Lit''

.-y ^-^

HARVARD UNIVERSITY

LIBRARY

OF THE

MUSEUM OF COMPARATIVE ZOOLOGY

GIFT OF

Linnean Soc. London.

1889

THE

TRANSACTIONS

or

THE LINNEAN SOCIETY

OF

LONDON.

SECOND SERIES— VOLUME IV.

ZOOLOGY.

LONDON:

I'RINTKD BY TAYLOR AND FRANCIS, BED LION COURT, FLEET STREET

ISOLD AT TUE SOCIETY'S APAKTMEXTS, BURLINGTON HOUSE;

AM) l',\ LONGMANS, GREEN, AND CO., I'ATERNOS I'EK-UOW.

1880-88.

CONTENTS.

A Mono(jr(ipli of Recent Brachiopoda. By Thomas Davidson, LL.B., F.R.S., F.L.S.

Issued in three parts as folloAvs : —

Part I., pp. 1-74, & Plates I.-XIII., published October 188C.

„ II., „ 75-182, „ XIV.-XXV., „ July 1887.

„ III., „ 183-218,

Titlepage, Couteuts, &c.

I „ XXVI.-XXX., „ October 188S.

NOTE. — At the request of the late Dr. Davidson, and with the sanction of the Council,

the proof-sheets of this Memoir have been laid before Miss Agnes Crane, of Brigliton,

by whom they have been read on the Author's behalf.

Previous to Dr. Davidson's lamented death, Miss Crane had Ijeen studying- the

Brachiopoda under his guidance, and was conversant with his wishes respecting the

publication of this work.

TRANSACTIONS

OP

THE LINNEAN SOCIETY.

I. A Monograph of Recent BracJdopoda. — Part I.

By Thomas Davidson, LZ.B., F.E.S., F.L.S., F.G.S., Sfc.

Eead 5th November, 1885.

(Plates I.-XIII.)

Introductory Remarks.

DUEING the last hundred years the recent Brachiopoda have attracted considerable

attention, and a large number of valuable memoirs and papers have been published upon

them. Their shells, shell-structure, anatomy, embryology, and affinities have alike been

carefully investigated. Observations on the living animals of several genera have also

been recorded. The sea-bottoms have been dredged for Brachiopoda in many latitudes

and over a wide geographical area, and their habitats and ranges of depth accurately

ascertained to a very considerable extent. Pour or five incomplete monographs, in

which the shells only of a large number of species have been well illustrated and briefly

described, have appeared during the present century; but no satisfactory general

monograph ti'eating of the shell and animal conjointly has yet been published. This

omission I have now endeavoured to supply.

In 1843, Klister, in his new edition of Chemnitz's ' Conchy lien-Cabinet,' described

some twenty-six or thirty species, of which several are now known to be synonyms.

These he figured in six quarto plates.

In 1846, G. B. Sowerby, in his ' Thesaurus Conchyliorum,' described and beautifully

illustrated forty- seven species, of which number several are synonyms.

In 1859-62, Lovell Eeeve, in his 'Conchyliorum Iconica,' described the shells of seventy-

hve species, of which some w^ere synonyms, accompanied with a series of beautiful

illustrations, drawn by G. B. Sowerby.

In 1873, in the ' Proceedings of the Academy of Natural Sciences of Philadelphia,'

Mr. W. H. Dall published a catalogue of all the recent species of Brachiopoda known to

SECOND series. — ZOOLOGY, VOL. IV, 1

2 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

him up to that date. In this catalogue without figures, ahout one hundred species are

enumerated, some of which are synonymous.

During the last thirty-five or more years, I have devoted much time to the study of

the recent forms, in conjunction with that of the fossil species, and have lost no oppor-

tunity of making myself acquainted with all that has been done and written upon the

subject, as well as in assembling all available material, so as to enable me to bring

together in a single monograph the chief results of many independent researches published

in a number of scattered papers and works often difiicult of access. The literature of

the subject is indeed voluminous, as may be realized by a glance at the ' Bibliography

of the Brachiopoda,' compiled by Mr. W. H. Dalton and myself, and published in vol. vi.

of my ' British Fossil Brachiopoda ' (Palfeont. Soc, 1886).

I have also, I believe, had advantages which few have possessed in being able to follow-

out the observations made with respect to the animal and its anatomy, and in having

been able to draw a very large number of figures from the types of the best-preserved

examples of almost all the known forms, as well as of a large series of individuals of

the same species at different stages of development. Tlie study of the adult condition of

a species gives insufficient data, and it is requisite to follow out the modifications it has

to go through during the different stages of its existence, and to note these differences.

The study of the embryo has also shown that the animal assumes a series of well-

defined stages in its development, a fact that was but little known prior to the publi-

cation in 1861 of Prof. Lacaze-Duthiers's admirable memoir on Thecidium medi-

terraneum. These observations were subsequently followed by the excellent

researches of Fritz Muller, Kowalcvsky, E. Morse, II. Friele, M'^Crady, Dall, Van

Bemmelen, A. E. Shipley, M. A. Schulgin, and one or two more. The results

obtained by these authors will be referred to in the sequel. It is very desirable that

these important investigations should be continued, as much still remains to be

discovered, described, and illustrated.

The shell-structure of the recent Brachioiioda has been admirably worked out by a

number of accurate observers, such as Dr. W. B. Carpenter, W. King, Van Bemmelen,

Hancock, and many others, and has led to very important results. To Herman Friele,

E. Deslongcbamps, and one or two others we are indebted for much accurate and im-

portant knowledge with respect to the development of the loop, of which but little was

known previous to 1852.

The anatomy of the animal has also l)een admirably investigated and worked out, and

it is sufficient to mention the names of Cuvier, Owen, Huxley, Hancock, Vogt, Gratiolet,

Lacaze-Duthiers, King, Brooks, Dall, Morse, E. Deslongcbamps, Van Bemmelen, Wood-

ward, Shipley, Schulgin *, and others, to show how important and varied have

been the additions to our knowledge with respect to this very necessary branch of

investigation. In drawing up the description of each species, I have considered it

desirable, whenever possible, to reproduce the words and illustrations of the authors, and

thus give them all credit for their careful, painstaking researches.

* To these names Dr. Davidson would doubtless have added that of H. G. Be3-er, who contributed an important

paper on the shell-structure and anatomy of Lmr/ida {Glottidia) pyramidata, Stimpson, to the Studies from the

Biological Laboratory of the Johns Hopkins University, Baltimore, vol. iii. no. 5, March 188(3. — [xi. C]

DR. T. DAVIDSON ON EECENT BRACIIIOPODA. 3

The perplexing question of the affinities of the Brachiopoda has given rise to mucli

discussion, and great difference of opinion, especially \yith regard to their relationship

to the group of worms. Now, although I do not admit the Brachiopoda to be worms,

they may, as well as the Mollusca and some other groups of invertebrates, have originally

diverged from an ancestral vermiform stem, sucb as the remarkable worm-like mollusk

Neomenia Avould denote. In a recent paper on the development of Arylope or Cistella,

Mr. A. E. Shipley observes, and, I think, with justice, that the Brachiopoda and Polyzoa

are not so closely united as to form a natural phylum ; and he adds, " I should propose

to follow Gegenbaur in making a primary class of the Brachiopoda, and though in their

development and adult structure they are widely separated from botli Vermes and

Mollusca, of the two classes I would place them nearer to the former class than to the

latter " *. Prof. Huxley f says : — " All known Polyzoa are compound animals, that is to

say, the product of every ovum gives rise, by gemmation, to great assemblages of partially

independent organisms, or zooids. The Brachiopoda, on the contrary, are all simple, the

product of each ovum not giving rise to others by gemmation. All the Brachiopoda

possess a bivalve sliell — a shell composed of two, more or less horny, or calcified, pieces,

whicb are capable of a certain range of motion on one another, and are very commonly

articulated together by teeth and sockets." The shell, the pallial lobes, the intestine, the

nerves, and the atrial system, afford characters amply sufficient to define the class.

In this view of Prof. Huxley I entirely concur.

As many species of Brachiopoda live at considerable depths, it is not surprising that

so small a number should have been known to early conchologists, and that for many

years they should have been such groat rarities in conchological collections. The

numerous well-conducted dredging expeditions have, however, brought to light a large

number of forms that were not previously known, and we may constantly expect to add

to the number of species as dredging operations extend to regions not yet explored.

It has been ascertained beyond doubt that Brachiopoda are much localized, and that

where they occur they are generally abundant. It has also been found that the

range in depth of one and the same species is often very variable, that abyssal forms

have generally a very thin shell, and that species living at a great depth have a much

greater geographical range, and are not nearly so localized as those species that live

in shallow waters.

The study of the species brought home by the ' Challenger ' Expedition, which I was

privileged to examine and describe, has revealed much valuable information with respect

to the Ijathymetrical and geographical distribution of many species. The greatest depth

at which a recent species of the class has been found alive was 2900 fathoms. A

number of forms inhabit and prefer rocky and stony parts of the bottom, or are attached

to corals, and are tlierefore more difficult to obtain.

It is necessary briefly to refer to the difficult question of classification, upon which

many different opinions have been entertained. In company with a larger number of

* •' On the Structure and Development of Arr/iojje." Mittheilungen aua der zool. Station zu Neapel, Band iv.

Heft 4, p. 516 (1883).

t An Introduction to the Classification of Animals, p. 27 (18G9).

DE. T. DAVIDSON ON RECENT BRACHIOPODA.

malacologists and palaeontologists, I have considered the interior skeleton that supports

the labial appendages as a classiflcatory character that could be advantageously made

use of, and have consequently grouped the recent species into the two great divisions

Arthropomata, Owen { = Clistenterata, King), and Lyopomata, Ovfen {^= Tretenterata,

King), and into six families, as follows :

Akthropomata., Owen= Clistenterata, King.

1st Family

TEREBEA-

TULIDJE.

Subfamily TerebratulinjK

I. Genus Lioihyris, Douville

II. Subgenus Terebratidina, d'Orbigny

III. Genus Waldheimia, King

Subfamily Teeebrateixin^

Subfamily Megerlin^

Subfamily Magasin^

Subfamily Kraussinin^ . . .

IV. Genus Terehratella, d'Orbigny

V. Subgenus MagaseJla, Dall. . . .

VI. Genus Megerlia, King

VII. Subgenus Laqueus, Dall . . .

VIII. Genus Bouchardia, Davidson

Subfamily AEGiopiNiE

IX. Genus Kraussina, Davidson.

X. Subgenus Mer/erlina, Deslongchamps.

XI. Genus Arriio]ie, Deslongchamps ....

XII. Subgenus Cistella, Gray

2?

1

L

Subfamily not yet determined.

2nd Family THECIDIID.E

XIII. ? Giuynia, King . .

XIV. Genus Platydia, Costa ....

XV. Genus TheckUum, Defiance

.) J T^ 1 T>TT1'^^T/-,TTf^-lTT^TTTT. TT. f XVI. Geuus Rhytichonella, FischeT

3rd Family EHl NCHOXELLID^ i , ^

I XVII. Subgenus Atrctia, Jeffreys . .

Jeffreys

Lyopomata, Owen=: Treienterata, King.

4th Family CRANIID.^ XVIII. Genus Crania, Retzius .

5th Family DISCINID^

{XIX. Genus Discina, Lamarck .

XX. Subgenus Discinisca, Dall

6th FamUy LINGULID^ | ^^^- ^'""' ^'"5'"^«' Bruguiere

I XXII. Subgenus Olottidia, Dall .

In 1884, M. E. E. Deslongchamps proposed a new scheme of classification for the

Terebratulidse, in which he objected to any arrangement based on either the extci-ior

shape of the shell or of the supports of the labial appendage.

His first group includes the different forms in which the calcified brachial apparatus

or loop does not undergo any important modifications from its first origin up to the

adult condition. To the characters drawn from the brachial apparatus or loop is added

tliat of the presence of spicula, more or less complicated, which occupy in the mantle

all the parts connected with the organs of circulation (arteries, veins or veiny sinuses,

&c.), the labial appendages and cirri whicli accompany them. In this group he places

the recent genera Liothyris, TerebratuUna, ^legerlia, Kraussina, and FlatycUa.

DR. T. DAVIDSON OX RECENT BRACHIOPODA. 5

lu his second group he unites those forms in which the brachial apparatus or loop

undergoes numerous transformations from the embryo up to the adult condition, and

which have been distinguished by the names of Platydiform, Magadiform, and Megerli

form stages. The mantle in this group is not provided with those calcareous spicuhi

which occur so constantly in the first grovip. The colour also of the dried animal is

yellowish, whilst in the first group the hue or tint of the dried arms and of the peri-

pheric portions of the mantle are of a very clxaracteristic dim white. This, I may,

however, remark, is not always the case, as I possess specimens of the dried animal of

several species of TerebratuUna that are of a decided yellow colour. The group would,

according to M. Deslongchamps, comprise the recent genera Waldheimia, Macandrevia,

TerebrateUa, Laqueus, and Magasella.

While fully appreciating the importance of all characters derived from a study of the

animal, I am not convinced that the temporary modifications in the shape of the loop,

or tlie presence or absence of calcareous spicula in the mantle, &c., are indications of

sufScient importance or permanence to supersede those derived from the adult shape of

the calcareous lamellae supporting the labial appendages, — characters which are often

accessible, and of important assistance in distinguishing the moi*e numerous fossil

members of the group. Moreover, Mr. W. H. Dall, in describing the animal of Wald-

heimia floridana (Bull. Mus. Comp. Zool. Harvard, vol. iii. p. 16, 1871), distinctlv notes

the existence of a few exceedingly delicate spicula in the floor of the great sinuses. It

would seem therefore that these spicula occur in a genus which M. E. E. Deslongchamps,

in his proposed new classification of the Terebratulidae, places among those forms charac-

terized by the entire absence of spicula.

After long and searching examinations of the recent forms, I have described in this

monograph about one hundred so-termed species, some varieties, and about twenty-

eight uncertain ones. Of course the vexed question as to what really constitutes a

species remains the same, and is likely to remain so for a long time to come.

It will not be necessary to extend these introductory remarks, as all details have been

fully given under each species. In conclusion I would tender my grateful thanks to the

many kind friends who have in so zealous a manner supplied me \\\t\\ valuable infor-

mation and specimens *.

AETIIROPOMATA, 0\veu=CLISTENTERATA, King.

Family TEREBRATULID^, (Gray) emend. Davidson.

Subfamily Tbrebkatulin^, Dall, 1870.

During the last few years a strong desire has been manifested by those palaeontologists

who consider an extreme subdivision of genera desirable, to separate from Terehratnla

proper those forms characterized by a small short loop, of which the principal stems are

united anteriorly by a slightly arched lamella, and of which Liothyris vitrea may bi-

taken as the type.

* The drawings for tho Plates were made by myself, on paper: but the state of my health would not allow of my

reproducing them on stone.

6 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

As there are certainly some differences observable in the two groups, and as none of

the recent species would agree in the characters of their loops and in certain other

particulars with the forms referred to the genus Terebratula of Llhwyd and Klein, it

may perhaps be better to adopt Douville's generic name Liothyris for the species we are

about to describe.

In the larger number of the recent species, sucli as in Liothyris vitrea, L. arctica,

L. Moseleyi, L. tiva, L. Bartletti, L. WyvilUi, and L. suhqnadruta, the connecting band of

the loop is narrow, while in L. splicBnoidea—cubensis it is larger.

The specific claims of Liothyris cernica, and L.? DalU are still uncertain, only a single

example of each of them having been hitherto discovered.

Very small, or scarcely any modifications in the shape of the loop have been observed ;

all the species have their shell minutely perforated l)y canals, and calcareous spicules are

abundant in the mantle.

1. Liothyris vitrea, Born, sp. (Plate I. figs. 1-12.)

Anomia vitrea, Bora, Testacea Musei Caes. p. 119, vignette, 1778; Linn^, ed. Gmelin, p. 3347,

1788.

Gnjphus vitrea, Megerle v. Miihlfeld, Berliu Mus. 1811.

Terebratula vitrea, Lamarck, An. sans Vert. vol. vii. p. 245, 1819; Payraudeau, Cat. p. 83, no. 160,

1826; G. Bronn, Italicus Tertiar-Gebilde, p. 125, 1831; Pliilippi, Enum. Moll. Sicilise, vol. i. p. 95,

t. 6. figs. 6-8, 1836, vol. ii. p. 66, 1844; A. Scacclii, Cat. Couch. Regni Neapolitaui, p. 8, 1836;

Kiister, Martini & Chemnitz, Conch. -Cab. vol. vii. p. 22, tab. 2. figs. 11-13, 1843; E. Forbes, Report

on the Mollusca of the Mgenn Sea, Brit. Assoc. Report, p. 141, 1843; D. Galvani, Illustrazione

delle Conch. Foss. 1845 ; G. B. Sowerby, Thes. Conch, vol. i. p. 353, pi. 70. figs. 56-59, 1846 ; Aradas

(pars) Conchiglie fossili di Gravatelli, p. 14, 1851 ; O. G. Costa, Fauna del regno di Napoli, p. 33,

pi. i. figs. 1-3, 1851-52; Davidson, Sketch of a Class, of recent Brachiopoda, Ann. & Mag. Nat. Hist,

vol. ix. p. 364, 1852, and Br. Foss. Brach. Pal. Soc. vol. i.. Introduction, p. 62, fig. 23, and pi. vi. 1852;

S. P. Woodward, Manual of Mollusca, p. 215, 1856; L. Reeve, Conch. Icon. pi. 3. fig. 8, 1860, and

Journ. de Conch, vol. ix. p. 124, 1861 ; Chenu, Man. de Couch, vol. ii. p. 201, 1862 ; Segucnza, Atti

della Soc. Italiana di Scienze Nat. vol. i. p. 17, pi. 1. figs. 1-7, 1865; H. C. Weiukauft', Die Conch.

Mittelmeeres, vol. i. p. 284, 1867 ; Davidson, Italian Tert. Brach., Ann. & Mag. Nat. Hist. vol. vii.

pi. xvii. fig. 11, 1870; Jeflreys, Ann. & Mag. Nat. Hist. 5th ser. vol. x. p. 28, 1882.

Liothyris vitrea, Douville, Bull. Soc. Geol. de France, 3'' ser. vol. vii. 1879 ; E. Deslongchamps, Note

sur la Classification des Terebratules, ou Etudes critiques sur les Brachiopodes, pp. 106 & 153, pi. xx.

figs. 7-11, 1884.

Shell longitudinally oval or ovate, globose, widest about the middle, laterally rounded

or more or less pinched in near the front, front margin nearly straight or gently

rounded. Colour nearly white, surface smooth, semitransparent, glassy, marked with

fine concentric lines of growth and perforated by minute canals. Dorsal valve tumidly

convex, longitudinally flattened along the middle, from which the anterior lateral portions

slope to the edge. Venti-al valve slightly deeper than the dorsal one, longitudinally

flattened along the middle ; beak incurved, moderately produced and slightly overlying

the umbo of tlie dorsal valve, obliquely truncated l)y a very small circular foramen

with thickened margin and separated from the hinge-line by a small triangular deltidium

in two pieces. Loop in the interior of the dorsal valve simple and short, attached by its

DR. T, DAVIDSON ON RECENT BRACHIOPODA. 7

crura to the hinge-plate and not exceeding a fourth of the length of the valve, the two

principal stems becoming soon united anteriorly by a transverse lamella bent upwards in

the middle ; no mesial septum ; cardinal process small and prominent, hinge-plate

disunited, four diverging grooves extending from under the cardinal process to about

half the length of the valve, tlie central pair being the longest. In the interior of the

ventral valve a similar numl)er of grooves ; muscular impressions small, situated at the

bottom of the valve under the loop and in the rostral portion of the bottom of the ventral

one. Animal attached by a peduncle ; labial appendages united to each other by a

membrane ; brachial disk trilobed ; central lobe elongated and spirally convoluted.

Very delicate spicula form elegant star-like plates in the mantle. Length 1 iucli 8

lines, breadth 1 inch 5 Hues, deptli 1 inch.

Hab. Abuudant in the Mediterranean iu depths of from 90 to 250 fathoms. Very

numerous in the Bay of Naples at depths of from 100 to 300 metres. Vigo Bay, 40

fathoms (M" Andrew^) . Dredged by Prof. Giglioli, during the Italian Expedition to the

Mediterranean in 1881, at a depth of 800 fathoms (see report in the Atti del iii.

Congresso Geografico Internaziouale). Also for distribution of this and other species, see

Jeffreys's papers " On the Mollusca of the ' Lightning ' and ' Porcupine ' Expeditions,"

Proc. Zool. Soc. Loud. 1878, 1879, 1881, 1882.

Ohs. Liolliyris citrea is a beautiful, well-known, and abundant Mediterranean species.

It varies considerably in its relative length, breadth, and degree of convexity ; some

specimens being quite elongated oval, 1 inch 8 lines in length by 1 inch 1 line in breadth,

while other examples of the same length would have a breadth of 1 inch and 3 or i< lines ;

some are much more pinched iu anteriorly than others, and, lastly, some are nearly

circular with an equal length and breadth.

Prof. E. Deslongchamps, in bis instructive memoir on the classitication of the Tere-

bratulidfE, gives us the result of his studies in connection with the embryo of L. vitrea,

as well as of its subsequent stages of development. He states, " I have been able to

examine the embryo at two millimetres of size, tliat is to say from the first moments

when the larval condition has ended and the shell has begun to be formed ; its shape is

then absolutely similar to that of the young of Terehratidina ; the dorsal valve is rounded,

and slightly convex ; the ventral one shows a triangular hole, of which tlie summit,

which does not yet show any trace of a notch, will eventually become the beak. Xo

trace of a deltidium is to be seen on the sides of this foramen. On opening this little

shell, one is at once struck by the dull white of the internal walls ; and, by the aid of a

lens, one recognizes granulous parts affecting a certain regularity. The same dull white

condition is seen on the fragments of the labial appendages that have remained adhering

to them, hiding to some extent the brachial appendages. On examination of these frag-

mentary labial appendages with an enlargement of 20 to 30 diameters, one immediately

observes calcareous spicula, the sharp extremities of which form a most elegant border,

encroaching on the brachial membrane. These spicula were formed therefore from tlie

beginning of the formation of the shell and, already very complicated, entirely resemble

those seen in the adult individual The cirri and the channel of the laijial

appendages are enveloped by a layer of spicula spread out on the interbracliial

8 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

membraue in a sort of border or festoon Having afterwards submitted the

minute shell to the action of water, accompanied by a little caustic potash, I was

able to isolate the brachial appendages without effecting any fracture. The calcareous

appendage, or loop, is formed at this stage of growth by two little short calcareous

processes only, which represent the origin of the crura and offer no traces either of the

principal stems or of the transverse connecting lamina of the loop. In this first stage,

the brachial appendages entirely resemble those of a Bhynchonella ; and if one limited

oneself to a superficial examination one would be more disposed to take the embryo of

Liothyris vitrea for a minute Rhynclionella, the then triangular aspect of the foramen

and the pointed beak heightening the illusion I next examined diffei'ent

examples of 6 and 7 millimetres in length ; the shell then, although still quite young, had

completely changed in aspect, its shape being essentially the same as in the adult condition.

The loop occupies about a fourth of the length of the shell, and is complete in all

its parts. I next examined specimens of 10 millimetres in length, in which the only

differences, and very sliglit ones, were limited to the loop being a little broader ante-

riorly, and it never afterwards assumed any difference Therefore the study

of Liothyris vitrea offers three facts of great general importance, namely : —

" 1. The brachial apparatus or loop follows in its development a regular progression.

It is at first as simple as possible, composed of two little branches which unite after-

wards so as to form a small apparatus in the shape of a crest.

" 2. This apparatus once formed does not undergo any metamorphosis, and does not pass

thi'ough the complications that one observes in Terebratella.

" 3. As soon as the labial appendages or arms have developed themselves, and the

brachial apparatus or loop has commenced to be formed, the mantle and the arms present

in the interior a very complicated system of calcareous spicula, especially destined to

protect the channel of circulation, whilst in the Terchratutcs with long loops, JFaldheimice,

and Terebratellce, one can discover not a trace of similar spicula."

The soft parts of the animal of Liothyris vitrea are very similar to those of Tere-

hratulina caput-serpentis, to which we allude in the sequel.

It is to be regretted that the anatomy of L. vitrea has not yet been published, and

still remains a desideratum. The intimate shell-structure of L. vitrea has been minutely

described and illustrated by Van Bemmelen in his memoir on the anatomy of the

Brachiopoda * ; tlie circular perforations, or canals, are widely separated from each other

(as may be seen in the figure) although very small on the surface of the shell itself.

Malformations in L. vitrea are not common. M. E. Deslongchamps has, however,

described and illustrated a very remarkable one (Plate I. fig. 10 of this work) in which

there exists a large longitudinal septum in both valves, which has been caused by an

accident similar to that which caused the formation of the hole in Terebratula diphya.

Liothyris vitrea is a common fossil in the Pliocene rocks of Sicily, and occm's at

Trapani, Tremonte, Gravitelli, and also at Terreti, near Eeggio, in Calabria.

The shell referred to L. vitrea, by Chemnitz, in his Neues Conch. Cab. p. 97, tab. 78,

* Over den Bouw der SchcIpeiJ van Bracbiopoden en Cliitoucn, 18S2.

mi. T. DAVIDSON ON EECENT BRACHIOPODA. 9

fig. 707, 1785, cannot surely belong to Bern's species, for he figures in it a longitudinal

septum, Avhich never occurs in that species.

Several varieties of Z. v'ltrea have received distinctive names.

LiOTHYRis viTREA, var. MINOR, Philippi. (Plate I. fig. 13.)

Terebratula ritrea, var. minor, Tliilippi, Enuracratio Moll. Siciliffi, vol. i. p. 99, pi. vi. fig. 8, 183G ; vol. ii.

p. (](), 1814..

Terebratula affinis, Calcara, Ceimo sui Mollusclii viventi c fossili di Sicilia, p. 48, 1845.

Terebratula vitrea (pars), A. Aradas, Descrizione dclle concliiglie fossili di Gravatelli presso INIessiua,

p. 14, 1847.

Terebratula minor, E. Suess, Ueber die Wohnsitze der Brachiopoden, 1859; Davidson, On recent

Terebratula;, Ann. & ]Mag. Nat. Hist. 3rd ser. vol. viii. p. 35, 18fil.

Terebratula affinis, G. Seguenza, Notizie succinte intorno etc. pp. 19, 2G, 32, 1862 ; id. Sulla

formazionc mioc. di Sicilia etc. p. 7, 1862.

Terebratula minor, Davidson, Outline of the Geology of the Maltese Islands by Dr. Leith Adams ;

and Description of the Brachiopoda by Thos. Davidson, Ann. & Mag. Nat. Hist. 3rd ser. vol. xiv.

p. 8, pi. i. fig. 8, 1864; Seguenza, Memorie della See. Ital. di Scieuze Naturali, vol. i. p. 21, 1865;

Kowalevsky, Observations on the Development of the Brachiopoda (in Russian). Nachr. Ges. Mosc. xiv.

1873.

Shell small, ovate, longitudinally oval, longer than wide, about 9 lines in length by G

in breadth and 5i in depth. Valves uniformly convex and smooth, no fold or sinus ;

ventral valve somewhat deeper than the dorsal one ; beak moderately incurved, and

truncated by a small circular foramen slightly separated from the hinge-line by a narrow

deltidium in two pieces ; loops short and simj)le. Colour pale yellowish white.

Hah. Living in the Straits of Messina and off the Eolio Islands in the Mediterranean;

off Cape of St. Vincent (' Talisman ' Expedition), in 298-818 fathoms.

Ohs. Considerable uncertainty has prevailed with respect to this small shell, which

Philippi, in 1836, described from fossil Pliocene specimens as a variety of Terebratula vitrea.

Suess and otlaers declare it to be a distinct species, while others look upon it as a young

stage of Liothyris vitrea. I have compared species of the fossil shell with species dredged

alive by Prof. Seguenza in the bay of Messina, and found them to be identical. I cannot,

however, get rid of the idea that Liothyris minor is more than a small race or variety

of Liothyris vitrea ; it occurs, associated with the last-named shell, in the same beds and

localities in Calabria and in Sicily.

To Kowalcvsky's memoir on the development of the Brachiopoda (1873) the reader is

referred for observations relative to the embryology of L. minor.

Liothyris vitrea, var. Davidsoni, A. Adams. (Plate I. figs. 14-16.)

Terebratula davidsoni, A. Adams, Proc. Zool. Soc. London, p. 314, 1867.

Terebratula minor, Davidson, Proc. Zool. Soc. London, p. 302, pi. xxx. fig. 10, 1871.

Shell ovate, broadest anteriorly, tapering posteriorly, longer than wide, marginally

rounded. Valves uniformly convex, no fold or sinus, surface smooth, with faintly marked

concentric lines of growth ; beak incurved, truncated by a small circular foramen

margined laterally by two small deltidial plates ; surface of shell finely punctured.

second series. — zoology, vol. IV. 2

10 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Colour light yellowisli white ; loop small and simple. Length 10, width 7, depth

6 lines.

Hah. Dredged by A. Adams at Satanomosaki, Japan, in 55 fathoms.

Ohs. I am not quite certain that this small species is really a variety of L. vitrea. I

have seen only two examples of the shell, and they much resemble the typical var.

minor. One of the specimens bore some resemblance to young examples of Liothyris uva

from the Gulf of Tehuantepec, but diifers from it, according to A. Adams, in its more

solid structure and globose form, and in the foramen being smaller and entire. More

Japanese examples will have to be examined before tlie variety can be definitely

accepted.

2. Liothyris arctica, Eriele, sp. (Plate I. figs. 17, 18.)

. Terebratula arctica, Friele, Sserskilt Aftryk af Nyt Magazin for Natm'videnskaberne, pi. i. fig. i.^

1877.

Shell small, globose, broadly ovate, rather longer than wide. Valves smooth, glassy,

semitransparent, Avhitish ; dorsal valve convex, squarely circular, without fold or sinus ;

ventral valve very convex and deep ; beak unusually short, slightly incurved and

truncated by a very small foramen margined anteriorly by rudimentary deltidial plates;

loop very small and simple. Length 7, breadth 6, depth 4 lines.

Hab. Dredged by Herman Priele some few miles south-west of Jan Mayen, in 263

fathoms depth. Shell abundant, but so brittle that most of the specimens were broken

during the dredging-operation.

Ohs. After having carefully compared a specimen of the shell under description, sent

to me by Friele, with others of the var. minor to which it had been referred by

Dr. Jeffreys, I could, as Friele had previously done, discover several differences which,

although not very great, have induced me to follow its discoverer in considering it a

distinct species. L. arctica is much more globose and squarely rounded than L. minor,

which is more of an elongated oval. As stated by Eriele, its form approaches most to

L. minor of Philippi, but the deviation is shown in the shorter beak and by the position

of the foramen, which, in i. arctica, is placed directly above the dorsal valve, the

deltidium bekig almost hidden. The loop in i. arctica is very much weaker and

thinner, and the cru.ra processes are placed further apart than in Jj. minor. It is the

first representative of the genus Liothyris that has been hitherto found in Arctic seas.

3. Liothyris tjva, Broderip, sp. (Plate II. figs. 5-7.)

Terebratula uva, Broderip, Traus. Zool. Soc. Lond. vol. i. p. 14.2, pi. .xxii. fig. 2, 1833; Sowerby, Thes.

Concli. vol. i. p. 353, pi. Ixx. figs. 53-55, 1846; Reeve, Monogr. of the genus Terebratula, Couch. Icon,

pi. iii. fig. ii., 1860 ; Dall, Cat. of the recent species of the Class Brachiopoda, Proc. Acad, of Nat.

Sciences of Philadelphia, 1873; Davidson, Report on the Brachiopoda, Voyage of H. M.S. 'Challenger,'

Zool. vol. i. p. 31, pi. ii. figs. 3 & 4, 1880.

Shell oblong-oval, posteriorly compressed on each side, longer than wide, slightly

diaphanous, white or of a very light salmon-colour. Dorsal valve convex ; marginal

DE. T. DAVIDSON OX EECENT BEACIUOPODA. 11

liuc flexuously rounded in front ; ventral valve deeper than the dorsal one ; beak incurved,

moderately produced, obliquely truncated by a large circular foramen sejiarated from the

hinge-line by a narrow concave deltidium. Surface smooth, marked by fine concentric

lines of growth. Shell finely punctated. Loop short, simple. Length 1 inch 1 line,

width 8 lines, depth 6 lines.

Hal). Mr. Broderip states that this species was obtained at Tehuantepec by Capt.

Dare, while dredging for 3Icleagrince margaritiferce, attached to a dead sea-worn bivalve,

at a depth of 10-12 fathoms, and on a bottom of sandy mud. The type, formerly in

Mr. Cuming's collection, is now iu the British Museum. The shell was also trawled by

the ' Challenger ' Expedition off Twofold Bay, iu 120 fathoms, and dredged off Buenos

Ayres by the same expedition at a depth of GOO fathoms, and again off Heard Island,

lat. 52° 4' S., long. 71° 22' E., at a depth of 150 fathoms.

Obs. Ltolhyris uva varies much in shape ; it is usually longer than wide, and oval, but

in some examples the length and depth do not differ materially.

4. LiOTHYKis MosELEYi, Davidsou. Plate II. figs. 1-4.

Terebratula Moseleyi, Davidson, Proc. of the Royal Society, vol. xx^ii. p. 43G, 1878 ; Report ou the

Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 30, pi. ii. figs. 12-1 1, 1880.

Shell broadly ovate, semiglobose, rather longer than wide, broadest anteriorly, slightly

tapering posteriorly, marginally and laterally convex, nearly straight in front, margin

sometimes thickened, surface smooth, white. Dorsal valve uniformly convex, without

fold or sinus ; A^entral valve slightly deeper than the dorsal one, uniformly convex ; beak

moderately produced, slightly incurved and truncated by a circular foramen separated

from the hinge-line by a very narrow and small deltidium, beak-ridges not defined.

Loop in dorsal valve short and simple, labial appendages occupying about two thirds of

the length of the valve, united to each other by a membrane, the central coil making

about three turns. Shell-structure perforated by numerous small canals. Colour white.

Length 11, breadth 10, depth 7i lines.

Hab. Dredged by the ' Challenger ' Exjoedition, west of Kerguelen Island, at a depth

of 210 fathoms. Types in the British Museum.

Obs. I have reproduced the description I have given in the ' Challenger ' Report.

Five examples of this shell were obtained, all of about the same dimensions. It seems

to be a smaller and more circular species than L. citrea and L. sjj/ieuoidea. It is less

elongated, and not quite so convex as the last-named species, and does not present the

flatness and angularity observable in the mesial and lateral portions of the ventral valve

of Ij. sjjhenoidea or in its synonym I/, cubensis.

I made an examination of the animal of one of the specimens, which did not differ

materially from that of i. viti^ea. The mantle is thin, and not furnished with seta3 at

its edges. On the dorsal lobe of the mantle I distinctly observed the ramified, bifurcated,

flue, thread-like pallial nerves as well as the pallial sinuses, muscles, and brachial or

labial appendages, these last occupying a much smaller space in the interior of the

shell ; and while the labial branches are visibly shorter, the cirri are of considerable length.

12 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

5. LioTHYRis SPHENOIDEA, Philippi, sp. (Plate II. figs. 17-22.)

Terebratula sphenoidea, Philippi, Enum. Moll. Siciliie, vol. ii. p. 68, tab. xviii. fig. 6, 1844; G.

SegLieuza, Pal. Malac. dei Terreni Terziarii del distretto di Messina, Memorie della Soc. Italiana di

Scienze Naturali, p. 24, pi. ii. figs. 1-5, 1865 ; also Studii Paleontologici sui Bracbiopodi dell' Italia

Meridionale, pi. i. figs. 18-26, Pisa, 1871.

Terebratula cubensis, Pourtales, Contributions to the Fauna of the Gulf Stream at great depths. Bull.

Mus. Comp. Zocil. vol. i. pp. 109 & 124, 1867 ; Dall, lleport on the Brachiopoda obtained by the United

States Coast Survey Exp., Bull Mus. Comp. Zo51. vol. iii. pp.3-9, pi. i. fig. 2, 1871; Davidson, Report

on the Brachiopoda, Voy. H.M.S. 'Challenger,' p. 28, pi. ii. figs. 10-11, 1880; Dall, Bull. Mus.

Comp. Zool. vol. ix. p. 103, 1881.

Terebratula vitrea, var. sphenoidea, Jeffreys, Ou the Mollusca procured during the ' Lightning ' and

'Porcupine' Expeditions 1868-70, Proc. Zool. Soc. p. 404, pi. xxii. fig. 6, 1878.

Shell longitudinally more or less trigonal, broadest and rounded anteriorly, tapering

posteriorly, lateral marginal line flexuous, that of the dorsal valve forming an outward

curve, flexuously varying with age. Dorsal valve uniformly convex, sometimes I'ather

inflated ; ventral valve somewhat deeper than the dorsal one, longitudinally broadly

flattened, sides of the flattened portion sloping away rather abruptly ou either side,

giving the valve a somewhat subquadrangular aspect ; beak moderately incurved and

truncated by a circular foramen sej)arated from the hinge-line by a narrow deltidium.

Surface smooth, sometimes marked by fine radiating lines. Loop narrow, small, and

simple, bent-up band connecting the principal stems of the loop long and narrow.

Colour soiled white. Length 1 inch 3 lines, breadth 11 lines, depth 9 lines.

Mab. Recent. Atlantic (Jeffreys). West-African coast (' Travailleur ' and 'Talisman'

Expeditions). Gulf of Florida in depths of 100-200 fathoms, rarer towards east end

of reefs (Pourtales). Coast of Cuba (Sigsbee), off Havana 270 fathoms. Barbados

100 fathoms, St. Vincent 88 fathoms, Martinique 210 fathoms. Ofi" Ascension 420

fathoms (' Challenger ' Expedition). Off Morocco (' Talisman ' Expedition) in 298 to

818 fatlioms.

Fossil. In Pliocene rocks of Calabria and Sicily (Philippi and Seguenza).

Obs. In 1844, Philippi described and figured, as his Terebratula sphenoidea, some

fossil Pliocene specimens he had collected in the valley of Lamanto in Calabria. Subse-

quently Signor Seguenza found the same fossil in Philippi's locality, as well as in rocks

of the same age in Sicily. In 1878, Dr. Gwyn Jeffreys described and figured as Tere-

bratula vitrea, var. sphenoidea, a living specimen Avhich he had dredged during the ' Por-

cupine ' Expedition in 1870, from the Atlantic, at depths of 292, 374, and 994 fathoms, and

remarks : — "After a protracted and very careful examination of my specimens, which I had

considered the T. sphenoidea of Philippi, and having compared them with fossil specimens

sent me by Prof. Seguenza as Philippi's species from the Sicilian Tertiaries, as well as with

a series of T. cubensis which I received from Count Pourtales and Professor Alexander

Agassiz, and also after a close comparison of all these specimens with the description and

figures given by Philippi, Seguenza, Pourtales, and Dall, I am convinced the T. sphenoidea

and T. cubensis are the same, and constitute a well-marked variety of T. vitrea. The

loop in T. sphenoidea and T. cubensis is precisely similar." In this last remark, Dr. Gwyn

DE. T. DAVIDSOX OX EECENT BRACHIOPODA. 13

Jeifreys is cleai'ly mistaken ; for there exists a well-marked difference LetAveen the loops

of T. splienoidea and T. cubensls and that of L. vitrea. The loops in the fossil speci-

mens of Liotlijjris spheiwklea and those of the recent X. ciibcusis are exactly the same,

as had been clearly illustrated by Pliilijjpi in ISii.

As justly remarked by Prof. DaU, L. spheiioklea vai-ies much in shape according to

age and specimen: some are longer than wide, others almost as wide as long; some

taper more than otliers posteriorly, while much diflFerence is observable in the degree of

convexity of their valves.

