Osgood

Doherty, Henry L. “Finlay, Prof. George I.

322 ANNALS VEW YORK ACADEMY OF SCIENCES ~

*Fishberg, Maurice, M.D.

*Fisher, G. Clyde, Ph.D.

Foot, James D.

+Ford, James B.

Fordyce, John A.

de Forest, Robert W.

Foshay, P. M.

Frissell, A. S.

Frothingham, John W.

Frueauff, Frank W.

*Gager, C. Stuart, Ph.D.

Gallatin, F.

Gallatin, Albert -

Gallatin, Mrs. Albert

Galliver, George A.-

Gardiner, Clarence Roe

Garvan, Francis P.

Gibson, R. W.

*Gies, Prof. William J.

Gilbrith, Frank B.

Goddard, Miss Annie C.

Goddard, Morrill

*Goddard, Pliny E.

Godkin, Lawrence

*Going, Charles B.

*Goldfarb, Prof. A. J.

Goldmerstein, Leon

Goodridge, Frederick G.

§Gould, Edwin

§Gould, George J.

*+Grabau, Prof. Amadeus W.

Gramer, Wm. A.

Granite, Hiranmkeloen sire

*Gratacap, Louis P.

Greene, James W.

*Gregory, W. K., Ph. D.

+Grinnell, G. B.

+Griswold, F. Gray

Guggenheim, Hon. Simon

Guggenheim, William

Guinzburg, A. M.

Gulick, Henry

Haines, John P.

Halls, William, Jr.

Halsey, Robert H., M.D.

Halter, Clarence R.

Hardinge, Mrs. H. W.

Hardon, Mrs. H. W.

*Harper, Prof. Robert A.

+Harrah, Chas. J.

+Harriman, Mrs. HE. H.

Harris, Alfred

Hasslacher, Jacob

Haughwout, Frank G.

Haupt, Louis, M.D.

Havill, O. A.

Hayner, B. A.

Hazen, George H.

Healy, J. R.

Heller, Samuel

Hellman, Milo

*Hering, Prof. Daniel W.

Hess, Alfred F., M.D.

Hess, Selmar

Hewlett, Walter J.

Hirsch, Charles 8.

* Hitchcock, Miss F. R. M., Ph.D

Hochschild, Berthold

Hodges, George W.

Hoffman, Samuel V.

Hollenback, Miss Amelia B.

*Hollick, Arthur, Ph.D.

+ Holt, Henry

+Hopkins, George B.

Hopkins, Russell

*Hornaday, William T., Se.D.

*+Hovey, Edmund Otis, Ph.D.

Howald, Ferdinand

Howe, Miss Caroline G.

*THowe, Marshall A., Ph.D.

MEMBERSHIP

Howell, Maxwell D.

Howes, Benjamin A.

+Hoyt, A. W.

tHoyt, Theodore R.

Hubbard, Ernest V.

Hubbard, Walter C.

Humphreys, Frederic H.

+Huntington, Archer M.

*Huntington, Prof. George 8.

Hurd, Dr. Lee M.

*THussakof, Louis, Ph.D.

Hutchinson, Cary T.

Hyde, A. Fillmore

+Hyde, B. Talbot B.

Hyde, E. Francis

{Hyde, Frederic E., M.D.

Hyde, Henry St. John

+Hyde, James H.

*Hyde, Jesse H.

tIles, George

*Irving, Prof. John D.

*von Isakovics, Alois

Iselin, Mrs. William E.

+Jackson, V. H.

*Jacobi, Abram, M.D.

James, Henry, Jr.

Janney, Reynold

{Jarvie, James N.

Jenkins, Mrs. Helen Hartley

Jennings, Robert E.

Johnson, Alice J.

*Johnson, Prof. D. W., Ph.D.

tJohnston, J. Herbert

*S Julien, Alexis A., Ph. D.

Jungbluth, Karl

Kahn, Otto H.

Kast, Ludwig, M.D.

Kautz-Eulenburg, Miss P. R.

Kay, William de Young

Kean, Mrs. Hamilton Fish

*tKemp, Prof. James F., Sc.D. «

+ Keppler, Rudolph :

Kernan, John Deveraux

+ Kessler, George A.

Kingsbury, N. C.

Kinney, Morris

*Klein, Otto H.

+Kleinberger, Francis

Kohlman, Charles

Koplik, Charles M.

*+Kunz, George F., M.A., Ph.D.

+Lamb, Osborn R.

Lang, Herbert

Langdon, Woodbury G.

Lawrence, Amos E.

Lawrence, Benjamin

Lawrence, John B.

tLawton, James M.

*TLedoux, Albert R., Ph.D.

*TLee, Prof. Frederic 8., Ph.D.

Lee, Miss Marguerite T.

Lemon, J. 8S.

*Levine, Victor EH.

*SLevison, Wallace Goold

Levy, Emanuel

Lewisohn, Adolph

vamoce egal

Lichtenstein, M.

Lichtenstein, Paul

Dieb; Ji: We, J.

Lindbo, J. A.

Lindsey, Edward

+tLoeb, James -

Loeb, Mrs. Morris

Longcope, Warfield T., M.D.

Lorsch, Henry

*Lowie, Robert H., Ph.D.

Lowther, Christopher M.

*Lucas, F. A., D. Se.

*Lusk, Prof. Graham, M.D.

Lydig, Philip M.

323

324 ANNALS NEW YORK ACADEMY OF SCIENCES

McCarthy, J. M.

McEwen, Alfred

*McGregor, James Howard

*§McMillin, Emerson

+MeMillin, Capt. Marion

MeNeil, Charles R.

MacArthur, Arthur F.

Macy, V. Everitt

Macy, Mrs. V. Everitt

Mager, F. Robert

Manchester, James G.