In his description of T. cuhensis, Dall enters into minute details, in order to point out

the differences which exist between this last-named species and Liothyris vitrea. lie

has also carefully studied the animal of T. cuhensis, and points out the differences it

presents from that of JF'aldheimia Jloridana . He says, " the mantle is of stouter consistency

than in IF. Jloridana, and may often be removed from the shell with but little injury if

care be exercised. The muscles are similar in disposition to those of the other members

of the Terebratulida3, and present no new features. The peduncle is solid, cup-shaped

at its extremity, and has the edge produced in cylindrical horny rootlets, which are

attached to foreign bodies. The regular arrangement in layers of the muscles and corium,

as well as the axial tube of the peduncle, found in Linyula, is less evident or absent in

these forms. In this species the peduncle is very short and stout, broadly cordiform at

its inner extremity when enveloped by its various tunics.

" The brachia are arranged as in T. vitrea, as figured by Woodward ; the central coil

makes about four turns. The cirrhi are very short behind the mouth, in front of the supra-

a3S0iDhageal body. A striking feature in its anatomy, which I believe has not yet been

noted in any publication on Brachiopods, is the absence of that great series of sinuses in

the anterior part of mantle, which was termed by Hancock the ' great pallial sinuses.'

So extraordinary did this appear to me, that I could not believe, at first, that I was not

deceived by the translucency of the membranes, and it was only after an examination

of many specimens that I became convinced that they do not exist in this species. There

is in the free lobes of the mantle an extensive and extremely close and fine network of

minute channels ; or perhaps it might be said that the whole of the mantle-lobes form

one great lacune, the upper and lower walls of Avhich are held apart by a profuse number

of jjillars of tissue, which appear like dark spots under the microscope, and which are

situated so close together that the spaces about them are reduced to minute channels.

This system occupies the anterior lobes of the mantle, which in some species also contain

large branching sinuses, here absent. ... In the inner lining of the mantle are scattered,

everywhere, delicate, branching spicuhe, looking more like briers than like deer-horns,

and, while more or less interlocked, and here and there stout and thick, are still much

more delicate and slender than those of Terehratulina capiit-serpentis and Megerlia

truncata, and do not often exhibit a stellar arrangement. They are much more numerous

in some individuals than in others, and when present in abundance are found in almost

every part of the epithelium, even to the brachial cirrhi, w here the spicules are slender

and not branched .... The oesophagus is wide and fuunel-sha2)ed, narrowest at its

junction with the stomach, w'hich it enters at an acute angle. The stomach is

14 DK. T. DAVIDSON ON EECENT BRACHIOPODA.

small and oval, tapering towards the intestine, which is nearly twice as long as the

oesophagus.

" The heart in most specimens was pyriform and of a moderately large size.

" The genitalia . . . are situated in a reticulated series of sinuses, on the surfaces of

the sides of the perivisceral tissues.

" Ahove and behind the mouth, and directly in front of the anterior occlusor (retractor)

muscles, the external tissu.es of the perivisceral membrane are thickened, or a mass of

cellular tissue is interposed between the laminse of the membrane.

" No peculiarities of note were observed in the shell-structure. The perforations appeared

to be slightly further apart than in T. vitrea, but the difference was not much greater

than that which may be observed in the shells of different individuals of the same species."

Mr. Dall then describes what he believes to be the young of T. cuhensis, dredged off the

Samboes, on the Florida reefs, a minute, polished, liyaline shell, 4-lOOths of an inch in

length, and follows by describing the muscular system, brachia, and organs of digestion.

.Liothyris sphenoidea and its synonym T. cuhensis appear to be very abundant in

their especial haunts. I have also been able to examine the animal from one of the

specimens dredged by the ' Challenger ' Expedition. The mantle in the dorsal valve

of one of the specimens showed in a most distinct manner the four principal pallial

simises, which again branched as they approached the front margin of the shell,

and bifurcated again before reaching the margin.

6. Liothyris Bautletti, Dall, sp, (Plate I. figs. 20, 21.)

Terebratula bartletti, Dall, The American Naturalist, vol. xvi. p. 885, Nov. 1882.

Shell ovate, globose, longer than wide, broadest anteriorly, dorsal valve convex, with a

wide flattened mesial fold of very small elevation, commencing at about two thirds of the

length of the valve and extending to the front. Lateral and frontal margins sinuovis,

front line of fold nearly straight. Ventral valve slightly deeper and more convex than

the dorsal one, with a wide, shallow, flattened, mesial depression or sinus near the front ;

beak short, much incurved, overlying the umbo of the opposite valve, and truncated by a

small, oval-shaped, incomplete foramen. Surface smooth, marked with concentric lines

of growth. Colour light yellowish brown. In the interior of the dorsal valve the loop

is short and simple. Length li inch, breadth 1 inch 2 lines, depth 1 inch.

Hub. Dredged by the United States Coast Survey. Gulf Stream (' Blake ' Expedition)

near Vera Cruz, in 218 fathoms.

Ohs. I have seen one specimen only of this species, kindly lent to me by Mr. Dall. It

approaches much in general shape to some specimens of Liothyris vitrea. It differs

from Liothyris s]3henoidea {= cuhensis) in the shape of its loop, which is similar to that

of L. vitrea.

7. Liothyris subquadrata, Jeffreys, sp. (Plate II. figs. 15, 16.)

Terebratula subquadrata, Jeifreys, On the Mollusea procured during the ' Lightning ' and ' Porcu-

pine' Expeditious in 1868-70, Proc. Zool. Soc. London, 1878, p. 102, pi. xxii. fig. 3.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 15

Shell somewhat subjientagoual or pear-shaped, broadest anteriorly, tapering posteriorly,

longer than wide, rounded laterally, slightly indented iu front. Dorsal valve moderately

and evenly convex, somewhat flattened along the middle. Ventral valve deeper than the

dorsal one ; beak slightly incurved and moderately produced, obliquely truncated by a

rather large circular foramen, separated from the obtusely angular hinge-line by a well-

defined triangular area and long, narrow, dcltidial plates ; beak -margins sharply defined.

Surface of valves marked with numerous, wavy, fine, radiating riblets, widely separated

and crossed at intervals by concentric lines of growth. Colour ochreous white, csecal

tubuli minute and close-set. Loop small and simple. Length 1 inch 1 line, breadth

1 inch, depth 7 lines.

Mab. OQ the coast of Portugal, in 500-600 fathoms ; in the Bay of Biscay.

Ohs. The only complete specimen of this shell that I have seen is the one described,

which I figured for Dr. Jeffreys. It was given to me by Mr. Saville W. Kent, who had

dredged it during his cruise in Mr. Hall's yacht ' Noma ' off the Setubal coast, near the

Tagus in 1870. Since then I have been informed by Dr. Jeffreys that young examples

were obtained during the dredgings of the French shij) ' Travailleur ' in the Bay of

Biscay. It seems to be a good and well-marked species.

8. LiOTHYRis Wyvillii, Davidsou. (Plate II. figs. 8-14.)

Terebratula Wyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 436, 1878, and T. wyvilUi, Report on

the Brachiopoda, Voyage of H.M.S. 'Challenger/ Zoology, vol. i. p. 27, pi. ii. figs. 7, 8, 1880.

Shell somewhat subpentagonal, variable in shape, about as broad as long, sometimes

almost square, with rounded angles, with a concave sinus on the dorsal valve and corre-

sponding fold in the ventral one. Shell very thin and exceedingly brittle, almost

transparent, smooth, glassy, light-yellowish white. Length 7, breadth 9, depth 4|

lines. Valves in the young slightly and evenly convex ; dorsal valve moderately convex,

with a depression of greater or less depth commencing close to the umbo, and gradually

widening and deepening as it nears the front, front line wide, straight, or presenting an

inward curve. Ventral valve deeper and more convex than the opposite one, with a wide

median coiixex elevation or fold commencing near the beak, and one extending to the

front. Beak very small, slightly incurved, truncated by a small, generally incomplete,

circular foramen, laterally margined by dcltidial plates. Surface of valves marked at

intervals by concentric lines of growth ; shell-structure with minute, widely separated

perforations or canals. In the interior of the dorsal valve the loop is short and simple ;

the adductor and other muscular impressions are small and delicate. The labial appen-

dages extend to two thirds of the length of the shell. In the interior of the ventral valve

the muscular impressions are small, and occiipy a limited area close to the beak.

Sab. This remarkable and very interesting species appears to abound over a wide

geographical area, and at depths from 1035 to 2900 fathoms.

It was dredged by the ' Challenger ' Expedition at six or seven different stations. In

South Australia, in lat. 42° 42' S., long. 134° 10' E., depth 2G00 fothoms : one example

was attached to a manganese nodule. In lat. 12° 8' S., long. 145 10' E., depth 1400

fathoms ; bottom-temperatm-c 1^-3 C. In lat. 33° 31' S., long. 74° 43' W., depth 2160

IG DK. T. DAVIDSON OX EECENT BRACHIOPODA.

fathoms. Off coast of Chili (Valparaiso), along Avith Wald/ieimia TFi/villii -dnd Discimsca

atlantk-a. In lat. 42° 43' S., long. 82° 11' W., tlei^th 1450 fathoms. Off coast of

Patagonia. One small example from the net-weights, not far from Falkland Islands, at

a depth of 1035 fathoms. And, lastly, in lat. 35° 22' N., long 169° 58' E., depth 2900

fathoms, the greatest deptli at which any Brachiopod was ohtaiued by the ' Challenger '

Expedition ; bottom-temperature l°-2 C. ; sea-bottom, red clay.

Ohs. Liotlujris JFyvillii is one of the most interesting species of deep-sea Brachiopoda.

The shell is of such extreme thinness that it is almost transparent ; indeed the valves, when

separated, are really so, and the muscular impressions may be seen through its transparency.

I separated the valves of a specimen in order to be able to study the auimal and its loop.

The latter, which I was much surprised to find short, is exactly similar to that oiLiothyris

vitrea, notwithstanding the outward Waldheimia-Yv^e appearance of the shell. It bears

also much resemblance to several species of the last-named genus occurring in the Jurassic

and Cretaceous formations. We meet with but few recent species with such a thin

shell ; but among others may be named the widespread Discinisca atlaiitica, King,

Atretia gnomon, Jeffreys, JP'aldheimia or Macandrevia tenera, Jeffreys, RhijncUonella

lucida, Gould, and one or two others.

In external shape and character of loop, Liothyrts JFyvillii also strongly resembles

the Terebratnla nucleata of Schlotheim. Zittel's figure 644, on page 700 of his

' Handbuch der Paliiontologie,' 1880, seems as if drawn from a specimen of the recent

L. IJ'yvilUi. Eor T. nucleata Douville proposes a genus Glossothyris ; but this I am

unable to admit or adopt.

Fncertain Species.

9. LiOTHYRis CEUNiCA, Crosse, sp. (Plate I. fig. 19.)

Terebratnla cernica, Crosse, Journal de Conchyliologie, vol. xxi. p. 285, and vol.xxii. p. 75, pi. i. fig. 3,

1873.

Shell longitudinally oval, somewhat pear-shaped, longer than wide, broadest anteriorly,

tapering posteriorly. Valves uniformly convex and globose, lateral margins rounded and

flexuous. Surface smooth, white, semitransparent and somewhat vitreous. Beak not

much produced, incurved and truncated by a small circular foramen, separated from the

hinge-line by a deltidium in two pieces. Loop not known, in all probability short and

simple, as in L. vitrea. Length 1 inch 4 lines, breadth 1 inch 1 line.

Sab. Off Mauritius Island (Lienard).

Ohs. Mr. Crosse, in his description, says that T. cernica, from the lateral compression

of its dorsal valve, possesses affinities with T. ura, Broderip, but that it is less elongated

and more globose, and approaches T. vitrea and, even more closely, T. ciibensis of Pourtales.

I have never seen the single example of the shell under description ; but from inquiries

I made in the Island of Mauritius, Mr. V. Ptobillard has informed me that it has not

been dredged, but was found in the stomach of a fish taken at 80 fathoms depth, that it

is the only .specimen existing, and that there is but little chance of finding it again. lie

adds that he does not know of any other species of Brachiopod from the Avaters of

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 17

Mauritius, although lie has been studying' conchology there for the last forty-live

years.

10. LiOTHYRis ? vel Terebratulina Dalli, Davidson. (Plate II. fig. 23.)

Tvrebrutula ? Dall'i, Davidsou, Proc. Eoy. Soc. vol. xxvii. p. 437, 1878; and Report on tlie Brachiojioda.

Voyage of H.IM.S. ' Cliallengcr/ Zool. vol. i. p. 38, pi. ii. figs. 15, 15 a,h, 1880.

Shell small, thin, longitudinally oval, globose, glassy, semitransparent. Dorsal valve

moderately convex, slightly depressed anteriorly. Ventral valve uniformly convex, a

little deeper than the dorsal one. Beak small, slightly incurved, and truncated by an

incomplete foramen, laterally margined by small deltidial plates. Surface of valves

covered with fine, radiating, raised stria?, with shorter ones here and there, interpolaterl

between the longer ones. Loop short and simple. Length 3, width 2 lines.

Hab. One example only, without the animal, Avas dredged by the ' Challenger ' Expedi-

tion near Yeddo, olf Japan, lat. 34° 37' N., long. 140° 32' E., depth 1875 fathoms.

Obs. I am not quite certain whether this small shell is a Liothyris or a Terebratulina.

Its generic claims must be considered uncertain.

Subgenus Terebratulina, d'Orbigny, 1847.

The subgenus Terebratulina is closely allied to Liothyris. Wheu young, and up to

a certain stage of its development, the loop is similar to that of Liothyris ; but with age

the crural processes become united and form a shelly band, which is never the case in

Liothyris. Apart from the last-named peculiarity of the ring-shaped loop, the subgenus

Terebratulina well defines a small group of shells distinguished and characterized by

the presence of ear-shaped expansions on each side of the umbo, and by the fine

radiatinii: striae that cover the surface of their valves.

-'o

11. Terebratulina caput-serpentis, Linne, .sp. (Plate III. fig. 11^ ; Plate IV. tigs. 1-11;

Plate V. figs. 32-34.) [Figs. 35-37, var. enumjinata, Ilisso=var. mediterranea .

Jeffreys. See footnote, p. 25.]

Anomki capul-serpviitin, Liune, Syst. Nat. cd. duodecima reformata, vol. i. p. 1153, Holmia^, 1767.

Anomia pubescens, id. ibid. p. 1153.

Anomia retusa, id. ibid. p. 1151.

Animal Anomia; nondum antea depidum, Ad. Murray, Fundamenta Testaceologiae, Upsala, \). I.'},

pi. ii. fig. 23, 1771.

Anomia caput-serpentis, Pennant, (Linn^) Nova Acta Regiae Societatis Upsaliensis, vol. i. \). .'58, tab. v.

fig. 4, 1773.

Terehratula capiit-s-erpenfis (animal), Grundler, Naturforscher, Bd. i. p. 81, tab. iii. figs. 1-0, 1774;

Besehreibung mul Abbildung zweier natiirlichen Terebrateln, Naturf. Bd. ii. p. 80, 1774; Born, Musei

Csesarei Vindobonensis, ]>. 119, 1780.

Anomia capvt-serpentis, Chemnitz, Conchylieu-Cabinet, vol. viii. p. 103, tab. 78. fig. 712, 1785.

Terebrutula pubescens, Retzius, Nov. Gen. xv., 1788.

Terehratula caput-serpentis, Dillwyn, Cat. Recent Shells, 1817 ; Lamarck, An. sans Vert. p. 247, 1819.

Terebralula aurita, Fleming, Phil, of Zool. ii. p. 498, tab. iv. fig. 5, 1822, and History of British

Animals, vol. i. p. 3()9, 1828.

SECOND SERIES. — ZOOLOGY, VOL. IV. 3

18 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

Terebratula costata, Lowe, Zool. Journal, vol. ii. p. IOj, 1825.

Terebratula emarginala, Risso, Hist. Nat. de rEurope Meridionale, vol. iv. p. 388, pi. xii. fig. 175, 182G.

Terebratula quadrata, Risso, ibid. p. 389, pi. iv. fig. 176, 1826.

Delthyris spatula, Menke, Synopsis Methodica MoUuscorum, 2nd ed. p. 96, 1828-30.

Terebratula caput-serpentis, Philippi, Enum. Moll. Siciliie, vol. i. p. 84, tab. vi. fig. 5, 1836; Anton,

Verzeichniss der Concliylien, p. 23, 1836.

Terebratula Gervillei, S. V. Wood, Ann. & Mag. Nat. Hist. 1st ser. vol. vi. p. 253, 1840.

Terebratula Chemnitsii, Kiister, Martini & Chemnitz, Concliylien-Cabinet, vol. vii. p. 37, pi. 2i.

figs. 19 and 20, 1843.

Terebratula caput-serpentis, G. B. Sowerby,Thes. Conch, vol. i.p. 343, pi. ixviii. figs. 1-4, and pi. Ixxii.

fig. 116, 1846.

Terebratulina caput-serpentis, d'Orbigny, Ann. des Sci. Nat. vol. viii. p. 67, pi. vii. figs. 7 & 8, 1848.

Terebratulina cornea, d'Orbigny, 1848.

Terebratula caput-serpentis, Forbes and Hanley, Brit. Moll. pi. ivi. figs. 1-4, 1849.

Terebratulina caput-serpentis, Davidson, Sketch of a Classification of Recent Brachiopoda, Ann. &

Mag. Nat. Hist. 2nd ser. vol. ix. p. 365, 1852; Davidson, Br. Tert. Brach., Pal. Soc. vol. i. p. 12, pi. i.

figs. 3-6,1852.

Terebratula striata. Leach, Br. Moll. 1852.

Terebratulina striata, S. P. Woodward, Manual of the Mollusca, p. 215, 1854; Hancock, Phil.

Trans, vol. cxlviii., 1858.

Terebratula striata, L. Reeve, Conch. Icon. pi. iv. fig. 15, 1860.

Terebratulina striata, E. Deslongchamps, Recherches sur TOrganisation du Manteau chez les Brachio-

podes articules, 1864; Brusina, Moll. Dalmati, Verh. zool.-bot. Ges, Wien, Bd. xvi., 1866; Dall, Proc.

Acad. Nat. Sciences of Philadelphia, p. 179, 1873 ; Kowalevsky, On the Development of the Brach., 1874 ;

G. O. Sars, Bidrag til Kundskaben om Norges Arktiske Fauna, Mollusca Regionis Arcticae Norvcgiae,

tab. i. fig. 5, 1878 ; Jeffreys, Brit. Conch, vol. ii. p. 14, and vol. v. pi. xix. fig. 2, 1873-79 ; E. Deslong-

champs, Etudes critiques sur des Brachiopodes nouveaux ou peu connus, 1884*.

Shell ovate, somewhat pentagonal, longer than wide, broadest about the middle,

slightly rounded or indented anteriorly ; dorsal valve more or less uniformly convex,

but with sometimes a mesial longitudinal depression, marginally flexuous on the sides ;

lateral sides of the umbo auricular ; ventral valve convex, rather deeper than the dorsal

one, anteriorly mesially depressed ; beak rather short, gently incurved and obliquely

truncated by an incomplete foramen, posteriorly margined by the substance of the beak,

anteriorly by the extremity of the umbo, laterally by two small deltidial plates, no

distinct cardinal area or beak-ridges ; surface of shell densely covered with fine radiating

striae, few in number, coarse and simple when young, but rapidly increasing in

number with age, by means of bifurcation, and by the interpolation of smaller and

shorter ribs; both valves are also crossed by numerous concentric raised lines of

groAvth, more prominent in the young, finer and closer as the shell increases in size.

Loop short and simple in the young, with age becoming annular through the union

of the oral processes. Colour whitish, with a tinge of yellow, sometimes rust-stained.

Dimensions variable ; a large example measured 1 inch 3 lines, breadth 1 inch, depth

\ inch.

* In addition to the above references, the species has been aUudcd to by many other eonchologists and palieonto-

logists, such as by Gualtieri, in his Index Conch, tab. 96. fig. 3, 1742 ; by Davila, Cat. i. pL xx. ; Favanno, Conch,

pi. 41. fig. A", 1780, and by many others.

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 19

Hab. Spitzbci'gen and Davis Straits ; uortli-east European seas ; Oban and off Cumbrae

Islands, Loch Torridon, Scotland; off Belfast; Finisterre and Croix de Gavic; Morl)i-

han ; Cape Breton ; Adventure Bank ; off Guetaria, Spain ; north-east coast of Jamaica ;

Corea and Sagami Bay, Japan, &c.

Fossil. In the Upper Tertiaries of Sicily ; Coralline Crag of England, Belgium, sontli

of Spain, Azores, &c., &c.

Obs. No species of Bracbiopoda has been more thoroughly or more carefully studied

than the Anomki caput-serpentis of Linne. It is a very common and well-knoun

species, abounding in the localities where it is found, and has since 1767 attracted the

attention of a large number of malacologists.

The shell varies somewhat in shape and especially, according to age, in the number

of its ribs. These modifications have been often described by myself and others, and

most recently, in 1881, by M. E. Deslongchamps *. In tlie youngest condition the

shell tapers posteriorly, and is widest anteriorly ; the hinge-line is then almost strain-bt.

the auricular expansions comparatively larger, the foramen triangular or elongated oval.

In a specimen, less than a line in length, forwarded for my examination by the Marquis

de Eolin, the posterior half of the valves was smooth, while on the anterior half some

seven, scarcely developed, rounded radiating ribs were present. At one and a half line

the surface of each valve was ornamented with about ten simple rounded ribs Avith

interspaces of about equal breadth, concentrically crossed by equidistant projectiui;-

ridges, most prominent on the surface of the ribs. As the shell grows lar"-er, tlie

auricular expansions become smaller, the hinge-line obliquely or obtusely angular, the

ribs more numerous and finer, the lines of growth less prominent, and the greatest

breadth at about half the shell's length. Similar important modifications take place also

in the interior of the valves. In the interior of the dorsal valve, when quite vouui;',

and up to a certain age, the crura are widely separated ; but as the shell grows, the

pointed extremities facing each other extend nearer and nearer towards each other until

they become united and form a well-defined band, giving the loop an annelliform sha])e

and character.

The intimate shell-structiu'e of T. caput-serpentis has been described and fi'i-ured l)v

Dr. W. B. Carpenter, Oscar Schmidt, Prof. W. King, E. Deslongchamps, and others.

Dr. Carpenter says that it is in T. cajyut-serpentis "that tlie canals are of smallest

dimensions, their largest diameter being about jinjo of an inch, whilst their averao-e

distance from each other is about the same as in the preceding case \_JFaldheimia

Jlatescens, -j^ inch] — their regular arrangement, however, being so modified, that the

external orifices are principally seen upon the elevated parts of the plications,

whilst they open internally in similar rows."

When alluding to the shell-structure of T. caput-serpentis, in his valuable memoir on

the histology of the test of the Palliobranchiata (Trans. Roy. Irish Acad. vol. xxiv.

p. 148, 1869), Prof. W. King says : — " The species just mentioned, which is longitudinally

ribbed, has two kinds of perforations : those lying in the furrows are simple ; while those

* ' Etudes, critiques sur des Brachiopodcs nouveaux ou peu connus :' Caen, 1884.

3*

20 DE. T. DAVIDSON ON BECEXT BEACHIOPODA.

Iielonging to the ribs are antler-shaped, that is, twice, thrice, or oftener subdivided.

Occasionally the perforations are confined to the ribs, which causes

them to lie in bauds. It is only by the most eai'eful examination,

while grinding down the ribs to the level of tlie intermediate furrows,

tliat the true forms of the perforations can be determined. As the

modification in question is a very important one in many respects,

I have given two representations of it taken from a section prepared

l)y Dr. Rowney. Pig. 10 shows a band of antler-shaped joerforations

in the simplest state, magnified 60 diameters : it would have been

difficult to have represented them under the complex form they some-

times assume. Eig. 11 shows a portion of one of the perforations, magnified 210 diameters,

having each termination of its branches furnished with a brush-like bundle, which in

tliis species, as in Terehratula vitrea, is smaller than usual." [See woodcut, fig. 1 A & B.]

The shell-structure of T. ca2)ut-serpentis being so very remarkable, I asked my friend

Mr. John Young, of the Hunterian Museum, Glasgow, to carefully examine the shell-

structure of this species. He writes me on the 20th of April, 1885 : — " The shell-structure

of this species is of great beauty. The numerous canals incline from the lower margin

of the shell upwards towards the beak, but on the ribs of the shell they radiate from

llie centre of each rib to either side, there being a central row of tubes or canals that

])oint neai'ly straight upwards, while the other rows diverge. It is this bending inwards

of the tubes on each side of the ribs towards the interior of the shell that caused Dr.

Carpenter, in the introduction to your monograph, to state that they open internally in

rows. Dr. Carpenter is, however, wrong when he states that the pores or canals are

principally seen on the elevated parts of the plications (in this sjiecies), my etched speci-

mens show that they ojien quite as numerously in the hollows between the ribs. It is

only internally that the perforations gather together into rows with bare spaces between.

On the exterior surface of the valves the pores are more evenly distributed, owing to

the divergence of the tubes on the ribs. The perforations are not so well seen on this

species, previous to etching. The tubes on their passage through the shell-surface often

have a wave outward and upwards."

The embryology of Terehratulina caput-serpentis and of T. septentrionalis has been ad-

mirably investigated by Prof. E. Morse * and Prof. Kowalevsky t- Prof. E. Morse says : —

" In the first stage the embryo becomes widened at one end. The segments are barely indi-

cated, tlie posterior end is the widest, the anterior portion is ornamented with a conspicuous

tuft of long cilia, so peculiar to the embryos of many worms. The embryo is also clothed

with vibratile cilia, and in this condition slowly moves along the bottom of the dish

\vithout rising from it, or remains quiet. In the second well-marked stage the embryo

is divided into two prominent segments ; these expand and contract upon each other

slightly, and the cephalic segment has the power of partially bending from side to side.

In tills stage tlie embryo is most active, swimming rapidly in every direction and turning

* "Embryology of TirchratiiUna," Mem. Boston Soc. Nat. Hist. vol. ii. pp. 251-264, 1873; and "The

SyBtematic Position of the Lrachiopoda," Proc. Boston >Soe. Ivat. Hist. vol. xv. pp. 315-372, 1873.

t ' Untersuchungeu iibcr die Embryologie der Brachiopodeu :" Moskau, 1874.

1)1^ T. DAVIDSON ON llECEXT BEACHIOPODA. 21

al)iuplly about. The oesophagus also becomes dimly delined. lu the third stage the

peduncular segment is developed and projects from the posterior portion of what can

now be called the thoracic segment. At this stage the embryo either remains immovable

upon tlie bottom of the dish or slowly moves about. In two cases delicately barbed

setae to the number of thirty-five projected directly backward from the peduncular

segment. The embryo is still clothed with cilia, though the long pencil of cilia has

disappeared. The head is closely drawn to the thoracic segment, whicli becomes Avider

in transverse diameter, so as nearly to hide -the peduncle. In the fifth stage the thoracic

ring commences to fold, or turn iipward upon opposite svirfaces of its circumference, so

as to gradvially enclose the head ; one fold being made slightly in advance of the other

represents the larger or ventral valve. In this stage appear clusters of barbed and

deciduous setge upon tlie anterior margin, and in a later portion of this stage the first

hardened areas of the dorsal and ventral plates make their appearance, and the cirri

appear as bkinted papillae about the mouth. In the sixth stage the shell becomes

rounded, the peculiar scaled structure makes its appearance, and the formation of tubules

perforating the shell and of permanent setse takes place." Tlie author adds, further on,

" that the eggs not only fill the large pallial sinuses, but liang in clusters from the

genital band ; from these parts they escape by dehiscence, and float freely in the

perivisceral cavity The eggs ai'e not uniform either in shape or size." Prof.

Morse then describes in detail each of the stages ; but space will not allow me to

proceed further with his elaborate investigations, as they would demand numerous

illustrations. (See Plate V. figs. 1-31.)

Dr. Gwyn Jeffreys states, in vol. ii. p. 7 of his ' British Conchology,' that in the fry-stage

the little creature can creep and swim ; but, " After quitting the embryonic state, they

become invariably and permanently fixed to other substances, being incapable of any

other motion than making a half turn round the peduncle or pivot."

Mr. Lucas Barrett, who had an opportunity of examining T. caimt-serpentis in life,

says*: — "This species shows more of itself than any other, and protrudes its cirri

further ; it was met with everywhere [near the coast of Norway], in small numbers,

iu 30 to 150 fathoms, often attached to Oculina. The cirri on the re- j,j„ g

fiected part of the arms are shorter than those on the first part, as shown /^

in the woodcut. The cirri were almost constantly in motion, and / \

often observed to convey small particles to the channel at their base, '!;

When placed in a small glass of sea-water, the valves gradually opened.

Individuals remaining attached to other objects manifested a re-

markable power and disposition to move on their pedicles. Detached y. ccnrnf-.ta-jjcitix,

specimens could be moved about without causing the animal to "^"1- L. Barrett,

close its valves. If any of the protruded cirri were touched, the cirri were retracted

and the valves closed A\itli a snap, but soon after opened again. When the oral

arms are retracted the cirri are bent up, but are gradually uncoiled and straightened

when the shell is opened, before which the animal has often been observed to prntrude

* Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi. p. 2.57, 1855.

22 DE. T. DAVIDSON OX EECENT BRACHIOPODA.

a few of its cirri and move them about, as if to ascertain if any danger threatened.

Only on one occasion a current was observed to set in on one side between the two rows

of cirri. I had been attempting to ascertain the existence of currents, by introducing

small quantities of indigo into the water surrounding the animal with a camel's-hair

brush ; three times the water was forcibly drawn in, and tlie particles of indigo were

seen to glide along the groove at the base of the cirri in the direction of the mouth."

See likewise a paper by Herouard " Sur les courants de nutrition des Bracliiopodes,"

Journ. de Conchyl. vol. xxv. p. 229, 1877.

Hancock * says : — " The pallial lobes extend forward, but do not project beyond

the side of the body, w^here they become united, the junction being marked by a groove,

bordered by a ridge on each side. They are very delicate and transparent, so that the

great pallial sinuses can be distinctly traced, even to their terminal ramifications "

(p. 793). "The arms of W. [TFaldhelmia'] cranium and T. caput-serpentis are

disposed in the same manner as in W. cmstnilis; and in the former the calcareous

loop is precisely similar to that of the latter ; but in T. caput-se)'pentis it is very much

reduced, the extended lateral portions having almost entirely disappeared, little more

than the transverse portion existing; and this, together with the crural processes, which

are united below across the median line, forms a collar upon which the bases of the

arms rest. In this species, therefore, the expanded lateral portions of the arms are

without any apophysary support, and accordingly other means are provided for sustaining

them. The two produced lobules of the dorsal pallial lobe reach to the ends of these

portions of the arms as in TP^. australls ; and are stiffened with numerous, imbedded,

calcareous spicula, to such an extent, that when the soft tissues are removed by mace-

ration the form of the parts remains unaltered. The spicula extend also over the

surface of the inner lamina of the pallial lobe, and pervade likewise the walls of the

canal, and even the cirri ; so that the brachial apparatus becomes firmly fixed, and in

this way a substitute is found for the usual apophysary support." (Loc. cit. p. 808.)

It is, however, to Oscar Schmidt, so far as I am aware, that we are indebted for the

first notice of these remarkable sj)icula f , and in the Annals & Mag. of Nat. Hist. 2nd

ser. vol. xvi. p. 439, pi. x., I gave a translation, with figures, of Schmidt's observations.

The author remarks " that the mantle, oral arms, and cirri in Terebratulina caput-

serpentis contain an innumerable number of calcareovis plates, generally flattened,

dilated and irregularly denticulated, situated in close vicinity to each other

It is easily conceived [he adds] that these calcareous masses stiffen the parts which

contain them, and seem particularly to serve this function in the hollow cirri, thus

preventing their sides from sinking doAvn."

We are also indebted to Prof. E. Deslougchamps for an admirable memoir ' Recherches

sur rOrganisation du Manteau chez les Brachiopodes articules ' (Caen, 1864), in which

* Phil. Trans, vol. cxlviii., 1S58.

t " Die ncusten UntersuchuDgen iiber die Braduopoden von Owen, Carpenter und Davidson, mit einigen

Zusiitzen," Zeitsch. f. gesammten Naturwissenschaften, p. 325, 18o4. In 1856, Dr. S. P. Woodward exhibited,

at a meeting of the Zoological Society, the spicnla in the pallial lobe of T. ccqjut-serjMiitis (Proc. Zool. Soc.

p. 368, 1856).

DE. T. DAVIDSON OX EF.CEXT BRACHIOPODA. 2:5

lie minutely describes and illustrates the arrangement of the spicula in Terebratullna caput-

serpentis as well as in other genera in which they occur (sec Pi. IV. figs. 10, 11). lie

tells us that each of the lobes of the mantle in this species has four vascular sinuses, of

which the lateral ones are more developed than the median two, which last contain

in their interior the organs of reproduction. The spicula cover these sinuses, and

afterwards line the walls of the visceral cavity, producing two large convex surfaces,

which become united and thus completely close this cavity. In the dorsal valve the

mantle reflects itself on the brachial apparatus, formed here of calcareous laminae bent

in the shape of a ring, and spread themselves on the labial appendages, of which they

line the interior of the great canal, as well as the cirri ; the cirri, he adds, which I

have also carefully examined in many specimens, are stated by Hancock to be large,

much-branched, colovu-less, glass-like, and pellucid, somewhat like the antlers of a deer,

only the branches are all on the same plane and are flattened and depressed a little ;

that they are, however, frequently much complicated, forming a central network with

irregular radiating branches ; in others, again, the branches pass from a single network

centre. The spicula lie in the outer layer of the inner lamina, and are crowded to such

a degree that the edges of the branches are almost in contact, thus forming an extensive

though incomplete network of calcareous matter over the trunks of the great jiallial

sinuses ; elsewhere they are sparingly distributed towards the margin of the lobes, where

they are rather numerous. The brachial disk is trilobed, the central lobe elongated and

spirally convoluted.

In 1771, in the ' Fundamenta Testaceologiae ' it is represented as the animal of Terehru-

tulina caput-serpentis without its shell. In 1773, Pennant describes the same species, and

gives a figure of its labial appendages. Grundler, again, in 1774, devotes a whole

plate to enlarged figures of the same appendages, and in two of them points out the

position of the loop. Since that period they have also been described and illustrated

by several malacologists, and more particularly by Albany Hancock, in his classical

memoir ' On the Organization of the Brachiopoda' (1858). Mr. Hancock informs us,

at p. 793 of his work, that, " To facilitate the examination of the soft parts, it is neces-

sary to reduce the valves by dissolving them in dilute acid. When the calcareous matter

has entirely disappeared, and the calcified shell-membrane has been removed, the trans-

parent tegumentary envelope of the animal is exposed to view ; and this, when placed

in water, assumes the form of the shell Towards the posterior or umbonal

region the enlarged extremities of the shell-muscles are always apparent, clustered

together on each side of the antero-posterior line, forming reddish-coloured patches."

The muscles naturally divide themselves into two groups, the valvular and those for ad-

justing the shell to the peduncle. As the arrangement of the muscles is stated by Hancock

to be essentially the same in all the articulated Brachiopoda, and they have been described

further on in JFakUieimkt flavescens, it will not be necessary here to refer further to those

details, although it may be added that Hancock mentions an important modification as

occurring in T. caput-serpentis, which consists in the large and powerful dorsal adjustor

muscles not being attached to the hinge-plate, as in W. Jlavescens, but having their

insertions in the valve itself. The posterior extremities of these muscles are seen on the

24 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

surface of the auimal, on each side of the median line, elongated in the antero-posterior

direction, and extending between the occlusors, almost as far forward as their anterior

margins. They are of irregular form, and enlarged posteriorly in T. caput-serpentis.

In PI. IV. figs. 8 & 9, we give Hancock's two enlarged figures showing the dorsal

and ventral views of TerebratuVma caput-serpentis deprived of the shell, and exhibiting

the respective positions of the various muscles above described.

While alluding to the digestive organs, Hancock states {I. c. p. 814) that " In

T. cajmt-serpentis there appears to be only two hepatic ducts, and both in it and in

TF. [Waldheimia] cranium the intestine is very short, terminating in a blind sac

before it reaches the ventral wall of the perivisceral chamber. It tapers gradually to

a point which is rounded, and suspended in its place by the mesentery." The genitalia

exhibit a somewhat different arrangement in T. caput-serpentis to what prevails in

W. Jiavescens ; " they are placed in large sinuses situated in the pallial lobes, one

at each side. These sinuses are, however, nothing more than the enlarged trunks of

the so-called pallial vessels or great pallial sinuses. They are four in number, two in

each lobe, and the genital band, which is placed within them, forms a thick convolute

layer, with small spaces between the folds."

" In T. caput-se7'pentis the heart is more decidedly pyriform than in the other species,

and it is placed a little further back, the branchio-systemic vein passing for some distance

down the stomach beyond the central gastro-parietal band . . . The setse in T.capiU-serpeatis

are placed rather far apart from each other, and issue from the mantle at the points

corresponding to the marginal crenulations of the shell ; these crenulations give to the

pallial membrane a scalloped appearance. The setae are rather robust ; the marginal fold

is deep, and the follicules are of considerable length and rather wide, with their bases

su.rrounded with glandular matter, forming a roundish, red-coloured spot at the end of

each seta " {I. c. p. 829). The blood-system of the brachial ajiparatus has likewise been

well investigated by Hancock. He says : — " This is beautifully developed, and presents

considerable variety in the character of the several plexuses of which it is composed. The

walls of the great canal, the ridge supporting the cirri, the membranes that unite the

upper and lower members of the loop, that which connects the spirals, and those which

form the small canal or channel at the base of the cirri, as well as that forming the

sheath of the apophysary support, — all have their system of lacunes which inter-

communicate and compose the brachial system " [1. c. p. 831).

Dr. Van Bemmelen questions the lacunary system as described by Hancock. He

concurs in the statement that in T. caput-serpentis and T. septentrionalis the sexes are

separate *.

While treating of the perivisceral chamber, Hancock observes that in T. caput-serpentis

the four trunks may be recognized. " Here the trunks are fused so as to form on each

lobe two large, lateral, semilunar sinuses, in which the genitalia are placed. The external

margins of these sinuses give ofi" numerous, rather delicate branches, which dividing

dichotomously run to the pallial margin ; the branches next the middle line, which

* •• Oil the Structure of the (Shells of liruchiopuds and Chitons," Ann. & Mag. Nat. Hist. 5th ser. vol. xi. p. 37y.

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 25

correspond to the inner sinuses, pass off from their internal margins, and divide once

or twice " (/. c. p. 840).

Terebratulina caput-serpentis, var. unguiculata. (Plate V. figs. 38-40.)

Terebratula unguicula, V. Carpenter, Proc. Zool. Soc. 1865, p. 201, figs. 1-4; Cooper, Gcogr. Cat.

California. Moll. p. 3, 1866 ; Dall, Amer. Journ. of Conch, vol. vi. p. 102, 1870, and Report on Brachiop.

of Alaska, 1877; S. T. Whitcaves, On Some Marine luvertebrata from the West Coast of North

America, Canadian Naturalist, n.s. vol. viii. p. 464, 1878.

Shell ovate, longer than wide ; valves almo.st equally convex, rounded laterally and

in front ; lateral sides of the umho strongly auricular, especially in young and middle-

aged specimens. Ventral valve evenly convex, but sometimes very slightly depressed

anteriorly ; beak short, obliquely truncated by a rather large incomplete foramen, margined

anteriorly by the umbo of the dorsal valve and by two small lateral deltidia. Surface

of valves marked with numerous radiating delicate riblets, simple aud stronger at their

origin, but rapidly augmenting in number from bifurcation and by the interpolation

of shorter riblets between the longer ones. Valves crossed with concentric raised striaj.

Loop short and simple, the crura disunited in the young, annelliform in the more advanced

age. Colour light yellowish white. Length 13, breadth 10, depth 5 lines.

Hab. San Diego, Cal., to the Aleutian Islands, San Pedro, Cal. (Cooper) ; Neeah Bay

(W. T. Swan) ; Victoria (V. W. Lord, J. Richardson) ; Port Etches ; Sliumargin Islands ;

Unalaska (Dall). Eange : low Avater to 100 fathoms, those from deep water, the largest,

adhering to shells and stones (Dall). At Race Island lighthouse, and Victoria Harbour,

in 30 to 70 fathoms; end of Texada Island, in 40 to 70 fathoms, mud (Richardson).