Mann, W. D.

Mansfield, Prof. William

Marble, Manton

Markoe, James W., M.D.

Marling, Alfred E.

+ Marshall, Louis

Marston, Edgar Lewis

Marston, E. 8.

*+Martin, Prof. Daniel S.

*Martin, T. Commerford

Martin, Walton, M.D.

+Matheson, W. J.

*tMatthew, W. D., Ph.D.

Maxwell, Francis T.

Meltzer, S. J., M.D.

_ Mendelson, Walter

Metz, Herman A.

Metzger, Herbert M.

Meyer, Mrs. Eugene, Jr.

Meyer, Gustave M., M.D.

Milburn, J. G.

Miller, Adam M.

Miller, Mrs. BE. C. T.

Miller, George N., M.D.

Millward, Russell Hastings

Milne, Clyde

*+Miner, Roy Waldo

Mitchell, Arthur M.

Mitchell, Westley C.

Monae-Lesser, A., M.D.

Mook, C. C.

Montcalm, S. R.

Moore, Barrington

tMorgan, J. P.

*Morgan, Prof. Thomas H.

Morgan, William Fellowes

Morris, Lewis R., M.D.

Morrison, A. Cressy

Morrow, Dwight W.

Mowbray, Louis L.

*Muller, Hermann J.

-Munn, John P.

Murphy, Robert Cushman

*Murrill, W. A.

Mutscheller, Arthur

+Nesbit, Abram G.

Neustadt, Mrs.’ Agnes R.

Newhall, Henry B., Jr. ~

*Noguchi, Hideyo

Notman, Arthur

Notman, George

Notman, Howard

Ochs, Adolph 8.

Oettinger, P. J.,, M.D:

*t Ogilvie, Miss Ida H., Ph.D.

. +Olcott, EH. E. ;

Olmsted, A. E.

Olney, Elam Ward

Oppenheimer, Henry S.

*+ Osborn, Prof. H. F., Se.D., LL.D.

Osborn, William C.

+Osborn, Mrs. William C.

*Osburn, Raymond C., Ph.D.

+Owen, Miss Juliette A.

*Pacim, A. B., Paw:

Pappenheimer, Alwin M., M.D.

+ Parish, Henry

Parrish, James C.

Parsons, C. W.

Parsons, Mrs. Herbert

MEMBERSHIP

t Patten, John

Patterson, T. H. Hoge

aml ohm J).

*Peoram, George B.

=Pellew, Prof. C., E., Ph.D.

Perkins, George E.

+Perkins, William H.

*Peterson, Frederick, M.D.

Pfizer, Charles, Jr.

Phelps, Mrs. von R.

Philipp, M. Bernard

Philipp, P. Bernard

Phoenix, Lloyd

Pierce, Henry Clay

TE evans tha

Plaut, Edward

Polk, Dr. W. M.

Pond, Miss Florence L.

*Poor, Prot. Charles L.

Poor, Roger M.

Post, Abram S.

*Post, C. A.

Powell, Frederick J.

Preston, Veryl

*Prince, Prof. John Dyneley

*Pupin, Michael Idvorsky

Putnam, H. S.

+Pyne, M. Taylor

Rathborne, Richard C.

*“Rautenstrauch, Walter

Raymond, Howard E.

Raymond, Robert M.

Reckendorf, John King

*Reeds, Chester A., Ph.D.

P paicketisw rot bP. de P.,. Ph.D.

Riederer, Ludwig

Ring, Mrs. George Stuart

Robert, Samuel

Roberts, C. H.

+Roebling, John A.

-Roelker, Hugo B.

t Roger, John

Rogers, E. L.

Rood, Mrs. L. A. S.

Rosenbaum, Selig

Rossbach, Jacob

tde Rubio, H. A. C.

Rudisch, Julius, M.D.

SE t Rusby, Prof. Henry lake M.D.

Rusch, Adolphe, Jr.

tRyle, Arthur

Sachs, Julius

Sage, Dean

Sage, John H.

Salomon, Harry R.

+Schermerhorn, F. A.

Schiff, Jacob H.

Schlicke, C. P.

Scholle, A. H.

Schoonmaker, Miss Mary

tSchott, Charles M., Jr.

*Schulte, H. von W.

*Scott, George G.

Scott, Thomas B.

Seaman, Dr. Louis L.

Seitz, Carl E.

Seligman, Isaac M.

Seligman, Jefferson

Sexton, Lawrence HE.

Sheehan, Mrs. William F.

Shepard, C. Sidney

SShepard, Mrs. Finley J.

“Sherwood, George H.

Shillaber, Wiliam

Shoemaker, Henry W.

*Sickels, Ivin, M.D.

' Siegel, Win.

Slack, HE. B.

*Sleight, Chas. H.

Sloan, Benson B.

320

$Slocum, Charles E.

Smidt, Thomas

*Smith, Ernest H., M.D., Ph.D.

Smith, Frank Morse

Smith, Martin De F.

Snow, Hlbridge G.

*Southwick, Edmund B., Ph.D.

+Sperhng, Emile M.

Spotts, Mrs. R. L.

_ Squibb, Edward H., M.D.

Starr, Louis Morris

*Starr, Prof. M. Allen

Steers, James R.

*+Stefansson, V.

*Stephens, George T., M.D.

*Stephens, Phinehas V.

Sterry, John D.

+Stetson, F. L.

Stevenson, A. H.

. *t Stevenson, Prof. John J., LL.D.

Stillman, Chauncey

Stine, Marcus °

Stockmann, Marie F.

+Stoekel, Carl

Stohr, Max W.

Stokes, James

Stokes, J. G. Phelps

+Stone, Miss Ellen J.