Obs. Mr. Dall states, in the paper already referred to, that this species is readily

separated from Terebratulina caput-serpentis, T. japonica, and other species, which

strongly resemble it externally, by the broad loop, which is usually open, instead of being

closed, as the genus requires. However, it finally becomes closed in fully adu.lt specimens,

which reach the size of T. caput-serpentis. I have also had the advantage of being able

to examine a large number of young and adult examples of Carpenter's species, which

were kindly lent to me by Mr. Whiteaves, as well as others which I purchased from

Mr. G. B. Sowerbv, who had obtained them direct from Vancouver Island. After havinsr

minutely compared their exterior and interior with a large number of European speci-

mens of T. caput-serpentis, I arrived at the conclusion that T. unguicula is no more

than a variety of Linne's species. Carpenter's specimens, as he himself admits, were all

of small size, and consequently the crura of the loop were disunited. The specimens of

T. unguicula I was able to open had not the broad loop described by Dall, but agreed

well with the European specimens of T. caput-serpentis which I had previously opened

and examined. In these specimens of T. unguicula, the front line was rounded, and

not indented; but this is also the case with very many examples of T. caput-serpentis.

In a letter dated December 1884, Mr. Dall writes me that he would not wish to be

quoted as believing T. unguicula distinct from T. caput-serpentis *, aud would be only

* [Dr. Davidson has given three excellent figures (sec PL V. figs. 35, 30, <fe 37) of the well-marked variety of

Terehratulina caput-serpentis from the Mediterranean Sea, to which Dr. Gwj-n Jeffreys gave the varietal designation

of mcditcrranea. He described it as longer aud more slender than T. caput-serpentis, " more compressed or flatter than

SECOND SERIES. — ZOOLOGY, VOL. IV. 4

26 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

willing to assert that the specimens he has seen seem distinguishable, and that as the dis-

tribution of the two forms is absolutely separate, their identity would seem to require proof.

12. Terebratulina. Cailleti, Crosse. (Plate V. figs. 41, 42.)

TerebratuUna Cailleti, Crosse, Journ. de Conch, vol. xiii. p. 27, pi. 1. figs. 1-3, 1865 ; Pourtales, Bull. ^lus.

Comp. Zool. (Harv.) vol. i. p. 109, 1867 ; Dall, Am. Journ. Couch, vi. p. 106, 1870, and Bull. Mus. Comp.

Zool. (Harv.) vol. iii., 1871 ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. Challenger,'

Zool. vol. i. p. 37, pi. 2. fig. 2, 1880; Dall, Bull. Mus. Comp. Zool. (Harv.) vol. ix. p. 103, 1881.

Shell ovate, longer than wide, broadest about the middle, rounded or slightly indented

in front ; dorsal valve evenly convex, no defined mesial fold, lateral sides of the umbo

auricular ; ventral valve moderately convex, with a strongly marked longitudinal depres-

sion or sinus, commencing at the beak and extending to the front ; front raised into a

rounded wave ; beak short, and obliquely truncated by a moderate-sized incomplete

foramen and two small disunited deltidial plates ; surface of valves marked with about

forty small radiating riblets, the larger number being shorter ones interpolated at various

distances between the larger ones ; surface marked also with fine concentric raised lines.

Loop short, crura disunited in the young, annelliform in the adult. Colour of a slightly

greyish white. Length 5, breadth 4, depth 2 lines ; but Mr. Dall mentions having taken

specimens 1 inch in length.

Hab. T. Cailleti was obtained by M. de Pourtales off Chorrera, Cuba, in 270 fathoms ;

near Cojima in 450 fms. Off Double-headed Shot Key in 471 fms., and near Tennessee

Eeef in 115 fms. Ofi" West Florida 30 fms., St. Vincent 88 fms. (Pourtales and Dall).

At Guadaloupe in 200 fms., by an Italian party who were searching for beds of coral.

Mr. A. Agassiz sent me a specimen dredged by the Hunter Expedition off Barbados, taken

at a depth of 100 fms., and I have also two young examples dredged by L. Barrett off

Jamaica, and by Sigsbee off Havanna, in from 80 to 450 fms. I am likewise indebted to

Mr. E,. Bathbun for several young specimens obtained in 70 fms. in lat. 21° 48' S. and

long. 40° 3' W. of Greenwich, which had been dredged by the Captain of the English

Atlantic steamer ' Norseman.' A single example was obtained by the ' Challenger '

Expedition, west of Pernambuco, in 350 fathoms.

Obs. This species has been minutely described by Mr. H. Crosse and by Mr. W. Dall.

Crosse says that it is easily distinguishable from T. caput-serpentis by its stronger radi-

ating riblets, these last being more separated from each other than in Linne's species.

When quite young, and measuring 1 line in length, it has only from nine to ten simple

ribs ; at 2 lines abeady two or three short interpolated riblets have made their appearance

close to the margin ; at 3 lines in length the interpolated riblets become more numerous,

and the whole surface is concentrically crossed by strongly marked, slightly projecting,

equidistant, concentric ridges. Tiie ridges become very much less marked as the shell

aj)proaclies and attains the adult condition ; but this feature is common to several species

of the subgenus.

usual, and more or less cloven in front " (" Mollusca of the ' Lightning ' and ' Porcupine ' Expeditions," Proc. Zool.

Soc. 187S, p. 401). From a MS. note attached to the types in the Davidson Collection, it is evident that Dr. Davidson

considered this to be " a good variety of T. caput-serpentis," but identical with the sheU named Terebratula

I'maiyinata by Risso in 1826, " of which the Terehratula <piadrata, Risso, is probably a synonym." The variety

mediterraneci should therefore be henceforth known as T. caput-scrpentis, var. eniargiiuita, Risso. — A. C]

DE. T. DAVIDSON OX EECEXT BEACHIOPODA, 27

Ml". Uall, iu bis paper in the Bull. Mus. Coiup. Zool. already referred to, enters into

many details to show that it is a distinct species. He has since then written me that,

although T. Cailleti may be a southern form of T. cajnit-serpentis, be has seen

probably nineteen twentieths of all the existing specimens, and that it seems to him to

be as well disting-uisbable as any of the fossil forms, and that he considers it at any rate

fully entitled to a varietal name, as it is well distinguished by its granulated ribs, and

varies much in form.

Dall says {I. c. p. 10) " That the smallest specimens of tliis species which I was able

to find among those sent by M. de Pourtales were nearly -1 inch in length. That

the characteristic sculpture was developed upon them to the very apex of the shell

The various muscles were already well developed. The mouth was as described in the

young of the T. cubensis. The intestine was short, cylindrical, and straight. The loAver

portion was embraced by a few hepatic digitations. These lobes were very dark brown,

the muscles of a deep reddish brown, and the brachia of a flesh-colour. The latter were in

the shape of a horseshoe, with no trace of a median lobe. They were close set and marked

with transverse lines as in T. cubensis. The membrane which covered the viscera was

covered internally with irregular hyaline spots with well-marked bou^ndaries, which no

doubt are the limits of the lacunar channels of circulation. The mantle was quite trans-

parent, with a brownish edge, and in each of the internal channels, corresponding to the

ribs of the outside of the shell, was a single bristle, composed of longitudinal fibres of

chitine, without any of the transverse markings which are seen in the setae of the adult.

The extreme tip of the bristle alone protruded from the mantle, and its inner extremity

was slightly bulbous. It was of a glistening yellow color throughout. In those adults

which I examined there Avere only five or six of these setse iu each mantle lobe. These

specimens were obtained off Havana, in two hundred and seventy fathoms water. The

very extraordinary manner in which all the soft parts were crowded and crammed with

masses of calcareous spiculse defied my best efforts to obtain any very satisfactory results

from the two or three alcoholic specimens at my command. A flocculcnt mass of white

matter resisted the action of acid, and filled all the interstices of the membranes so as to

render them quite opaque The intestine was cylindrical, and ended much as it does

in T. cajnit-serjjends. The mouth was surrounded by a dark-brown line. There were no

structures above and behind the mouth, such as are described as existing in T. cubensis.

The attached extremities of the muscles were of a very bright red-brown. . . . The peduncle

is white, slender, and exceedingly long, the exposed portion sometimes equalling in length

one third of the shell. A brownish tinge pervaded all the tissues of the adult. Transverse

markings were noticed iu the brachia, as described in other species by Hancock. One

specimen, growing on a rock which had become covered with sponge, afforded an interesting

observation. The peduncle was exceedingly long, and on cleaning off the sponge it was

seen that the creature, on the growth of the sponge towards it, had apparently lengthened

its peduncle to get out of the way ; and while the original attachment still remained, . .

. . somewhat further on, nearer the shell, a second attachment of the peduncle had taken

place by the outgrowth, from the underside, of a biincli of cylindrical rootlets, exactly

resembling the attachment of an ivv to a stone.

4*

28 DK. T. DAVIDSON ON RECENT BEACHIOPODA.

13. Terebratulina sbptentrionalis, Couthouy. (Plate V. figs. 1-31 & 48-52.)

Terebratulina septentrionalis, Couthouy, Boston Journ. Nat. Hist. vol. ii. p. 6.5, pi. iii. fig. 18, 1838.

Terebratula septentrionalis, G. B. Sowerby, Thes. Conch, p. 342, pi. xviii. figs. 5 & G, 18-J.6; Stimpson,

Test. Moll. New England, p. 75, 1851.

Terebratula cujjut-serpentis, L. Reeve, Monogr. of Terebratula, Conch. Icon. 1861.

Terebratulina septentrionalis, E. Morse (On the early Stages of), Mem. Boston Soc. Nat. Hist. vol. ii.

(read Oct. 1869) ; Gould, Invert. Mass., Binney's 2nd ed. p. 208, fig. 500, 1870.

Terebratulina septentrionalis, Dall, Cat. of Recent Bracli., Proc. Acad. Nat. Sci. Philadelphia, 1873,

p. 180; Sars, Fauna Moll. Regiouis Arctics Norvegise, p. 10, tab. i. fig. 4, 1878.

Terebratulina caput-serpentis , var. septentrionalis, Davidson, Report on the Brachiopoda, Voyage of

H.M.S. 'Challenger,' Zoology, vol i. p. 33, pi. i. figs. 3-9, 1880.

Terebratulina caput-serpentis, W. F. Ganong, The In^'ertebrate Zool. of Passamaquoddy Bay, Nat.

Hist. Soc. of New Brunswick, Bull. No. 4, p. 91, 1884.

Shell rather thin, longitudinally broadly ovate, pear-shaped or somewhat subpen-

tagonal, narrow and tapering posteriorly, abruptly widening below the beak, broadest

anteriorly ; front line nearly straight, slightly indented or rounded ; colour yellowish

white, nearly diaphanous ; dorsal valve gently convex, especially towards the middle,

slightly depressed towards the front, eared at the umbo ; ventral valve feebly convex,

or slightly deeper than the dorsal one, somewhat depressed towards the front; beak

short, attenuated, slightly incurved and truncated by a moderately large and incomplete

semielliptical foramen, completed below by the umbo of the ventral valve, and laterally

margined by small deltidial plates; surface of both valves covered with a variable

number of fine rounded radiating raised striae or riblets (240 in some specimens when

counted at the margin), these increase in number at variable distances from the beaks

by the interpolation of shorter riblets; shell-structure perforated by numerous small

canals. In the interior of the dorsal valve the loop is short and simple, rendered

annular, with age, by the union of the oral processes. The brachial appendages are

united to each other by a membrane, cirrated and develoijed from each side of the mouth,

divided into three lobes, the two lateral ones extending to a little more than two thirds

of the length of the valve, the central one not exceeding half the length of the valve,

and spiral at its extremities. Proportions variable. Length 16, breadth 11, depth

6 lines.

Sab. The geographical range of T. sejjtentrionulis seems to be very extended. The

' Challenger ' Expedition dredged it abundantly olf the New- York coast at depths of

61 fathoms, also, at a depth of 83 fathoms, off Halifax. Again, accordmg to the ofiicers

of the expedition, ofi" the Cape of Good Hope (but I should like to have this last state-

ment confirmed), at latitude 46° 40' S., long. 37° 50' E., at a depth of 160 fathoms.

Mr. Couthouy, in his description of T. septentrionalis, says that it has been found at

Lubec Bay by Dr. C. T. Jackson during his geological survey of the State of Maine, and

that it is proljably an inhabitant of deep water on the whole New-England coast.

Dr. Gould mentions having found it in considerable numbers in the stomach of fishes,

and occasionally on the sea-beach, and that its usual habitat is in the Laminarian or

deep Coral zones of northern seas. At Eastport, at low water, it is common off the

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 29

Isle of Slioals, 20 fathoms ; Grand Manau, common (Packard, Stimpson) ; Halifax

harbom- (Willis); Trias Cove, Passamaquoddy Bay, in 12 fathoms, where they occm-

clinging; together in bunches, large and small together, and seem to prefer the clear

fresh water on pebbly bottoms (W. P. Ganong).

Ohs. The above description is the one I published in my ' Challenger ' Report. Some

difference of opinion has prevailed with respect to the specific claims of the species under

description. Certain malacologists consider it a distinct species, others as only a simple

variety of T. capuf-serpeiitis. Gould, in 1838, believed it to be distinct ; but in the ' Report

on the Invertebrates of Massachusetts ' (2nd ed. by W. H. Binney, 1870) we find stated

at p. 208 : — " An examination of the descriptions of T. caput-serpentis given by Linnaeus,

Miiller, and Chemnitz, and a comparison of them with our shell, has well satisfied me of

their correspondence. The downy epidermis is a character too rare and singular to be over-

looked. This, however, is rubbed ofi" very easily. The shell is much thinner, in general

more elongated, and the strise nearly twice as nvimerovis, being about thirty to forty in

the Eui'opean, and fifty to sixty in the American specimens. No account of the internal

bony processes is given in any description except that of Mr. Couthouy. These would

afford the best possible specific character, were it not that they are usually more or less

broken. But I have been relieved from all further speculation by the receipt of specimens

from Dr. Loven, which settle the identity of om- species with the European caput-serpentis.'"

Mr. TV. H. Binney seems to be of a difi'erent opinion, for he adds, after Gould's observa-

tions just recorded : — " I have retained the above remarks from the former edition, because

our shell is so generally still regarded as identical with the European species. But further

examination of numerous specimens has led me to coincide with Dr. Stimpson, who has

dredged extensively, both in the British and American seas, in his opinion that the species

differs from the European caput-serpentis, sufficiently in both shell and animal."

G. B. Sowerby, on p. 344 of his ' Thesaurus Conchyliorum ' (1846), observes that

T. septentrionalis is distinguished from T. caput-serpentis by its much finer radiating

striae, its larger and less oblique foramen, and by its rather more extended and somewhat

difi'erently formed internal appendage.

Since publishing my description of this shell in the reports of the ' Challenger ' Expe-

dition, I feel more disposed to leave T. septentrionalis and T. caput-serpentis as separate

species, the first being evidently more regularly oval and rounded in front than in

Linne's species ; and even in the young stage the riblets are more numerous than in

T. caput-serpentis. I have been able to examine specimens from less than 1 line in

length up to that of 1 inch and 3 lines. Up to about 3 lines, and sometimes even more,

the ribs are very few in number, prominent and radiate from tlie extremity of the beak

to the margin, and are crossed by strongly indented concentric lines, which give to the

ril)lets the so-termed tuberculated appearance that has been so often described in the

species of this subgenus. As the shell grows the ribs become more delicate and more

numerous from repeated interpolations of shorter ribs, and tlie concentric ones become

more and more faintly marked.

It is, however, to Prof. E. Morse that science is most indebted for the knowledge we

30 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

at present possess of the embryology, or early stages, of Terehratulina septentrionalis *.

This distinguished zoologist having dredged in 15 fathoms of water in the harbour of

Eastport, Maine, in 1869, individuals of all ages, has minutely and elaborately described

all the stages of its development, which he illustrates in the most complete and admirable

manner. The details and illustrations he communicates are so numerous that we feel

ourselves obliged to refer the reader to the author's memoir, and to limit ourselves to

the reproduction of the following selected observations and illustrations ; he says : —

"The species occur in great numbers, at various depths, and have also been collected

at low-tide mark, by Dr. Stimpson and Prof. Verrill. The specimens were found

attached to stones brought up in the dredge, and also adhering to the lower valve of

adult individuals, generally near the peduncle f The eggs were generally kidney-

shaped, though very irregular as to form and size [see Plate V. figs. 1-4] ; they

were spermaceti-white in color, and opaque, though having a central area, translucent,

and apparently depressed This form recalled the general proportions of Argiope

and Megerlia, in being transversely oval, in having the hinge margin wide and straight,

and in the presence of a proportionately wide foramen. This stage was exceedingly

minute, .... the shell showed nothing of the scale-like structure so characteristic

in later stages. Between this stage and the next, tlie shell rapidly elongates, while

the hinge margin remains nearly the same in width ; this is also shown in the concentric

lines of growth seen faintly on the surface, indicating a rapid increase in the length of

the shell, while no corresponding increase takes place in the widening of the hinge

margin. The peduncle is longer than the shell, having distinct walls apparently enclosing

a clear interspace, the end slightly dilating and forming a pear-shaped adhering disk.

The structure of the shell showed clearly the scale-like structure, with the csecal tubules

of the pallial lobes perforating it. The anterior margin of tlie pallial lobes gave rise to

seven setse of variable lengths, all of them projecting forward [Plate V. fig. 21]. . . . The

future position of the calcareous loop was indicated by a strongly arched process midway

the length of the shell, from which sprang six short and stout cirri, all of them curving

towards the mouth, which occupied the centre of the base from which the cirri sprang.

The digestive sac hung from the mouth, and was twice as long as broad, having a strong

constriction in the centre, forming two chambers, the lowermost one being globular in

shape, and having its walls colored a light reddish-brown, this colored portion evidently

indicating hepatic cells. The cavity next the mouth indicates the stomach, whilst the

lowermost cavity indicates the future intestine or cul-de-sac. The cirri moved fre-

quently, and in various directions, though generally performing a grasping motion, as if

securing some bit of food In this stage, and several succeeding stages, the outline of

the shell is remarkably like that of Lingula, and this resemblance is more striking from

the proportionally long peduncle. [Plate V. fig. 31.]

" In another stage, the numerous irregular shaped calcareous spiculae lined the outer

* " On the Early Stages of. Tcrehratulhia septentrionalis," Memoirs of the Boston Society of Natural History,

vol. ii. p. 29, 1871 ; and " Embryology of Terehratulina''' ibid. p. 249.

t On an adult specimen of T. septentrionalis, dredged by the ' Challenger ' expedition, I counted no less than

twenty-eight young shells of the species attached to the surface of both valves, and more especially to its peduncle. — T. D.

DE. T. DAVIDSON OX RECENT BRACHIOPODA. 31

margin oi' the cirri, while the future position of the calcareous loop, or crura, was indi-

cated by a row of irregular-shaped spiculae. ... In these slightly advanced stages, the

peduncle becomes much shoi'ter in proportion to the length of the sliell In aU these

stages the peduncle has very slight adhesion to the rock or whatever substance it may be

attached to, in this respect differing greatly from the adult, which often requires at this

age great force to detach it I was fortunate in observing an individual [slightly

larger] in motion. The animal whirled quickly on its peduncle ; when at rest the sheUs

were always closed, and rested on the rock ; from this position it turned slowly more

than half way round, raising the body at the same time almost erect ; this movement

being completed, the valves would very slowly open, and the cirri expand as if to perform

a grasping motion ; in no case, however, were they projected beyond the margin of the

valves. The cilia lining the cirri produced gentle currents in the water. In this position,

with the valves widely open and the ckri expanded, the animal would remain motionless

for twenty or thirty seconds, and then, wdth an abrupt closing of the valves, suddenly

assume its first position In watching these motions for a long time, one could not

help being impressed with the fact that great caution was evidently indicated in the slow

and careful movements made in elevating and opening the shell, while the prompt closing

of the valves, and the alert manner in which the animal regained its first position, seemed

to show that food had been secured, and fm-ther caution was unnecessary."

Prof. Morse then goes on to describe how in successive stages a fold on each side of

the stomach was first noticed, these folds being the first appearance of the liver, then the

upper portion of the digestive sac and that portion which answers to the CBSophagus and

stomach in the contracted state, while the lower portion is widely expanded. In a still

more advanced stage, he says : — " The shell is now becoming proportionally broader and the

cirri increase in number, though still forming a simple circle around the mouth. The

crura have also begun to form. At a considerably more advanced stage " The cirri are

more numerous, numbering thirty-one : two of them are seen encroaching upon the

circular lophophore, and at this stage the lophophore has begun to assume its hippo-

crej)ian character.

" The crura are plainly seen supporting the crown of cirri, and the liver already shows

the first indications of its differentiations under the peculiar csecal ramifications which

become so numerous in the adult The divaricators are completely formed, and

between these two muscles is seen the lengthened intestine, the blind extremity of

which is held firmly to the shell by a membrane, called by Hancock the ventral

mesentery." At this stage " Radiating ribs, to the number of fifteen, ornament the

shell."

Successive stages are then described. At p. 35 of his admirable memoir. Prof. Morse

enters into Ions: details in connexion with the structure of the shell ; he savs : — " In the

youngest stages of the shell the scale-like structure may be studied to the best advantage.

The scales are few in number, but slightly overlapping, and form a layer quite distinct

from the outer layer, which appears to be homogeneous, save the concentric lines of

gi'owth appearing like rows of oblong and flattened nodules. The terminal portions of

the pallial caeca within or upon this outer layer, are brown in colour and distinctly

32 DE. T. DAVIDSON ON EECENT BKACHIOPODA.

arrauulated. . . . the tubules radiate from the larsjest diameter of the caeca, and not from

the periphery of the granulated disk, and this is in accordance with the admirable obser-

vations made by King *. The scales do not appear to encroach upon the walls of the

caeca."

Then follow many very important details on the growth of the shell, as well as the

gradual development of the crura and loop. The crura of the calcareous loop, although

not connected by a calcareous shelly layer in the young animal at all stages, have

portions nevertheless connected by a membrane charged with spicula. The peduncular

opening also, with age, becomes more circular, while the cardinal process, which does

not appear in the earlier stages, is latterly present.

In Prof. Morse's memoir in question a vast number of important details are

given, to which we have only briefly alluded.

I have myself examined specimens at all stages of growth, brought home by the

' Challenger ' Expedition, and I am able to confirm Prof. Morse's accurate observations.

When half a line in length the dorsal valve is elongate semicu-cular, the hinge-line

straight, and nearly as long as the breadth of the shell, only eight or nine rounded ribs

ornamenting the surface of each of its valves ; by degrees the hinge-line becomes shorter

and obtusely angular, and the ribs that ornament the surface of the valves become more

numerous.

14. Terbbratulina Wyvlllii, Davidson. (Plate III. figs. 1-3.)

TerebratulinaWyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 436, 1878, and [T.ivyvilii) Report on the

Bracliiopoda, Voyage of H.M.S. 'Challenger/ Zoology, vol. i. p. 32, pi. i. figs. 1-2, 1880.

SheU large, trigonal, longer than wide, broadest anteriorly, light yellowish; dorsal

valve triangular, anterior angles rounded ; hinge-line obtusely angular, moderately

convex, somewhat flattened along the middle, and abruptly bent inwards close to the

margin; lateral sides of the umbo auricular; ventral valve convex, deeper than the

opposite one, flattened anteriorly, abruptly bent inwards close to the margin ; beak

incurved, truncated by a large oval-shaped foramen, separated from the hinge-line by a

triangular concave depression sharply defined laterally ; surface of shell nearly smooth

to the naked eye, but marked by very fine radiating raised lines ; perforations rather

large. In the interior of the dorsal valve the loop is short and simple, rendered annular

by the tmion of the oral processes. Length 2J inches, breadth 2 inches, depth 1 inch

4 lines.

Mab. A single specimen of this fine species was dredged on the 25th of March, 1873,

by the ' Challenger ' Expedition off Culebra Island, to the north-west of St. Thomas, in

the West Indies, depth 390 fathoms. It was also obtained in some abimdance by the

Erench expeditions of the ' Travailleur ' and ' Talisman ' in 1882 and 1883, near the

western coast of Africa. It is alluded to by Prof. A. Milne-Edwards in the ' Comptes

Rendus de 1' Academic des Sciences,' tom. xciii. Nov. 1881, and has also, according to

Dr. P. Eischer, been dredged off the coast of Spain.

* " On the Histology of the Test of the Class Palliobranchiata,"' Traus. Royal Irish Academy, vol. xxiv.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 33

Obs. This is the largest species of Tercbratulina with whicli I am acquainted, eitlier iu

the recent or fossil condition.

16. Teeebratulina Crossii, Davidson. (Plate III. iigs. 4-6.)

Terebrutulina Crossei, Davidson, Journal do Conchyliologie, vol. xx\. ]>. lOH, pi. vii. fig. 1, 1882.

Shell large, elongated oval, longer than wide ; valves almost equally convex, mesial

fold and sinus scarcely indicated ; dorsal valve feebly auriculated ; beak of ventral valve

sliglitly incurved, obliquely truncated by a rather large foramen, margined in part by

the umbo and by two small lateral deltidial plates ; surface of valves covered with

numerous fine radiating strise, at times almost obsolete, and crossed by concentric lines

of growth. Colour light yellowish or light salmon. Loop short, not quite a third or

fourth of the length of the valve. Length 2 inches 1 line, width 1 inch 8 lines, depth

1 inch.

Ilab. This magnificent species occurs in Sagami Bay, Japan, where it was dredged by

Dr. L. Doderlciu. The locality is situated iu the neighbourhood of station No. 232 of the

* Challenger' Expedition, only a little nearer the coast, and in about 100 to 250 fathoms.

Dr. Doderlein, who kindly lent me the fine series of Brachiopoda procured by himself in

tliat locality, tells me that the sea-bottom is covered with mud, stones, and fragments

of volcanic origin, with abundant animal life of astonishing variety, and that there is

no better locality for dredging-purposes in Japanese waters.

Obs. I became first acquainted with this fine species in 1882, M. II. Crosse having

kindly forwarded a specimen he had received from Japan, which I subsequently described

and figured in his valuable ' Journal de Conchyliologie.' Soon after I was able to

purchase from Mr. G. B. Sowerby another good specimen of the same shell, and subse-

quently two other fine examples were lent to me by Dr. Doderlein. I have given figures

of three of the specimens. It does not appear to be a very rare species in the locality

where it is found.

I may also mention that no single locality has hitherto afforded a larger or more varied

assemblage of specific forms of Brachiopoda than the waters that surround the Japanese

islands, Corea, and the neighbouring coast of China. I have been able from those seas to

examine and describe the following species : —

1. Terehratuhi or TerehratuUna DalU, I)a.\\ihon. , 14. Terebruidla frontalis, l>.lu\i\cnAor^.

:>.

Davidsoni, Adams.

TerebratuUna Crossii, Davidson.

caput-serpentis , Linne.

japonica, G. B. Sowerby.

(5. Ctimiiiyi, Davidson.

7. radiata, Reeve.

8. Waldheimia Raphaelis, Dall.

9. Grayi, Davidson.

10. Tert'bratidia siiitzbcrijmsis, Davidson.

11. Blanfordi, Dunkcr.

12. coreanica, Reeve.

13. Maria-, Adams.

SECOND SERIES. — ZOOLOGY, VOL. IV.

15. Magasellu Adumsi, Davidson.

16. Gouldi, Dall.

17. Megerlia or Ismenia savgiiinea, Chemnitz.

18. Reevei, Davidson.

19. pidchella, G. B. Sowerby.

20. Laquem picta, Chemnitz.

21. rubella, G. B. Sowerl)y.

22. Plutydia aiiomioidcs, Seaeehi.

23. Rhyncltoiiellupsittacea, var. IVoodwardi, Adams.

24. lucida, Gould.

25. Doderlcini, Davidson (a s])ecies covered

with spines).

34 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

26. Crania japonica, Adams.

27. Discinisca stella, Gould.

28. Linciula anatina, Lamarck.

29. Adamsi, Dall.

30. Lim/ula jaspidea, Adams.

3 1 . smaragdina, Adams.

32. lepidula, Adams.

16. Terebrathlina japonica, Sowerby, sp. (Plate III. figs. 7-11.)

Terebratula japonica, Sowerby, Proc. Zool. Soc. 181(3, p. 91 ; Thes. Conch, vol. i. p. 314, pi. Ixviii.

figs. 7-8, 1846; Adams & Reeve, Voyage of tLe ' Samaraiig,' Mollusca, p. 71, pi. xxi. fig. 1, 1848.

Terebratula anyusta, Adams & Reeve, Voyage of the ' Samarang,' Mollusca, p. 71, pi. xxi. fig. 2, 1848.

Terebratiilina japonica, L. Reeve, Conch. Icon., Monogr. of Terebratula, pi. iv. fig. 16, 1860; A. Adams,

Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 98, 1863.

Terebratulina caput -sej-pentis, var. japonica, Davidson, Proc. Zool. Soc. 1871, p. 303, pi. xxx. fig. 8.

Terebratulina japonica, Dall, Cat. of the Recent Species of the Class Brach., Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 180.

Terebratulina caput-serpentis , var. japonica, G. Duuker, Index Moll, maris Japouici, p. 251, 1882.

Shell obloug, ovate, alnioud-shaped, widest about the middle, rounded iu front, valves

nearly equally and uniformly convex, no defined fold or sinus ; beak slightly incurved

and obliquely truncated by an incomplete circulai- foramen ; deltidial plates rudimentary.

Auricles in dorsal valve very small, marginal line nearly straight, inclining to the sides

near the hinge. Surface of valves longitudinally striated, striae numerous and radiating,

augmenting in number at intervals through the bifurcation of some of the ribs and by

the interpolation of shorter ones of variable thickness. Valves crossed by concentric

lines of growth. Colour light salmon or nearly white. In the interior of the dorsal

valve the loop is small and ring-shaped. Length 1 inch 4> lines, breadth 1 inch, depth

7 lines.

Ilab. Gotto, 48 fathoms ; Tsusalei, 55 fathoms (Adams) ; Sagami Bay, Japan

(Doderlein).

Obs. This species is remarkable on account of its spindle-like shape ; it is nearest related

to T. Crossii, and easily distinguished from the other recent species of the genus. Lovell

Ileeve says, in his Monograph of Terebratula, that " T. japonica is very closely allied to

T. caput-serpentis and is without doubt its representative in the Corean and Japanese

waters." I must, however, differ from Mr. Ileeve in this matter, although in 1871 I

expressed a similar opinion. Dr. Doderlein, it is true, dredged in Sagami Bay a specimen

which I could not distinguish from Linne's T. caput-serpetitls, but it differs in many

respects from T. japonica, which occurs in the same locality. I am, however, quite

prepared to concur with Mr. Reeve's statement that T. angusta, Adams & Ileeve, is only

a smaller form of T. japonica. Dall places T. ahijssicola, Reeve, T. angusta, Ileeve,

and T. Ctim'mgi, Davidson, among his synonyms of T. jajwnica. Reeve's figures of

T. abyssicola would hardly lead me to consider it a synonym of the above-named species,

and a similar doubt may be entertained with respect to T. Cumingi.

17. Terebeatulina radiata, Reeve. (Plate VI. figs. 9-11.)

Terebratula {Terebratulina) radiata, L. Reeve, Conch. Icoi). pi. iii. figs. 7 a~b, 1860, and Ann. & Mag.

Nat. Hist. 3rd ser. vol. vii. p. 173, 1861.

Terebratulina radiata, Dall, Proc. Acad. Nat. Sci. Philadcl|)hia, p. 180, 1873.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 35

Shell subpeutagoual or ovate, longer than wide, indented in front, fiexuously waved

towards the margin. Dorsal valve convex, anterior half biplicated, a median concave

depression commencing at about half the length of the valve, separating the two rounded

ribs. Ventral valve convex, somewhat flattened along the middle and divided on the

anterior half by a median rounded rib, with concave groove on either side. Beak short,

obliquely truncated by a rather large foramen, completed by a part of the umbo of the

opposite valve and by two small lateral deltidial plates. Surface of valves densely

covered with very fine radiating stria; of unequal width, and increasing in number through

bifurcation and the interpolation of shorter riblets. Colour dirty white, sometimes rayed

with broad pencils of black. Loop short and simple, incomplete when young, but with

age becoming annular through the union of the crural processes. Length 11 lines, by

9 in breadth and G in depth.

Rub. L. E,eeve says " Mr. Cuming possesses two or three specimens, all exactly alike,

procured, he fancies, from the dredgings of Sir E. Belcher in the Strait of Corea." I have

seen and possess a number of specimens of tliis shell, which Mr. Sowerby assures me were

obtained near the Cape of Good Hope, its probable habitat.

Ohs. ]\tr. Lovell Reeve considers this to be a good and well-marked species, and in

this statement I feel disposed to concur. I have seen a great many specimens of the

shell, some as wide as long, others longer than wide, and all presenting a more or less

well-marked biplication. In some exceptional examples there existed also an additional

rib on the lateral portions of the dorsal valve. T. radiata is remarkable, as observed by

Mr. E-eeve, on account of being very often sparingly rayed with black. It is a smaller

shell than T. cancellata, its nearest ally. In some specimens the foramen becomes

complete by the union of the deltidial plates, but this appears to be the exception and

not the rule.

18. Terebkatulixa cancellata, Koch, sp. (Plate VI. figs. 1-8.)

Terebratula cancellata, Koch, in Kiister, Concli.-Cab. vol. vii. p. 35, pi. 24. figs. 11-13, 181-3.

Terebratula, species quajdam ignota, Menke, Moll. Nov. Holland, specim. p. 35, no. 192.

Terebratula cancellata, So-nerby, Tlies. Concliyl. p. 358, pi. Ixxi. figs. 93-95, 1846.

Terebratula [Terebratulina) cancellata, Reeve, Conch. Icon. pi. iv. fig. 13, 18G0.

Terebratulina cancellata, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 179, 1873; Davidson, Report on

the Brachiopoda, Voyage of H.M.S. 'Challenger,' Zool. vol. i. p. 37, pi. i. figs. 11-16, 1880.

Shell rather large, elongated oval, livid brown or light yellowish with darker concentric

bands, widest about the middle, nearly straight in front. Dorsal valve very convex,

flattened longitudinally along the middle, from which the lateral portions slope away at

a strong angle. Ventral valve convex, rather less deep than the opposite one and some-

times flattened towards the front ; l)eak incurved, tapering, moderately produced and

truncated by a rather large foramen, which is very slightly separated from the hinge-line

by a very narrow deltidium, the beak often slightly overlying the um])o of the dorsal

valve. Surface of both valves ornamented with a great number of delicate raised striic

or riblets, increasing in number at various distances from the beaks by the interpolations

of shorter riblets. The surface is also crossed at intervals by fine concentric lines of

36 DK. T. DAVIDSON ON EECENT BRACHIOPODA.

i;;l•o^A'tb. In the interior of tlie dorsal valve the loop is simple and short, and rendered

annular in the adult by the union of the crural processes. Sliell-structure perforated by

canals. Brachial appendages united by a membrane and divided into three lobes, the

central shorter one spirally coiled. Length 1 inch 7 lines, breadth 1 inch, depth

10 lines.

Hab. Kiister informs us that his types were derived from Western Australia. His

figures are not good, and he colours them dark brown; some specimens, it is true,

are of livid brown, but those brought back by the ' Challenger ' Expedition were of a

yellowish colour. It was dredged abundantly by the ' Challenger ' Expedition in 1874

off Moncoeur Island, Bass's Strait, in a depth of 35 to 40 fathoms, sea-bottom mud ;

many of the specimens being attached by their peduncle to Fecten, Cardium, Area,

spines of Cidaris, stones, &c. A dwarfed form Avas also dredged for the first time by

Mr. John Brazier of Sydney, at Old Man's Hat Point, Inner North Head, oft' Port

Jackson, N.S.W., near the rocks, in 7 fathoms, bottom of dead broken shells with coarse

sand and stones ; also at Sow and Pigs Reef, eastern side, Port Jackson, near the rocks,

in 3 fathoms bottom. One example was Ibvmd adhering to a valve of TrUjonia

Lamarckii, Gray, and is the only specimen Mr. Brazier ever found on Trigonla.

Obs. When young T. cancellata is often longitudinally spindle-shaped and oval, but

with age shows more of a straight front. Some of the ' Challenger ' specimens have also

much exceeded in size those figured by Kilster, G. B. Sowerby, and L. Reeve. Tlicre exists

likewise in some exceptional sjoecimens a median depression on the anterior portion of

the dorsal valve, commencing at about the middle of the shell and extending to the front.

19. Terebratulina (Agulhasia) Davidsoni, King. (Plate VII. figs. 1-5.)

Ar/idhasia Davidsoni , King, Annals & Mag. of Nat. Hist. 4tli scr. vol. vii. p. Ill, pi. xi. figs. 1-7, 1871.

Terebratulina Davidsoni, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 180.

Shell very small, elongated triangular, much longer than wide. Dorsal valve about as

wide as long, broadest and slightly rounded anteriorly, more tapering posteriorly,

uniformly and moderately convex without fold, lateral sides of umbo gently auriculated.

Ventral valve pyramidal, rather deeper or more convex than the dorsal one and Avith a

slight mesial depression near the front, beak solid, nearly one third of the length of the

valve, tapering to a small incurved point, area in form of an acute isosceles triangle ;

deltidium long and narrow, closed except at the cardinal termination by the internal

plate, foramen incomplete and notch-shaped, lying close to the umbo of the opposite

valve. Surface of valves radiately striated with about twenty small ribs, of which about

half the number are shorter ones interpolated between the longer ribs. Loop in dorsal

valve short and simple, furnished with long crural spurs. Colour white. Length 3 lines,

by 2 in breadth and 1 in dejith.

Hab. Agulhas bank, South Africa, and obtained from a depth of 45 to 60 fathoms.

Ols. In 1870 several specimens of this elegant lyre-shaped shell were placed in my

hands by Mr. G. B. Sowerby, and having sent them to my distinguished friend Prof. W.

King, he kindly offered to publish a description of the shell under the name of Agidhasia

Davidsoni. Although possessing characters bearing relation to Terebratulina, Prof. King

DE. T. DAVIDSON ON EECENT BKACHIOPODA. 37

arrived at thr opiniou that it could be generically distiuguislied. Tiic chief ditfereuces

are to be found in the shape and character of the beak. " The long narrow form of the

deltidium," writes Prof. King, " causes the area to appear as if divided longitudinally by a

linear groove ; whch part is at once striking and unique. The foramen, which appears like

a notch in the centre of the cardinal edge of the large valve, is made entire 1)y the juxta-

position of the cardinal edge of the small valve. The area is well defined laterally I)y

each of the sutures whicji separate it from the inilexed sides of the beak. The loop

agrees very closely in form and relative size with that of Terebratula vitrea ; perhaps its

crural spurs are more produced. The tubuli apjjcar to run in rows, and to be most

numerous in the ribs, from which they branch olf laterally towards the furrows."

Mr. Dall believes the specimens described by Prof. King to be the young of some species

of Terehratid'mu, but the specimens I have in my possession Avould lead me to consider

them the adult condition of a very remarkable small species.

Uncertain Species.

20. Terebratulina Cumingi, Davidson. (Plate V. fig. 53.)

Terehratulina Cuminyii, Davidson, Proc. Zool. Soc. 18.12, p. 71), pi. xiv. figs. 17-19; Keeve, Coucli.

Icon., Mouogr. of Terebratula, pi. iv. fig. 12, LSGO.

Shell small, squarely ovate, somewhat pentagonal, nearly as wide as long; valves

almost equally convex ; beak small, obliquely truncated by a large incomplete foramen,

deltidial plates disunited, a small ])ortion of the aperture completed by the umbo ;

auricular expansions on either side of the umbo, very small ; valves rather gibbously

convex. Surface ornamented by a great number of minute radiating stria3, augmenting

rapidly by the interpolation of smaller riblets at variable distances from the beaks ; front

margin in ventral valve forming a convex curve, and slightly depressed near the front.

Loop small, annelliform. Colour opaque white. Length 3|, width. 3, dei^th 2 lines.

Hub. Chinese Seas.

Obs. Mr. L. Eeeve says that this is " An extremely characteristic well-defined species.

The radiating ridges do not all diverge together from the beak ; a new ridge com-

mences between each former ridge as the space enlarges to receive it." T. Cuminyi

seems to be distinguished from other species of the subgenus by its size and relative

width and length, being much more convex and globular. In 1871 (Proc. Zool. Soc.) I

thought that T. Cwningi might perhaps be a variety of T. caimt-serpentis, but am now

not of that opinion, for having seen a number of specimens of the Little Chinese shell, I

found them all to be possessed of the same shape and character.

In his " Catalogue of the Itecent Species of the Class Brachiopoda ' (Proc. Acad. jS'at.

Sci. Philadelphia, 1873), Mr. Dall places T. Cumingi among liis synonyms of T.japonica,

but I cannot agree Avith him in this particular.

21. Teeebrattjlina abyssicola, Adams & Eeeve, sp. (Plate V. fig. 54.)

Terebratula abyssicola, Adams & Reeve, Moll. Voyage of the ' Saniarang,' p. 72, pi. xxi. fig. 5, 1850 ;

L. Reeve, Conch. Icon. pi. iv. fig. 14, 18G0.

38 DR. T. DAVIDSON OX EECENT EEACHIOPODA.

" Shell triangularly pear-shaped, orange flesh-colour, radiately obsoletely ridged, ridges

distant, with numerous bifurcated striae coming between them, beak obtusely produced,

foramen rather large, incomplete, deltidium obsolete ; loop short" (Reeve). Length 5,

breadth 4|, depth 2^ lines.

Rab. Cape of Good Hope (dredged at a depth of 120 fathoms by Sir E. Belcher).

Ohs. I have seen three examples only of this species (?), one of which was attaclied to a

specimen of Krauss'ma rubra. In the type ligured by E-eeve there is evidence of a

longitudinal depression along the middle of the dorsal valve, and in an authenticated

example in my possession the riblets seem somewhat fasciculated.

Dall, at page 180 of his " Catalogue of the Recent Species of the Class Brachiopoda "

(Proc. Acad. Nat. Sci. Philadelphia, 1873), places T. abijssicola among his synonyms of

T. Jajionica ; but I fear I cannot concur with my friend in this identification. The Cape-

of-Good-Hope form is evidently more nearly related to T. caput-serpentls than to

T. jafonica. More specimens will have to be examined before a positive conclusion can

be arrived at with respect to its specific claims.

22. Terebratulina ? incerta, Davidson, (Plate VI. figs. 23-25.)

Megerlia (?) incerta, Davidson, Proc. Royal Sec. vol. xxvii. p. 438, 1878; and Report on the Brachio-

poda, Voyage of H.M.S. ' Challenger/ Zoology, vol. i. p. 49, 1880.

Shell small, nearly circular, somewhat broader than long, widest towards the middle.

Hinge-line long, nearly straight or very obtusely angular, rather exceeding two thirds of

the breadth of the shell, with obtuse cardinal angles. Dorsal valve somewhat semicircular,

very slightly convex, most so at the umbo, lateral sides of the umbo auricular, no fold or

sinus. Ventral valve a little deeper or more convex than the opposite one, slightly longi-

tudinally depressed along the middle ; beak short and truncated by an incomplete circular

foramen margined by the umbo of the dorsal valve and by two lateral deltidial plates ;

beak-margins sharply defined, leaving between them and the hinge-line a narrow area.

Surface of both valves marked by numerous fine rounded radiating riblets with concave

interspaces, some of the ribs bifurcating near the front, other shorter ones intervening

between the longer ones at variable distances from the beaks. Valves crossed by

numerous irregular concentric lines of growth. Shell perforated by minute canals.

Colour yellowish white. In the interior of the dorsal valve the cardinal process is long

and narrow ; the loop short and simple. Lengtli 5, breadth 5^, depth 2| lines.

Hab. One young example attached to L'mioims aurifa {?), Brocchi, and two or three

more were dredged by the ' Challenger ' Expedition between Sierra Leone (Africa)

and Eernando de Noronha (South Atlantic) in 1850 fathoms, associated witli Disciniscu

atlantica.

Obs. In 1880, when describing this shell for my ' Challenger ' lleport, I felt very

uncertain with respect to the genus to which it should be referred, especially as I was

unacquainted with the sliape and character of its looj:), and did itot like to run the risk of

opening the shell and separating its valves. Since then a number of specimens having

been obtained during the ' Blake ' Expedition, Mr. Dall was able to examine the loop,

which he found to be simple and short, as in Terebmtida or Terebratulina ; the lateral

DR. T. DAVIDSON ON EECENT BEACHIOPODA. 39

portions of the umbo are decidedly auricular, and the character ol' the radiating

riblets would, he thinks, warrant us in classing the shell in the last-named subgenus.

It appears to be a good species.

23. Terebkatulina Mtjrrati, Davidson. (Plate VI. figs. 15-17.)

Terebratvla Murrayi, Davidson, Proc. Roy. Soc. vol. xxvii. p. 437, 1878; and {Terebratulina murrayi)

Report of the Braehiopoda, Voyage of H. M.S. ' ChaUengcr,' Zoology, vol. i. p. 39, pi. i., 1880.

Shell small, obscurely trigonal, about as broad as long, widest anteriorly, tapering

posteriorly, white ; surface of valves marked with about seventeen rounded ribs, of which,

in some specimens, a few are due to the interpolation of smaller and shorter ribs between

the longer ones, the whole surface crossed also by fine concentric lines of growth.

Hinge-line obtusely angular. Ventral valve a little deeper than the dorsal one, beak

very slightly incurved, foramen rather large and incomplete, margined laterally by small

deltidial plates. In the interior of the dorsal valve the loop is simple. Length 2,

breadth 2 lines.

Hah. Dredged by tin; ' Challenger' Expedition in 1871, lat. 38° 35' S., long. 177° 50' W.,

near Kermadoc Island, soutli of Fiji Islands, in a depth of 600 fathoms.

Obs. .Some eleven examples of this small shell were dredged by the ' Challenger '

Expedition, and none exceeded the dimensions above given. It varied a good deal with

respect to the character of its ribs ; in some they were all simple, while in others smaller

and shorter ribs were interpolated here and there between the longer ones. The crura

likewise in some examples in the younger individuals were disunited. In 1879 I sent a

specimen to Mr. Dall for examination, and he wrote me, saying that " by devoting about

half an hour to this little shell, I have cleared away all the animal matter, leaving the loop

perfect. You will see at once that it is a young Terehratidimi. I suspected this before

I could see the loop, from the character of the punctuations, which, you will recollect, is

peculiar to the group." I had also previously ascertained that the loop is simple, and

that the mantle rises from the bottom of the shell near the loop and adheres to its sides,

as was so well illustrated by E. Deslongchamps in TerehratiUina caput-serpentis.

21. Terebratulina tuberata, Jeffreys, sp. (Plate VI. figs. 18-20.)

Terebratula tuberata, Jeffreys, MoUusca of the ' Lightning' and 'Porcupine' Expeditions, 1868-70,

Proc. Zool. Soc. 1878, p. 401, pi. xxii. fig. 2.

Shell somewhat triangular, broadest and rounded anteriorly, tapering posteriorly,

longer than wide. Dorsal valve semicircular ; hinge-line nearly straight, shorter than

the Avidth of tln^ shell ; vahe moderately convex and somewhat compressed, lateral sides

of umbo auricular. Ventral valve rather deeper than the dorsal one; beak pointed, very

little incurved ; area triangular ; foramen oval-shaped and incomplete, margined anteriorly

by the umbo of the ventral valve, laterally by small deltidial plates. Surface of valves

traversed by about twenty radiating ribs, of which some are shorter and interpolated

between the longer ones. Valves crossed likewise by numerous equidistant concentric

raised lines, sometimes slightly projecting and prickly in the young. In the dorsal valve

40 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

the crural processes are separated in the young, arched in tlie adult. Colour dirty white.

Length 4, lireadth 3, depth 2 lines.

Obs. This small shell was discovered by T)r. J. Gwyn Jeffreys, who described it as a

small or young specimen of TerebraUila, which he had obtained during the ' Porcupine '

Expedition in 1870, at a depth of 795 fathoms; and he adds that Prof. Loven bad lent

him a perfect example from the Josephine Bank off the Straits of Gibraltar, di-edged iu

340 to 430 fathoms. Since then several larger and more adult examples were also

obtained by the French dredging expeditions in 1882 and 1883, off the western coast

of Africa, at a depth of about 4787 metres, and off Morocco and Sahara (' Talisman '

Expedition), in 300 to 1261 fathoms.

25. Teeebratulina teigona, Jeffreys, sp. (Plate VI. figs. 21, 22.)

Terebratula trigona, Jeffreys, Mollusca of the 'Lightning' and 'Porcupine' Expeditions, 18fi<S-70,

Proc. Zool. Soc. 1878, p. 402, pi. xxii. fig. 3.

Shell small, ovate, broadly rounded anteriorly, tapering posteriorly, moderately

convex, semitransparent between the ribs and glossy ; beak short, foramen rather

large, incomplete, lateral deltidial plates small ; hinge-line obtusely angular. Sur-

face of the valves marked by about eleven simple rounded ribs, of which the three

central ones are the largest. Coecal tubuli numerous. Margins gently curved and

scalloped in front. Surface of valves marked with numerous equidistant raised lines.

Loop short, simple, and semicircular. Colour clear white. Length scarcely 2 lines,

breadth 1 i.

Obs. We know so very little about this so-called species that its specific claims cannot

])e substantiated. I have only seen a single living specimen, that dredged by Mr. Saville

Kent in Marshall Hall's yacht ' Noma' off the coast of Portugal, in about 500 fathoms.

Dr. J. Gwyn Jeffreys, who described the shell in 1878, says : — " It may perhaps be

immature ; but I cannot identify it with the young of any other species." In this I

feel disposed to agree with Mr. Jeffreys, as I examined the specimen with great

attention while drawing the figures for his paper.

Genus WALDHEIMIA, King, 1850*.

This excellent genus was founded in 1850 by Prof. AV. King for those Terehratulce

in which the dorsal valve was jn-ovided with a long deeply reflected loop, having its

crura attached to the hinge-plate, as is seen in the recent type Terebratula jlavescens,

Lamarck. In the same year Prof. King proposed a genus Macandrevia for a shell with

a similar loop, in which the umbonal cavity of the ventral valve is furnished with two

dental plates, passing somewhat perpendicularly from tlie dental prominences to the

surface of the valve, the umbonal cavitv in the dorsal valve lieing also furnished with

o

* In 1840, four years jirior to the p\ililication of King's name WaJdheimia for a Eraohiopod, the same name had

heen given by Brulle to an insect ; and both Prof. J. Hall and E. Deslongchamps question whether it can consequently

be retained for a Brachiopod,

DK. T. DAVn)S(1N OX EECEXT BEACHIOPODA. -tl

similarly directed iiUites, aud for this geuus he selected the recent Terehralida craniuni.

Miiller, as his type.

In 1880 M. Douville proposed a genus Neothyris for another recent species with a

similar long loop, of Mhich the Terebratula lenticularis, Deshayes, would constitute the

type.

I cannot, however, hut consider these so-termed genera to he very nearly conne(!t<Ml

and as mere moditications of Waldhcimia, and not sufficiently important to warrant theii-

separation into distinct genera.

After a long examination and much thought, I determined to retain the following ten

species and one uncertain one : —

1. It'ald/iei/nia flavescens, Lamarck

2. kergmdenensis, Davidson.

.3. Grayi, Davidson.

4. sept i (/era, Loven.

5. Rupluu'lis, Dall.

0. Wnldheimia floridana, Pourtalcs,

7. vvnosa, Solander.

<S. ■ leniicularis , Deshayes.

9. [Macundrevla) craniam, Miillcr.

10. ( ) tencra, Jetfreys.

Uncertain : Waldheimia IVyviUii, Davidson.

The characters of hotli Waldheimia and Macandrevia will he found fully recorded in

our descriptions of W. flavescens and W. cranium.

Calcareous spicula are absent or almost so in the species above named. Numerous

metamorphoses or changes take place in the shape or development of the loop during;' thr

different stages of its growth, as will he fully described in the sequel.

26. Waldheimia flavescens, Lamarck, sp. (Plate VII. figs. G-19.)

Terebratula flavescens, Valenciennes apud Lamai'ck, An. sans Vert. vol. vi. p. 24G, 1819.

Terebratula australis, Qnoy & Gaimard, Voyage de I'Astrolabe, Zool. p. 551, pi. Ixxxv. figs. 1-5, 1831.

Terebratula incurva, Quoy & Gaimavd, loc. cit. p. 551, pi. Ixxxv. tigs. 11 & 12, 1834.

Terebratula australis, G. B. Sowerby, Thcs. Conch, p. 349, pi. Ixix. figs. 25-33, 1846.

Waldheimia australis. King, English Permian Fossils, Pal. Soc. p. 145, pi. xx. figs. 10-12, 1849.

Terebratula australis, Davidson, Classification of Recent Brachiopnda, Ann. & Mag. Nat. Hist. 2ii(l

scr. vol. ix. p. 3U5, 1852.

Waldheimia Jlavescens, Davidson, Brit. Foss. Bracli. vol. i. p. 64, figs. G & 7, 1853 ; R. Owen, David-son's

Mon. Pal. Soc. vol. i. chapter 1, 1853.

Waldheimia australis,?). Woodward, A Manual of the Mollusca, p. 216, figs. 113 & 111, 1854; Gratiolet,

Etudes Anatomiqucs sur la Terebratula australis, Journal de Concliyliologie, 1857; A. Hancock, On

the Organization of the Brachiopoda, Phil. Trans. Royal Soc. vol. 148, p. 791, 1858.

JJ'aldheimia flavescens, H. & A. Adams, The Genera of Recent Mollusca, vol. ii. p. 575, vol. iii. pi. cxxx.

fig. 3, 1858.

Terebratula {Waldheimia) flavescens, L. Reeve, Monogr. of Terebratula, Conch. Icon. pis. 1 & 2,

fig. 1 a, b, 1860.

Waldheimia australis, Huxley, An Introduction to the Classif. of Animals, p. 28, fig. 10, 1869.

Waldheimia flavescens, Dall, Amer. Journ, of Conch, vol. vi. p. 108, 1870, and Proe. Acad. Nat. Sci.

Philadelphia, 1873, p. 181 ; Tenison Woods, Proe. Roy. Soc. of Tasmania, 1877, p. 57 ; Douville, Bull.

Soc. Geol. de France, 3« ser. pi. vii., 1879 ; Davidson, Report on the Brachiopoda, Voyage of H.]\I.S.

' Challenger,' Zool. vol. i. p. 41, pi. iii. figs. 10-12, 1880; Zittel, Handbuch der Palaontologie, pp. 645

SECOND SEKIES. — ZOOLOGY, VOL. IV. 6

42

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

& 702, 1880 ; E. Deslongchamps, Etudes critiques sur les Brachiopodes, pp. 172 & 177, 1881 ; Davidson,

Pal. Soc. Brit. Foss. Brach. vol. v. p. 323, 1884.

Shell longer thau wide, ovate or subpentagonal, broadest about the middle, straight

in front, yellowish or light brown. Dorsal valve convex, sometimes flattened from

about the middle of the valve to the front ; ventral valve rather deeper and more convex

tlian the opposite one, with a slightly raised longitudinal flattened elevation or fold

along the middle. Beak moderately incurved, truncated by a circular foramen, some-

wliat separated from the hinge-line by adeltidium ; beak-ridges sharply defined. Surface

of both valves from the beaks generally smooth up to a certain age, then radiating and

irregularly plaited, some ribs being shorter than others, the central one straight, those on

tlu> lateral portions of the valves somewhat curved. Shell-structure perforated by canals.

In the interior of the dorsal valve the loop is long and simple ; after being attached to

the hinge-plate and its crural processes given off, the principal stems are outwardly

Fis. 3.

Fig. 4.

Waldheimiajlavescens. Interior of both Valves, enlarged.

Fig. 3. Interior of the ventral valve : /, foramen ; d, deltidium : t, teeth ; a, adductor impressions (=occlusors

of Hancock); c, divaricators ( = cardinal muscles of King = muscles diducteurs principaux of Gratiolet) :

c , accessory divaricators ( = muscles diducteurs of Gratiolet) : h, ventral adjusters ( =ventral peduncular

muscles, or muscles du pedoncule, paire superieure, Gratiolet) ; 6', peduncular muscle.

Fig. 4. Interior of the dorsal valve : c, c , cardinal process : h, h', hinge-plate ; «, dental sockets ; I, loop ; q, crura ;

.^ a, «,, adductor impressions ; m, septum.

curved, and on reaching to about three fourths of the length of the valve become

reflected. The median septum extends along the bottom of the shell from under the

hinge-plate to a little beyond one third of the length of the valve. Brachial or labial

appendages largely developed and united to each other by a membrane. The principal

lateral branches commence on either side of the mouth, curving outward and facing

the bottom of the smaller valve, extend to within a short distance of the front ; then

becoming suddenly bent back upon themselves to within a short distance of the

mouth, are by an elegant semicircular curve directed towards the centre of the larger

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 4:{

valve, and form the commencement of the shorter spiral central lobe. Dimensions very

variable, a large well-shaped example measured — length 1 inch 7 lines, breadth 1 inch

4 lines, depth 1 inch.

Hah. Waldheimia fiavescens { = aus(rcd!s) was picked up in great numbers by thr

' Challenger ' Expedition on the 3rd of June, 1874, at Port Jackson, N. S. W., on the

shore, and in from two to ten feet depth of water. Mr. John Brazier, who has dredged

extensively in the seas adjoining New South Wales, has kindly sent me specimens from

Point Piper, Port Jackson, found under stones in clusters like grapes during low spring-

tides, also on Os/i'ca glomerata, Gould, with a specimen of Kraussina Lamarcldano

on the inside ; a young or smooth variety on a piece of shell with Ismenia or Mecjerlift

pulchella, from the inner north head of Port Jackson, at 10 fathoms, on a bottom of

sand and broken shells ; likewise from Bottle and Glass Rocks, Port Jackson ; and also

from off Shark Point, Port Jackson, at a depth of 14 fathoms. Quoy and Gaimard

found this species, in 1834, in immense numbers at Port Western, Bass Strait. Tliey

observe that hundreds were brought up at each haul of the dredge, either grouped

among themselves, or attached to other shells ; also at Port Jackson, in four feet of

Avater. Prof. Beete Jukes collected any number while boating in South Australia,

among the reefs at Port Jackson ; indeed this is one of the commonest species in the

locality. The Rev. Tenison Woods observes, in his ' Census of the Marine Shells of

Tasmania,' that Waldheimia jlavescens is found off all South Australia, but only on the

north coast of Tasmania.

Obs. I have nothing much to add to my description of this well-known species given

in the ' Challenger ' Report. The shell has received four or five different specific

names, but the best known are those oi jlavescens, Lamarck, and uustraUs, Quoy. In

1819, Lamarck having become blind, Valenciennes described for Lamarck the species

in question, under the names of Terehmtula flavescens and T. dentata ; but he gives

no figures of his species, and upon inquiring from Valenciennes, in 1882, I found that

it was to a specimen from Port Jackson tliat he gave the name o'i Jlavescens. Tlic

larger number of malacologists have preferred the name of austraUs, given to it iii

1834 by Quoy and Gaimard, Avho gave a number of good illustrations of the shell,

including that of the loop *. Quoy's T. recurca is no more than a short variation in

form of a specimen in which the beak is much incurved ; and the same may be said of

Lamarck's T. dentata.

Waldheimia flavescens is very variable in shape and ribbing. In some examples the

beak is longer or more produced than in others, and the foramen much more distant

from the hinge-line in some individuals than in others. Some specimens are also more

or less subpentagoual, others elongated oval, some lozenge-shaped and circular. The

valves in some examples are quite smooth in the young, and very often up to an advanced

stage of growth. In other specimens the ribs are simple or bifurcating, and of differeni

size and strength on the same individual, and begin to rise close to, or at some distance

from, the extremity of the beak and umbo. In PL VII. some of these modifications

in shape and character have been illustrated.

* Voyage dc TAstrolabo, Atlas, pi. 85 (18:34).

6*

44 DE. T. DAVIDSON ON KECENT BRACHIOPODA.

The loop passes likewise through a series of metamorphoses from the very young

state up to the period when it assumes the simple adult Tfaldheinda-chareicter, as has

been so elaborately described and illustrated by Herman Friele in the case of TFald-

heimia septlgera and Wcddheimia (or Macandrevia) cranium.

The intimate shell-structure of JValdheimia ficwescens has been minutely described and

admirably illustrated by Dr. W. B. Carpenter, in his chapter " On the Intimate Structure

of the Shells of the Brachiopoda," which he kindly prepared in 1853 for vol. i. of my

' Monograph on British Fossil Brachiopoda,' and to which the reader is referred. But we

may here mention that he found the perforations in 7?^. jiavescens to average a diameter

of about 8^0 inch, and the distance of their centres about j^. Three of his illus-

trations have been given in PI. VII. figs. 17-19.

In 1869, in vol. xxiv. of the Transactions of the Royal Irish Academy, Prof. W. King

gave an excellent description of the shell-structure of the species under description, in

which he observes that Quekett, in 1850, discovered that the extremity of the caecal

appendages, as they are now^ generally called, is more or less flattened or disk-shaped, and

encircled with a fringe of exceedingly minute radiating lines or membranous filaments.

Prof. King adds, " In position and arrangement the ^laments belonging to the termina-

tions of the ca?cal appendages so completely agree with the radiating lines which intersect

the apertural rims of the perforations, as to leave no doubt on my mind that the latter

are tubular and enclose the former." The shell of JF. Jiavescens and its intimate shell-

structure is also described by Gratiolet, in his admirable memoir " Etudes anatomiques

sur la Terebratule australe," Journal de Conchyliologie, 1857. He says, at p. 214 of his

memoir, that the shell, when divested of the foreign objects that generally cover its

surface, is of a tolerable transparency. One notices in it, besides the concentric lines of

growth, diverging costae which give to the sharp edge of the valves an undulated appear-

ance ; examined with a lens, its surface is finely granulous, so much so, that one might

think it formed of veiy fine granulations ; but this aj)parent granulation is due to a

multitude of microscopic perforations with Avhich the shell is riddled. These perforations

are, besides, very irregularly disposed on parallel bands which intercept quadrilateral

spaces. He adds that the substance of the shell is formed of small calcareous prisms,

somewhat attenuated at their extremity and disposed in parallel layers, which give

to the fractured shell a fibrous aspect ; these elements are closer together towards the

edges of the shell than in their central poi'tions.

The soft parts of the animal of Waldheimia Jiavescens have been admirably described

and elaborately illustrated by several eminent anatomists. First by Owen in 1853, in

the Introduction to vol. i. of my work on ' British Fossil Brachiopoda ; ' subsequently,

in 1857, by Pierre Gratiolet, in his memoir above quoted, and in the following year by

Albany Hancock, in his classical memoir " On the Organization of the Brachiopoda "

(Phil. Trans. Boy. Soc. vol. cxlviii.). To these works the reader is referred for more

complete anatomical details than we are able to reproduce in this monograph.

The body proper is small when compared with the size of the shell, and has both its

valves lined by a delicate bilobed integument or membrane, termed the ' pallium ' or

mantle ; this secretes the shell and is fringed with horny bristles. The mantle is composed

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

45

of an outer and an inner layer, between wliicli are situated tlie blood-channels or lacunae.

There are four principal arterial trunks in the dorsal lobe of the mantle, and these run

direct to the front and bifurcate at intervals (see PI. VII. figs. 15, 16 d). The aperture

of the mouth is situated in the middle line between the pallial lobes, and on each side

of it is a prolongation of the body provided with ciliated teatacula.

The muscles have been minutely described by the three anatomists above named.

Five or six pairs are connected with the opening and closing of the valves, or with their

attachment to, or movements upon, the peduncle. First of all the adductoi- or occlusor

consists of two muscles, which, bifurcating near the centre of the cavity, produce a large

quadrangular impression on the internal surface of the dorsal valve. The function of

FiE

Waldhwnia JldvcKCtns (after Hancock).

M, ventral Talvc : X, dorsal valve ; J, loop : r, mouth ; :. extremit)- of intestine : a, adductor : f, divaricators ;

(■', accessory divaricators; h, ventral adjustors; h\ peduncular muscle; h" , dorsal adjustors ; P, peduncle.

this pair of muscles is the closing of the valves. Two other pairs have been termed

dkarlcatoi's by Hancock, and have the function of opening the valves. The divaricators

proper arc stated by the same eminent authority to rise from the ventral valve, one on

each side, a little in advance of and close to the adductors, and after rapidly diminishing

in size, become attached to the cardinal process, a space or prominence between the sockets

in the dorsal valve. The accessory divaricators are a pair of small muscles which have

their ends attached to the ventral valve, one on each side of the median line, a little

l)ohind the united basis of the adductors, and again to the extreme point of the cardinal

process. The two pairs of muscles, apparently connected with the peduncle and their

limited movements, have been minutely described by Hancock as having one of then-

extremities attached to this organ. Tlie dorsal adjustors are attached to the ventral

surface of the peduncle, and are again inserted into the hinge-plate of the smaller valve.

The ventral adjustors are considered to pass from the inner extremity of the peduncle,

and to become attached by one pair of their extremities to the ventral valve, one on

each side of and a little behind tlie expanded base of the divaricators. The function ot

these muscles is not only that of erecting the shell, but also that of attaching the

46 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

peduncle to the shell, and thus controlling the steadying of it upon the peduncle. These

details and the figure taken from Hancock will sufficiently explain the functions of the

different muscles. Hancock describes the peduncle as composed of a dense muscular,

semi-cai'tilaginous mass of a cylindrical form.

The nature of the muscles has also been well described and illustrated by Owen,

Gratiolet, and more recently by Van Bemmelen, in his anatomical memoir ' On the

Structure of the Shells of Brachiopods and Chitons ' *.

Owing to the strong and tiglit interlocking of the valves of Waldhelmia flavescens and

other species, by means of curved teeth and sockets, the Brachiopoda would seem to open

their valves very slightly.

At p. 806 of the admirable memoir already alluded to, Hancock says that in Waldlieimia

flavescens and in other forms of the genus, the " loop originates in the hinge-plate in

two necks or processes, — the crvira, from which two jioints project downwards, called the

crural processes. The upper or dorsal members of the loop, passing from these two

lateral necks, stretch forward for about two thirds the length of the valve, then bend

towards the ventral valve, and turning back upon their course, are united across the

median line, a short way in advance of the crural processes. The lateral portions of

the loop are curved a little outwards. The whole of this calcareous support, in-

cluding the crura and crural processes, is a product of the inner lamina of the dorsal

pallial lolje. This lamina, with the exception of a portion at each side, which is con-

tinuous with the similar lamina of the ventral lobe, forming with it the anterior wall of

the perivisceral chamber, is turned downwards and forwards, and extends as far as the

transverse portion of the loop. It then divides into two lobules, one passing to the

anterior extremity of each of the lateral portions of this calcareous support, binding

together the dorsal and ventral members. The loop in its sinuous course follows tlie

margins of this bifurcated pallial process, and lies imbedded in its substance.

" The arms themselves taper to fine jioints, having taken their origin at each side of the

mouth, which is situated at the back of the pallial chamber in a central position, opening

downwards. They pass outwards and forwards in connection with the calcareous loop and

the pallial lobules, running along the outer edge of the dorsal member of the former ;

they then turn back upon the reflected or ventral part of it, and on reaching the trans-

verse portion bend inwards and doubling sharply upon themselves, again advance and

go to form two vertical spirals turned towards the dorsal valve. The spirals are placed

parallel to each other, and throughout the coil, consisting of two or three turns, they

are united across the median line by a rather wide, stout, semicartilaginous membrane,

which is attached behind the transverse portion of the loop."

The labial appendages have been magnificently illustrated by Owen in plates 1 & 2

of his chapter on the ' Anatomy of the Terehratula ' already referred to. They are also

minutely described and illustrated by Gratiolet in his ' Etudes anatomiques sur la

Terebratule australe,' 1857.

These appendages are, in TF'aldheimia flavescens, as well as in other species of the

* ' Over den Bouw der Schclpcn van Brachiopodeii en Chitonen,' Leiden, 18S2, and of which an English note will be

found in the Ann. & Mag. Nat. Hist. 5th ser. vol. xi. p. '37Q, 1S83.

DR. T. DAVIDSON ON RECENT BRACHIOPODA.

47

genus, a pair of very remarkable organs, eminently cbaraetcristie of the Brachiopoda.

'J'hey are often and more correctly termed labial appendages, on account of each member

being a prolongation of the lateral portions of the lips of the margins of the mouth.

They occvipy the larger portion of the cavity of the shell in front of the visceral chamber ;

FiK. 0.

Fis;. 7.

Wahlheimia Jlavescen.t.

Vi". 6. Interior of dorsal valve, to show the position of the labial appendages. (A portion of the fringe of the

cirri has been removed to show the brachial membrane and a portion of the spiral extremities of the

arms.) Enlarged.

Fig. 7. Longitudinal section, with a portion of the animal. (/, 7;, brachial appendages ; a, adductor : c, c', divari-

cator muscles ; s, septum ; v, mouth ; :, extremity of alimeutarj* tube. (The peduncular muscles have

been purposelj- omitted.) Enlarged.

and are mainly composed of a membranous tube fringed on one side Avith long flexible

hollow cirri, which are not capal)le of being protruded in those families and genera in

which they ai"e folded back upon themselves and supported T)y a skeleton, as in JFald-

heiiJiia. Hancock says (Phil. Trans, vol. cxlviii. p. cxliii.) that the arms or labial appendages

" are normally composed of a membranous tube or canal bearing a semicartilaginous

grooved ridge. The latter stretches from end to end of the former, and gives support

to the fringe of cirri. As far back as the commencement of the spirals the arms are as

above stated ; but for the entire length of the lateral portions of the loop, wiiere the

arms are doubled ujion themselves, and Avhere, of course, two tvibes or canals might have

been expected, thex'e is only one, the two having, as it were, coalesced. These large canals

at the roots of the arms are continuous with those of the spirals, and terminate in blind

sacs, one at each side of the oesophagus, close to the mouth. On making a transverse

section of this part of the arm, the enlarged terminal portion of the brachial corn' i-

seen connected with the external edges of the dorsal and ventral mem])ers of the loop ;

and the pallial lobule, stretching between the inner edges, forms a sort of inner tube.

This inner tul^e opens widely into the perivisceral chambei*, is in fact a prolongation of

48

DE. T. DAVIDSON ON RECENT BRACHIOPODA.

this chamber, aud terminates at the anterior extremity of the lateral portion of the loop,

forming what may be designated as the brachial pouches. The cirri are tindoubtedly

contractile to some extent, and are also endowed Avith the power of motion individually,

as proved by the observations of Mr. Barrett. It would likewise appear that the

entire fringe of cirri can be elevated or depressed, there being ample means provided for

tlie purpose." Many other highly important details have been recorded by Owen,

Gratiolet, and Hancock, which I regret I am unable to reproduce.

Mr. Hancock states, at p. 811 of his memoir, that "the mouth, in all the Brachiopods,

as previously stated, is situated in the brachial groove, at the posterior junction of the

arms, and is a simple, oval, transverse slit, or orifice devoid of any armature. In

JF. australls there is, however, a slight bulging-out of the posterior wall immediately

within the orifice, which is somewhat like the valvular appendage of Phimatella, and may

perhaps assist in swallowing. The alimentary tube assumes the form of a siphon bent in

the vertical plane, the arch turned towards the dorsal valve ; the oesophagus represents

the short, the stomach and intestine the long arm."

There is no anal outlet in this species. According to the same author, the mesentery

is divided into two portions, the dorsal and ventral : it sustains the alimentary canal in

the vertical plane, and altogether with it divides the anterior portion of the chamber

into lateral halves. The gastro-parietal bands are three in number, two lateral and one

median.

In W. flaveseens, Mr. Hancock says, " the genitalia are formed of thick bands,

Fig. 8.

Lateral view of the Viscera of WaJdheimiaJiavescms, after Hancock,

n, anterior layer of mantle ; b, posterior layer; c, anterior walls of the body between the mantle-lobes ; (7, arms;

p, gullet ; q, stomach, with cut biliary ducts of the left side ; r, right hepatic mass : s, intestine ending

ca'cally between j and k ; v, so-called " auricle " of the right " pseudo-heart," the left being almost wholly

removed ; w, pyriform vesicle fixed to the back of the stomach, and probably performing the function of a

true heart ; r, oesophageal ganglia. (This figure is also given by Huxley on page 28 of his ' Introduction to

the Classification of Animals,' 1869.)

DR. T. DAVIDSON ON EECEXT BRACIIIOPODA. 49

somewhat convoluted and branched ; they are of a full yellow colour, and are thrust

into the trunks and main branches of the great pallial sinuses" (p. 817).

" The heart is a simple, unilocular, pyriform vesicle, suspended from the dorsal aspect,

and projects freely into the perivisceral chamber " {loc. cit. p. 831).

Prof. Huxley, in his ' Introduction to the Classification of Animals,' 18G9, says that

" The precise characters of the true vascular system of the Brachiopoda probably

require still further elaboration than they have yet received ; and the same may be

said, notwithstanding the valuable contributions of P. Midler and of Lacaze-Duthiers,

of their development ; but the shell, the pallial lol^es, the intestine, and the nervous and

the atrial systems, afford characters amply sufficient to define the class " (p. 30). He also

says (p. 29), " In all Brachiopoda which have been carefully dissected, a singular system of

cavities and canals situated in the interior of the body, but in free communication \\i\\\ the

surrounding medium, has been discovered. This, which I shall term the ' atrial ' system

(from its close coi'respondcnce with the system of cavities, which has received the same

name in the Ascidians), has been Avrongly regarded as a part of the true vascular system,

and the organs by which it is placed in communication with the exterior have been

described as ' hearts.' There are sometimes two and sometimes four of these ' pseudo-

hearts,' situated in that part of the body-wall which helps to bound the pallial chamber.

Each pseudo-heart is divided into a narrow, elongated, external portion (the so-called

' ventricle '), Avhich communicates, as Mr. Hancock has proved, by a small apical aperture

with the pallial cavity ; and a broad, funnel-shaped, inner division (the so-called ' auricle '),

communicating, on the one hand, liy a constricted neck with the so-called ' ventricle,'

and on the other, by a wide, patent mouth, with a chamber which occupies most of the

cavity of the body proper, and sends more or less branched diverticula into the pallial

lobes. These have been described as parts of the blood vascular system; and the

arterial trunks, Avhich have no existence, have been imagined to connect the apices

of the ventricles with vascular networks of a similarly mythical character, supposed

to open into the branched diverticula. In fact, as Mr. Hancock has so Avell shown in

his splendid and exhaustive memoir published in the ' Philosophical Transactions ' for

1857, the true vascular system is completely distinct from this remarkable series of

' atrial' chambers and canals, the function of which would appear to be to convey away

excretory matters and the products of the reproductive organs, which are developed in

various parts of the walls of the atrial system."

In an exquisitely beautiful enlarged illustration in his ' Anatomy of the Terebratiila,'

Owen represents the bracliial aponeurosis and spii*al arms of JJ^aldheimia Jlavcscens,

showing the central part of the nervous system, with the brachial and the beginning

of the pallial nerves.

27. WALBHEniiA VEXOSA, Solaudcr, sp. (Plate YIII. figs. 1-5 ; Plate IX. fig. 1.)

Anontia venosa, Solander, G. Dixon, A Voyage round the World, Appendix no. 1, p. 355 and fig., 1789.

Terehrutula glohosa, Valenciennes, apiid Lamarck, An. sans Vert. vol. vi. j). 2ifi, 1819, with

reference for figui-e to Encyclop. Method, p. 239, figs. 5 a, b, 1789.

Terebratula dilatata, Valenciennes apud Lam., An. sans Vert. vol. vi. p. 215, 1819.

SECOND SERIES. — ZOOLOGY, VOL. IV. 7

50 Dli. T. DAVIDSON ON EECENT BEACHIOPODA.

Terebrafula Gaudichaudi, Blainville, Diet. Sci. Nat. 1824.

Terebratula globosa, Anton, Verzeichniss der Couchylien, p. 23, 1839.

Terebratula eximia, Philippi, Kiister, Conch.-Cab. vol. vii. p. 39, pi. 2. figs. 9 & 10, 1843.

Terebratula Fontaineana, d'Orbigny, Voy. Amer. Merid. vol. v. p. 675, pi. 85. figs. 30 & 31, 1847.

Terebratula {Waldheiinia) ylobosa, Heeve, " Mouogr. of Terebratula," Conch. Icon. pi. ii. fig. 3, 1860,

and pi. vi., 1861.

Terebratula {Waldheimia) globosa, Reeve, Ann. & Mag. Nat. Hist. vol. vii. p. 173, 1861.

Terebratula [Waldheimia) dilutata, Reeve, Conch. Icon. pi. vi. fig. 2, 1861.

Terebratula physema, Valenciennes, MS. ; Reeve, Conch. Icon. pi. vi. fig. 23, 1861.

Waldheimia venosa, Davidson, Ann. & Mag. Nat. Hist. 3i'd ser. vol. viii. p. 36, 1861.

Terebratula venosa, Cunningham, Voyage o£ H.M.S. Nassau, Trans. Linn. iSoc. vol. xxvii. p. 488, 1871.

Waldheimia venosa, Dall, Amer. Journ. of Conch, vol. vi. p. 109, 1870, and Proc. Acad. Sci. Phila-

delphia, p. 182, 1872.

Shell large, longitudinally oval, ovately globose, widest about tlie middle, longer than

wide. Dorsal valve convex, with a shallow flattened longitudinal depression or sinus

along the middle, commencing at about half the length of the valve and extending to

the front. Ventral valve a little more convex than the opposite one, with a slightly

produced and flattened mesial fold commencing near the beak and extending to the

front ; beak moderately incurved and truncated by a rather large circular foramen, with

thickened margin and completed anteriorly by a deltidium in two pieces ; beak-ridges

sharply defined. Surface of valves smooth, marked only by concentric lines of growth.

Shell-structure punctate. Colour light olive-horny. Loop long and reflected ; cardinal

process and hinge-plate large. Under the hinge-plate a rather strong mesial septum

extends to a third or a little more of the length of the valve, and on either side on the

bottom of the shell are situated the adductor and other muscular scars. Length 3 inches

2 lines, breadth 2 inches 8 lines, depth 2 inches.

Sab. Tierra del Fuego ; Falkland Islands (Dixon) ; Port William, Falkland Islands

(B. J. Sulivan) ; Coquimbo ; off Cape Possession in about 15 fathoms ; Port Famine

(Cunningham).

Obs. This is the largest recent Brachiopod at present knov\^n, and its history has been

somewhat confused. It was, however, well described and figured in 1789 by Captain

George Dixou, who says, at p. 356 of his work ' A Voyage round the World ' : — "At Falk-

land Islands we met with a curious kind of shell of the Anomia genus of Linnaeus, of

which, though the species are numerous in a fossil state in most parts of the world, few

have been discovered recent, or fresh from the sea. Only one of this sort was before

known in Europe, which was brought over by my late worthy commander, the much

regretted Captain Cook, in his first voyage round the world. It was in the Portland

Museum, and was named by the late celebrated Dr. Solander, in his MSS. description of

the shells of that splendid cabinet, Anomia venosa ; the specimen is now in the

collection of Mr. Calonne, of London. This kind (as do all that are propei'ly of this

genus) adheres to coral rocks by a ligament that comes from the animal through the

hole in the larger valve. The internal structure peculiar to the shells of this genus

is very singular, and consists of two testaceous rays, which commence near the

hinge in the lesser valve, where they adhere ; from w hence, leaving the shell, they

DE. T. DAVIDSON ON RECENT BEACHIOPODA. 51

proceed to ncai' the edge, then bend towards the other valve, and turn back to their

commencement, where they nnite. This internal part is very delicate, and breaks upon

the smallest touch, but is thicker in the parts nearest to the large valve. The shell takes

its name from certain parts of the animal, which run in a branched form along the inside

of the shell, which being held to a strong light, or a candle, gives a beautiful veined

appearance. The outside is smooth and of a pale brown colour. The specimen from

which the engraving was made, is in the private collection of Mr. George Humphrey,

dealer in natural curiosities, London " (Plate VIII. fig. 1).