Stone, I. Frank

Straight, Willard

Strauss, Charles

Strauss, Frederick

+Streat, James

Stroock, Joseph

Stroock, Moses J.

Sturgis, Mrs. Elizabeth M.

Swan, Mrs. J. Andrews

Swann, Mrs. Arthur W.

Taggart, Rush

Takamine, Jokichi

ANNALS NEW YORK ACADEMY OF SCIENCES

Tallman, Malcolm H., M.D.

*+Tatlock, John, Jr.

“Taylor, Norman

Taylor, W. A.

Tesla, Nikola

Thaw, Stephen Dows

Thayer, B. B.

Thomas, Marion L.

Thompson, Mrs. Frederick F.

Thompson, Lewis 8S.

t'Thompson, Robert M.

*Thompson, Prof. W. Gilman

Thompson, Walter

Thomson, George W.

*Thorndike, Prof. Edward L.

Thorne, Samuel, Jr.

Tibbals, Samuel G.

Tilney, Frederick, M.D.

Abmonolintn, als (Ey

“ower li.) Wes ees

*Townsend, Charles H., Se.D.

Townsend, Charles H. T.

lives teiiaehss

“Trowbridge, Prof. C. C.

tTuckerman, Alfred, Ph.D.

Tuttle, Mrs. B. B.

Tweedy, Mrs. Alice B.

Tyrrell, Charles A.

+Vail, Theo. N.

+ Vanderbilt, F. W.

Vanderpoel, Mrs. J. A.

tVan Slyck, George W.

+Van Wyck, Robert A.

Vogelstein, Ludwig

Vreeland, Frederick K,

Waite, Guy B. -

Walker, William I.

Wallace, H. Vincent

*tWaller, Prof. Elwyn, Ph.D.

Wallerstein, Leo

MEMBERSHIP 391

Warburg, F. M.

Warburg, Paul M.

Ward, Artemas

+Ward, Charles Willis

Warner, Mrs. Henry W.

Warren, Howard 8.

Washburne, Chester W.

Waterbury, J. I.

Watson, John J., Jr.

Webster, Walter Coates

Weed, Walter Harvey

Weeks, Harold Eastman

Weeks, John E., M.D.

Weil, Richard, M.D.

Weinberger, Bernard, W.

*Wells, F. Lyman

Wessell, Arthur L.

West, William, M.D.

Westervelt, William Young

Wheeler, H. R.

Williams, J. Leon

Williams, L. W.

ASSOCIATE

Benedict, Miss Laura E.

Berckhemmer, Dr. F.

Billingsley, Paul

Blanchard, Ralph C.

Brown, A. M.

Camp, C. L.

Colony, R. J.

Elwyn, Adolph

Fenner, Clarence N., Ph.D.

Fettke, Chas. R.

Gordon, Clarence EH.

Haseman, J. D.

Williams, R. H.

Wallsoxeploroten Hempel ne) sales 0)

Wilson, J. H.

Wilson, Miss M. B., M.D.

Wimpfheimer, Charles A.

*Winslow, Prof. Charles-H. A.

Wintringham, J. P.

*Wissler, Clark, Ph.D.

Woerishoffer, Mrs. Anna

Wood, Mrs. Cynthia A.

*Wood, Miss Elvira

Wood, William C.

“Woodbridge, Prof. F. J. E.

*Woodhull, Prof. John F., Ph.D.

“Woodman, Prof J. Edmund

*Woodward, Prof. R. 8.

*Woodworth, Prof. R. 8.

Wright, Jonathan, M.D.

Yeatman, Pope

Zabriskie, George

Zimmerman, H. C.

MEMBERS

letmamme, 18, 18. Vir Je lad)

Knappen, R. 8.

Knight, Samuel H.

Mook, Mrs. C. C.

Morris, F. K.

Northrup, Dwight

O’Connell, Miss Marjorie

Plough, Harold H.

Shumway, Waldo

Smith, Warren S.

Van Tuyl, Francis M.

Wang, Y. Tsenshan

328 ANNALS NEW YORK ACADEMY OF SCIENCES

NON-RESIDENT MEMBERS

*Berry, Edward W. *Mayer, Dr. A. G.

Buchner, Edward F. Meyer, Adolph

*Bumpus, H. C. Petrunkevitch, Alexander, Ph.)

Burnett, Douglass pleatenGiy Wig dl. et:

*Davis, William H. Reuter, L. H.

English, George L. Pies Eno tela

Frankland, Frederick W. *Sumner, Dr. F. B.

Hoffman, S. V. *van Ingen, Prof. G.

Kendig, Amos B. “Wheeler, Wm. Morton

*Lloyd, Prof. F. E.

GENERAL INDEX TO VOLUME XXVII

Names of Authors and other Persons in Heavy-face Type

Titles of Papers in SMALL CAPS

Active Members, Hlection of, 245, 251,

267, 282, 290, 301

Active Members, List of, 319

AGE OF THE Morrison ForMATION, 150

Aiken, Robert T., Porto Rican BURIAL

Caves [Abstract], 250

Akeley, Carl E., Fellow, 305

Allen, J. A.. AN HExtTInct Ocropont

FROM, THE ISLAND OF PoRTO RICO,

WEST INDIES, 17

ANATOMY OF A Farat Balenoptera

borealis, ON THE, H. von W.