In 1819 Valenciennes briefly described the same species by the name of Terehratula

globosa, referring at the same time to plate 239, fig. 2, of the ' Encyclopedic M6thodique '

for a figure of his species. The figure in the ' Encyclopedic ' is not well drawn ; but the

specimen from which it was taken is in the collection of the Jardin des Plantes, and was

lent by M. Valenciennes to Lovell Reeve, who gave a good figure in plate vi. fig, 3 of his

' Monograph of Terehratula ' in 1861. In 184<3 the same species received the name of

T. eximla from Philippi and Kiister ; that of T. Fontaiueana from d'Orbigny, and to a

large specimen of the same form in the collection of the Jardin des Plantes, measurin"-

2^ inches in length, M. Valenciennes gave the MS. naxaeoi physema. Under this name

it is also described and figured by Reeve in his ' Monograph of Terebratnla ' in 1861. The

specimen was brought from Coquimbo by M. Gaudichand in 1833 (Plate VIII. fig. 6). In

his description of this specimen Mr. L. Reeve observes that " It would be satisfactorv if

the species could l)e confirmed by the discovery of further specimens. It is intermediate

in its characters between T. dllatata and T. globosa, inclining I'ather to the latter species,

of which it may prove to be a colossal broadly inflated variety," and this I have no doubt

it is.

It was Valenciennes, however, who descril^ed and gave the names to all the recent

Brachiopoda published in 1819 in the ' Animaux sans Vertebres ' of Lamarck, that

celebrated zoologist having unfortunately lost his sight at that period.

I am quite convinced, after the inspection of the original specimen and figure of

T. dilatatu, Val., as well as from Reeve's figures in plate vi. fig. 2 of his ' Monograph '

(the type having been lent to him by M. Valenciennes out of the collection of the Jardin

des Plantes), that it is only a smaller and more transverse form of Waldheimia veuosa.

Several other specimens of the same form which have also passed through my hands

have tended to confirm this view, which had already been expressed by Mr. W. H, Dall

in his memoir published in the 'American Journal of Conchology,' vol. vi. p. 109,

where he notes also that the T. Gaudichamli of Blainville is another synonym of

W. venosa. In a paper I published in the 'Ann. & Mag. Nat. Hist.' for August 1867,

I described and figured the largest example of TF. venosa that had been discovered, which

had been dredged in 1843 or 1814 by Rear-Admiral B. J. Sulivan at Falkland Islands,

in the same locality whence the type of the species had been procured by Dixon.

Admiral Sulivan informed me, when lending me his specimen, that the depth at which

the animal lived was from 6 to 7 fathoms, the bottom on which the shell lay being a

compact quartzose sand only, as no mud ever came up with the dredge, although a

stiflf muddy clay underlies the sand, on which anchors hold very firmly.

7*

52 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

JFaldheimia venosa, like all its congeners, is variable in external shape. The foramen

is larger in some specimens than in others. As is the case with W. lenticularis when

quite young and sometimes until half its growth, W. venosa is either almost circular

or transversely oval. W. dilatata seems to be a half-grown individual with a large

foramen (Plate IX. fig. 1).

IF. venosa has often been confounded with Laqnetts calif ornicus of Koch, both species

attaining large dimensions ; but the loop in both is entirely different, and in the last-

named species the beak is much more incurved, the foramen very small, and separated to

a greater or less extent from the umbo of the dorsal valve by a deltidium in two pieces.

In Vol. clxviii. of the Phil. Trans., 1879 (Transit of Venus Exped.), Mr. Edgar A. Smith

mentions Waldhelniia {Terebratida) dilatata, Lamarck, as having been obtained at Obser-

vatory Bay at a depth of 4 fathoms. I may, however, remark that the ' Challenger '

Expedition did not bring back a single specimen of Solander's species.

28. "Waldheimia lenticularis, Deshayes, sp. (Plate IX. figs. 2-13.)

Terebratula lenticularis, Deshayes, E.evue Zoologique par la Soc. Cuvierienne, p. 359, 1839, and Mag.

de Zoologie, d'Anatomie comparee et de Paleontologie, p. 41, figs, a, b, c, d, 1841 ; G. B. Sowerby,

Thes. Coucliyl. vol. i. p. 360, pi. Isxii. figs. 108-110, 184G; Davidson Ann. & Mag. Nat. Hist. 2nd ser.

vol. ix. p. 305, 1852; L. Reeve, Monogr. of Terebratula, Conch. Icon. pl. 2. fig. 4, I860.

IValdheimia lenticularis, Gray & Woodward, Brit. Mus. Cat. of the Brachiopoda, p. 58, 1853 ; Dall,

Proc. Acad. Nat. Sci. Philadelphia, p. 182, 1873.

Neothyris lenticularis, Douville, Bull. Soc. Geol. de France, 3" ser. t. vii., 1879.

IValdheimia lenticularis, E. Deslougchamps, Notes sur les Modifications h. apporter jl la Classe des

Terebratulidae, pl. xvii. figs. 5-7, 1880.

Shell large, orbicular, elongated oval, globose, longer than wide, thick, rounded

laterally, less so in front. Dorsal valve uniformly convex or slightly depressed at or close

to the frontal margin. Ventral valve deeper, and a little more convex than the dorsal

one and slightly longitudinally carinated ; beak rather sharply incurved, overlying the

umbo of the opposite valve, and truncated by a small circular foramen, separated from

the hinge-line by a wide, narrow, concave deltidium in two pieces ; beak-ridges very

sharply defined. Surface smooth, marked by concentric lines of growth, punctate.

Colour pinkish red or yellowish horny. Loop simple, long, and reflected ; cardinal process

rather large and prominent ; under it a mesial sejitum extends to about one third of the

length of the valve on either side the adductor and other muscular scars. Length

2 inches 2 lines, breadth 1 inch 11 lines, depth 1 inch 3 lines.

Sal). Lives abundantly attached to rocks in the Straits of Eouveau, New Zealand, in

15 fathoms. It occurs also in great numbers in the Pleistocene rocks of New Zealand.

Capt. F. W. Hutton, in his ' Catalogue of the Tertiary Mollusca of New Zealand,' p. 35,

1873, quotes the following localities : — " Wanganui, The Deans, Waipara, Waitotari,

Chatham Islands." The fossil is also well described and figured by Prof. E. Suess from

tlie ' Novara ' Expedition, in his fine memoir " Eossile MoUusken und Echiuodermen aus

Neu-Seeland," Palajontologia, p. 56, pl. x. figs. 3, 4 (18GG).

Obs. I have in my possession a very large series of specimens of this fine species from

DR. T. DAVIDSON OX EECENT BRACHIOPODA. 53

2 up to 23 lines iu length. When young and up to nearly half its growtli the shell is

almost circular and broadest anteriorly, ta^jering at the beak, and nearly as wide as long ;

with age the shell becomes elongated and gibbous.

I have carefully observed and drawn the modifications that take place in the shape of

the loop, of which I give some illustrations in Plate IX. figs. 11, 12, 13. My figures

agree well with tliose published by M. E. Dcslongchamps in his ' Etudes Crititjues ' above

quoted, and they do not diftur from those peculiar to other species of the genus. In a

specimen two lines in length the whole loop is small, not extending further than to

about half the length of the valve, its principal lamellae, as well as the reflected portion,

becoming attached to the extremity of the upper sides of a perpendicularly elevated

septum, as in Ilagasella. After a time the septum becomes less elevated, the principal

stems of the loop acquire greater length, and give ofi" at about half their length a

horizontal lamella, which is also fixed to the septum, as in Tcrehratella ; later on this

horizontal lamella detaches itself from the septum, the principal stems of the loop

become more separate, and the reflective portion assumes the appearance of that of a

fuU-grown Waldheimia.

Waldheimia Icnticiilaris was well described and figured by Desliayes in 1841, and also

by G. B. Sowerby and L. Reeve. It has had the good fortune to preserve the same

specific name, although located iu the genera Terehratula, Waldheimia, and Neotliyris.

As observed by Reeve, in his ' Monogr. of Terehrahila,' " Were it not that the habitats of

this and the preceding species [Terebratiila {Waldheimia) glohosa'] are well authenticated, it

would be difficult to believe that there is any specific difference between them. This is

rather lighter [with an] inflated growth, and the colour is remarkable, but the characters

n other respects are the same in detail throughout. The foramen is probably as small

as in T. globosa ; in all the specimens of T. Icnticularis that I have seen it is more or less

eroded, according to the circumstances of its attachment. The loop is precisely the same

in both species." There are, however, differences between W. venosa and W. lenticularis

which must not be overlooked. In well-preserved specimens of the last-named shell the

foramen is small, iu fact much smaller than in W. venosa, and separated from the hinge-

line by a well-developed deltidium in two pieces, in this respect more nearly resembling

Laqneus californicus. The beak is more incvirved, and the dorsal valve more uniformly

convex. The colour is also very difi'erent in the two species. It is also a smaller shell.

29. Waldheimia kerguelenensis, Davidson. (Plate X. figs. 7-17.)

Waldheimia kerr/uelerms, Davidson, Proc. Roy. Soc. vol. xxvii. p. 437, 1878, and {IV. kerguelenensis)

Report on the IJrachiopoda, Voyage of H.M.S. ' Challenger/ Zool. vol. i. p. 40, pi. iii., 1880.

Shell OA-ate, ventricose, longer than wide, light yellowish white, smooth. Dorsal valve

most convex near the umbo, a slight mesial depression commencing about the middle of

the valve extends to the front, and is more or less distinctly margined on either side by a

faint raised line or ridge ; front line slightly depressed or nearly straight. Ventral valve

rather more convex than the opposite one, and more or less distinctly keeled by the

presence of a wide, convex, but slightly raised fold, which corresponds with the depression

in the dorsal valve. Beak moderately produced and incurved, truncated by a small

54 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

circular foramen laterally margined by two small disunited deltidial plates. Cardinal

process prominent, and formed of three distinct parts. In the interior of the dorsal

valve, and under the incurved extremity of the umbo and hinge-plate, there rises a

wide short and massive septum, and on either side on the bottom of the valve the

muscular scars are visible. Loop delicate, elongated and reflected. Shell-perforations

numerous. Length 2 inches, breadth 1 inch 4 lines, depth 1 inch 2 lines.

Hah. It was dredged by the ' Challenger ' Expedition in great numbers ofi" Marion

Island, west of Kerguelen Island, at a depth of 100 fathoms. Two examples oi Platydia

anomioides were attached to one of the specimens. Also at Balfour Bay, near

Kerguelen Island, in 20 to 60 fathoms, south of the same island at a depth of 150 fathoms.

Three examples of Wiynclionella nigricans, var. pixidata, were obtained with it.

Obs. I have examined several specimens of the animal that had been dredged alive by

the expedition, as well as of the shell from 1 line up to 24 lines in length. Some examples

were nearly circular and as broad as long, bvit the larger number were of an elongated

oval shape, becoming ventricose with age. When the peduncle by which the shell

adhered to foreign bodies was sufiiciently long, and did not interfere with the animal's

limited movements, the beak was much incurved and the foramen small ; but in most

cases the peduncle was exceedingly short, and the shell came into contact with the hard

bodies to which it was moored, causing erosion and the consequent enlargement of the

foraminal aperture. The animal closely resembles in general character that of Wald-

heimia Jlavescens, so admirably described by Owen and Hancock.

Some specimens bear a certain resemblance to Waldlieimia lenticularis ; but this last

is smaller, more ovate or regularly oval, and more especially in the young and inter-

mediate stages of growth. Having forwarded two examples for Mr. Ball's examination,

he informs me : — " I have carefully compared it with d'Orbigny's Waldheimia Fontaineana,

and feel more sure than ever of the correctness of my reference of his species to

Waldheimia venosa. It is certainly not this fine species ( Waldheimia kerguelenensis),"

though it is possibly identical with the shell erroneously described and figured by G. B.

Sowerby, at p. 359, and plate xxi. figs. 99-101, of his ' Thesaurus Conchyliorum,' in

1846, as the Terebratula glohosa, Lamarck. The specimen Sowerby figured under that

name (said to have been taken from Lamarck's collection) is now in the British Museum,

and Sowerliy was certainly mistaken in stating " It agrees perfectly with the represen-

tation in the ' Encyclopedic Methodique,' tab. 339. fig. 2 " !

30. Waldheimia Gbayi, Davidsou. (Plate X. figs. 1-4.)

Terebratula Grayi, Davidson, Proc. Zool. Soc. 1852, p. 7(\, pi. iv. figs. 1-3.

Terebratula [Waldheimia) Grayi, L. V. Schrenck, Reiseii mid Forschungem in Amur-Lande, p. 465,

1854-56.

Waldheimia Grayi, E. Suess, Sitzungsb. Akad. Wissenschaften, Bd. xxxvii. p. 201, 1859.

Terebratula [Waldheimia) Grayi, L. Reeve, Couch. Icon. pi. 2. figs. 5 a, b, c, 1860, and Ann. &

Mag. Nat. Hist. 3rd ser. vol. vii. p. 175, 1861 ; Journal de Couchyl. p. 123, 1861.

Waldheimia Grayi, Carpenter, Rep. Brit. Assoc. 18G3, p. 636.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 55

Waldheimia Grayi, A. Adams, Anu. & Mag. Nat. Hist. 3rd ser. vol. xi. p. {)[), 18G3 ; Davidson, Proc.

Zool. See. p. 30I-, pi. xxxi. figs. 7 & 8, 1871 ; Dall, Am. Journ. of Concli. vol. vi. p. 110, 1870, ami

Proc. Acad. Sci. Philadelphia, 1873, p. 182; G. Duiiker, Index Moll. Maris Japonici, p. 252, 1882.

Shell variable in shape, squarely subpentagoual or subtriaugularly semicircular,

longer or broader than ^vide. Iliug-e-line either nearly straight or very obtusely angular,

shorter or longer than the breadth of the shell ; lateral margins rounded, nearly straight

or gently curved in front. Dorsal valve very moderately convex, somewhat flattened

and more or less longitudinally depressed along the middle. Ventral valve very much

deeper and more convex than the dorsal one ; beak short, bent backwards, nearly straight

or very Little incurved, and obtusely truncated by a large, transversely oval, incomplete

foramen, always more or less eroded, margined anteriorly liy the dorsal valve and by two

small labial rudimentary deltidial plates ; beak-ridges strongly marked, leaving between

them on the hinge-line a wide triangular almost flat area. Surface of valves marked by

a number of strong bifurcating radiating angular costse, of which the central one is

usually the largest. Valves traversed by numerous more or less prominent scale-like

zigzag concentric lines or ridges of growth. Shell-structure punctate. Colour

yellowish, with concentric bands of crimson colour, deeper in tint at or near the

projecting concentric ridges of growth. Proportions very variable. Two large examples

measured : —

Length 1 inch 4 lines, breadth 1 inch 3 lines, depth 10 lines.

1 '^ 17 9

') -■- 3) — J5 )) -■- 5) ' >5 55 ^ 55

In the interior of the dorsal valve the cardinal process is wdde and narrow, the hinge-

plate large, mesial septum strong, extending to abovit half the length of the valve. Loop

long and simple ; the principal stems attached to the base of the hinge-plate extend to

about four fifths of the length of the valve before becoming reflected.

Sab. Hakodadi, Mososeki, Japan, in 7 fathoms (Adams). Strait of Corea (Belcher

and St. John), in 37 fathoms. Dall mentions also Catalina and Monterey.

Obs. This very remarkable and beautifvil shell is, as already stated, very variable in

shape, so much so, indeed, that some malacologists have felt disposed to divide it into

two species ; and, as observed by Dall, it is sometimes hardly possil)le to distinguish it

exteriorly from some specimens of Terebratula transversa, Sow., var. caurina, Gould,

or T. occidentalis, Dall, except by the loop, which in W. Grayi is simple, while in the

others it is three times attached, as in Terebratella.

Prior to 1852, the shells of the species under description had erroneously been referred

to the Terebratula {Krausslna) rubra of Pallas, to which they also bear some external

resemblance ; and it was only after careful examination of the interior calcareous support

of the labial appendages that I discovered that they belonged to two very distinct

genera. As observed by Lovell Eeeve, m his ' Monograph of Terebratula,' the foramen of

the shell naturally becomes more or less eroded and enlarged according to the roughness

with which the creature is liufTetcd about in the place of its attachment, owing to the

shortness of its peduncle. He also observes that the deltidial plates meet in tlie middle

in very young examples, and that the ribs of W. Grayi are not really scaled, but scales

56 DE. T. DAVIDSON OX RECENT BEACHIOPODA.

are formed on them by the overlapping of the concentric lines of growth. The ribs are

also somewhat irregular in some specimens.

Waldheimia Orayi is extremely abundant in its favourite haunts. In Corean waters

it was dredged in great abundance by Admiral Sir Edward Belcher during the voyage

of H.M.S. ' Samarang.' A. Adams and Capt. St. John obtained it in similar abundance,

and say that it could be collected by thousands in certain places where it had been

washed on shore. Mr. Dall has observed that the blood in this species is red.

31. "Waldheimia septigera, Loven, sp. (Plate XI. figs. 1-10.)

Terehratula septigera, Loven, Index MoUuscorum Litora Scandiuavise occidentalia habitantium,

Ofversigt af K. Vet.-Akad. Fovb. 1846, no figure.

TValdheimia septigera, Gray & Woodward, Cat. of Bracli. in the Brit. Mus. p. 59, 1852; Davidson,

Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi. pi. x. fig. 1, 1855; E. Suess, Ueber die Wobnsitze der Bra-

chiopoden, Sitzunsgb. k. Akad. Wissensch. Wien, Bd. xxxvii. p. 200, 1859.

Terehratula [Waldheimia) septigera, Reeve, Monogr. of Terehratula, Concb. Icon. pi. iii. fig. 10, 1860.

Terehratula peloritana, Seguenza, Notizie succinte, p. 19, 1862.

Waldheimia peloritana, Sequenza, Memorie della Soc. Ital. di Scieuze Naturali, voL i. p. -19, pi. vi.

fig. 10, 1865.

Terehratula septula, Jeffreys (not Pbilippi), Brit. Concb. vol. ii. p. 14, 1863.

Waldheimia septigera, Seguenza, Mem. della Soc. Italiaua di ScienzeNat. vol. i. p. 44, pi. vi. figs. 1-10,

1865 ; Bull. Soc. Geol. France, 2nd ser. vol. xxv., 1808 ; Bull. Malacologica Italiaua, anno iii., 1870.

Terehratula septata, Jefl'reys, Proc. Zool. Soc. 1878, p. 407, pi. xxiii. fig. 1 (not Pbilippi) ; G. O.

Sars, Bidrag til Kuudskabcn om Norges arktiske Fauna : Mollusca Regionis ArcticcC Norvcgioe,

Christiania, pi. i. fig. 2, 1878 (not Pbilippi).

Terehratula floridana, Jeffreys (not Pourtales), Proc. Zool. Soc. p. 407, 1879.

Waldheimia septigera, Dall, Bull. Mus. Com. Zool. Harvard, vol. iii. p. 13, pi. 1. fig. 4, pi. 2. fig. 9, and

Proc. of tbe California Acad, of Sciences, p. 182, 1872; H. Friele, "Bidrag til A'estlandets Mollusk-

fauna, Vidensk.-Selsk. Forband. p. 57, pi. 1. fig. 2, 1875, and Tbe Development of tbe Skeleton of tbe

genus Waldheimia, Arcbiv for Matbematik og Naturvidenskab, Bd. ii. p. 380, pi. iii. figs. 5, 6, and

pi. iv. figs. 12-14, 1877; E. Deslongcbamps, Etudes Critiques sur les Bracbiopodes, p. 98, pi. i. figs. 17

& 18, pi. XV. figs. 4-6, and pi. xvi. figs. 1-3, 1884.

Shell somewhat square, ovate or subpentagonal, broadest anteriorly, more attenuated

posteriorly, longer than wide, lateral edges rounded, wide and nearly straight in front,

anterior margin sinuated, corners obtusely rounded anteriorly. Dorsal valve evenly

convex to abovit half its length; anterior half divided into three lobes, the central one

by far the largest and widest, forming a slightly raised, rounded, wide mesial fold.

Ventral valve deeper than the dorsal one, with a wide concave sinus commencing at a

short distance from the beak, and gradually widening until it reaches the front ; beak

incurved and truncated by a rather large circular foramen, completed and separated

from the hinge-line by a deltidium in two pieces ; lateral portions of the beak rounded.

Surface of valves smooth, but marked by numerous fine concentric lines of growth.

Colour light yellowish or greyish white. Shell-structure punctate. Dimensions variable,

two large specimens measured: —

Length 1 inch 8 lines, breadth 1 inch -l lines, deptli 1 inch.

„ 1 „ 8 „ „ 1 „ 1 line, „ 10 lines.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 57

In the interior of the dorsal valve, tlu; eanlinal process is so small that it can hardly

be diirerentiated from the hinge-plate, and from under which a mesial septum extends

to one half the length of the valve. Loop long, simple and reflected, the lamella of the

reflected portion being wide, the principal stems nearly parallel.

Rab. Off Norway, Finmark, &c., in 100 to 300 fathoms. Atlantic coast of Spain.

Dredged by the ' Porcupine ' Expedition at various northern stations, at depths from 75

to 755 fathoms (Jeffreys). In British Seas between Shetland and Faeroe, by Jeffreys

and J. Murray, in 345 to 570 fathoms. A'igo Bay (M'Andrew). Off Marocco and the

Canary Islands (' Talisman ' Expedition) in 331 to 861 fathoms.

Obs. The shell and some parts of the animal have been carefully examined. Mr. Ball

says that its visceral area is very small, the muscular attachments being even smaller

than in Waldheimia floridana. The stomach, produced into a point without diffei'entia-

tion of the intestine, is very much shorter than in W. Jloridaiia.

The development of the skeleton or loop in this species has been well studied and

illustrated in two papers by Herman Friele in 1875 and 1877, and by E. Deslongchamps

in 1S84<. Dr. Gwyn Jeffreys and myself have also followed out the same investigations.

Herr Friele begins by informing us that he has not been able to examine the first stages

in the development of the loop in this species, as he had done for that of Waldheimia

cranmm ; that the youngest examples of W. septigera he has seen measured 1, 2, and 3 lines

in length, and represented the second stage of JF. craii'mm, in which the united lamellte

begin to split apart at the anterior end ; and that the only essential difference at that

age is in the form of the septum, being 4'5 millimetres and 5*5 millimetres respectively.

The next stage he terms the Megerlla stage, the shell having attained 4 lines in length.

In this stage in Waldheimia cranium the lateral walls were broken down by an aper-

ture appearing in the middle of each and widening backwards. In W. septigera the

break occurs, on the contrary, on the posterior end of the walls, and extends in a forward

direction, the similarity at this stage to Terebratella being striking. The connection

between the process of the lamellae and the sejitum is severed in a specimen G lines in

length, and in a specimen 8 lines in length the lamellae are separated and the character

of the loop is that of the adult Wcddhehnia. In Plate XI., figs. 7, 8, 9, TO are from

Friele's memoir, showing the modifications above described.

Waldlieimia septigera was described for the first time by Loven, in 1846 ; but having

neglected to give a figure of his species, the shell was very little known until 1855, when

I gave a figure of it in the Ann. & Mag. Nat. Hist. In 1863, in vol. ii. of his ' British

Conehology,' and subsequently in a paper in the Proc. Zool. Soc, Dr. Gwyn Jeffreys

erroneously maintained that Lov6n's Waldlieimia septigera was a synonym of Philippi's

Terebratnla sepAata, and this mistaken view he maintained to the last. In 1840, Signor

Seguenza, after much trouble and skill, examined the perfect loop in several adult

examples of Philippi's T. septata, and found it to be three times attached, as in Tere-

bratella, while the loop in W. septigera is only twice attached, as in Waldheimia.

The same indefatigable palaeontologist also examined the loop of his Pliocene Tere-

bratula peloritana, and found it to agree with that of Waldheimia septigera, of which

he admits it to be a synonym.

SECOND SERIES. — ZOOLOGY, VOL. IV. 8

58 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

My valued and distinguished friend Dr. Gwyu Jeffreys was again mistaken when he

said, at p. 408 of his paper in the ' Proceedings of the Zoological Society ' for 1878, that

Waldheimia j)eloritana and W.floridana appear to be the same variety of Terebratula

septata. Having had all the developed sjoecimens in my hands, I am able to give my full

support to Prof. Seguenza's statement.

Waldheimia septigera and W. Ilaphaelis are much more nearly related than either of

them are to W. jioridana. Terehratella Ilarice (Adams), from Japanese waters, is also

said by Dr. Gwyn Jeffreys to be possibly a variety of W. septigera (his T. sepdata) ;

but in the small specimen of T. Marice I have been able to examine the loop was three

times attached, as in Terehratella.

Waldheimia septigera, undejc the name of W. peloritana, has been well described

and illustrated by Signor Seguenza, in his Monograph of the Brachiopoda from the

Tertiary def)osits of Messina in Sicily, p. 49, pi. vi. figs. 1-10 (1865). It occurs plentifully

in the UpiJer Pliocene rocks at Gravitelli.

32. Waldheimia Raphaelis, Dall. (Plate XI. figs. 11-13.)

Waldheimia Rapftaelis, Dall, Am. Journ. of Conch, vol. vi. p. 3, pi. vii. figs, a, b, c, d, 1870 ; Davidson,

Ou Japanese recent Brachiopoda, Proc. Zool. Soc. 1871, p. 303, pi. xxxi. fig. 9.

Shell elongated, longer than wide, somewhat subtrigonal, widest about the middle

and anteriorly, tapering posteriorly, nearly straight or gently curved outwardly in front.

Dorsal valve moderately convex, with a very wide mesial fold, commencing at about a

third of the length of the valve, uniformly and gently convex, or divided longitudinally

by a small mesial groove. Ventral valve deeper and more convex than the dorsal one,

with a broad deep mesial sinus commencing at a short distance from the extremity of

the beak, and becoming deeper and wider as it reaches the front margin ; on either side

of the sinus the valve slopes abruptly to the lateral margins. Beak slightly incurved

and truncated by a large circular foramen, separated from the hinge-line by deltidial

plates. Surface smooth, marked only by concentric lines of growth ; punctures oval-

shaped outside, smaller, more distant, and cii'cular on the interior surface of the valves.

Colour light yellowish, with a slight rufous tinge. In the interior of the dorsal valve

tlie cardinal process is small, quadrate, and stout ; under it commences a small septum

that does not reach to quite half the length of the valve. Loop long, reflected portion

broad ; crura much curved at their extremity. Length 1 inch 10 lines, breadth 1 inch

5 lines, depth 1 inch 1^ lines.

Hab. Japanese coast, near Yeddo (Plumpelly and Dall). Sagami Bay, depth 100 to

200 fathoms (Doderlein).

Ohs. I have seen five good examples of this remarkable sjiccies. In Mr. Dall's and

Dr. Doderlein's specimens the fold in the dorsal valve is gently convex throughout ; in a

fine example I obtained from Mr. G. B. Sowerby the fold was probably exceptionally divided

into two lobes by a median groove. The shell is named after Prof. Raphael Plunqielly,

its nearest ally being the Waldheimia septigera of Loven.

Waldheimia septigera, W. Ilaphaelis, and W. Jioridana belong, as was justly remarked

by Mr. Dall, to a peculiar group in the genus Waldheimia, and are specifically distinct.

The first is froin northern European seas, the second from those of Japan, and the third

from the Florida coast or reefs.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 59

33. Waldheimia floridana, Pourtales. (Plate XII. ligs. 1-.5.)

Waldheimia floridana, Pourtales, Bull. Mus. Comp. Zool. Harvard, vol. i. p. 127, 1868; Dall, Bull.

Mus. Comp. Zool. Harvard, vol. iii. p. 12, pi. i. figs. 1-3, 18"1.

Eudesia floridana, Bull. Mus. Comp. Zoiil. arvard, vol. ix. p. 103, 1881.

Shell trians:^ular, widest anteriorly, tapering posteriorly, generally as wide or wider

than long ; anterior margins strongly flexuous. Dorsal valve uniformly convex poste-

riorly, anteriorly divided into three lobes, the central by far the largest, forming a

wide moderately elevated fold ; lateral edges of valves flexuous, anterior corners rounded.

Ventral valve deeper than the dorsal one, with a large wide mesial sinus commencing at

a little distance from the extremity of the beak and gradually widening as it I'eaches the

front ; lateral lobes nearly flat or gently concave, sloping rapidly from tlie outer side of

the fold and sinus to the edsjes of the shell. Beak incurved and truncated by a small

circular foramen, very little separated from the hinge-line by a narrow deltidium in two

pieces ; beak-ridges rounded. Surface smooth. Colour greyish or brownish white with

a slight touch of yellow. Length 11, width 12, depth 8 lines.

In the interior of the doi'sal valve the cardinal process is small, the hinge-plate rather

large, and from under its base a mesial septum of small elevation extends to about two

thirds of tlie length of the valve. Loop simple, very broad and separate anteriorly,

narrow posteriorly. Stomach spherical, with a long cylindrical intestine.

Uah. Very abundant, attached to Plorida Reefs, depth 100 to 200 fathoms, on rocky

1)ottom (Pourtales) ; off Sand Key, 125 fathoms (Sigsbee) ; off Havana, 175 fathoms

(Dall).

Obs. Thanks to the great liberality of Prof. A. Agassiz, I have been able to examine a

large number of specimens of this remarkable and Avell-characterized species from the

dimensions of five up to eleven lines in length. When quite young and up to a some-

what advanced period of its growth, the shell is longer than wide, the fold and sinus

being scarcely indicated in very young examples. Dall, in his excellent description of

this species, states that it belongs to a peculiar group including W. Jloridana, W. septigera,

and W.BaphaeUs; he adds : — "Thus it is seen that the smallest species [^F.j'^orJdrtP/rt] is

by far the widest and most inflated proportionately ; the second species is the flattest

in proportion to its length ; and the third the most elongated."

" The greater portion of the mantle of W. Jioridana is of the most extreme tenuity and

perfect transparency. It is furthermore so closely attached to the shell as to render its

removal intact — even with the aid of acid— a matter of great difficulty. With this excep-

tion, the examination of its anatomy is easy The soft parts are mostly of a translucent

whitish color. The number and disposition of the muscles are similar to those of W. mis-

tralis, already described by various authors. The muscles themselves are of a glistening

tendinous appearance, except at their points of attachment, where they are of a more or

less dark yellowish-brown. The peduncle is moderately long, and the portion which is

external or contained in the foramen is covered with a dark, horny, reddish-brown

membrane or skin, and the attached extremity is trumpet-shaped. Upon opening the

shell in its normal position, the median spires of the brachia are seen to be somewhat

widely separated, and between them is stretclied a flne translucent membrane extending

S*

60 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

forward from the under lip of the mouth and foUowing the downward curve of the

median lohes. In this great extension of this membrane this species differs from T. caput-

serpentis and W. australis, in which species the cirrhi of the median lobes touch at their

extremities, and are separated by only a very narrow sti"ip of membrane between their

bases, so that the appearance is almost as if there was but a single broad band of cirrhi

in the median line. This intervening membrane in ordinary specimens of W. fioridana

is about "24 of an inch in width at its narrowest visible portion. The upper and lower

bands of cirrhi in the lateral loops are also much more widely separated by a similar

membrane than in W. australis The spiral portion in the middle lobe makes

about two complete turns The mouth is, as usual, just in front of the posterior

junction of the brachial bands, and is in a rather long flexuous groove, tlie edges of

which are of a dark brown colour, and somewhat thickened The oesophagus is

about half as long as the intestine, and has a slight curve, of which the convexity is

anterior ; it is transversely flattened close to tlie mouth, and is a little compressed

laterally, behind that portion. It is of a nearly uniform calibre throughout. It has

quite a thin lining membrane, which becomes thicker, though still smooth, in the

stomach, and quite thick and longitudinally plaited in the intestine. The stomach is

well differentiated from the alimentary canal and intestine, and is of an oval shape. It

is embraced by the hepatic digitations, which are of a greenish-yellow color, and empty

into the stomach by four ducts. The orifices of these ducts are of a compressed oval

shape, obliquely inclined, and the anterior pair, which correspond to the right and left

anterior congeries of hepatic digitations, are twice as large as the posterior pair, which

similarly correspond to the anterior lobes or bunches of digitations The intestine

is twice as long as the oesophagus, of uniform calibre, and perfectly straight. It leaves

the stomach abruptly without any dilatation of the portion adjacent to the latter

organ, and reaches aljout half-way to the dorsal valve. The heart is situated behind the

junction of the stomach and intestine. The termination of the intestine is abruptly

rounded off and not at all pointed. It is entirely closed, and is upheld by the mesentery.

It is also of a much darker color than the rest of tlie alimentary canal, being of a

deep chestnut brown hue."

" The great pallial sinuses and their ramifications in W. florkkma are of much less

extent and disposed in quite a different manner from that which obtains in W.

australis. The hfemal pallial system consists essentially of four branches which are

remarkable for their straight course and the paucity of their ramiticatious. The neural

pallial system is very similar, wdth a greater number of small sinuses about the peri-

visceral cavity, but in both lobes the narrowness and small extent of the sinuses, as

compared with those of other species, is very marked, and the same is true with regard

to the ovaries. But a very few exceedingly delicate spicukTe were observed in the floor

of the greater sinuses. The lieart consists of a very minute pyriform vesicle situated

behind the intestine at its junction with the stomach, and sending one vessel in the

hsemal direction along the median line of the stomach, and another on each side laterally.

The ovaries are very limited in extent and principally confined to that portion

of the sinuses which surrounds the visceral cavity, only their ultimate extremities entering

DR. T. DAVIDSON ON llECENT BRACHIOPODA. Gl

the larger branches of the great sinuses The ova were visible in all stages of

growth. Those floating free in the lacunes were nearly spherical, and of a flesh-colour ;

their substance seemed of a granular consistency, due perhaps to the action of the spirit

in which they were preserved. The immature ova were pyriforin, attached to the ovary

by their pointed ends No sperraatophora; or spermatozoa were observed in any

of the specimens examined. The oviducts are situated as in IV. aiistralis. The lining-

membrane of their trumpet-shaped portion was drawn into tiiin plicie. Their apices

were teat-shaped, with very small oriflces The setae are very slender and tine,

irregularly marked with transverse lines, but smoother towards their outer ends. They

protrude from their follicles, hardly more than one third of their length The

mantle edge was brownish and seemed to have a slightly villous epithelium."

I have reproduced this long extract from Mr. Dall's admirable memoir, as I have done

in similar cases from the works of other authors, because all that relates to the animal of

different species of the same genus is of the utmost importance. The animals of species

of the same genus no douljt agree in their general character, but often differ considerably

in their respective details, and these differences should always, when possible, be carefully

noted. The animal of every species should also under favourable circumstances be

anatomically examined and described.

In his " Contributions to the Fauna of the Gulf Stream at great Depths " (Bull. Mus.

Comp. Zool. vol. i. p. 127), Count L. T. de Pourtales informs us, in his description

of Waldheimiafloridana, i\vd.i " Very young specimens are flatter, rounder, and have a

straight margin ; they could scarcely be distinguished from the young of Terebratulu

cubensis, if it was not for the loop and septum seen by transparency. There is also some

variety of form in tlie old; in some specimens the length is greater than the breadth,

and there is considerable diversity in the sinuosity of the frontal margin It is

always associated with Terebratula cubensis, the latter being still more common (in the

proportion of about three to one), and making its first appearance in 100 fathoms.""

34. Waldueimia (Macandrevia) cranium, Miiller, sp. (Plate XII. tigs. 11-23 ; Plate

XIII. figs. 1, 2.)

Terebratula cranium, Miiller, Zool. Danica; Prodronius, p. 249, no. 3U0(J, 177G.

Anomia vitrea, Cliciuuitz ? (not Born), Conch. -Cub. vol. viii. p. 97, t. 78. figs. 707 & 709, 179.').

Terebratula cranium, Moutagu, Trans. Liun. Soc. vol. xi. p. 188, tab. xiii. fig. 2, 1811 ; Turtou, Conch.

Diet, of British Isle.s, 1819.

Terebratula vitrea, Fleming (not Born), Phil, of Zool. vol. ii. p. 498, pi. iv. fig. 4, 1822 ; Schumacher

(not Born), Essai iriai nouveau Systeme des Hab. des Vers Testaees, p. l;3;3, pi. ix. fig. 1, 1817.

Terebratula eutlnjru, Philippi, Enum. Moll. Siciliie, vol. ii. p. 68, tab. xviii. fig. 8, 1814.

Terebratula cranium, C. B. Sowerby, Thes. Conch, vol. i. p. 354, pi. Ixx. figs. 60-G2, 18 10 ; Loven, Index

Moll. Scandinaviie, (Efvers. K. Vet.-Akad. Forh. p. 183, 1846 ; Davidson, IMonogr. Brit. Foss. Bracli. Ter-

tiary Species, vol. i. pi. i. fig. 8, 1852, and Ann. & Mag. Nat. Hist. 2ud ser. vol. xvi. pi. x. fig. 8, 1855.

Terebratula (jlabra, Ijcaeli, Brit. j\Ioll. p. 359, pi. xiv. figs. 3, 4, 5, 1852.

Terebratula subvitrea, Leach {teste Reeve).

Waldheimia cranium, Barrett, Report Brit. Assoc. Glasgow, 1855, p. 107 ; Hancock, Phil. Trans. Roy.

Soc. vol. cxlviii. 1858; Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. Wissensch.

Wien, p. 200, 1859.

62 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

Mocandrevia cranium, King, Proc. Dublin Univ. Zool. and Bot. Assoc, vol. i. p. 261, 1859.

Terebratula {Waldheinda) cranium, Reeve, Concli. Icon., Monogr. of Terebratula, pi. iii. fig. 6, 1860.

Te^'ebratula cranium, Jefi'reySj Brit. Conch, vol. ii. p. 11, and vol. v. p. 163, pi. xix. fig. I, 1863.

Waldheimia euthyra, Seguenza, Pal. Mai. Class. Brach. p. 46, pi. v. figs. 6-14, 1865.

Waldheimia cranium, Dall, Am. Journ. of Conch, vol. vi. p. 110, 1870; Friele, Yidensk. Selsk.

Forhandl. pi. i. fig. 1, 1875, and Archiv for Mathematik og Natnrvidenskab, pi. i. figs. 1-4, pi. ii.

figs. 5-7, pi. iii. figs. 1-4 and 7, 1877 ; G. O. Sars, Mollusca Region. Arct. Norveg. (Christiania) p. 10,

tab. i. fig. 3, 1878; Jeffreys, Proc. Zool. Soc. 1878, p. 405.

Macandrevia cranium, Douville, Bull. Soc. Geol. de France, 3'' ser. vol. vii., 1879; K. A. Zittel,

Handb. der Palaontologie, p. 703, 1880 ; E. Dcslongchamps, Etudes critiques sur les Brachiopodes,

pi. xiii. figs. 13-16, pi. xiv. figs. 4-9, and pi. xv. fig. 5, 1884.

Shell lenticular or ovate globose, longer than Avide, broadest about the middle, lateral

margins rounded, antex'iorly subquadrate or rounded, sometimes much thickened at the

margins. Dorsal valve evenly convex, without fold or sinus. Ventral valve deeper than

the dorsal and evenly convex ; beak slightly incurved, short, and truncated by an in-

complete circular foramen, margined anteriorly by the umbo and by two rudimentary

deltidial plates, which are in many specimens absent ; beak-ridges not very sharply

defined. Surface smooth, marked only by concentric lines of growth. Colour yellowish

white or light horny. Shell-perforations separated by interspaces of about equal size.

Dimensions variable — length 1 inch 1 line, width 10 lines, depth 7 lines. In the interior of

the dorsal valve there is no defined cardinal process or mesial septum, but two deviating

septa commence under the extremity of the umbo and extend to a little more than

one fourth of the length of the valve ; loop long, attached to the base of the hinge-

plate, and extending to about four fifths of the length of the valve before becoming

reflected *. In the interior of the ventral valve the teeth are supported by strong

dental plates.

Hah- W. cranium is an abundant shell near the coast of Norway and in the northern

seas. It was dredged on several occasions by R. MacAndrew and L. Barrett between

Vigten Islands and the North Cape, in 25 to IGO fathoms, attached to stones; only abun-

dant at Omnsesoe. Dr. Gwyn Jeffreys dredged it many times during the ' Lightning'

and 'Porcupine ' Expeditions off the Faeroe Islands, in 161 and 208 fathoms, and as deep

as 690 fathoms during the ' Porcupine ' cruise in 1869. MacAndrew obtained it outside

Vigo Bay in 30 fathoms, Vl'allich in Greenland, and the Marquis de Polin and Dr.