Schulte [Abstract], 247

Andrews, Roy C., THE SEI WHALE (Ba-

tenoptera borealis). Irs His-

TORY, HABITS, HXTERNAL ANAT-

OMy, OSTEOLOGY, AND RELATION-

SHIP [Title], 246

ANNUAL MEETING, MINUTES OF THE,

Henry E. Crampton, 305

Anthony, H. E., PRELIMINARY REPORT OF

Fossi1 MAMMALS FROM PORTO

Rico (WITH DESCRIPTIONS OF A

NEW GENUS OF GROUND SLOTH AND

TWO NEW GENERA OF HISTRICO-_

MORPH RODENTS), 193; Abstract,

217

Fellow, 305

APPLICATION OF PHYSIOGRAPHIC

METHODS TO THE CORRELATION OF

NON-MARINE FORMATIONS IN THE

Rocky MounrtvaAins, Willis T. Lee

[Abstract], 266

ARCHEOLOGICAL WORK IN PorTO RIco,

H. K. Haeberlin [Abstract], 250

ARCHITECTURE OF Two CETACEAN

SKULLS, Xiphius anv Kogia, J.D.

Kernan and H. von W.| Schulte

_ [Abstract], 294

ARE THERE ATOMS oF LigHiv?—THE

QUANTUM ‘THEORY, George B.

Pegram [Abstract], 268

Armstrong, E. H., OPERATING FEATURES

OF THE AUDION, 215

Associate Members, Election of, 251, 261

Associate Members, List of, 327

ASSOCIATION AND CLASSIFICATION, G. C.

Myers [Abstract], 258

Atkinson, James P., Foop Poisons [Ab-

stract], 262

Atmospheric Disturbance, Effects of, on

Receiving Systems, 238

Audio Frequency, 228

BACTERIOLOGY OF AtR, THE, W. W.

Browne [Abstract], 264

Baleanoptera borealis, ON THE ANAT-

OMy OF A FEatar, H. von W.

Schulte [Abstract], 247

REMARKS ON THE WAR oF, J. D.

Kernan, Jr. [Abstract], 249

Bagg, Halsey J.. THE GENETICS OF CER-

TAIN TYPES OF ANIMAL BEHAVIOR

[Abstract], 304

Barbour, T., SomE REMARKS UPON MArT-

THEW’S CLIMATE AND H\VOLUTION, 1

Barnhart, —, Councilor, Election as, 306

Baskerville, Charles, CoLLomps IN THEIR

; RELATION £O ANIMAL AND VEGE-

TABLE Oris [Abstract], 285

Beebe, C. W., ZOOLOGICAL STUDIES OF

BRITISH GUIANA [Title], 306

Bell, J. C., A COMPARISON OF THE BINET-

Simon TESTS OF INTELLIGENCE

AND THE SQUIRE GRADED TESTS

[Abtract], 300

Berkey, Charles P., GroLocicaL HISTORY

or Porro Rico [Title], 306

(329)

he)

Poa

Berkey, Charies P., PLANS FOR FIELD

Work IN Porto RIco DuRING 1916

[Title], 277

UNSTABLE CONDITIONS WXHIBITED

BY SOME OF THE Rock HouNDA-

TIONS OF THE HUDSON VALLEY

[Abstract], 256

Franz, GENERAL HTHNOLOGICAL

Notes FROM Porro Rico [Title],

250

Boveri, Theodor, Minute Relative to the

Death of, E. B. Wilson, 274

Brainin, Clement S., ComMPaARATIVE Iyn-

TENSITIES OF X-RAYS FROM VARI-

ous METALS [Abstract], 302

Britton, N. L., Report as Chairman of

the Porto Rico Committee, 311

Brown, A. J.. THE DEVELOPMENT OF THE

SPINE IN THE Car [Title], 254

Brown, Lucius P., and C. V. Ekroth, A

PROMISING CHART FOR DETECTING

ADULTERATED SAMPLES OF MILK

. [Abstract], 285

Browne, W. W., THE BACTERIOLOGY OF

Arr [Abstract], 264

BUSINESS MEETINGS, MINUTES OF,

Henry H. Crampton, 245, 251, 261,

267, 274, 282, 290, 301

Boas,

Centennial Celebration, 251, 305

CAHU AND OTHER Extinct PETRELS,

Tue, R. W. Shufeldt [Title], 253

Cannon, James G., Death of, 284, 307

Carty, John J., Fellow, 305

Cascade Systems, 235

Cattell, J. McKeen,

Hlection as, 306

Chapin, James P., DISTRIBUTION AND

MIGRATIONS OF CENTRAL AFRICAN

Birps [Abstract], 287

Character of the “Uplift,” 205

CHEMICAL AND PHYSICAL CHANGES OF

Hees AND THEIR SIGNIFICANCE IN

GRAFTING, A. J. Goldfarb [Ab-

stract], 252

CHEMICAL COMPOSITION OF THE BLOOD

IN DISEASES OF THE KIDNEY, Vic-

tor C. Myers | Abstract], 261

Vice-President,

0 ANNALS NEW YORK ACADEMY OF SCIENCES

CHEMICAL REDUCTIONS IN THE LIVING

ORGANISM, V. E. Levine [Title],

301

CHEMICAL VALENCE, J. M. Nelson [Ab-

stract], 292

CHONDROCRANIUM OF A 20-mM. HuMAN

Empryo, J. D. Kernan, Jr. [Ab-

stract], 254

Clark, W. C., Some PHASES OF BONE

GROWTH IN THE ADULT [Title],

276

“CLIMATE AND EVOLUTION,’ SOME RE-

MARKS UPON MATTHEW’S, T. Bar-

bour, 1

CLIMATIC CONDITIONS IN SOUTHERN WY-

OMING DURING DEPOSITION OF THE

“Rep Bens,” S. H. Knight [Ab-

stract], 256

Cochran, Henry J., Treasurer, Election

as, 306

Report of the Treasurer, 309

COMPARATIVE INTENSITIES OF X-RAYS

FROM VARIOUS METALS, Clement

S. Brainin [Abstract], 302

COMPARISON OF THE BINET-SIMON 'TESTS

OF INTELLIGENCE AND THE SQUIRE

GRADED MENTAL Tssts, J. C. Bell

[Abstract], 300

Corresponding Members, List of, 316

Corresponding Secretary, Report of the,

306

COLLOWS IN THEIR RELATION TO ANIMAL

AND VEGETABLE Ors, Charles

Baskerville [Abstract], 285

Councilors, Election of, 306

Crampton, Henry E., CorRESPONDING

SECRETARY, HWLECTION AS, 306

MINUTES OF THE ANNUAL MEETING,

305

REPORT OF THE AcTING Hprror, 308

REPORT OF THE ACTING RECORDING

SECRETARY, 307

REPORT OF THE

SECRETARY, 306

CoRRESPONDING

Dean, Bashford, Finance Committee, 306

Deaths, 245, 251, 261, 284, 291, 301, 306,

307

GHNERAL INDEX TO'VOLUME XXVII Sal

DEVELOPMENT AND DISTRIBUTION OF

FRESH-WATER FISHES IN AFRICA,

J. T. Nichols [Abstract], 304

DEVELOPMENT OF THE WXTERNAL ILIAC

ARTERY IN MAN, H. D. Senior,

[Abstract], 303

DEVELOPMENT OF THE SPINE IN THE CAT,

A. J. Brown [Title], 254

Dinosaurs WHicH MIMIC THE Os-

TRICHSS AND OTHER STRUTHIOUS

Birps, H. F. Osborn [Abstract],

247 ;

DISTRIBUTION AND MIGRATIONS OF CEN-

TRAL AFRICAN BIRDS, James P.

Chapin [Abstract], 287

Dickerson, Mary C., Fellow, 305

Dugongs, Place and Origin of the, 27

EXCHOLALIA IN Ip1ots: Its MEANING FOR

MopERN THEORIES OF IMITATION,

L. 8. Hollingworth [ Abstract], 299

Editor, Hlection of, 306

Report of the Acting, 308

Ekroth, C. V., and Lucius P. Brown, A

PROMISING CHART FOR DETECTING

ADULTERATED SAMPLES OF MILK

[Abstract], 285

ELECTRICAL THEORY OF NERVE IMPULSE,

AN, H. B. Williams [Title], 268

HEXLECTRON STEAM AMPLIFIER, AN HILEC-

TRICAL ULTRAMICROSCOPE, J. H.

Morecroft [Title], 275

HTHNIc RELATIONS BETWEEN PORTO

Rico AND VENEZUELA, Herbert

Spinden [Title], 306

Hxplanation of the Action of the Audion

as an Amplifier and as a Detector

of High Frequency Oscillations,

215

Falk, George, THE PRODUCTION OF AN

HEINZYME-LIKE SUBSTANCE BY THE

ACTION OF ALKALI ON PROTEIN

[Abstract], 293

FAUNAL RELATIONS OF CENTRAL AFRICA,

Herbert Lang [Abstract], 287

Fauna of the Morrison Formation, In-

vertebrate, 126; Vertebrate, 131

Fellows, Election of, 305

Finance Committee, HWlection of, 306

Finlay, George I., THE GEOLOGY OF

NortH Park, CoLorapo [Ab-

stract], 272

Flora of the Morrison Formation, 126

Foop Porsons, James P. Atkinson [Ab-

stract], 262

Foss. FaAuNAS OF Porto Rico, Chester

A. Reeds [Abstract], 280

Fosstz1 MAMMALS FROM PorTO RICO,

PRELIMINARY REPORT OF, H. E.

Anthony, 193; Abstract, 277

GENERAL HTHNOLOGICAL NOTES FROM

Porto Rico, Franz Boas [Title],

250

GENETICS OF CERTAIN TYPES OF ANIMAL

Beuavior, Halsey J. Bagg [Ab-

stract], 304

GEOLOGICAL History or Porto Rico,

Charles P. Berkey [Title], 306

GEOLOGICAL OBSERVATIONS IN THE ANDES

OF PERU AND BottiviA, B. L. Miller

[Abstract], 289

GEOLOGY oF NorTH PARK, COLORADO,

George I. Finlay [Abstract], 272

GEOLOGY OF OESEL, NOTES ON, Marjorie

O’Connell [Abstract], 273

GEOLOGY OF THE COAMO-GUAYAMA RE-

GION, Porto Rico, EH. T. Hodge

[Abstract], 277

GEOLOGY OF THE ISLAND OF GOTLAND IN

THE BALtTic SEA, A. W. Grabau

[Abstract], 272

GEOLOGY OF THE SAN JUAN DISTRICT,

Porto Rico, D. R. Semmes [Ab-

stract], 279

Goddard, Pliny E., THE Soctat ORGANTI-

ZATION OF THE ARIZONA APACHE

[Abstract], 290

Fellow, 305 —

Going, Charles B., Fellow, 305

Goldenweiser, A. A., NoTES ON THE

MELANESTAN ORGANIZATION

[Title], 267

Goldfarb, A. J.. CHEMICAL AND PHYSI-

CAL CHANGES OF Hegs AND THEIR

SIGNIFICANCE IN GRAFTING [Ab-

straect], 252

Gould, Russel L., Tests of MANUAL

ACCURACY OF PRE-VOCATIONAL

ScHoot Boys [Abstract], 257

Grabau, A. W., GEOLOGY OF THE ISLAND

OF GOTLAND, IN THE Batric SEA

[Abstract], 272

SoME PARALLELISMS IN THE GE-

OLOGY OF WESTERN EUROPE AND

AMERICA [Abstract], 246

STRATIGRAPHIC RELATIONS OF THE

OIL-PRODUCING TO THE OIL-BEAR-

ING SHALES IN THE PALEOZOIC OF

NortH AMERICA; INVOLVING A

NEw THEORY OF OW DISTRIBU-

TION [Abstract], 298

Gregory, William K., THEORIES OF THE

ORIGIN OF BIRDS, 31

Ground Sloth, New Genus of, 195

Haeberlin, H. K., ARCHEOLOGICAL WORK

IN Porto Rico [Abstract], 250

Hill, Arthur E., REPoRT ON THE ABSORB-

ING POWER OF CERTAIN COLLOIDS

[Abstract]. Discussion by Dr.