* So delicate and brittle is the loop at the point where the primaiy lamellte become reflected, that both Dr. J.

(fwyu Jeffreys and Dr. W. B. Carpenter for some time entertained the mistaken opinion that at that point they were

naturally disunited. This led Dr. Jeffreys to remark on p. 13 of the second volume of his ' British Conchology ' : —

'• Having carefully cleaned the inside of a specimen of T. cranium, containing the dried remains of the animal, with

a weak solatiou of potash, and examined several other perfect shells of different ages, I could not perceive the least

ajtpearance of a loop, which is so evident in 7'. austraJix. The lamellar processes in the lower valve of T. cranitim

are eijual in length, and end in sharp points. They may be compared to the chariot-blades used by the ancient

Sevthiaus, and they somewhat resemble the falcifonu apophyses of Teredo and Pliolds. In the young of T. craminn

these processes are extremely short. Their airaugcment and .shape are so dissimilar in species closely allied in other

respects, that I should be inclined to consider their importance, as characters of generic distinction, somewhat

doubtful.'' It was some considerable time before I could convince my distinguished friend that the loop of Wcdd-

heimia cranium differed hut little from that of W. Jlavcscens.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 63

P. Fischer off the south-west of France, iu from 5 to 650 fathoms. It was also dredged

by Prof. Sars, Friele, and others off the Norwegian coast ; east coast of Shetland

(Fleming and Jeffrey.s) ; North Hebrides by Dr. W. K. Carpenter and Sir WyvUle

Thomson, in 170-050 fathoms, &c.

Waldheimia cranium occurs fossil under the name of Terehratula euthyra, Philijjpi,

in the Upper Pliocene rocks of Valle Lamato in Calabria, and near Catancaro near

Reggio, at Gravitelli, Rometto, and other places near Messina in Sicily (Seguenza).

Prof. Sars and others quote it from the glacial and post-glacial deposits of Norway.

Waldheimia cranium has been recorded as from Ualifax in Nova Scotia by the late

Mr. Willis ; but I have been informed by Mr. Dall, Mr. Whiteaves, and others,

that w'hat he took for the shell under description w^as a specimen of Terebratella

■spitzbert/emis.

Obs. This species, its shell, animal, and different stages of development have been

carefully investigated and admirably described by several competent zoologists. It

has, however, been classed iu the genera Terebratula, Waldheimia, and Macan-

drevia. In 1859, Prof. W. King considered that the species should be separated from

Waldheimia, on account of the deviating septa and want of a mesial septum in the

dorsal valve, as well as bv the absence of dental lamina in the ventral one. I, how^ever,

with Mr. Dall, question Avhether the differences brought forward are of sufficient value

to warrant us in admitting it as a separate genus ; they are, at most, we think, sub-

generic differences.

To Herman Friele we are indebted for a most valuable and important investigation

into the modifications assumed by its loop, from the very youngest age up to the adult

condition, which I now propose, in part, to transcribe from his memoir published in

1877. I also reproduce some of his figures on Plate XII., regretting that space will not

permit me to give them all. He says : — " The earliest stage at which a coherent apophy-

sary system of the Waldheimia cranium is observed, has a size of a little less than three

millimetres [1 line], the haemal valve being two millimetres [Plate XII. fig. 16]. Two

long thin lamellae project from tbe crura, connect with a filiform septum and run

together in an acute angle iu front, where they unite. By the connection of the lamelke

two close-set walls are given off, which by a refieetion form a tube, the posterior end of

which is closed. The size of the haemal valve has reached 2-5 millim., but the state of

things remains the same, save that both the loop (or the tube) and the lamellce have

expanded. [See PI. XII. figs. 17, 17 «] a the lamellae, b the two issuing vertical walls,

or the lateral walls of the tube, c the closed tube (or the loop).

" The first visible change occurs hi/ an opening in the closed end of the tube [figs. 18,

18 a]. The united lamellas then begin to split apart at the anterior end. The haemal

valve has now attained the size of 4-5 millim. A continuous expansion of the loop-

complex causes a perforation in the lateral walls [PL XII. fig. 19], and the septum becomes

thinner and thinner. The next sizes observed were 5*2 millim. and 5-6 millim. (haemal

valve) [PI. XII. fig. 21]. The same characteristics as those seen in [PL XII. fig. 19]

are still in the main prevailing, but the connection with the septum is broken off, and

there remains but a little lump of the latter at the bottom of the valve. The wedge-

64 DR. T. DAVIDSOX ON RECENT BRACHIOPODA.

formed separation of the lamellae have progressed so far [PL XII. fig. 21], that only a

short hand of connection is left betAveen them ; the apertures in the walls have likewise

widened, and a narrow slip is all that still combines the lower and the upper parts.

" The stage of growth illustrated liy [PL XII. figs. 19-21], may properly be designated

tlie Megerlea Stage, and it would be difficult to recognize in this state either the

individual described in [PL XII. figs. 16 and 17], or the fully developed Waldheimia.

In order to become a mature Waldheimia the band between the lamel-processes and

the loop must vanish and the connected lamellae must separate." In another figure, which

we have not reproduced, " the hinder connection between the wpper and lower parts is

completely severed, but the lamelte are still, though slightly, connected." In the nest

stage the connection is cut, PL XII. fig. 22, and in fig. 23 we have the most mature Wald-

heimia cranium. Here Friele gives figures from one fifth of a line in length up to one

line, the smallest of Avhieh is no bigger than a dot.

Waldheimia cranium has sometimes been confounded with Liothyris vitrea, to which

it occasionally bears some general external resemblance ; but the two forms are not only

specifically, but completely generically distinct. Mr. Lucas Barrett was able to examine

the animal alive, and states that " the oral arms are so fixed to the calcareous skeleton

as to be incapable of motion, except at their spiral terminations It has been sup-

posed that these conjoined spiral ends can be unrolled like the proboscis of a butterfly ;

I never saw any disposition of the kind manifested. This species is more lively than

caput-serpentis, moving often on its pedicle, and is more easily alarmed." The cirri are

not protruded beyond the margins of tlie valve ; when the shell is closed they are

bent up ; no currents were detected by Barrett, though frequently sought for. Dr. Gwyn

-leff'reys states likewise {op. cit. vol. v. p. 163) that he has also frequently observed

W. cranium turn round its peduncle, apparently in order to improve its position for the

purpose of feeding, and that the valves on being touched close with a snap.

In Van Bemmelen's " Over den Bouw der Schelpen van Brachiopoden en Chi-

tonen," 1882, and in his " Untersuchungen fiber den anatomischen und histolugischen

Bau der Brachiopoda Testicardinia," 1883, the author enters upon many anatomical and

structural details with respect to Waldheimia cranium^ ; he says that the number of caeca

on the same part of the shell-structure in very old and young specimens was found to

he the same ; this fact, showing that the distance betw^een two caeca (perforations)

does not change with age, led him to the conclusion that no i?itussusception

occurs diiring the growth of the shell. The bases of the calcareous prisms were found

to be very regular-shaped at the margin of the shell (especially in Terehratiila and

Terebratulina sept entriona lis) ; they became very irregular towards the older parts.

The concentric lines of growth occurring on the outer surface were totally absent on the

inner surface, which is explained by supposing the apposition at the margin to stop

for some time, while the formation of new layers on the whole under surface continued.

In Waldheimia cranium he found the sexes were separate.

Mr. Albany Hancock describes and figui-es the soft parts of the animal in his admira-

ble memoir already so often referred to, and from which I now give a few extracts, with

reproductions of his admirable figures of the dorsal and ventral views of Waldheimia

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 65

cranium (PI. XIII. figs. 1, 2). lie says that in Waldhehnia cranium, and in TerebratuUna

caput-seryentis, "the dorsal adjuster muscles are not attached to a hinge-plate, as in

W. australis, but have their insertions in the ventral valve itself, and are very large and

powerful. In both species the superior extremities of these muscles are seen at the

surface of the animal, on each side of the median line, elongated in the antero-posterior

direction and extending between the occlusors almost as far forward as the anterior

margins. . . . The divaricators and the accessory divaricators in W. cranium are likewise

united in the same manner as in the species before alluded to." Mr. Hancock further

observes that " the arms in W. cranium and T. caput-serpentis are disposed in the same

manner as in W. australis ; and in the former the calcareous loop is precisely similar to

that of the latter ; but in T. caput-serpentis it is very much reduced, the extended lateral

portions having almost entirely disappeared, little more than the transverse portion

existing ; and this, together with the crural processes, which are united below across the

median line, forms a collar upon which the bases of the arms rest.

" In W. cranium the intestine is very short, terminating in a blind sac before it

reaches the ventral wall of the perivisceral chamber. It tapers gradually to a point,

which is rounded, and suspended in its place by the mesentery. The mucous membrane,

lining the intestinal tube of If. cranium, is exceedingly thick, and produced into five

or six excessively stout, longitudinal folds, which in transverse sections exhibit a pyra-

midal contour, their apices almost meeting in the centre of the tube .... In W. cranium

the genitalia are arranged as in W. australis, only the bands do not extend so far

forward, and are of a pale yellow colour. The red matter is also present, sprinkling the

surface with distant round spots. The bands arc very finely granular, and in no instance

have I detected eggs in them. It is therefore probable that those examined were out

of season." Mr. Ilancock also observes: — "There is no modification to note in the

perivisceral chamber in any of the Terebratulidaj that I have had an opportunity of

examining. The pallial sinuses, however, vary in several species. Thus in W. cranium,

though there are still four such sinuses in each lobe, the trunks are proportionately

smaller, and more nearly of a size ; the branches are fewer and more attenuated, but, as

in the other species, divided dichotomously twice or thrice, without any very marked

symmetry."

The animal of Waldheimia cranium although differing in some unimportant details

from that of Waldheimia flavescens is essentially similar. In both the loop is the same,

and there is no difference, of any great importance, in the shape of the shell. I therefore

question the necessity of bm'dening the nomenclature by placing W. cranium and

IF. Jiavescens in difi'erent and distinct genera. But as the contrary view has been

expressed by such excellent observers as Prof. W. King, Douville, Zittcl, Waagen,

Deslongchamps, and others, I would not wish to press my own views too far, in

opposition to theirs. M. DouvUle seems to think that W. cranium possesses a special

development of its loop ; while M. E. Deslongchamps, at page 1-il of his Etudes

critiques sur les Brachiopodes,' 1881-, difiers from M. Douville, and expresses his opinion

that the general appearance of the loop of Macandrcvia cranium is actually the same as

that attributed to JFaldheimia. The shape of the principal stems show s the greatest

SECOND SEUIES.— ZOOLOGY, VOL. IV. U

66 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

resemblance to those of Zeilleria ; but the position of the larger-sized adductor muscles

is no longer the same as in Waldhelmia, while the complete absence of a mesial septum

and the shape of the largely divided hinge-plate wovild, in his opinion (Deslongchamps'),

be valid grounds for separating the genus Macandrevia from Waldhelmia.

35. Waldheimia (Macandrevia) tenera, Jeffreys, sp. (Plate XII. figs. 6-10.)

Terebratula tenera, Jeffreys, Ann. & Mag. Nat. Hist. 4th ser. vol. xviii. p. 250, 1876, and Proc.

Zool. Soc. 1878, p. 405, pi. xxii. fig. 7.

Shell rather small, extremely thin and delicate, oval, longer than wide, rounded

laterally, less so in front ; surface smooth, marked only by fine concentric lines of

growth, and perforated by minute canals. In the interior of the dorsal valve po cardinal

process is observable ; hinge-plate comparatively large, and divided into two parts by a

narrow mesial depression, between which, in the middle, a very narrow delicate longi-

tudinal ridge or rudimentary septum is present, which extends to about one fifth of

the length of the valve. The inner slopes of the hinge-plate extend likewise in the

shape of two septa of small elevation to about the same distance, first diverging, then

converging to the anterior extremity of the small median ridge. At the base of the

hinge-plate the principal delicate stems of the loop are attached, and these extend to

about two thirds of the length of the valve before they are reflected. Colour light

brown. Length 6, breadth 4, depth 3 lines.

Hab. Dredged by Dr. Gwyn Jeffreys during the return voyage of H.M.S. ' Valorous '

from Davis Strait, in lat. 56" 11' N., long. 37° 41' W., at a depth of 1450 fathoms,

on a sea-bottom of Globlf/erlna-ooze and stones.

Obs. I have seen two or three perfect examples of this extremely delicate species,

brought home by Dr. Gwyn Jeffreys. The shell seemed full-grown. A specimen about

one line in length showed traces of one of its early stages of growth, in the presence of a

small vertical septum, at about half the length of the valve, to which the loop at that age

had an attachment, as Friele has so well described to be the case in Waldheimia cranium.

Dr. Gwyn Jeffreys observes that " this species differs from T. cranium in being only half

the size in exact measurement, and consequently one fourth in bvilk ; it is of a different

shape, texture, and colour, compressed instead of convex, having a much shorter beak

and smaller orifice, with not half the proportionate number of tubei'cles ; and the blades

are closer together, and do not extend so far towards the front. In the young of each

species the comparative number of tubercles and prominence of the beak are distinctly

marked ; and the septum in the present species is shorter, although conspicuous and

gnomon-shaped."

Uncertain Species.

36. Waldheimia Wyvillii, Davidson. (Plate X. figs. 5, 6.)

Waldheimia Wyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 438, 1878; and {W. tvyvillii) Report

on the Bracliiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 44, pi. iii. figs. 13 a, b, 1880.

Shell ovate or longitudinally oval, very thin, semitransparent, light brownish yellow,

smooth, marked at intervals by concentric lines of growth. Dorsal valve moderately

DE. T. DAVIDSON OX EECENT BEACIIIOPODA. 67

convex longitudinally, slig-litly flattened along the middle. Ventral valve deeper and

more convex than the dorsal one, without sinus ; beak incurved, truncated by an

incomplete foramen, margined laterally by small deltidial plates. In the interior of the

dorsal valve the loop is long and simple, the principal branches extending to a little

beyond two thii'ds of their length before becoming reflected. Length 9, width 7, depth

5 lines.

Hah. Only one incomplete example was dredged by the 'Challenger' Expedition, off

Valparaiso, at a depth of 21C0 fathoms. Terchratida Wi/vlllii and Discinisca atlantica

were obtained at the same time.

Ohs. In external shape this species approaches Waldheimia cranium, which is, however,

a thicker and more convex shell. The extremely delicate shell of W. Wyvtllil is very

remarkable, and reminds us of that of W. tenera, from which, however, it seems to

differ in size and in some other particulars.

The fact that several of the species obtained at such depths as Terehralula Wyv'dlii

and Discinisca atlantica possess such extremely thin and delicate glass-like shells, is

certainly worthy of notice.

Note. — In accordance with the verbally expressed wishes of the late Thomas Davidson, LL.D.,

F.R.S., " The Davidson Collections of Recent and Fossil Brachiopoda" were presented to the nation,

with the manuscripts and original drawings for many of his publications on the Brachiopoda, and the

extensive sci-ics of works and pamphlets he had accumulated during nearly fifty years' investigation of

this group of animals. The recent specimens are associated with the fossil species in the Geological

Department of the Natural History Branch of the British Museum at South Kensington. The literature

now forms part of the libraiy of the same department in that Institution. [A. C]

DESCRIPTION OE THE PLATES.

Plate I.

Figs. 1-6. Liothyris vilrea, Born, sp., at various stages of growth. Mediterranean Sea (Davidson

Collection, Geological Department, British jNIuscum). G. Interior of the dorsal valve,

enlarged, cp, cardinal process ; si, short loop ; clg, diverging grooves for the attachment of the

pallial sinuses.

Fig. 7. Exterior of ventral valve of the same species, showing the four internal radiating furrows which

serve for the attachment of the pallial sinuses, seen tlirough the transparent shell.

Fig. 8. Interior of the ventral valve after E. Ueslongchamps. cv, visceral cavity ; ap, raised portion of the

mantle forming the walls of the visceral cavity ; svl, furrow corresponding to the lateral

venous sinus ; svm, furrow corresponding to the median venous sinus.

Fig. 9. Interior of the ventral valve showing the position of the muscular impressions, a, adductor

or occlusor ; b, ventral adjustors ; c, divaricators.

Fig. 10. Malformation of Liothyris viirea (after E. Deslongchamps) , seen in profile, showing a longitu-

dinal frontal septum in both valves.

Fig. 11. Full-grown spieulum, much magnified (after E. Deslongchamps), from a venous sinus near the

raised part of the mautle oi Liothyris vitrea.

Fig. 12. Portion of the shell of Liothyris vitrea, magnified (after Van Bemmclcu), to show the perforations

and imbricated arrangement of the prisms.

9*

68 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Figs. 13-13 b. Liothyris vifrea, var. minor, Philippi, from the Straits of Messina (Davidson Collection,

Geol. Dept., British Museum).

Figs. 14-16. Liothyris vitrea, var. Davidsoni, A. Adams, from Satanomosaki, Japan. 14. (Davidson

Collection, Geol. Dept., British Museum.) 16. Interior of dorsal valve.

Figs. 17, 18. Liothyris arctica, Friele, sp. 17. Exterior, of natural size. 18. Interior of dorsal valve,

enlarged. (Davidson Collection, Geol. Dept., British Museum.)

Fig. 19. Liothyris cernica, Crosse, sp. : after Crosse's figure, Jouru. de Couch, vol. xvi. pi. i. fig. 3. The

specimen was obtained near the Island of Mauritius, from the stomach of a fish.

Figs. 20, 21. Liothyris Bartletti, Dall, sp., from near Santa Cruz (Museum of Comp. Zool., Harvard).

Plate II.

Figs. 1-4. Liothyris Moseleyi, Davidson. \-lb. Exterior of the shell. 2. Interior of dorsal valve, to

show the loop. 3. Interior of ventral valve, enlarged, showing the muscles ; a, occlusor j

b, ventral adjustor ; c, divaricator ; m, mantle ; n, dorsal pallial nerves ; d, dorsal pallial arteries.

4. Interior of dorsal valve, showing the labial appendages. ' Challenger ' Expedition. West

of Kei-guelen Island. (Zoological Department, British Museum.)

Figs. 5-7. Liothyris uva, Broderip, sp. 5-5 b. Type from Gulf of Tehuantapec (Zoological Department,

British Museum). 6-6 6. A smaller specimen, from the same locality (Davidson Collection,

Geol. Dept., British Museum). 7. Interior of dorsal valve, to show the loop.

Figs. 8-14. Liothyris WyviUii, Davidson, at various stages of growth. 12. Interior of dorsal valve, to

show the loop. Dredged by ' Challenger ' Expedition at different places named in the description

of species. (British Museum and Davidson Collection.)

Figs. 15, 16. Liothyris subquadrata, Jeffreys, sp. 15, 15 a, 15 6. Exterior of the shell after the type, in

Davidson Collection, Geol. Dept., British Museum; 15c. Shell-sculpture enlarged. FromSetubal,

coast of Portugal, near the mouth of the Tagus. 16. Interior of dorsal valve of the same species.

Figs. 17, 18. Liothyris sphenoidea, Philippi, sp. : ' Travailleur ' Expedition; off Morocco. (Museum

d'Histoire Naturelle, Paris.) 18. Interior of dorsal valve, to show the loop.

Figs. 19-22. Liothyris sphenoidea, Philippi { — cubensis, Pourtales). 19, 19 a, 19 6, 21, 22. Florida reefs,

dredged by M. de Pourtales (Davidson Collection, Geol. Dept., British Museum). 20. Ascension

Island; dredged by 'Challenger' Expedition (Zoological Departmeut, British Museum).

Figs. 23-23 6. Terebratula (or Terebratulina ?) Dalli, Davidson. 23. Type, natural size : dredged by

'Challenger' Expedition, lat. 34° 37' N., long. 140° 32' E. 23 a, 23 6. Enlarged. The only

known specimen is in the Zoological Department, British Museum.

Plate III.

Figs. 1-3 fl. Terebratulina WyviUii, Davidson. 1, 1 a, 1 6. Exterior of the type, dredged by 'Challenger'

Expedition, N.W. of St. Thomas, West Indies, in 390 fathoms. 2. Interior of dorsal valve from

same species (Zool. Dept., British Museum). 3. Smaller specimen dredged by the ' Travailleur '

Expedition, from the western coast of Africa (Museum d'Histoire Naturelle, Paris). 3 a. Shell-

sculpture enlarged.

Figs. 4-5 a. Terebratulina Crossii, Davidson. 4,4 a. Type from Japanese water (Coll. of M. H. Crosse).

5, 5a. A smaller specimen, same habitat (Davidson Collection, Geol. Dept., British Museum).

Fig. 6. Tei-ebratulina Crossii, Davidson. A large light salmon-coloured specimen obtained from Sagami

Bay, Japan, by Dr. L. Doderlein, and from his Collection.

Figs. 7-11 a. Terebratulina japonica, G. B. Sowerby, sp. A series of specimens from Japanese waters

(British Museum and Davidson Collection) . 11,11a, represent the Terebratula angusta, Adams

and Reeves, which is only a young Terebratulina japonica.

Figs. 12, 12 a. Terebratulina caput-serpentis, Linne, sp., from Sagami Bay, Japan, found associated with

T. japonica. In the Collection of Dr. DiJderlein.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 69

Plate IV.

Figs. 1-5. Various stages of growth of Terebratidina caput-serpentis, Liniie, sp. 1, 2. Large specimens

in the Zool. Dcpt., British Museum. 3, 4, 4«, 4 b. Specimens of ordinary size from the coast

of Scotland. 5. A very young specimen (after E. Deslongchamps).

Fig. 6. A young specimen in which the crura of the loop are not yet united.

Fig. 7. Interior of the dorsal valve of TerebratuUna caput-serpentis (after E. Deslongchamps), showing

the labial appendages and the cirri, ac, cardinal process ; vc, visceral cavity ; b, mouth ; be,

descending or primary portions of the arms ; br, ascending or reflected portions of the arms ;

mi, interhranchial membrane ; e, shield ; sp, median poi'tion of the arms spirally coiled.

Fig. 8. Dorsal view of Terebratidina caput-serpentis deprived of its shell (after Hancock), n, pallial

lobe ; b, body ; c, peduncle ; d, d, great pallial or genital sinuses ; e, ramifications of ditto ;

/, muscular ties passing between the walls of ditto ; ij, genitalia seen through the walls of

ditto ; h, marginal fold ; i, setae ; j, extreme pallial margin ; k, depressions corresponding to

the bases of the crura ; /, ridge formed by the union of the pallial margins ; m, edge of dorsal

mesentery; n, liver seen through the walls of the perivisceral chamber; o, extremities of

anterior occlusors ; p, ditto of posterior occlusors ; q, ditto of divaricators ; r, ditto of dorsal

adjusters.

Fig. 9. Ventral view of the same (after Hancock) ; the letters up to j agree with those of fig. 8. k, ex-

tremities of occlusor muscles ; /, ditto of divaricators ; m, ditto of ventral adjusters j n, ditto

of peduncular muscle ; o, peduncular nerves.

Fig. 10. Interior of the ventral valve of T. caput-seipentis (after E. Deslongchamps), showing the mantle

in its entirety, vc, visceral cavity ; ap, raised portion of the mantle forming the wall of

the visceral cavity ; o, organs of reproduction ; svl, lateral venous siniises ; svl*, trunks

accruing from the division of the sinuses ; svm, median venoiis sinus ; r, small branches of the

venous sinuses ; on all the circumference one sees distinctly the festooned muscular border of

the mantle, whereon arc implanted a multitude of hairs (enlarged 5 diameters) .

Fig. 11. Interior of the dorsal valve of the same species (after E. Deslongchamps), showing the mantle

also in its entirety. The same letters indicate the same jiarts on this valve, and the parts cor-

respond with those of the ventral valve, with the excejition of ab, which shows the brachial

apparatus in the shape of a ring (enlarged 5 diametez's).

Plate V.

Figs. 1-30. TerebratuUna septentrionalis, Couthouy, after Morse, "Embryology of TerebratuUna," Mem.

Soc. Boston Nat. Hist. vol. ii. pi. viii., 1873. — 1. Acluster of eggs from the genital band. 2,3,4.

Eggs from the perivisceral cavity immediately after their escape from the pallial sinuses. 5. Firet

ciliated stage. G, 7 , 8. Successive stages of transverse division of embryo, showing long tuft of

cilia at cephalic extremity. 9, 10, 11. From a single embryo, showing various outlines assumed

while swimming. 12, 13, 14. Different embryos showing first appearance of caudal or pedun-

cular segment. 15, 16. Representing the same embryo contracted and expanded. 17, 18, 19.

Embryos just attaching themselves by their caudal segment. 20. Embiyo showing first appear-

ance of ventral (?) area by the bulging of the thoracic ring. 21, 22. Embryos in various

stages showing widening of thoracic ring, and its gradual growth towards enclosing the

cephalic ring. 23, 24, 25. Successive stages of the embryo, showing formation of dorsal and

ventral areas by the folding and growth of the thoracic ring. In fig. 26 the head is still seen

projecting from the dorsal and ventral folds of the thoracic ring. 27 to 30. Succeeding stages

of embryos drawn in various positions. The deciduous setae appear in these stages.

Fig. 31. One of the earliest stages of TerebratuUna septentrionalis, after Morse {op. cit. pi. i. fig. 3),

" in which the body has rapidly lengthened, and the peduncle is equal in length to the

70 DH. T. DAVIDSON ON RECENT BEACHIOPODA.

remaining portion of the animal." p, peduncle; ^ja, point of attachment of peduncle; c<b,

pallial cfeca ; se, setae. (" Early Stages of TerebratuUna," Mem. Soc. Boston Nat. Hist. vol. ii.

pi. i. fig. 3.)

Fig. 32. A spiculum of TerebratuUna caput-serpentis : highly magnified (after Hancock) .

Fig. 33. Portion of the internal surface of the shell of T. cajjut-serpentis , showing the imbricated

arrangement, and the intei'nal orifices of the vertical perforations arranged in rows : magnified

100 diameters (after Carpenter).

Figs. 34, 34 a. TerebratuUna caput-serpentis : very young, dredged by the ' Travailleiir ' Expedition. Coll.

of the Marquis de Folin.

Figs. 35-37. TerebratuUna caput-serpentis, var. emargmata, Eisso, = var. mediteiTanea, Jeffreys; from

the Mediterranean Sea; 37, was dredged alive between Pantellai'ia and Sciacca, Sicily. All

in Davidson Collection, Geol. Dept., British Museum.

Figs. 38-40. TerebratuUna caput-serpentis, var. unguicitlata, Carpenter : 38, 39, exterior of shell ;

40, interior of dorsal valve. Off Vancouver Island. (Davidson Collection, Geol. Dept.,

British Museum.)

Figs. 41-42 a. TerebratuUna CaiUeti, Cross e. 41-41 c. From Barbados (Davidson Collection, Geol.

Dept., British Museum) ; 42, 42 a. Type, after Ci-osse's figure.

Figs. 43-52. TerebratuUna septentrionaUs, Couthouy, from off Halifax, Nova Scotia, and Lockport,

Maine, at different ages (Davidson Collection, Geol. Dept., British Museum). 43, 44. Full-

grown individuals. 47. A cluster of specimens attached to one another. 50, 51. Young

examples. 48. Interior of dorsal valve and loop; 49. Dorsal valve, showing labial appendages.

52. Portion of shell, magnified.

Figs. 53-53 b. TerebratuUna Cumingi, Davidson : type. From China seas.

Fig. 54. TerebratuUna abyssicola, Adams and Reeve, sp. : after Reeve's figure. OfE Cape of Good Hope.

(Davidson Collection, Geol. Dept., British Museum.)

Plate VI.

Figs. 1-8 b. TerebratuUna canceUata, Koch, sp. 1-7. Specimens dredged by the ' Challenger ' Expe-

dition off Moncoeur Island, Bass Strait, in from 38 to 40 fathoms ; 7. Interior of the dorsal

valve, enlarged, showing the labial appendages. 8-8 b. A small dwarfed form, dredged by

Mr. J. Brazier at Inner North Head, Port Jackson, N.S.W. (Davidson Collection, Geol. Dept.,

British Museum.) Specimens 1-7 in Zool. Dept., British Museum.

Figs. 9-14. TerebratuUna radiata. Reeve, sp. Different forms from the Cape of Good Hope (Davidson

Collection, Geol. Dept., British Museum). 12. Specimen showing black colour-markings.

Figs. 15-17. TerebratuUna t Murrayi, Davidson. 15. Outline of shell, natural size. 15 a,b, enlarged.

16. Dorsal valve, with loop magnified. 17. Dorsal valve, showing mantle, enlarged. Dredged

by the ' Challenger ' Expedition near Kermadec Island, south of the Fiji Islands, depth 600

fathoms. (Zool. Dept., British Museum.)

Figs. 18-20. TerebratuUna ? tuberata, Jeffreys, sp. From Josephine Bank, 340 to 430 fathoms (Collection

of Dr. Gwyn Jeffreys, now in the Smithsonian Institution, Washington, U.S.A.: figures all

much enlarged. 19. Interior of the dorsal valve.

Figs. 21, 22. TerebratuUna ? trigona, Jeffreys, sp. A young and immature shell, dredged by Mr. Saville

Kent off the coast of Portugal, at a depth of 501) fathoms (Coll. of Dr. Gwyn Jeffreys, Smith-

sonian Institution, Washington, U.S.A.). 22. The shell opened, to show the loop.

Figs. 23-25 ft. Terebi-atuUna? incerta,Da.\'idson. 23, 24«. Dredged by the ' Challenger ' Expedition in

lat. 1° 47' N., long. 24° 26' W. (Zool. Dept., British Museum, and Davidson Collection).

25, 25 a. Interior of dorsal valve, with loop, after Dall, magnified 2i diameters ; dredged by

the ' Blake' Expedition off Bequea. (Smithsonian Institution, Washington, U.S.A.)

DE. T. DAVIDSON ON EECENT BEACIIIOPODA. 71

Plate VII.

Fig. 1. TerebratuUna [Agulhasia) Davidsuni, King: natural size. 1 a, 1 b, 1 f. Shell enlarged.

Fig. 2. Ditto, interior of ventral valve, enlarged.

Figs. 3, 4. Ditto, interior of dorsal valve and sectional diagram of same, enlarged.

Fig. 5. Tubuli cliaracteristic of TerebratuUna caput-sei-pentis {1-d after King). (Davidson Collection,

Gcol. Dept., British ISIuseum.)

Figs. 6-lt. Waldheimia flavescens, Lamarck, s]). ( = Terebratula australis, Quoy). Different specimens from

Port Jackson, N.S.W., showing modifications in shape and in ribbing. 10, (afterG. B. Sowerby),

shows the extent the animal opens its valves. 13, represents the var. recurva, Quoy, ft-om Shark

Point, Port Jackson. 12, 12 a. A young smooth shell, from Bottle and Glass Rocks, Port Jack-

son. All the specimens, with the exception of fig. 10, from the Davidson Collection, Geol.

Dcpt., British Museum.

Fig. 15. Dorsal view of IValdhebnla flavescens, the .shell having been removed (after Hancock) . «, pallial

lobe ; b, body ; c, peduncle ; d, great inner pallial sinuses, giving off branches to the margin ;

e, outer ditto ; /, genitalia seen through the pallial membrane ; g, red matter of ditto ; /;, mar-

ginal fold ; i, seta; ; j, eircumpallial vessel ; k, extreme pallial margin ; /, median fissure, corre-

sponding to longitudinal plate in valve ; m, depression occasioned by the hinge-plate and the

bases of the crura ; n, orifices for the passage of the crura ; o, ridge formed by the union of the

pallial margins ; p, extremities of anterior occlusors ; rj, ditto of posterior occlnsors ; r, ditto of

divaricators ; s, ditto of dorsal adjustors ; t, liver seen through the wall of the body.

Fig. 16. Ventral view of the same; the letters up to and including k correspond to those of fig. 15.

/, extremities of the occlusor muscles ; m, ditto of divaricators ; n, ditto of accessory divaricators ;

0, ditto of ventral adjustors; ;;, ditto of peduncular muscles; g, cjecal extremity of intestine,

seen through the wall of the perivisceral chamber ; r, peduncular nerves.

Fig. 17. Thin lamella of shell of Waldheimia flavescens (after Carpenter), showing the parallel disposition

of the flattened prisms, and the regular arrangement of the passages which intervene between

them ; and at a the outcrop of these prisms of the internal surface of the shell. Magnified

100 diameters.

Fig. 18. Internal surface of Waldheimia flavescens (after Carpenter), showing the imbricated arrangement

of the extremities of the prisms, which are seen longitudinally at a. Magnified 100 diameters.

Fig. 19. External surface of shell of Waldheimia flavescens (after Carpenter), showing the large trumpet-

shaped ends of the vertical passages, covered in by opercular disks, which have radiating lines

proceeding from them. Magnified 100 diameters.

Note. — Figures of the dorsal and ventral valves, of the muscular system, and of the labial

appendages and animal of W. flavescens are given in the text at pp. 42, 45, 47, and 48 (woodcuts,

figs. 3, 4, 5, G, 7, & 8).

Plate VIII.

Fig. 1. /r«W/(t'm/a wwo*«, Solandcr, sp. Type. (See Dixon, ' Voyage round the World,' 1789.) From

Falkland Islands.

Figs. 2-2 c. Waldheimia venosa. The largest specimen known, dredged alive in Stanley Harbour,

Falkland Islands, by Admiral B. J. Sulivan in 5 or 6 fathoms, 1844.

Fig. 3. Widdheimia venosa. Type of the Terebratula globosa of Lamarck, which was badly figured in

the Encyclopedic Methodique, pi. 239. fig. 2, 1789. (Museum d'Histoire Naturelle, Paris.)

Fig. 4. Ditto. Type of the Terebratula physema, Valenciennes, after Reeve's figure, ' ^Monogr. of Tere-

bratula, Conch. Icon.' pi. vi. fig. 23. From Cocpiimbo. (Museum d'Histoire Naturelle, Paris.)

Fig. 5. Ditto. Interior of the dorsal valve of a full-grown specimen, to show the loop.

Fig. G. Ditto. Type of the Terebratula Fontaineana, A. d'Orbigny, ' Voyage dans I'Am^rique Meri-

dionale,' vol. v. pl. 85. figs. 30 & 31, 1847. (Reduced f natural size.) From Coquimbo.

72 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Plate IX.

Figs. 1, 1 a. Waldheimia venosa, var. dilatata, Lamarck. Type of Lamarck's Terebratula dilatata, from

a drawing made in Paris from the type in the Museum d'Histoire Naturelle, Paris.

J'igs. 2-'13. Waldheimia lenticuluris, Deshayes, sp. A series of specimens of different forms and ages from

the Straits of Fouveau, New Zealand, in 15 fathoms water (Davidson Collection^ Geol. Dept.,

British Museum). 2-3 b. Large specimens. 10. Interior of dorsal valve, showing loop in the

adult condition. 11-13 a. Modifications assumed by the loop previous to its attaining the

adult state.

Plate X.

Figs. 1-4. Waldheimia Grayi, Davidson. 1, 1 a, 2. Typical form. 3. Interior of dorsal valve, to show the

loop. 4j 4 a, 4 b. Variety transversa. All dredged from Japanese waters except the specimen

shown in fig. 2, which was dredged by Sir E. Belcher in the Straits of Corea. (Davidson

Collection, Geol. Dept., British Museum. )

Figs. 5, 6. Waldheimia Wyvillii, Davidson. 5, 5 a. Exterior of shell. 6. Interior of dorsal valve,

enlarged, showing the loop. Dredged by 'Challenger' Expedition, lat. 33° 31' S., long.

74° 43' W., depth 21G0 fathoms. (Zool. Dept., British Museum.)

Figs. 7-17. Waldheimia kerffuelenensis, DnYidson. 7-15. A series of forms of different ages. 16. Interior

of dorsal valve, showing the loop. 17. Interior of dorsal valve, showing the labial appendages.

All dredged by the ' Challenger ' Expedition south of Kerguelen Islands, also off Marion Islands.

Found in depths varying from 100 to 150 fathoms. AU the specimens figured are in the Zool.

Dept., British Museum.

Plate XI.

Figs. 1-10. Waldheimia septigera, Loveii,sT^. 1-1 c. From Faeroe Sound, 570 fathoms (Davidson Collec-

tion, Geol. Dept., British Museum) . 2-2 b. A very large broad specimen, after Sars. 3. A young

example, from the British sea, between Shetland and Faeroe (' Porcupine ' Expedition), depth 345

fathoms. 4. Interior of dorsal valve with its fully developed loop. 5. Profile view of the same

(after Sars). 6. View of the loop seen from the front, much enlarged. 7-10. Different stages in

the development of the loop, after H . Friele, figures magnified ; all from Norwegian waters.

Figs. 11-13. Waldheimia Kaphaelis, Dall. 11-11 e. A very perfect example from off the coast near

Jeddo, Japan (Davidson Collection, Geol. Dept., British Museum). 12, 12a. A large typical

example from Sagami Bay, coll. Dr. Doderlcin. 13. Interior of dorsal valve, showing its fully

developed loop. 12-13. In the Museum of the Smithsonian Institution, Washington, U.S.A.

Plate XII.

Figs. 1-5. Waldheimia floridana, Pourtales, at different ages, dredged by Agassiz and de Pourtales off

Florida reefs, between 100 and 200 fathoms (Davidson Collection, Geol. Dept., British

Museum). 5. Interior of dorsal valve, to show the loop.

Figs. 6-10. Waldheimia {or Macandrevia) /t'Me?-«, Jefireys, sp. 6-6 b. Specimen of the natural size. 7. In-

terior of ventral valve, enlarged. 8. Interior of dorsal valve, to show the loop. 9. Posterior portion

of the interior of the dorsal valve very much enlarged, to show the hinge-plate and septa. 10. A

very young example in which a small pillar-shaped ventral septum is seen in the interior of the

dorsal valve. These figures, drawn by Davidson, were published by Jeffreys in the Proc. Zool.

Soc. for 1878. Dredged by Dr. Gwyn Jeffreys, lat. 56° 11' N., long. 37° 41' W., 'Valorous'

Exjjedition, at a dejjth of 1450 fath. (Jeffreys Collection, Smithsonian Institution, Washington,

U.S.A.)

Dli. T. DAVIDSON ON RECENT BKACIIIOPODA. 73

Fifi;s. 11-23. IVuhlheimia (or Macandrevia) craftiww, Miillcr, sp. \\-\^ b. A series of dift'ercut ages.

11. A very large example (after Sars). 15-15 b. A very minute or first stage (after Friele).

10. Tlic first stage of the development of the loops with a coherent apopliysis (Friele).

17, 17a. Sijccimen a little further advanced: a, lamellae; b, vertical walls; c, tube (Friele).

18, 18 ff. Opening of the posterior end of the tube (Friele). 19. Perforation of the lateral

walls (Friele). 20, 21. Connection with the septum is broken (Friele). 22. The lamel-

processes separated. 23. Adult and fully developed loop. All the specimens from Norwe-

gian waters. (See Friele, Develop. Skelet. in Jl^alr/heimia, Archiv Math, og Naturviden-

skab, ii. p. 380, pis. i. & ii., 1877.)

Plate XIII.

Fig. 1. IVuldhelmia {ov Macandrevin) cranium, Miiller, sp. Dorsal view of the animal, much enlarged

(after Hancock), o, pallial lobe ; Zi, body; c, peduncle; d, great inner pallial sinus; e, outer

ditto ; /, genitalia appearing through the walls of the sinuses ; y, marginal fold ; h, setae ; i,

cireumpallial vessel ; _;', extreme pallial mai-gin ; k, two lobes corresponding to cavities at the

sides of the foramen ; /, similar lobes corresponding to the cavities in the umbonal region of

dorsal valve ; m, ridge resulting from the union of the pallial margins ; n, extremity of anterior

occlusoi's ; 0, ditto of posterior ocelusors ; p, ditto of dorsal adjustors ; q, ditto of divaricators.

Fig. 2. Ventral view of the same (after Hancock). The letters up to k as in fig. 1 : — I, extremities

of the occlusor muscles ; m, ditto of divai'icators ; ni*, portions of ditto, corresponding to

the accessory divaricators ; n, ditto of ventral adjustors ; o, ditto of peduncular muscle ;

p, peduncular nerves.

P'igs. 3-9 ff. Terebratella coreanica, Adams and Reeve, sp. 3. Type specimen figured by Reeve. 4-4 c. A

fine and large specimen. 5, 5 a. A still larger example {Terebratula miniata, Gould), dredged

by L. V. Schrenk, from Hakodadi, Japan. G, Ga. An elongate globose variety, dredged by Capt.

St. John in Tsuga Strait. 7. Interior of dorsal valve, to show loop. 8, 8 b. Elongate variety

(7". 2?o(/c//a;-</«, Davidson) . 9, 9«. Var. Bo«cAo«/i, Davidson. Specimens 4, 5, fi, 7, and 8, in

the Davidson Collection, Geol. Dept., British Museum ; 9, in the Zool. Dcpt., British

Museum.

SECOND SERIES. — ZOOLOGV. VOL. IV. ]()

[ 75 ]

II. A Monograph of Hecent BracMopoda.—Vavt II.

i?y Thomas Davidson, LL.D., F.ll.S., F.L.S., F.G.S., §-c.

Read 3rd June, 1886.

(Plates XIV.-XXV.)

Subfamily Tekebeatellin^.

Genus TEEEBEATELLA, d'Orbigny, 1847.

In this genus Alcide d'Orbigny proposed to include all those species in which the long

reflected loop has its principal stems twice attached : — first by their crura to the base of

the hinge-plate, and again by horizontal laminae given off from about the middle of the

principal stems, which afterwards become attached to the anterior extremity of a low

mesial septum. The Terebratula dorsata of Gmelin was selected as the type.

In 1870 Mr. Dall proposed to separate from Terebratella, as thus defined, those forms in

which the reflected portions united form a loop, and in which the mesial septum is very

large, elevated, and projects beyond the anterior extremities of the loop. Ty^pe Mar/asella

Jiexiiosa, P. King.

It has been ascertained that great changes take place in the form of the loop of Tere

bratella during the progress of its development from the young to the adult condition

and that when young, and up to a certain age, it shows the loop and septum of Magasella

Indeed Mr. Dall has frankly admitted to me that some of the species referred to Maga

sella are immature forms of Terebratella ; but for some others, such as Magasella flexuosa,

P. King, Magasella siiffusa. Peeve, which retain the Magasella loop and septum in their

adult condition, he proposes to retain the subgenus Magasella.

We have recognized nine species of Terebratella and three uncertain ones, viz. : —

1. Terebrntella dorsata, Gmelin.

2. transversa, Vt. B. Sowerby.

G. Terebratella rubicunda, G. B. Sowerby.

7. frontalis, MiddendoriF.

8. cruenta, Dillwyn.

9. Marue, Adams.

3. corcanira, Adams & Reeve.

4. liluiifordi, Diiiikcr.

5. spUzbergensis, Davidson.

The uncertain species are Terebratella putvinata, Gould ; Terebratella rubiginosa, Dall , Terebratella

Frielii, Davidson.

The very numerous synonyms have been added to the descriptions of the species.

37. Terebratella dorsata, Gmelin, sp. (Plate XIV. figs. 9-19.)

Anomie Magellanique striee, Davila, Catalogue Systematiciue dcs Curiosites dc la Nature, vol. i. p. 312,

pi. XX. fig. A, 17G7.

? magellanique, Walchs, Naturforseher, p. 202, pi. iii. figs. 3, 4, 1774.

? magellanique, Favanne de Monteervcllc, Conebyliologie, pi. xli. fig. A. 3, 1780.

SECOND SERIES. — ZOOLOGY, VOL. IV. 11

76 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Anomia striata Mayellanica, Chemnitz, Neues syst. Coocli. -Cabinet, vol. viii. p. 101, tab. 78. figs. 710,

711, 1785.

Terebratula dorsata, Gmelin, ed. Linne's Syst. Nat. vol. iv. p. 3348, 1788; Bruguiere, Encycl. Meth.

pi. 242. fig. 1, 1789 ; Lamarck, An. sans Vert. vol. vii. p. 246, 1819 ; G. B. Sowerby, A Catalogue of Shells

of the late Earl of Tankerville, p. 28, 1825.

Terebratula bilohata, Blainville, Diet. Sci. Nat. vol. liii. p. 166, 1828 (refers for fig. to Encycl. Meth.

pi. 242. fig. 1).

Delthijris dorsata, Menke, Synopsis Methodica Molluscorum, 2nd ed. p. 96, 1830.

Terebratula chilensis, Broderip, Trans. Zool. Soc. vol. i. p. 141, pi. 22. fig. 1, 1833 ; Owen, On the

Anatomy of the Brachiopoda, Trans. Zool. Soc. vol. i. p. 146, pi. xxii. figs. 3-11, 1833.

Terebratula Sowerbii, Owen, Ou the Anatomy of the Brachiopoda, Trans. Zool. Soc. vol. i. p. 149,

pi. xxii. figs. 15, 16, 1833 ; King, Zool. Journ. vol. v. p. 338, 1835.

Terebratula dorsata, Anton, Verzeichuiss der Conchylien, p. 23, 1839; Kiister, Chemnitz's Conch. -

Cab. vol. vii. p. 23, pi. 1. fig. 17, pi. 2. figs. 14, 15, 1843.

Terebratula lupinus, Philippi, Neuen Conchylien, Archiv fiir Naturgeschichte, Jahrg. xi. Band i. p. 58,

1845.

Terebratula dorsata, King, Ann. & Mag. Nat. Hist. 1st ser. vol. xviii. p. 39, 1846; G. B. Sowerby,

Thes. Conch, p. 346, pi. Ixviii. figs. 15-17, 1846.

Terebratula Chilensis, G. B. Sowerby, Thes. Conch, p. 347, pl. Ixviii. figs. 18, 19, 1846.

Terebratula Soverbii, G. B. Sowerby, Thes. Conch, p. 348, pl. Ixviii. figs. 20-22.

Terebratula dorsata and T. chilensis, A. d'Orbigny, Voyage dans I'Amer. Merid. vol. v. pp. 675, 676,

1847.

Terebratella chilensis, d'Orbigny, Mem. de I'Acad. des Sci. pl. vii. fig. 13, 1847.

Terebratella dorsata and T. Chilensis, Davidson, Sketch of a Class, of Recent Brach., Ann. & Mag.

Nat. Hist. 2nd ser. vol. ix. p. 367, 1852, and Br. Foss. Brach., Pal. Soc. vol. i. Introduction, p. 65, pl. vi.

figs. 11-13, 1853.

Terebratula dorsata, T. Chilensis, and T. Soverbii, Woodward & Gray, Cat. of the Brach. in the Brit.

Mus. pp. 87, 88, 1853.

Terebratula dorsata, S. P. Woodward, A Manual of Mollusca, p. 217, fig. 115, 1856.

Terebratella dorsata, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissenseh.

Wien, Bd. xxxvii. p. 208, 1859.

Terebratula {Terebratella) Mayellanica, Reeve, Conch. Icon, vol.xiii. pl. v. figs. 21, a-d, 1860 ; Ann. &

Mag. Nat. Hist. 3rd ser. vol. vii. p. 176, 1861.

Terebratella dorsata, Dall, Amer. Journ. Conch, vi. p. 116, 1870; Proc. Acad. Nat. Sci. Philadelphia,

p. 184, 1873; Zittel, Handb. der Palaontologie, p. 705, fig. 552, 1880; Davidson, Report on the

Brachiopoda, Voyage of H.M.S. 'Challenger,' Zoology, vol. i. p. 44, pl. iv. fig. 4, 1880.

Shell somewliat transversely oval, wider than long, or of a suborbieular trapezoidal

form, broader posteriorly, tapering anteriorly, vritb a mesial flattened sinus of moderate

breadth and depth, commencing at about one third of the length of the valve and

extending to the front. Ventral valve deeper than the dorsal one, with a moderately broad,

gently convex mesial fold of small elevation, corresponding to the sinus in the opposite

valve ; margin flexuous in front, the fold and sinus projecting a little beyond the curved

lateral margins ; beak moderately produced, incurved, and truncated by a large circular

foramen, very little separated from the hinge-line by a deltidium in two pieces ; beak-

ridges sharply defined, and leaving a flattened space between them and the long obtusely

angular hinge-line. Surface of valves marked n'ith numerous narrow angular ribs,

DE. T. DAVIDSON ON RECENT BEACHIOPODA. 77

increasing in number at various distances from the beak and umbo by the interpolation

of shorter ribs between the longer ones, and crossed at intervals by concentric lines of

growth. Shell-structure punctate. Of a very light yellowish white or ochreous colour.

Length 1 inch 8 lines, breadth 1 inch 10 lines, depth 11 lines.

In the interior of the dorsal valve the cardinal process and hinge-plate are well defined.

The loop is long and doubly attached, first to the hinge-plate, again by horizontal lamintc

given off from the principal branches of the loop to a slightly elevated mesial septum,

previously becoming deflected.

Hab. Straits of Magellan ; Bay of Valparaiso, in depths of from 60 to 90 fathoms

(Cuming) ; Eoyal Sound, Kerguelen Island (' Challenger ' Expedition).

Obs. This fine species has received several denominations, and some considerable dif-

ference of opinion has been expressed as to the name the shell should retain. The first

notices I can find of the shell are those of Davila in 1767, Favart d'Herbigny, Walchs in

1774, Favanne in 1780, and Chemnitz in 1785. These early naturalists had described and

figm-ed the species under the designation of the Magellan striated Anomia ; and as that

name is not binomial, Gmelin, in 1778, named it Terehratula dorsata, and, I believe, the

larger number of malacologists have preferred that designation, although some others

have insisted on retaining the name of Magellanica for the shell, which Gmelin should

have adopted. The names chilensis and Soioerbli are certainly synonyms, and L. Reeve

would likewise add to them the T.flexuosa of P. King. If this view were adopted,

one would have also to include the Terebratula rhombea, Philippi, and, in all probability,

the Terehratula htpinus of the same author ; but as these last-named species have large

Magasella-&\iii.\)eA septa and are adult, it may be better, at any rate provisionally, to locate

them in the subgenus MaQasella. I am the more inclined to adopt this view, as many

specimens of Terebratella dorsata, when compared with others of Magusella flexuosa, of

equal dimensions and age, can be distinguished by the absence of the elevated mesial septa.

Terebratella dorsata varies also somewhat in shape and striation ; young specimens

have their valves quite smooth, and even in some full-grown examples the umbo and beak

remain smooth, the ribbing commencing a little lower down. In 1867 Commodore Acton

dredged in the Straits of Magellan a very large number of specimens of Terebratella

dorsata, from the dimensions of one line in length up to twenty, and on his return kindly

presented me with a series of examples illustrating the different ages of the shell.

When quite young, there exists in the interior of the dorsal valve a large and elevated

mesial plate or septum, from the anterior sides of which the principal stems of the loop

take their second attachment. Over these, but quite separate, are two small anchor-

shaped lamelltE, which are attached to the sloping portion of the septum facing the

hinge-plate. After a time these anchor-shaped lamellae become united, and their lower

edges are connected with those of the primary branches ; by degrees the principal stems

of the loop are separated again, become larger, and give ofi' a transverse branch, which

fixes itself to the upper anterior edge of the then low median septum.

In 1847 A. d'Orbigny proposed his excellent genus Terebratella, giving the full-grown

condition of Terebratula dorsata, Gmelin, as his type. King's Terehratula Sozccrbil, from

the Straits of Magellan, is nothing more than a rust-coloured example of Terebratella

11*

78 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

dorsata. It is always necessary to give the characters oi c species from its adult condi-

tion, noting the changes its apophysary system undergoes during the different stages in

its development.

In 1845 Dr. Philippi described, under the name of Terebratula lupimis, a young smooth

examjjle of Terebratella dorsata, in which the dorsal valve still 'detains the elevated

Magasella septum. The type is preserved in the Berlin Museum. Philippi did not

figure his so-termed species, and I am indebted to Prof. E. v. Martens for a series of

excellent figures of the species (PI. XIV. figs. 20 a, h, 21 a).

In 1833 Prof. Owen described, with great care and minuteness, the soft parts of the

animal in the sjiecies under description. He says that " the arms and viscera, as in

Lingttla, are inclosed between the lobes of the mantle, which are precisely adapted to the

inner surface of their corresponding valves, and are in such close contact with them as to

require great care in separating the valves from them. That lobe of the mantle which

corresponds to the perforated valve, is traversed longitudinally by four large vessels ; the

opposite lobe is similarly traversed by two such vessels. . . . The margins of the mantle

are thickened . . . the marginal cilia are so minute as only to be perceptible by means

of a lens. At the posterior part of each of the lobes the expanded fleshy extremities of the

muscles are seen ; those which were attached to the perforated valve being nearer the

hinge by their whole length, than the anterior pair of the opposite valve. Each of tlie

oval muscular disks is composed of an anterior larger muscle and a posterior smaller one.

Through the transparent mantle may also be seen the green-coloured follicular liver

intervening between and stirrounding the muscles, and the folded ciliated arms." Prof.

Owen then describes at some length the great arterial trunks, adding that " The size of

these vessels at once suggests their subserviency to other purposes than that of merely

returning the blood necessary for the nutrition of the mantle. . . . Corresponding to the

large branchial veins there appear under the microscope much smaller vessels, which I

regard as the branchial arteries ; these run parallel with the middle of the branchial

veins, and terminate in the margins of the mantle from which the veins commence.

These margins present the following appearances when viewed with a high magnifying

power : — they are puckered at regular distances, the puckering being apparently caused

by the insertions of delicate cilia, which pass as far within the mantle as they project

beyond it ; in the interspaces of the cilia the margin of the mantle is minutely fringed :

and within this fringe is a canal, which extends itlong the whole circumference of the

lobe, and from which the branchial veins appear to take their origin : the marginal canal

is contracted where the cilia are inserted into it, which gives it a sacculated appearance,

like that of the canal of Petit in the human eye. The uniform results of repeated obser-

vations on aU the specimens of Terebratula wliich I have had at my disposal, convinced

me that the vascular mantle was the chief, if not the sole respiratory organ ; and the

utility of the marginal cilia in reference to this function can now be readily appreciated,

in consequence of the discovery of the i-emarkable property which cilia possess of

exciting determinal currents in the surrounding water."

After having stated so much. Prof. Owen then describes the shape and double attach-

ment of the loop, and adds, " the interspace between the two folds of the calcareous loop

is filled up by a strong but extensile membrane, which binds them together, and forms a

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 79

protecting wall to tlir^ 'viscera ; . . . The arms in Ter. chilensis, when detached from the

supjoorting processes and unfolded, exceed the length of the shell by two thirds of that

length ; and their length is to their breadth as eight to one. Their stem, from which

the cilia airse, as it has not to execute the movement of Lingula, so it is much more

slender. The cilia, therefore, are proportionally increased, in order to excite the neces-

sary currents in the Avater ; which, being directed between the folds of the arms

towards the mouth, as to a focus, carry thither tlie nutrient molecules, which are retained

by the natural sieve formed by the decussating cilia of the terminal processes in front of

the mouth ; and though this apparatus is apparently less perfect than in Limjula, it is

evidently adjusted in due relation to the support of so small a mass of body as exists

in Tercbratula."

Prof. Owen then refers to the muscles and peduncle; but as these bear a general

resemblance to those already noted in Waklheimia and in other genera, we will not

repeat his description here. He also describes the alimentary canal, the oesophagus,

and liver: this last he states to be "a bulky gland of a green colour and minute

follicular texture ; it is disposed in two principal masses, which lie on each side of the

alimentary canal, and between the two lateral arches of the testaceous loop iu tho^p species

of Terehmtula which possess that appendage ... In two of the larger specimens of

Ter. Sowerbii, the ova were lodged external to the liver, and had also insinuated themselves

between the layers of the mantle-lobes, in close proximity to, and partly surrounding,

the branchial vessels. They are probably discharged in this way from the mantle,

having previously been exposed to the influence of the branchial currents. ... In

dissecting a Terehratula I have found it most convenient to cut transversely through the

perforate valve, so as to leave the orifice and the pedicle connected to the opposite valve,

by which means the disposition of the muscles is satisfactorily seen, and the delicate parts

within are less liable to be disturbed than by attempting to separate the entire valve."

I regret not being able to reproduce Prof. Owen's admirable illustration.

The muscular system of Terehratula dorsata has also been described by Prof. W. King

in the Ann. & Mag. Nat. Hist. ser. 1, vol. xviii. p. 39, 1846.

38. Terebratella transversa, Sowerby, sp. (PI. XVI. figs. G-9.)

Terebrutula Iramversa, G. B. Sowerby, Descriptions of thirteen new Species of Brachiopoda, Proc. Zool.

Soc. 184G, p. 91 ; Tlies. Conch, vol. i. p. 3G1, ])1. 72. figs. 114, 115, 1846.

Terehratula caurina, Gould, Proc. Boston Soc. Nat. Hist. iii. p. 347, 1850 ; Gould, U. S. Esplor. Exped.

xii. Shells, p. 468, pi. 44. fig. 582 ; Otia Conch.p.97, 1862; Carpenter, Supp. Rep. Brit. Assoc. 186.3, p. 636.

Terebratella caurina, E. Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. Wissensch.

Wien, Bd. xxsvii. p. 207, 1859.

Terebrutula canrena, P. P. Carpenter, Rep. Brit. Assoc. 1856, p. 298.

Terebratula (Terebratella) transversa, L. Reeve, Conch. Icon. INIonog. Ter. pi. v. fig. 22, I860 ; A Revision

of the History, Synonymy and Geograxihica! Distribution of the Recent TerebratuLe, Ann. & Mag. Nat.

Hist. 3rd ser. vol. vii. ]>. 176, 1861.

Terebratella caurina, Dall, Amer. Journ. of Conch, vol. vi. p. 119, pi. vi. figs. 1, 2, 3, 1870.

Terebratella occidentalis, Dall, Proc. Acad. Sci. of California, vol. iv. p. 182, pi. 1. fig. 7, 1871.

Terebratella transversa, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 185.

Terebratella occidentalis, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 181.

80 BE. T. DAVIDSON ON EECENT BEACHIOPODA.

Terebratella transversa, J. E. Whiteaves, Ou some Marine Invertebrata from the "West Coast of North

America, Canadian Naturalist, n. s. vol. viii. p. 468, 1878, and On some Marine Invertebrata from Queen

Charlotte Island, Keport Geol. Surv. Canada, 1878-79, p. 195 (1880).

Shell very variable in shape, usually quadrispherically transverse, wider than long,

broadest posteriorly or near the hinge-line, which is very obtusely angular, almost straight,

very little shorter than the breadth of the shell ; marginal line flexuous and sinuated in

front. Dorsal valve moderately convex, channelled longitudinally along the middle by

a concave depression or sinus. Ventral valve much deeper than the dorsal one, with a

longitudinal elevation or fold extending from the beak to the front ; beak short, slightly

incurved, and truncated by a large incomplete foramen, margined anteriorly by a portion

of the umbo of the opposite valve, and laterally by two small deltidial plates ; beak-

ridges strongly defined, leaving between them and the hinge-line a flat or gently con-

cave smooth area. Surface of valves either smooth or more or less covered with faint

or strong angular ribs, here and there bifurcating, or with a short rib interpolated

between the larger ones. Shell-structure perforated by minute canals. In the interior

of the dorsal valve the hinge-plate is divided ; cardinal process small, and from under it

a mesial septum of small elevation extends to about half the length of the valve. Loop

long, doubly attached, first to the base of the hinge-plate, then to the anterior extremity

of the mesial septum by means of an oblique lamina given off from about the middle

of the length of the principal stems of the loop, when, after having attained their greatest

length, they become reflected in the shape of a loop. Colour varying from light ashy

yellow to a light or dark livid purple or red mixed with yellow, deeper in colour on the

lines of growth. Length 1 inch 3 lines, breadth 1 inch 7 lines, depth 10 lines.

Hab. Off Vancouver Island, mouth of Cumshewa Harbour, in 20 fathoms; Houston-

Stewart Channel, in 15-20 fathoms (Whiteaves) ; Puget Sound to Sitka (Swan), Alaska

territory, peninsula of Aliaska ; Neeath Bay, from Aleutian Islands to Oregon (Dall) ;

coast of California at Monterey (Cooper and Dall) ; Catalina Island (Cooper).

Obs. Dall justly observes, in his description of this species, in the ' American Journal

of Conchology ' for 1870, that " it presents every possible variation from longitudinally

oval to quadrispherically transverse, that many are unsymmetrical, and most of them

overgrown with Polyzoa, Serpulse, and Corallines." He also mentions that " some

specimens have from thirty to forty ribs or many fewer, and varying very much in

prominence; some have none at all, and others have theu* valves smooth and half

ribbed, some ribbed only on the umbones, others again near the margin." I have

detected all these modifications even in the limited number of specimens I have been

able to examine.

To the completely smooth examples, Sowerby, in 1846, gave the name transversa ; to

a ribbed individual, Gould, in 1850, applied that of caurina (PL XVI. figs. 10-12), and, in

1871, Dall named a red variety, from the coast of California, Terebratella oceideiitalis.

Peeling somewhat uncertain with respect to the last-named species, I forwarded to Mr. Dall

a red specimen, of which I give figures (PI. XVI. figs. 13 & 11), and which agreed in every

detail, except in colour, with specimens from Sitka and Vancouver Island. In returning

DE. T. DAVIDSON ON EECENT BEACHIOPODA, 81

it to me Mr. Dall wrote that it was his Terebmtella occkleiitalis, which may prove to be a

southern race of Terehratella transversa of Sowerby ; and I quite believe this to be the

case. The lines of growth, Mr. Dall states (under T. caurma, Eevision of the Terebratulidae,

Amer. Journ. Conch, vol. vi. 1870, pp. 120, 121), " are usually strong and often imbricated,

especially when the radiating ribs are strong. . . . The punctures are smaller, more cir-

cular, and fewer in number than in Terehratella pulvinata. An examination of the young

shells only about '2 inch in extreme width, showed some interesting points. The septum

is calcified very early, and is thick, prominent, bifurcate at its extremity, and serrated on

its anterior edge. The bifurcation is the first indication of the septal processes, which

are the last to be calcified ; and when the extremely thin hcemal processes are yet incom-

plete, the young shell closely resembles a Magas. In the beak of the neural valve just

inside the foramen, is a very prominent thin lamina or septum which half closes the

foramen. In the adult the muscular system is not largely developed. The pedicel

muscles are the strongest. The cardinals are slender and their bases are spread over a

wide extent of the neural valve, but the muscular impressions are imperceptible. The

adductors are small and slender. The brachia foUow the lateral loops of the apophyses

and cross below the mouth on the reflected portion and the septal processes. There is

no central spiral lobe. The fringes are in a single row, flattened and extremely thin ;

in an adult they are about "IS inch long. They are much more slender than in Terebra-

tulina or Megerlia. When fully extended they are far from the margin of the valves.

The mouth is circular, situated between the adductors. The visceral part of the system

is protected by a tliin tough membrane. The colour of the animal is reddish or brownish,

the ovaries vary in the same way. The perivisceral fluid is of a reddish-yeilow colour.

The umbones of both valves are generally eroded by contact with stones. The animal

seemed to have the power of turning half around on its peduncle at will."

Although the name traiisversa, Sowerby, should be retained for the species, the

smooth variety is less abundant than the costated one. The ribs are, in some specimens,

quite simple, and the variety occidentalis has, according to Dall, been sometimes mistaken

for the Waldheimia Grayi, Davidson, from Japanese waters.

39. Terebratella coreanica, Adams & Reeve, sp. (Plate XIII. figs. 3-9.)

Poulette de la Tartarie, Lamanon, Voyage de la Perouse autour du Monde, vol. iv. p. 119, pis. 1 and 8,

1797.

Terebratula coreanica, Adams & Reeve, Voyage of H.M.S. ' Samarang,' p. 71, pi. xxi. fig. 3, 1850.

Terebratella coreanica, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 3G7, 1853.

Terebratella Bouchardii, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 367, 1852, and Proc.

Zool. Soc. 1852, pi. xiv. figs. 4-6; Woodward & Gray, Cat. of the Brach. in Brit. IMus. p. 88, 1853;

E. Suess, Uebcr die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissensch. Wicn, p. 206,

1859.

Terebratella miniata, Gould, Proc. Boston Soc. Nat. Hist. vol. rii. p. 323, 1861.

Terebratula {Terebratella) Coreanica, Reeve, Monogr. of Terebratula, Conch. Icon. pi. rii. fig. 28, a,b,

1861 ; A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. ii. p. 99, 1863; L. v. Schrenck, Reisen und

Forschungcn im Amur-Landc, Zool. p. 468, pi. xviii. fig. 7, 1867.

? Terebratella Lamanoni, L. v. Schrenck, ibid. 1867.

? Terebratella Coreanica, Carpenter, Supp. Rep, Brit. Assoc. 1863, p. 636.

82 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

Tercbratella Coreanica, Dall, Amer. Journ. Conch, vol. vi. p. 121, 1861, and Proc. Acad. Nat. Sci.

Philadelphia, p. 183, 1873 ; Davidson, Proc. Zool. Soc. 1 871, p. 304, pi. xsxi. figs. 4-5 ; G. Dunker,

Index IMollusc. Maris Japonici, p. 252, 1882 ; C. E. Leschke, Japonische Meeres Conchylien, Suppl.

p. 181, 1884.

Shell large, semicii'cular, or somewhat transversely or elongated oval, broadest poste-

riorly, slightly winged, with an almost straight or obtusely angular hinge-line, or broader

about the middle, with a more obtusely angular hinge-line ; lateral margins flexuous, more

so in front. Dorsal valve convex, sometimes ventricose, channelled or depressed longi-

tudinally along tlie middle. Ventral valve deeper than the dorsal one, strongly keeled

longitudinally ; beak incurved and truncated by a circular foramen, incomplete in some

specimens, in others margined anteriorly by a deltidium in two pieces ; beak-ridges

strongly marked. In the interior of the dorsal valve the hinge-plate and cardinal process

are large and well defined ; a mesial septum of small elevation extends to about half the

length of the valve. Loop large, attached to the base of the hinge-plate and by a

transverse lamella to the anterior extremity of the septum before again proceeding and

doubling itself in the shape of a loop. Shell smooth, orange-red throughout, or fulvous-

white rayed with bright red, and traversed by concentric lines of growth stained with

red at their edges ; shell punctate. Proportions variable, a large example measured :

length 1 inch 10 lines, breadth 1 inch 11 lines, depth 1 inch 1 line.

Bah. Corean Archipelago (Belcher) ; Ilakodadi, Japan, in 7 fathoms, and Straits of

Korea in 48 fathoms (A. Adams) ; dredged also at Hakodadi, in 1868, by L. v. Schrenck,

and in 1872 by Capt. St. John in Tsuga Strait, in 35 fathoms ('Sylvia' Expedition);

Sea of Tartary (Lamanon, Voyage de la ' Perouse,' 1798).

Ohs. This beautiful large red species was dredged, if I am not mistaken in my identi-

fication, by Lamanon in 1797, iu the Sea of Tartary. He described and figured the shell,

its loops and labial appendages, with tolerable accuracy, and showed that its loop was

twice attached, although his large figure 11 is evidently incorrectly drawn. He gave it

the name of " Poulette de la c6te de Tartaric," and subsequently, in 1867, Dr. L. v.

Schrenck named it Terebrattila Lamanoni, after its discoverer. In 1850, Adams and

Reeve described and figured two smaller examples, delicately painted with irregular

crimson-scarlet rays, dredged by Sir Edward Belcher during the voyage of H.M.S.

' Samarang,' under the name of Terehrtdella Coreanica; and this name must be retained

for the shell. To some larger examples Gould, in 1861, gave the name of Terehratella

miniata, and I now consider the shell I described in 1852 by the name of Terehratella

BoucJiardii to be merely an elongated bleached example of Terehratella coreanica. This I

am more ready to believe, as I subsequently procvired an exactly similar-shaped specimen

from tlie locality where Terehratella coreanica abounds, marked with red as in that species.

Terehratella coreanica is extremely variable in shape, as may be seen from the illus-

trations I give of it in PI. XIII. figs. 3-9. The largest examples I have seen of the shell

were obtained at Hakodadi during Dr. v. Schrenck's Russian Government dredging-expe-

dition in Amur Land, 1854-56. Dr. v. Schrenck gives seven figures in pi. xviii. of his

work ; but fig. 7, representing the loop, is not correct, as I ascertained from a type specimen

he kindly presented to me shortly after his return. In the specimen in question the

DE, T. DAVIDSON ON RECENT BRACHIOPODA. 83

reflected portion of the loop was mucli larger, and agreeing with the figure I give of it

on Plate XIII. fig. 7.

I may also mention that searcli was made at the Jardin des Plantes for Lamanon's

specimens, but none of them could be discovered.

Having examined some young examples of the shell under description, I found that its

loop underwent similar modifications to those I have described as taking place in

Terehratella ruhicunda.

40. Terebratella Blanfordi, Dunker, sp. (Plate XV. figs. 9-12.)

Terebratula Blanfordi, Dunker, Index Mollusc, maris Japonici, p. 251, pi. xiv. figs. 4, 5, 6, 1882.

Sliell thin, nearly as wide as long, rotundate quadrate, lateral margins moderately

curved ; hinge-line obtusely angular, front line long, with a greater or less inward curve.

Dorsal valve moderately convex, with a broad shallow depression commencing at a short

distance from the umbo, and gradually widening as it approaches the front. Ventral valve

deeper and more convex than the dorsal one, with a similar broad depression commencing

at a short distance from the beak and extending to the front. Beak rather small, incurved,

and truncated by a circular foramen partly margined by a deltidium ; beak-ridges sharply

defined. In the interior of the dorsal valve the loop is long and doubly attached, first to

the hinge-plate and then to the median septum, before becoming reflected. Surfaces

smooth, marked here and there with fine concentric lines of growth. Colour dull yellow.

Length of a large specimen 13, breadth 12, depth 8 lines.

Ohs. This remarkable and well-characterized species is well described and figured by

Dunker, who gives as its habitat Wakayama, Japan. It varies somewhat in contour ;

some specimens are more circular, and in some the frontal indentation is greater than in

others. Terehratella Ula nfordl is associated in the same sea-bottoms with Terehratullna

Crossil, Davidson, and Waldhe'imia Raphaelis, Dall.

41. Terebratella spitzbergensis, Davidson. (Plate XVI. figs. 1-5.)

Terebratula , Lyell, On the Proofs of a gradual Rising of the Land iu certain parts of Sweden,

Phil. Trans. Roy. Soc. 1835, p. 3G, pi. ii. figs. 32, 33.

Terebratula caput -serpentis, Hisinger, Lcthfea Suecica, p. 83, 1837 (not of Linnaeus).

Terebratella Spitzbergensis, Da-iddson, Proc. Zool. Soc. 1852, p. 72; Ann. & Mag. Nat. Hist. 2nd ser.

vol. xvi. p. 442, pi. X. fig. 3, 1855; and Proc. Zool. Soc. 1871, p. 305, pi. xxx. fig. 13; M'Audrew,

List of the MoUusca from Spitzbergen, Ann. & Mag. Nat. Hist. 2nd ser. xvi. p. 465, 1855 ; O. Torell,

Bidrag Spitzbergens MoUuskfauna, p. 121, pi. i. fig. 1, 1859 ; E. Suess, Ueber die Wohnsitzeder Brachio-

padcii, Sitzungsb. k. Akad. Wissench. Wien, p. 204, 1859 ; L. Reeve, Conch. Icon. jjl. vii. fig. 2, 1861,

and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 178, 1861.

Magasella Spitzbergensis, Dall, Amer. Journ. of Conch, vol. vi. p. 37, 1870; Terebratella, id. Proc.

Acad. Nat. Sci. Philadelphia, p. 185, 1873.

Terebratella spitzbergensis, Jeffreys, Proc. Zool. Soc. 1878, p. 409, pi. xxiii. fig. 2 ; H. Priele, The

Development of the Skeleton in the genus JValdheimia, Arch, flir Mathematik og Naturvidenskab, pi. vi.

1877; G. Dunker, Index Mollusc, maris Japonici, 1882, p. 252.

Shell small, ovate, longer than wide. Valves uniformly and nearly equally convex ; no

fold or sinus in either valve ; beak in ventral valve moderately produced, incurved and

SECOND SERIES. — ZOOLOGY, VOL. IV. 12

84 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

truncated by an incomplete, longitudinally oval foramen, margined anteriorly by the

ximl)0 of the dorsal valve and by two small lateral triangular deltidial plates ; beak-ridges

not very sharply defined. Surface of valves smooth, strongly punctate, and marked by

fine concentric lines of growth. The apophysary system in dorsal valve composed of

a doubly attached loop extending to about two thirds of the length of the valve, first

attached to the base of the hinge-plate, the principal stems widening gradually and,

at about half their length, becoming attached to the upper edge of an elevated median

septum, then again extending towards the front before becoming reflected. Colour light

whitish yellow. Length 4^, breadth 3|, depth 2| lines.

Hab. Homsund and Bellsund, Spitzbergen, 40 to SO fathoms (Torell) ; Wellington

Channel (Belcher) ; Shetland, 35 miles N.N.W. of Unst, in 90 to 100 fathoms ; Channel

Slope, about 185 miles from Cape Clear and Usliant, and 165 miles from the Scilly Isles,

in 358 fathoms ; Channel Slope, 339 fathoms ; otf Cape St. Vincent on the coast of Spain,

292 fathoms (Jeffreys) ; Gulf of St. Lawrence (P. P. Carpenter and Whiteaves) ; Japanese

Waters (A. Adams) ; off Iceland (' Valorous ' Expedition) ; Possil at Uddevalle (Hisinger

and Jeffreys) ; and in another raised bank near Christiauia in 1866 by Messrs. Crosskey

and Robertson.

Ohs. I have seen a number of specimens of this small well-marked species ; none of

them exceed the dimensions above recorded. Terebratella spitzbergensis evidently

enjoys an extended geographical range.

In 1834 Sir Charles Lyell collected in a Swedish postglacial deposit a single ventral

valve of this brachiopod, while investigating the proofs of a gradual rising of the land

in certain parts of Sweden. He simply called it a Terebratula, and gave two figures of it

in the ' Philosophical Transactions ' of the Royal Society for 1835. According to Torell

the species was confounded in 1837 by Hisinger with TerebraMina caput-serpentis.

In 1852 I described and figured the shell in the Ann. «& Mag. Nat. Hist, from a

perfect specimen lent to me by Mr. H. Cuming, and then gave it the name of Terebratella

Spitzbergensis, which it has since retained. In 1859 Torell published an incomplete

figure of the loop, but sufficient to show that it was doubly attached as in Terebratella.

The young of Terebratella spitzbergensis have not yet been examined; but in a paper by

Herman Priele on 'The Development of the Skeleton in the genus Waldheimia,' a. whole

plate is devoted to enlarged illustrations of the loop, and the author remai^ks that in one

example " remnants of the lateral walls are still left on the lamel-processes at their point

of connection with septum, which signifies an earlier stage like that in Tf^aldheimia."

42. Tekebbatella btjbicunda, G. B. Sowerby. (Plate XV. figs. 15-29.)

? Terebratella sanguinea, Quoy & Gairaard, Voyage de TAstrolabe, Zool. vol. iii. p. 556, pi. 85. figs. 7-8,

1834 (not T. sanguinea, Cbemnitz).

Terebratella rubicunda, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 92, and Tbes. Coucb. i. p. 351,

pi. kx. figs. 45-47, 1846.

Terebratella inconspicua, Sowerby, Proc. Zool. Soc. 1846, p. 93, and Tbes. Concb. p. 359, pi. Ixxi.

figs. 102-104, 1846.

II alionia Fatewdewwem, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol, v. p. 475, pi. xv. fig. 1, 1850.

DE. T. DAVIDSON OX EECENT BEACHIOPODA. 85

Terebratella rubicunda, Davidson, Aim. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 36", 1852 ; Woodward

6 Gray, Catalogue of the Bracliiopoda in the British Museum, p. 89, 1853 {T. inconspicua is now

considered a synonym of T. rubicunda) ; E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb.

k. Akad. der Wissensch. Wicii, p. 207, 1859 (T. inconspicua and a syn.) ; L. Reeve, Conch. Icon. pi. vii.

fig. 27, 18GI {T. inconspicua a syn.) ; Dall, Amer. Journ. Conch, vol. \\. p. 117, 1870, and Proc. Acad.

Nat. Sci. Philadelphia, 1873, p. 185.

Magasella inconspicua, Dall, Amer. Journ. of Couch, vol. vii. p. dl , 1871, and Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 189.

Terebratella rubicunda, F. W. Hutton, Marine Mollusca of New Zealand, p. 85, 1873.

Shell somewhat orbicular or triangularly ovate, widest about tlie middle, acuminated

posteriorly ; dorsal valve moderately convex, channelled along the middle by a broad

concave sinus, commencing at the umbo and extending to the front, where it is produced

a little beyond the lateral curved margins of the valve. Marginal line flexuous on the

sides. Ventral valve deeper than the dorsal one, with a convex, well-defined, mesial fold

extending from the extremity of the beak to the front ; l)eak incurved and truncated by

a large circular foramen, lying close to the umbo or just separated from it by two rather

large deltidial plates that barely meet in the middle ; beak-ridges sharply defined. Surface

of valves either entirely smooth or more rarely with small short rounded ribs commencing

at a short distance from the lateral and frontal margins of the valves ; surface of valves

crossed by concentric strongly marked lines of growth. In the interior of the dorsal

valve the hinge-plate is well defined, with a cardinal process at its posterior extremity.

A mesial septum of small elevation proceeds from the base of the hinge-plate to about

one half the length of the valve. Loop doubly attached, first to the base of the hinge-

plate, and then by a transverse lamella proceeding from about the middle of the

length of the principal lamella to the anterior extremity of the septum, when, after

again extending a little further, the lamell.Te become reflected and united. Colour

pale or deep red, sometimes colourless. Length 1 inch 1 line, breadth 1 inch, depth

7 lines.

Sab. Fauveau and Cook's Straits, New Zealand ; Dusky Bay (Hutton).

Ohs. Terebratella rubicunda is an exceedingly abundant shell in the seas of New

Zealand. It varies much in shape and character from the young up to the adult condition,

and its loop passes through several modifications during the progress of growth.

The youngest individual I have been able to examine measured three lines in length ; at

this stage and for some time after its septum is remarkable in shape and of considerable

elevation as in Ilagasella, but low at its origin under the hinge-plate. It soon assumes an

upward concave curve, to be followed by another still more oblique ; where it attains

its highest elevation, a flattened plane occurs and then gradually thins out by an abrupt

inward curve, until it reaches nearly to the bottom of the valve, the anterior half of

the septum presenting the form of a wide, elevated, flattened plate. In the young

stage under description the principal laminae or stems of the loop, after being attached

to the hinge-plate, form a curve and become fixed by their anterior edges to the

lateral sides of the septum ; a little higher up, and attached to the edge of the septxim,

are two wide, curved, disunited anchor-shaped lamellije. To this immature condition

I gave in 1850 the name Waltonia Valenciennesii, which must be expunged. To a

12*

86 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

shell in the same condition, or a little older, G. B. Sowerby, in 1846, gave the name of

Terebratula inconspmict. In 1852 I expressed the opinion that the shell " seems to be

only a young and ill-gvown specimen of T. riihicmida;" and in this opinion S. P.

Woodward, E. Suess, and L. Reeve have concurred. Mr. Dall, however, maintains

it as a distinct species, and places it in his genus Ifagasella. When a little older, or at

about four or five lines in length, the septum becomes very much less elevated, and the

principal lamellge approach closely to the septum, where they become attached prior to

continuing their course and becoming reflected. In the adult or full-grown state the

septum is quite low, and at about half their length the principal lamellse, which are now

wide apart, give off a long, oblique lamella, which connects them to the anterior

extremity of the septum. A glance at the figures on Plate XV. will show these different

conditions better than any verbal description.

Groups of specimens at different stages of growth are often found attached to a single

adult example. The shell is generally smooth throughout, but a tendency to plication is

not uncommon on the anterior portion of the shell. The peduncle is very short.

Mr. Donovan states, in the second volume of his ' Naturalist's Repository,' that

Solander had given the MS. name of rubicunda to the shell we noAV kuow^ as Ki-aussina

rubra of Pallas, 1766 ; but as Solander did not publish his name, that of rubicunda,

Sowerby, must be retained for the shell under description.