Mutscheller, 252

Hill, George W., Death of, 306

Hodge, E. T., GEOLOGY OF THE COAMO-

GUAYAMA REGION, Porto RIco

[Abstract], 277

Hollingworth, L. ‘S., EcHOLALIA IN

Iprots ; Irs MEANING FOR MODERN

THEORIES OF ImiraTIOoN [Ab-

stract], 299

How PSYCHOANALYSIS CURES NERVOUS-

NESS, Samuel A. Tannenbaum

[Title], 276

Horr Cian, THE. R. H. Lowie [Ab-

stract], 290

Huntington, George H., Tor RELATION

OF THE LYMPHATIC AND H&MAL

CHANNELS IN THE VASCULAR SYS-

TEM OF THE VERTEBRATES [Ab-

stract], 276

Hystricomorph, New Genera of, 199, 202

Honorary Members, List of, 315

INDUCED ELECTROMOTIVE FORCE AND THE

RELATIVITY THEORY, George B.

Pegram [Abstract], 293

ANNALS NEW YORK ACADEMY OF SOIENCES

Isolobodon portoricensis, gen. et sp.

nov., 19

Johnson, D. W., THE STRATEGIC VALUE

or LANDFORMS IN THE GREAT

RUSSIAN RETREAT [ Abstract], 246

Vice-President, Election as, 306

Jonas, Anna I., PRE-CAMBRIAN AND TRI-

ASSIC DIABASE IN HASTERN PENN-

SYLVANIA [Abstract], 279

Kernan, John D., Jr., REMARKS ON THE

Ear or Balenoptera borealis

[Abstract], 249

THE CHONDROCRANIUM OF A 20-

MM. HUMAN HEmpryo [Abstract],

254

Kernan, John D., Jr., and H. von W.

Schulte, ON THE ARCHITECTURE

oF Two CETACEAN SKULLS,

Xiphius and Kogia [Abstract],

294.

Klein, Otto H., Fellow, 305

Knight, S. H., Climatic CONDITIONS IN

SOUTHERN WYOMING DURING

DEPOSITION OF THE “RED BEDS”

[Abstract], 256

Kunz, George F., REMARKS ON A PSEUDO-

METEORITE, [RON PYRITE CRYSTALS

AND A Brack DramMonD [Ab-

stract], 271

Ladd-Franklin, Christine, VISIBILITY OF

THE NERVE CURRENT [Title], 276

Lang, Herbert, FAUNAL RELATIONS OF

CENTRAL AFrica [Abstract], 287

Langmann, Gustav, Death of, 291, 307

Lee, F'. S., Finance Committee, 306

Lee, Willis T., APPLICATION OF PHYSIO-

GRAPHIC METHODS TO THE. CORRE-

LATION OF NON-MARINE FoORMA-

TIONS IN THE Rocky MOUNTAINS

[Abstract], 266

Levine, Victor E., CHEMICAL REDUC-

TIONS IN THE LIVING ORGANISM

[Title], 301

Lew, T. T., Tasoos In Cuina [Title],

276

Librarian, Report of the, 308

GENERAL INDEX TO VOLUME XXVII

LIMESTONE PLATEAUS OF THE CAUSSES,

SOUTHERN FRANCE, HE. de Mar-

tonne [Abstract], 296

Low, Seth, Death of, 284, 307

Memorial to, 291

Lowie, R. H., THE Horr CLan

stract], 290

[Ab-

Martonne, HE. de, THE LIMESTONE PLAa-

TEAUS OF THE CAUSSES, SOUTHERN

FRANCE [Abstract], 296

Matausch, Ignaz, Death of, 251, 507

Matthew, W. D., Supplementary Note,

New Sirenian from the Tertiary of

Porto Rico, 23

Some RESULTS OF AMERICAN Mv-

SEUM EXPLORATIONS FOR Fossm

MAMMALS DURING THE Past SuM-

MER [Title], 294

MELANESIAN ORGANIZATION, NOTES ON,

A. A. Goldenweiser [Title], 267

Merrill, F. J. H., Death of, 301, 307

Miller, B. L., GEOLOGICAL OBSERVATIONS

IN THE ANDES OF PERU AND

Borrvia [Abstract], 289

Molar-premolar Formula in the Sire-

nians, 28

Mook, Charles Craig, A Study of the

Morrison Formation, 39

Morecroft, J. H., THE ELectron STEAM

AMPLIFIER—AN ELECTRICAL

ULTRAMICROSCOPE [Title], 275

MorRPHOLOGY OF THE AZYGOS VEINS,

H. von W. Schulte [Abstract], 268

Morrison Formation, A Study of the,

C. C. Mook, 39

Mulhall, Edith F., Tests or THE MEMORY

oF ScHOOL CHILDREN [Abstract],

259

Murray, George, Death of, 291

Myers, G. C., SHRINKING OF ImAcES [Ab-

stract], 300

ASSOCIATION AND CLASSIFICATION

[Abstract], 258

Myers, Victor C., THE CHEMICAL CoM-

POSITION OF THE BLOOD IN DIs-

EASES OF THE Kipney [Abstract],

261

3390

Nash, Nathaniel C., Death of, 261, 307

Nelson, J. M., CHEMICAL VALENCE [Ab-

tract], 292

New Genus of Ground Sloth, 195

New Genus of Hystricomorph, 199, 202

Nichols, J. T., DEVELOPMENT AND DIs--.

TRIBUTION OF FERESH-WATER

FisHes rn Arrica [Abstract], 304

ON PRIMARILY UNADAPTIVE VARI-

ANTS AMONG VERTEBRATES [Ab-

stract], 255

Noguchi, Hideyo, Fellow, 305

Non-resident Members, List of, 328

NOTES ON MELANESIAN ORGANIZATION,

A. A. Goldenweiser [Title], 267

NOTES ON THE GEOLOGY OF OESEL IN THE

GuLF or Rica, Marjorie O’Connell

[Abstract], 273

O’Connell, Marjorie, NorES ON THE

GEOLOGY OF OESEL IN THE GULF

or Rica [Abstract], 273

Officers, Election of, 306

On PRIMARILY UNADAPTIVE VARIANTS

_AMONG VERTEBRATES, J. T. Nichols

[Abstract], 255

ON THE ANATOMY OF A Fara Balenop-

tera borealis, H. von W. Schulte

[Abstract], 247

ON THE ARCHITECTURE OF Two CETA-

CEAN SKULLS, Xiphius and Kogia,

J. D. Kernan, Jr., and H. von W.

Schulte [Abstract], 294

Origin and Interpretation of the Mor-

rison Formation, 157

ORIGIN OF BIRDS, THEORIES OF THE, Wil-

liam K. Gregory, 31

Osborn, Henry Fairfield, Dinosaurs

WHICH MIMIC THE OSTRICHES

AND OTHER STRUTHIOUS BIRDS

[Abstract], 247

OXYGEN UTILIZATION IN FISHES, George

G. Scott [Abstract], 265

Palzontology of the Morrison Forma-

tion:

Flora, 126

Invertebrate Fauna, 126

Vertebrate Fauna, 131

Bot

Pegram, George B., ARE THERE ATOMS

oF LigHt?—THE QUANTUM

THEORY [Abstract], 268

INDUCED ELECTROMOTIVE FORCE AND

THE ReELavTiviry THEORY [Ab-

stract], 298

Fellow, 305

Petrography and Structure of the Mor-

rison Formation, 115

Pike, F. H., THE SIGNIFICANCE OF CER-

TAIN INTERNAL FAcTORS IN OR-

GANIC EvoLutTion [Abstract], 265

Place and Origin of Dugons, 27

PLANS FOR FIELD WoRK IN Porto Rico

DURING 1916, Charles P. Berkey

[Title], 277

Porto RIcAN BuRIAL CAVES, Robert T.

Aiken [Abstract], 250

Porto Rico:

An Extinct Octodont from, 17

Committee, Report of, 306, 311

New Sirenian from the Tertiary of,

PRELIMINARY REPORT OF FossiL

MAMMALS FROM, 193 ; Abstract, 277

PRE-CAMBRIAN AND TRIASSIC DIABASE

IN HASTERN PENNSYLVANIA, Anna

I. Jonas [Abstract], 297

PRELIMINARY REPORT OF Fossir Mam-

MALS OF PoRTO RICO; WITH DE-

SCRIPTION OF A NEW GENUS OF

GROUND SLorTH AND Two NEw

GENERA OF HyYSTRICOMORPH Ro-

DENTS, H. HE. Anthony, 193; Ab-

stract, 277

Previous Theories of the Origin of the

Morrison Formation, Discussion

of, 163

PRODUCTION OF AN HNZYME-LIKE SUB-

STANCE BY THE ACTION OF ALKALI

ON PROTEIN, George Falk [Ab-

stract], 298

PROMISING CHART FOR DETECTING ADUL-

TERATED SAMPLES OF MILK, Lucius

P. Brown and C. V. Ekroth [Ab-

stract], 285

Pupin, Michael I., President, Election

as, 306

ANNALS NEW YORK ACADEMY OF SOIENCES

Rautenstrauch, Walter, Fellow, 305

Recent Developments of the Audion Re-

ceiver, 223

RECORDING SECRETARY, REPORT OF ACT-

ING, 307

Reénforcement of Radio Frequency Os-

cillations by the Audion, 224

Reeds, Chester A., Fosstt FAUNAS OF

Porto Rico [Abstract], 280

Reichling, G. A., UNUSUAL METEORO-

LOGICAL CONDITIONS OBSERVED

DURING A WINTER FLIGHT IN A

TRACTOR BIPLANE [Abstract], 263

RELATION OF THE LYMPHATIC AND

H@MAL CHANNELS IN THE YVAS-

CULAR SYSTEM OF THE YERTE-

BRATES, George H. Huntington

[Abstract], 276

Relation of Topography and Geoiogy,

212

REMARKS ON A PSEUDO-METEORITE, [RON

PYRITE CRYSTALS AND A BLACK

DIAMOND, George F. Kunz [Ab-

stract], 271

REMARKS ON THE HAR or Balenoptera

borealis, J. D. Kernan, Jr. [Ab-

stract], 247

REPORT ON THE ABSORBING POWER OF

CERTAIN CoLLoms, Arthur E. Hill

[Abstract], 252; Discussion by

Dr. Mutscheller.

Rogers, Herbert W., SomME HPMPIRICAL

TESTS IN VOCATIONAL GUIDANCE

AND SELECTION [Title], 276

Roscoe, Sir Henry Enfield, Death of, 245.

Resignations, 284

Schulte, Hermann von W., ON THE

ANATOMY OF A FatraL Belenop-

tera borealis [Abstract], 247

THE MORPHOLOGY OF THE AZYGOS

Veins [Abstract], 268

Vice-President, Election as, 306

Schulte, H. von W., and John D. Kernan,

Jr... ON THE ARCHITECTURE OF

Two CETACEAN SKULLS, Xiphius

and Kogia [Abstract], 294

GENERAL INDEX TO VOLUME XXVIII

Scott, George G., OXYGEN UTILIZATION

IN Fisues [Abstract], 265

SECTION OF ANTHROPOLOGY AND Psy-

CHOLOGY, Robert H. Lowie, 250,

257, 267, 276, 290, 299

SECTION OF ASTRONOMY, PHYSICS

CHEMISTRY, V. H. Levine,

261, 267, 275, 285, 292, 301

SEction or BioLoey, W. K. Gregory, 246,

258, 264, 268, 276, 286, 294, 303

SECTION OF GEOLOGY AND MINERALOGY,

C. A. Reeds, 245, 255, 266, 271,

277, 288, 295

SEI WHALE (Balenoptera boreatis), ITs

History, HAsits, HXTERNAL ANAT-

OMY, OSTEOLOGY AND RELATION-

sHip, R. C. Andrews [Title], 246

Semmes, D. R., GEOLOGY OF THE SAN

JUAN District, Porto Rico [Ab-

stract], 279

Senior, H. D., THE DEVELOPMENT OF THE

EXTERNAL IniAc ARTERY IN MAN

[Abstract], 303

‘SHRINKING OF IMAGES, G. C. Myers [ Ab-

stract], 300

Shufeldt, R. W., THE CAHU AND OTHER

Extinct PETRELS [Title], 253

SIGNIFICANCE OF CERTAIN INTERNAL

FAcTORS IN ORGANIC HVOLUTION,

F. H. Pike [Abstract], 265

SKYKOMISH BASIN, PHYSIOGRAPHY OF

THE, Warren S. Smith, 205

Smith, E. E., Vice-President, Election

as, 306

Smith, Warren S., PHYSIOGRAPHY OF THE

SKYKOMISH BASIN, WASHINGTON,

205

SOcIAL ORGANIZATION OF THE ARIZONA

APACHE, P. HE. Goddard [Ab-

stract], 290

SoME HMPrRIcAL TESTS IN VOCATIONAL

GUIDANCE AND SELECTION, Her-

bert W. Rogers [Title], 276

SOME PARALLELISMS IN THE GEOLOGY OF

WESTERN HUROPE AND AMERICA,

A. W. Grabau [Abstract], 246

SOME PHASES OF BONE GROWTH IN THE

ADULT, W. W. Clark [Title], 276

330

Some Recent Developments of the Au-

dion Receiver, 223

SOME RESULTS OF AMERICAN MUSEUM

EXPLORATIONS FOR Kossir Mam-

MALS DURING THE PAST SUMMER,

W. D. Matthew [Title], 294

‘Spinden, Herbert, HTHNIc RELATIONS

BETWEEN Porto RICO AND VENE-

ZUELA [Title], 306

Stenquist. J. L., Tests oF MECHANICAL

ApiLiry [Abstract], 260

Stephens, Phinehas V., Fellow, 305

STRATEGIC VALUE OF LANDFORMS IN THE

GREAT RUSSIAN RETREAT, D. W.

Johnson [Abstract], 246

STRATIGRAPHIC RELATIONS OF THE OIL-

PRODUCING TO THE OIL-BEARING

SHALES IN THE PALEOZOIC OF

NortH AMERICA; INVOLVING A

New THEORY OF Or DISTRIBU-

TION, A. W. Grabau [Abstract],

298

Stratigraphy of the Morrison Forma-

tion:

Eastern Colorado and New Mexico,

Northern Colorado, 45

Hastern New Mexico and Okla-

homa, 61

Colorado and Utah, 66—79

Montana and Wyoming

Black Hills area), 80

Black Hills area, 99

Atlantic coast, 109

Summary, 110

Structure and Petrography, 115

SUPPLEMENTARY NOTE TO “SOME RE-

MARKS ON MaAtTHEw’s ‘CLIMATE

AND EvoLuTion’,’ W. D. Matthew,

11 ;

(except

Tasoos IN CHINA, T. T. Lew [Title],

276

Tannenbaum, Samuel A., How PsycHo-

ANALYSIS CURES NERVOUSNESS

[Title], 276

Tatlock, John, Finance Committee, 306,

310

336

Tests oF MANUAL ACCURACY OF PRE-

VOCATIONAL ScHOOL Boys, Russel

L. Gould [Abstract], 257

Tests oF MrEcHANICAL Apiiity, J. L.

Stenquist [Abstract], 260

TESTS OF THE MEmory oF SCHOOL CHIL-

DREN, Edith F. Mulhall [Abstract],

259

Tower, R. W., Librarian, 306

Recording Secretary, Hlection as,

306

Editor, Election as, 306

Records of Meetings, 245

REPORT OF THE LIBRARIAN, 308

TREASURER, REPORT OF THE, 309

UNSTABLE CONDITIONS PEXHIBITED BY

SOME OF THE ROocK FOUNDATIONS

ANNALS NEW YORK ACADEMY OF SCIENCES

OF THE HuDSON VALLEY, Charles

P. Berkey [Abstract], 256

UNUSUAL METEOROLOGICAL CONDITIONS

OBSERVED DURING A WINTER

FLIGHT IN A TRACTOR BIPLANE,

G. A. Reichling [Abstract], 263

VISIBILITY OF THE NERVE CURRENT,

Christine Ladd-Franklin [Title],

276

Williams, H. B., AN ELECTRICAL THEORY

OF NERVE IMPULSE [Title], 268

Wilson, E. B., MINUTE RELATIVE TO THE

DeEATH OF Theodor Boveri, 274

ZOOLOGICAL STUDIES OF BRITISH GUIANA,

C. William Beebe [Title], 306

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