The intimate shell-structure of Terebratella rubicunda has been carefully investigated

by Dr. W. B. Carpenter. In plate iv. of his chapter on the structure of the shells

of Brachiopoda, contributed to vol. i. of my ' British Possil Brachiopoda,' he gives

three enlarged figures, one of these, which we reproduce (PI. XV. fig. 25), is a portion of a

vertical section of the loop-bearing valve, taken in the transverse direction through the

origin of the calcareous appendages, -nhich shows that the latter are not traversed by

canals. In this figure the ordinary trumpet-like form of the vertical passages is

shown, and the remarkable contractions which they exhibit in the inner and (probably)

later-formed layer ; in Plate XV. fig. 26 the occasional l)ifurcation of the vertical

passages is represented.

43. Terebratella prontalis, Middendortf, sp. (Plate XV. figs. 1-8 a.)

Terebratula frontuUs, Middenclorff, Beitriige zu einer Malacozool. Rossica, iii. 1849, Mem. Acad. St.

Pctersbourg, t. vi. p. 518 ; aud Reise in d. ausserst. Nordeu und Osten Sibiriens, 1851, Bd. ii. jj. .LMl,

t. xviii. figs. 9-li; E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch.

Wien, p. 204, 1859; Dall, Amer. Jourii. of Conch, vol. vi. p. 1.23, 1870; Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 184 ; Dall, Report on the Brachiopoda of Alaska and the adjacent shores of North-

west America, ibid. 1877, p. 15G; Duuker, Index Mollusc, maris Japonic!, p. 252, 1882.

Shell somewhat subpentagonal, longer than wide, broadest about the middle, mar-

ginally curved, slightly indented in front. Dorsal valve posteriorly evenly convex,

anteriorly divided by a narrow^ longitudinal depression or groove, commencing at a very

short distance from the front margin. Ventral valve rather deeper than the dorsal one,

w^ith a very slight elevation close to tlie margin; beak rather large, truncated at right

angles by an unusually large incomplete foramen, posteriorly margined to a considerable

DK. T. DAVIDSON ON EECENT BEACHIOPODA. 87

extfint by tlie umbo of the dorsal valve and by two very small rudimentary deltidial

plates ; beak-ridges sharply defined, leaving between them and the hinge-line a small

flattened space. Hinge-line obtusely angular. Surface of valves smooth, marked with

strong concentric lines of groA\th ; shell-punctures rather large; and soin(>what widely

interspaced. In the interior of the dorsal valve the cardinal process is small, the hinge-

plates are disunited and form two concave projections, on each side of w^hich deep

dental sockets are situated. The principal lamella; of the loop are attached to the

bases of the hinge-plate, and these by a curve meet a slightly raised mesial septum, to

which they lioconie again attached ; at a short distance from this second attachment the

lamellae become reflected in a very remarkable and unusual manner. The large paired

adductor muscular impressions are situated at the bottom of the valve, and at some

distance from the mesial septum or ridge. In the ventral valve the curved articulating

teeth arc large and powerful. Colour ashen or yellowish grey. Length of a large

specimen 11 lines by 10 in breadth and 6 in depth.

Hab. Western Aleutians from Atka Island westward ; Atka, Amchitka, Attn (Dall) ;

Ocbotsk Sea (Middendorff ) ; Japan seas (Capt. St. John). From low water to 45 fathoms ;

abundant in 10 fathoms.

Obs. This is a very good and well-characterized species, well but not completely fio-ured

by Middendorff in 1819. The shell was subsequently al)undantly collected by Mr. Dall

and Capt. St. John. The Japanese examples are a good deal smaller than those figured

by the Eussian author, as well as those dredged by Dall at Atka Island, in the Aleutian

channel. Their interior is exceedingly remarkable, and differs in detail in many respects

from that occurring in the larger number of species of the genus, first in the shape of the

loop, and secondly in the position and dimensions of the adductor muscular impressions,

which are very powerful. These characters and differences will become at once apparent

by a glance at the figures, which I have drawn with all possible care and accuracy. The

shell is thick and presents a coarse appearance.

44<. Teuebratella cruenta, Dillwyn, sp. (Plate XIV. figs. 1-8.)

Anomiu saiif/iiinca, Solander, MS. Portland Cabinet; Leverian Cat. sec. part 15.

Tert'brutuhi saiirjiiinea, Leach, Zool. Misc. p. 7Q>, tab. xxxiii. 1814 (not Chemnitz).

? TerebratuJa sanyuinea, Lamarck, An. sans Vert. voL vi. p. 247, 1819 (not Chemnitz?).

Terebratula cruenta, Dillwyn, Descrip. Cat. Recent Shells, vol. ii. p. 295, 1817.

Terebratula sanffuinea, E. Donovan, Naturalist's Repository, vol. i. pi. 34, 1823.

Terebratula Zelaiidica, Deshayes, Revue Zoologique par la Soc. Cuvierienne, p. 359, 1839, and Mag.

de Zoologie, Mollusques, pi. 42, 1841.

Terebratula rubra, G. B. Sowerby, Thes. Conch, i. p. 345, pi. isviii. figs. 9-11, 1846 (not Pallas).

Terebratula Zelandica, G. B. Sowerby, Thes. Conch, p. 361, pi. Ixxii. figs. 111-113, 1846.

Lampas sarir/uineu.f, Calonne, Cat. Humphrey, MS.

Terebratella Zelandica, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vo p. 367, 1852.

Terebratella Evansii, Davidson, Proc. Zool. Soc. 1852, p. 77, pi. xiv. figs. 7-9.

Terebratella cruenta, Woodward and Gray, Cat. of Brachiopoda in the Brit. ^lus. p. 89, 1853.

Terebratella Zelandica, E. Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. der

Wissensch. AVien, Bd. xxxvii.p. 207, 1859.

88 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

TerebrafeJla {Tcrebratuhi) crventa, L. Reeve, Conch. Icon. pi. v. fig. 20, a, b, 1860.

Terebratella {Magus) Evrinsn, L. Reeve, Concli. Icon. pi. viii. fig. 31, 1861.

Terebratella cruenta, Dall, Proc. Acad. Nat. Sci. Philadelpliia, 1873, p. 183; F. W. Hutton, Catalogue

of the Marine Mollusca of New Zealand, p. 85, 1873.

Shell rather large, somewhat subpentagonal, subtransverse, ventricose, longer than

broad. Dorsal valve convex, channelled longitudinally along the middle by a well-defined,

flattened, mesial sinus or depression. Ventral valve deeper and moi-e convex than the

opposite one, with a longitudinal mesial fold of moderate breadth and elevation, some-

what flattened, extending from the beak to the front; margins flexuous both laterally

and in front ; beak incurved and truncated by a large circular foramen, separated from

the hinge-line by a deltidium in two pieces ; beak-ridges not very sharply defined. Sur-

face of valves rad lately costellated ; ribs narrow, numerous, increasing in number

at various distances from the beak and umbo through bifurcation and the interpola-

tion of smaller and shorter riblets between the larger ones ; surface of valves crossed

at various distances by concentric lines of growth. In the interior of the dorsal

valve the cardinal process and hinge-plate are large and well defined ; the mesial septum,

of low elevation, extends to lialf or a little more of the length of the valve. Loop large,

doubly attached, the principal stems, before attaining their greatest length, give oflP a

flat oblique lamella, which becomes fixed near the anterior extremity of the septum, the

lamella proceeding again and doubling in the shape of a loop. Colour sanguineous or

paler red, deepest in intensity at the lines of growth. Length 1 inch 10 lines,

breadth 1 inch 11 lines, depth 1 inch 2 lines.

Mab. Very abundant in Cook's and Fauveau Straits, New Zealand.

Ohs. This beautiful shell has been rather unfortunate on account of the many con-

fusing names it has received. In 1823, Donovan, in vol. i. of his ' Naturalist's Reposi-

tory,' described and figured the shell, and enters into long details with respect to its early

history. He informs us, that it is one of those very choice accessions to the conchological

knowledge of the last century, that it occurred to them upon the coast of New Zealand,

and that after the Banksian Cabinet had been supplied, duplicates were presented to

Dr. Solander, Captain Cook, the Duchess of Portland, Mr. Cracherode, and Mr. G.

Humphrey, and to some others. That it was named and described for the first time, in

manuscript, by Solander under the name oi Anomia sanguinea *, was subsequently so desig-

nated in the museum of the Duchess of Portland ; and that it appeared under the same

appellation in the catalogue of that museum pul)lished in 1786. Donovan complains

very bitterly that Dillwyn should not have adopted, in 1817, Solander's manuscript name,

and should have given it instead that of cruenta, a name Solander had also made use of

in manuscript for another species. Dillwyn was, however, justified in rejecting Solander's

designation, since Chemnitz had previously, in 1785, applied the name sangu'mea to

another species ; for manuscript names cannot claim a right to priority over any others that

have been really published. It is to be regretted, however, that Dillwyn had selected for the

* " Obovato longitudinaliter sulcata, triloba : sinu profundo nate producta latere angulata foramen ambiante.

Solander's Miiii —Bab. in 0. Pacifico, G. R. Forster "(Donov. Nat. Rep. I.).

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 89

New Zealand species the name of crucnta, wliicli had, in manuscript, been applied hy

Dr. Solander to another species.

Although a well-marked species, TerehrcUella crueiila, Dillwyn, has been confused

by some conchologists with others to which it does not belong-, such as with the Kraussina

rubra of Pallas (Solander's MS. Anomia ruhicunda). Its young stage received from myself

the name of Terebratella Ecansii before I had ascertained that in the young the loop

presented the character of Jf«/7«'s<?^Za. All the early authors prior to 1817 knew the shell

we are describing by the name given to it by Solander. It is so named in the Levcrian

Cabinet, sec. j)art 15 ; also in Dillwyn's Couch, i. p. 293, 21 ; and in Leach's Zool. Misc. x.

p. 76 ; and in Lamarck's ' An. sans Vert.' vol. vi. p. 217 (1819), for he refers to Leach's Zool.

Misc., but was evidently in error Avhen he gives, as its synonym, the Anomia capensia of

Gmelin and Chemnitz. Terehratella cruenta, like all its congeners, is very vai-iable in

shape, and its loop passes through several metamorphoses, from the very young state up to

the full-grown condition. I have already given the dimensions of the largest example in

my collection, which I obtained some years ago from Mr. G. B. Sowerby. Up to six

lines in length and much less the apophysary system is composed of a large central

longitudinal septum, not exceeding half the length of the valve, arising rapidly in the

form of a narrow elevated plate, almost reaching the centre of the ventral valve, to the

middle of Avhich, and to the base of the hinge-plate, are attached the principal stems of

the riband-shaped lamellre before becoming reflected. Mr. L. Reeve and several other

malacologists have adopted my name Ecansii, but I have had to relinquish it after a very

careful study of a large number of specimens from one and a half up to twenty-two lines

in length. Atone time, as stated by Donovan, Terebratella crnenta, Dillwyn, was a rare

shell, a specimen having fetched five guineas at the Leverian sale ; now, however, it has

become an almost common shell, and may be had for a few shillings.

45. Terebratella Mari.e, A. Adams. (Plate XV. figs. 13, It )

Terebratella MaricB, A. Adams, On some new Genera and Species of ^Mollusca from Japan, Ann. &

Mag. Nat. Hist. 3rd ser. vol. v. p. 413, 1860, and Ann. & Mag. Nat. Hist. Srtl scr. vol. xi. p. 9U, 1863;

Davidson, On Recent Japanese Brachiopoda, Proc. Zool. Soc. 1871, j). 305, pi. xxx. figs. 15-17; Dall,

Proc. Acad. Nat. Sci. Philadelphia, p. 181., 1873; G. Duuker, Index Mollusc, maris Japoniei, p. 252,

1882.

Shell small, somewhat squarely oblong, longer than wide, lateral margins very little

rounded, nearly sub^iarallel, front broad, almost straight. Dorsal valve moderately

convex, with a broad, slightly raised, mesial fold, commencing near the front. Ventral

valve much deeper than tlie opposite one, with a broad, slightly concave dej)ression

commencing at about half the length of the shell, and extending to the front ; beak

short, incurved and truncated by a circular foramen, anteriorly margined by two narrow

deltidial plates. Front margin raised into a rounded wave, lateral margins fiexuous.

Surface smooth, traversed by fine concentric lines of growth ; shell-structure finely

punctate. Length G, breadth 4, depth 3| lines. Colour white, glazed, semitransparent.

In the interior of dorsal valve the loop, twice attached, extends to about two thirds of the

90 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

length of the shell ; mesial septum most elevated anteriorly, extending to within a third

of the length of the valve ; principal stems of the loop attached first to the hase of the

hinge-plate, and then at about a third of their length by a transverse lamella to the upper

edge of the anterior extremity of the septum, when, after extending for some distance,

they become widely reflected, the reflected lamella being much broader than that of

the principal branches.

Sab. Dredged by Mr. A. Adams at Uraga in 21 fathoms; Gotto in 48 fathoms;

and at Satanomosaki in 55 fathoms : all in Japanese waters.

Obn. This pretty little shell was briefly described, but not figured, in 1860 by A. Adams.

It is an imj)ortant species, and nearly approaches in shape and character to the

Upper Pliocene Terebratella septata, described by Philippi in vol. ii. of his work, ' Eauna

Molluscorum E-egni utriusque Sicilise,' p. 69, pi. xvii. fig. 7, 1814, and by Seguenza in

vol. i. Memorie della Soc. Ital. di Scienze Natural!, 1865. Terebratella septata is,

however, a much larger shell than the Japanese Terebratella Maivce, measuring

over an inch in length by ten lines in breadth. The principal branches of the loop

seem to be closer, and the reflected portion broader, than in the two specimens of the

recent shell that I have been able to examine. Dr. Gwyn Jeffreys considered Tere-

bratella MaricB to be the living representative of the Sicilian species ; but this point

cannot be definitely determined until more specimens of the Japanese species have been

examined and compared.

UMcertain Species.

46. Terebratella pulvinata, Gould, sp. (Plate XVI. fig. 15.)

? Terebratula pulvinata, Gould, Proc. Boston Soc. Nat. Hist. vol. iii. p. 347, 1850; U.S. Exploring

Expedition, Shells, p. 467, pi. xliv. figs. 581 a-e.

Terebratula [Waldheimia) pulvinata, Gould, Otia Coucli. pp. 97 & 255, 186.2; Cooper, Geogr. Cat.

California Moll. p. 3, no. 4, 1867.

Terebratella pulvinata. Carpenter, Check-List West Coast N. Amer. Shells, 1860; Dall, Amer. Journ.

Conch, vol. vi. p. 117, 1870.

Terebratula pulvilla, Carpenter, Rep. Brit. Assoc. 1856, p. 213.

Sliell orbicular, about as broad as long, widest posteriorly, tapering anteriorly, sides

and front margins rounded, hinge-line obtusely angular. Dorsal and ventral valves

regularly convex ; beak small, truncated by a circular foramen lying close to the umbo

of the dorsal valve, but slightly separated from it by a small deltidium in two pieces

Colour light yellowish white. Length 10, breadth 10^, deptli 5 lines. In the interior of

the dorsal valve the loop is long and doubly attached, first to the base of the hinge-plate,

then to a mesial septum which extends from under the hinge-plate to about two thirds

of the length of the valve.

Eab. Puget Sound, Oregon.

Obs. I have only seen the figures given of this shell by Dr. Gould, and a photograph

of the type sent to me by Mr. Dall. I feel very uncertain with respect to its

specific value, and have long been under the impression that it might be only one

of the young stages of Waldheimia venosa. Mr. Dall, however, writes to me : —

" Terebratella pulvinata is, I believe, an excellent species. It resembles, externally,

the young flatfish forms of Waldheimia venosa, but it is a perfect and mature Terebratella

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 91

and in no way related to Terehratella dorsata. I may, however, remark that I have

smooth examples of T. dorsata that I could scarcely distinguish from the figures of

Gould's specimen. Gould's types can all he seen in the National Collection at Wash-

ington. Dr. Gould says that the surface of the shell, when examined by the aid of a

lens, is tessellated with elongated dots arranged in quincunx, which seem to he specks of

opaque white coloiu* rather than punctures. T. jndvinata m.ust, however, for the present,

be looked upon as a doubtful so-termed species.

47. Terebratella (?) bubiginosa, Dall. (Plate XVI. fig. 19.)

TerebrateUa ?, Dall, Amcr. Jouru. of Conchology, vol. vi. p. 122, pi. vi. fig. 4, 1870.

Terehratella suffusa, Dall, Amer. Joui-u. of Concliology, vol. vii. p. 65, 1871 (not of Reeve).

TerebrateUa rubiyinosa, Dall, ibid. vol. \'ii. p. 65, and Proc. Acad. Nat. Sci. Philadelphia, 187.3,

p. 185.

Shell almost circular, about as broad as long ; margins fiexuous. Dorsal valve mode-

rately convex, with a faint depression near the middle of the margin, but which is not

noticeable in the younger portions of the valve. Ventral valve convex, rather deeper

than the dorsal one ; beak short, slightly incurved and truncated by an incomplete round

foramen, margined by the umbo of the dorsal valve, and by two very small rudimentary

lateral deltidial plates. In the interior of the dorsal valve the loop is long and doubly

attached, first to the base of the hinge-plate, and then to a short mesial septum. Surface

smooth to within a short distance from the margin, when the valve presents a few irregular

rounded areas. Colour a rather light brown. Length 1 inch 1 line, breadth about the

same.

Hah. ? Cape of Good Hope. (?? Types in the Smithsonian Cabinet.)

Ohs. I am very doubtful with respect to the specific value of this species. In 1870,

Dall referred it with uncertainty to the Terehratella suffusa of Reeve (Conch. Icon. pi. v.

fig. 18), but after my subsequently sending him Reeve's type of T. siffusa for examination,

he wrote back that as Reeve's type is possessed of a lai'ge elevated septum and loop Hke

Magasella, he has given the name Terehratella ruhiginosa to his species. In his de-

scription of the shell he informs us that " the crura are small, slender, short, and acute.

The loop processes are exceedingly slender, mere threads in fact, and roundly deflected

outward at first ; bending inward just before the neural bend, they give off two

moderately broad septal processes, which meet each other at the end of the septum at

an angle of 60° (not at right angles to the septvim and behind its end, as in T. dorsata

or chilensis). The main processes are then deflected neurally, and the extreme

' bight ' of the loop is straight and somewhat angulated at each side. The perforations

externally are moderate, arranged in quincimx order, .smaller and more regular than in

T. dorsata, which is its nearest analogue."

Never having seen any specimen of T. ruhiginosa, I can only reproduce Mr. DaU's

statements upon the subject. He says that the species appears to him to be perfectly

distinct from any other described Terehratella. The loop he figures is certainly very

peculiar in its mode of attachment to the short mesial septum.

SECOXD SERIES. — ZOOLOGY, VOL. IV. 13

92 DK. T. DAVIDSON ON RECENT BRACHIOPODA.

48. Teeebkatella Frielii, Davidson. (Plate XVI. figs. 16-17 h.)

Terehratella Frieli, Davidson, Proc. Royal Soc. xxvii. p. 438, 1878 ; and T. frielii, Report on the

Brachiopoda, Voyage of H.M.S. ' Challenger/ Zool. vol. i. p. 46, pi. iii. figs. 19, 20, 1880.

Shell small, ovate, slightly longer than vfide, smooth, white. Dorsal valve moderately

convex, slightly flattened or depressed anteriorly. Ventral valve deeper than the dorsal

one. Beak short, truncated by an incomplete foramen, laterally margined by two very

short and small deltidial plates. In the interior of the dorsal valve, the loop, which

extends to about two thirds of the length of the valve, is doubly attached, first to the

hinge-plate, and then to a mesial septum. Length 5 lines, width 4 lines, depth 3 lines.

ITab. Two small specimens were dredged off Halifax by the ' Challenger ' Expedition at

a depth of 1340 fathoms ; and two other examples close to the Philippine Islands, in 82 to

102 fathoms.

Obs. 1 feel much uncertainty, as I have stated in my ' Challenger ' Ueport, with respect

to the identification of the two small immature shells above described. I forwarded one

of them to Mr. Dall for examination, and he wrote back that he could not positively

identify it with any of the described species. Dr. Gwyn Jeffreys expressed a similar

opinion, adding that the septum and ccecal tubercles are very peculiar and remarkable,

and that he felt certain that it was an undescribed species of Terehratella. I therefore

give it here, merely for reference purposes.

Subgenus Magasella, Dall, 1870.

To this subgenus six species have been referred, viz. : —

1. Magasella flexuosa, P. King.

2. crenulata, Sowerby.

.3. aleutica, Dall.

The following are uncertain species : —

Magasella pataffonica, Gould.

Icevis, Dall.

MalvincB, d'Orbigny.

4. Magasella Adamsi, Davidson.

5. Gouldi, Dall.

6. Cumingi, Davidson.

Magasella incerta, Davidson.

radiata, Dall.

labradorensis, Sowerby.

I am not, however, satisfied that even all those recorded as species can be definitely

accepted. "We know very little that is satisfactory about Magasella (?) crenulata,

Magasella aleutica, Magasella Adamsi, and Magasella Gouldi, and still less about the

six uncertain species. The material I have been able to collect was scanty and insuf-

ficient, and further investigations will be requisite whenever circumstances permit. It

is therefore at present not possible to determine which are really good species, which

varieties only, or synonyms. Magasella Jlexuosa and M. Cumingi are, however, good

species, and have been carefully studied.

49. Magasella flexuosa. King, sp. (Plate XVII. figs. 1-5.)

Terehratula flexuosa, P. P. King, The Zool. Journ. vol. v. p. 337, 1835.

Terehratella flexuosa, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 367, 1852; Woodward &

Gray, Catalogue of the Brachiopoda in the British Museum, p. 87, 1853.

DR. T. DAVIDSON ON EECENT BEACHIOPODA.. 93

Terebratula rhombea, Philippi, Archiv fiir Naturgesch. Jahrg. xi. Bd. i. p. 59, 1845.

Terebratula flexuosa, G. B. Sowerby, Thes. Concli. i. p. 317, pi. Ixix. figs. 23,24, 1846.

Terebratdla dorsata, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wis-

sensch. Wien, Bd. xxxvii. p. 208, 1859.

Terebratula {Terebratella) stiffusa, L. Reeve, Conch. Icon. pi. v. fig. 18, 1800.

Terebratula {Terebratella) Magellanica, L. Reeve, Coucb. Icon. pi. v. fig. 21, 1860; and Ann. & Mag.

Nat. Hist. 3rd ser. vol. vii. p. 176, 1861.

Magasella flexuosa, Dall, Amcr. Journ. of Conch, vol. vi. p. 135, 1870; and Proc. Acad. Nat. Sci.

Philadelphia, p. 189, 1873 ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challeuger,' Zool.

vol. i. p. 46, pi. iv. fig. 5, 1880.

Shell somewhat subtetragonal, about as broad as long, yellowish or light I'cddish

brown, widest near the hinge-line, tapering anteriorly, lateral and frontal margins

flexiious. Dorsal valve moderately convex, longitudinally depressed mesially from about

half the length of the valve to the front. Ventral valve deeper than the dorsal one,

longitudinally keeled. Beak short, incm'ved and truncated by a rather large incomplete

foramen, completed by a small portion of the umbo of the dorsal valve, and by rather

large lateral slightly-separated deltidia ; l)eak-ridges well defined, leaving a flattened

space or false area between them and the long obtusely angular hinge-hnes. Surface of

both valves ornamented with from thirty to forty radiating diverging angular ribs,

ciu'ving to the lateral margins, straight along the middle, with shorter ribs interpolated.

Shell-structure traversed by small canals. In the interior of the dorsal valve the loop

is doubly attached. Mesial septum large, abruptly elevated at its anterior extremity,

extending from under the hinge-plate to about two thirds of the length of the valve.

The upper edge of the septum commences by presenting a gentle curve iu the shape of

a half-circle, then by an oblique nearly straight line reaches its greatest elevation, and

again assumes an almost straight line, to be followed by an abrupt inward curve until

it reaches near to the bottom of the valve, where it gradually terminates by another

gentle curve. The greatest elevation attained by this vertical plate in a specimen ten

lines in length was four lines. The principal stems of the loop at about two thirds of

their length increase in breath and become fixed to the sides of the septum near the upper

portion of the first slope, and, after proceeding a little further, become reflected,

the anterior portion of the septum being prolonged for some distance in front of them

(PL XVII. fig. 5). The muscular impressions are rather large, and are seen on the

bottom of the dorsal valve on each side of the septum. The ribs observable on the

surface of the valve are reproduced on their interior surface. Length and breadth about

1 inch, depth 6 lines.

Hub. Straits of Magellan, in the vicinity of Port Famine ; Orange Harbour ;

Gulf of Patagonia, near Cape Horn, and not far from the Falkland Islands, iu 1450

fathoms ; Port Stanley, at a depth of 5 to 12 fathoms (' Challenger ' Expedition).

Captain P. P. King, K.N., the first discoverer of the species, states, " this shell was

dredged in the Bay of Port Famine, attached to stones ; it is a common shell in the

Straits."

Ohs. In external shape this shell nearly approaches Terebratella dorsata, Gmelin,

and, indeed, L. Reeve places it among the synonyms of tho last-named species. It differs,

13*

94 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

however, iu being subtetiagonal and tapering more anteriorly, with a less sharply defined

mesial depression or sinus in the dorsal valve, and by its ribs being more angular,

and more especially by its elevated mesial Magasella-sha])ed septum, which is always

observable in the interior of the dorsal valve in its adult condition, while, on the contrary,

in fully-developed examples of Terebt^atella dorsata of similar dimensions the septum

rises but little above the bottom of the valve. The mode of attachment of the loop of

the septum is also different in detail.

In 1845, Philippi described, in the ' Archiv fiir Naturgeschichte,' a Terehratula under

the name of T. rlwmbea, a shell similar in shape and character to Magasella jlexuosa.

The type is in the Royal Zoological Museum of Berlin. Philippi did not figure his

shell, and I am indebted to the kindness of Prof. E. von Martens for the figures I am

able to give of the so-termed species, which I believe to be a full-grown example of

Terehratula Jlexuosa, P. King (PL XVII. figs. 6-8 a). It is also stated to have been

procured from the Straits of Magellan.

Terebratellu Jlexuosa is the type of Ball's subgenus Magasella. He states that " the

punctures [on the surface of the shell] are very large, circular, and under the glass

recall the cells of Polyzoa. The margin of the valves is sharply crenulated from the

extremities of the external plications."

Magasella Jtex'uosa does not seem to attain to the dimensions of Terehratella dorsata.

Under the name Terehratella suffusa,, L. Reeve describes (Monogr. Terehratula, pi. v.

fig. 18) what he admits to be a doubtful sj)ecies partaking of the general character of

Terehratula dorsata. In 1861 Mr. Reeve kindly presented me with his type and the only

specimen of the so-termed species with which he was acquainted. The specimen measures

9 lines in length by 8 in breadth and 5 in depth, and is not symmetrical, one half

being narrower than the other, or, in other words, it is to some extent a malformation.

Mr. Reeve says that it shows no indication whatever of a mesial depression in the

dorsal valve ; but this is a mistake, for in reality there exists a slight depression. In

the interior of the dorsal valve there is a large prominent mesial septum to which the

principal branches of the loop are attached previously to being reflected, exactly as we

find to be the case in Magasella Jl£xuosa, to which species therefore I would refer

Reeve's species (PI. XVII. figs. 14 a, h, 15), No specimen of this size of Terehratella

dorsata presented a similarly shaped and elevated septum. Terehratula snjfusa is

evidently a malformation, and its habitat is not known, but it was in all probability

obtained in the Straits of Magellan.

50. Magasella crenulata, Sowerby, sp. (Plate XVII. figs. 9-11.)

Terehratula crenulata^ G. B. Sowerby, Descriptions of 13 new Species of Brachiopoda, Proc. Zool. Soc.

1846, p. 91 ; and Tlies. Concli. vol. i. p. 358, pi. 71. figs. 96-98, 1846.

Tercbratella crenulata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 368, 1852; E. Suess,

Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissenscli. Wien, p. 206, 1859.

Magasella crenulata, Woodward & Gray, A Catalogue of tbe Brachiopoda in the British Museum,

p. 98, 1853.

Terehratula {Magas) crenulata, L. Reeve, Conch. Icon. Mon. Terehratula, pi. viii. fig. 32, 1861 ; and

Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 179, 1861.

DE. T. DAVIDSON OX RECENT BEACHIOPODA. 95

Magasella crenulata, Dall, A Revision of the TcrcbratulicUe, Amer. Journ. of Conch, vol. vi. p. 137,

1870; and Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 188.

Shell suborbicular, about as wide as long, margin rounded laterally, subtruncate in front.

Dorsal valve moderately and uniformly convex, without fold or sinus. Ventral valve

rather deeper than the dorsal one ; beak produced, slightly incurved and truncated by a

large complete foramen, separated anteriorly from the hiuge-linc by a deltidium in two

pieces ; beak-ridges sharply defined, leaving between them and the hinge-line a flattened

false area. Marginal line flexuous and slightly sinuated in front. Surface of the valves

often smooth at the beak and umbo, or marked throughout with from twenty to twenty-

two rounded ribs, of which a few are due to the interpolation of shorter ones. In the

interior of the dorsal valve the loop is doubly attached, first to the hinge-plate, secondly

to an elevated mesial septum. Colour light yellowish white. Length 8, breadth 8, depth

4 lines.

Hab. Santa Cruz, Canaries (Cuming).

Obs. This small species still requires further study before being definitely admitted.

The material I have had for examination consisted of only three examples. It is much

more circular than Gould's Magasella patagoiiica, and seems to difi^er likewise from

specimens of Terebratella Oorsata of similar dimensions. The foramen was entire in

the few examples that have come under my observation.

51. Magasella aleutica, Dall. (Plate XVII. figs. 16-17 h)

Magasella aleutica, Dall, Preliminary Descriptions of new Species of Mollusca from the North-west

Coast of America, Proc. California Academy of Sciences, vol. iv. pi. i. fig. 6, 1872; and Proc. Acad. Nat.

Sci. PhUadelphia, 1873, p. 188.

Shell small, ovate, greatest breadth about the middle, tapering posteriorly and

anteriorly, slightly indented in front. Dorsal valve convex, most so near the umbo, with

a very slight longitudinal depression commencing at about the middle of the valve and

extending to the front. Ventral valve not much deeper or more convex than the dorsal

one, margins nearly straight ; beak short, incurved and truncated by an incomplete

foramen, margined anteriorly by the umbo and by two small lateral deltidial plates ; beak-

ridges not sharply defined. Surface smooth, marked only by concentric lines of growth;

salmon-coloured, brighter on the lines of growth, pale on the umbones. Length 6 lines,

breadth 7, depth 3^ lines. Loop doubly attached, very slender, except the lateral arms

of the reflected portion, which are wide ; septum rather broad from behind forward, not

produced above the reflected portion of the loop.

Hub. In the Aleutian Islands, from Akeutan Pass to the Shumagins, attached to the

under surface of rocks at extreme low water in spring-tides (Dall).

Obs. I have two examples of this small species presented to me by Mr. Dall, and in

sending them to me he wrote : — " In regard to Magasella aleutica I am disposed to

consider it an adult species, for very thorough dredgings in the region where it is common

have failed to indicate any other species of which it might be the young. I have seen

young Terebratella frontalis, and they appear to differ specifically from Magasella

96 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

aleutica. T. frontalis has never been found at the Shumagin Islands, where M. ctleutica

abounds. Still all that can be said is hardly decisive, and must be left to individual

judgment to be weighed, and future collectors to prove either way." Mr. Dall observes, in

his description of the shell, that " the animal is rather sluggish, and living specimens

kept in sea-water for several days exhibit no further signs of life than the slight opening

of the valves. The soft parts are of a darker reddish colour, and show through the shell

to some extent, as in Waldheimia venosa. There is some variation in form, some speci-

mens being much broader than others."

52. Magasblla Adamsi, Davidson. (Plate XVII. figs. 18, 19.)

Magasella Adamsi, Davidson, Proc. Zool. Soc. p. 307, pi. xxx. figs. 2.3, 24, 1871 ; Dall, Proc. Acad.

Nat. Sci. Philadelphia, 1873, p. 188 ; G. Dunker, Index Mollusc, maris Japonici, p. 253, 1882.

Shell smaU, nearly circular, as broad as long. Dorsal valve slightly convex, and

marked with about eleven more or less prominent ribs, of which the ventral one, in the

dorsal valve, is both the largest and the most elevated. Ventral valve deeper than the

dorsal one, with about twelve ribs, of which the central ones are both the largest and

most prominent, leaving a rather deep median sulcus between them ; beak truncated

by a rather large incomplete foramen ; deltidium-plates small ; shell-punctures large and

prominent. In the interior of the dorsal valve the loop is doubly attached, first to the

base of the hinge-plate and then to a large prominent septum, extending from under

the umbonal beak to about half the length of the valve. Colour white. Length

9 lines, width 2, depth 1 line.

Sab. Two examples only of this small species were dredged by Mr. A. Adams, in 26

fathoms, in the Sea of Japan, off the island of Kuro-puna.

Obs. In one specimen the ribs were almost obsolete. We know, however, far too little

about this shell to be able to speak in a decided manner with respect to its specific

value. In external appearance it differs from all the known recent forms with which I

am acquainted.

53. Magasella Gouldi, Dall. (Plate XVII. figs. 20-22.)

Mayusella Gouldi, Dall, MS. in Davidson, Japanese Brachiopoda, Proc. Zool. Soc. 1871, p. 307,

pi. xxxi. fig. 11 a,b,c; Dall, Amer. Journ. of Couchology, vol. vii. p. 67, pi. xi. fig. 11, 1871, and

Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 189 ; G. Dunker, Index Mollusc, maris Japonici, p. 253,

1882.

Shell very small, transversely oval, wider than long ; hinge-line nearly as long as the

breadth of the shell ; beak somewhat produced and slightly incurved, with a large

incomplete horseshoe-shaped foramen ; deltidial plates very small and widely separated ;

false area flattened. Ventral valve deep ; dorsal valve slightly convex, with a shallow

longitudinal mesial depression or groove beginning at half the length of the valve

and extending to the front surface of each valve ; marked with about eighteen ribs,

of these, two median ones lie in a kind of sulcus in each valve and extend from the

umbo to the front, while the others are both irregular in width, stouter, and do not

extend to more than half the length of the valve from the margin. The lines of growth

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 97

are well marked. In the interior of the dorsal valve there is no hinge-plate or distinct

cardinal process. The muscular scars are thick and excavated ahove; the septum

and loop are similar to those descrihed in Magasella Adamsi. The shell is yellowish,

with strong rose-colour on the ril)s and towards the edges. Length 2 lines, width

nearly 3 lines.

Ilab. Hakodadi, Japan, on Terehratella coreanica, in GO fathoms (Stimpson).

Obs. I have never seen this shell ; the ahove description was taken from a figure of the

single specimen in the possession of Mr. Dall, which he kindly forwarded to me for

examination, stating at the same time that it agreed with no other described species. It

evidently approaches in character to Magasella Adamsi ; but there are differences between

the two that cannot he cleared away by the inspection of a single specimen. A search

for more examples should be made in the locality where this one was obtained, in order

to determine their real specific value.

54 Magasella Cumingt, Davidson, sp. (Plate XVII. figs. 23-32.)

TerebrateUal Ciiminc/u, Davidson, Ann. & Mag. Nat. Hist. 2nd scv. vol. ix. p. .308, 1852, and Proc.

Zool. Soc. 1852, p. 78, pi. xiv. figs. 10-10.

Magasella Cummyii, Woodward & Gray, Catalogue of the Bracliiopoda m the British Museum,

p. 99, 185.3; Woodward, A Manual of the Mollusca, p. 217, 1856; A. Adams, The Genera of Recent

Mollusca, p. 577, i)l. cxxxi. fig. 1, 1858.

Terebratula {Botichardia) Cumingii, L. Reeve, Conch. Icon., Monogr. of Terebratulu, pi. viii. fig. 30,

1861, and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 179, 1861.

Terebratula [Bouchardia) fibula, L. Reeve, Conch. Icon., Monogr. of Terebratula, pi. viii. fig. 30, 1861,

and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 180, 1861.

Magasella Cumingii, Dall, A Revision of the TerebratulidcTe, Amer. Journ. of Conch, vol. vi. p. 137,

1870, and Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 188 ; Davidson, Report on the Brachiopoda,

Voyage of H.M.S. 'Challenger,' Zool. vol. i. p. 48, 1880; E. Deslongchamps, Etudes critiques sur

des Brachiopodes nouveaux ou peu connus, p. 204, 1884.

Shell very thick, ovato-oblong, marginally rounded laterally and in front, tapering

posterioi'ly. Dorsal valve uniformly convex, or mesially slightly depressed, close to the

front. Ventral valve deeper and more convex than the dorsal one, beak produced,

incurved, and truncated by a small oval-shaped foramen beginning at the summit of the

beak and directing itself on the opposite side to the area. Area triangular, elongated

and excavated, deltidium narrow. Surface smooth, strongly marked with concentric hnes

of groAvth, salmon-coloured with a tinge of red. Shell articulating by means of two

strong teeth in the larger valve and corresponding sockets in the smaller one. Hinge-

plate large, hollowed out, with a narrow longitudinal elevation along the middle,

cardinal process divided along the middle ; a longitudinal mesial elevated triangular-

shaped septum extends from under the hinge-plate to about two thirds of the length of

the dorsal valve, and by a gentle curve reaches and touches the top of the larger

valve near to its anterior portion, whence it descends by an almost perpendicular line to

the bottom of the valve. The calcareous riband-shaped lamellae first proceed from the

socket-walls, directing themselves by a gentle curve to the anterior portion of the septum,

where they become attached ; above these another pair, which are anchor-shaped, are

98 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

fixed close to the sloping portion of the upper edge of the septum, but later unite before

becoming reflected. Length 5 lines, width 4, depth 2J lines.

Hah. This beautiful little species was dredged in large numbers by Mr. John Brazier

at South Eeef, Port Jackson, Heads and Pigs Eock, New South Wales. It was found alive

in the first-named locality, and presented a salmon-red colour. Dead perfectly white

specimens are to be obtained in large numbers. The ' Challenger ' Expedition obtained

it also at Port Jackson in from 2 to 4 fathoms. It is said to have been found also in

Bass's Straits, South Australia {=T. fibula, Eeeve). (See PI. XVII. fig. 33.)

Ohs. When I described this species in 1852, only two dead specimens were known in this

country, and their habitat was uncertain. It is a very remarkable and excellent species,

but its exact generic position has been the theme of some difi'erence of opinion. Mr. L.

Beeve says, in his Revision of the Terebratulidse, Ann. & Mag. Nat. Hist. p. 11, 1861, that

" it is in my opinion neither a Terehratella nor a Magas. It begins to show internally

the caDous thickening both of the valves and of the apophysis of Bouclmrdia tulipa, and

is, above all, distinguished by the acuminated beak and terminal foramen peculiar to that

and to the following species " \_T. fihiduX I quite agree with him in this respect. There

exist also differences between it and McKjasella ; still, for all that, it is to the last-named

genus that the shell bears the strongest affinities, and I am disposed to coincide with

Mr. Dall in placing it in that genus. Magasella Cumingi varies a little, according to age,

in the manner in which its loop is attached to the sides of the mesial septum ; thus in

some specimens the anterior edge of the principal lamellae are fixed to the septum quite

independently of the upperanchor-shaped lamellae, which in those examples have a separate

attachment to the septum (PL XVII. fig. 30) ; again in other specimens the anterior edges

of the principal lamelkie cm've close along the sides of the septum, and become united to

the lower edges of the anchor-shaped pair previous to becoming reflected (PI. XVII.

fig. 31).

In 1861, Mr. Lovell Beeve described and figured, in the paper already referred to, a

shell a little larger, but so similar in shape and character to Magasella Cummgi, by the

name of Terebratula (JSouchardia) fibula, that I am very much disposed to regard it

as nothing more than an unusually large example of M. Cumingi. Mr. Beeve states,

I. c. p. 180, that " This remarkable shell is curiously intermediate in its characters between

T. {Bouchardia) Cumingii and tidipa. The beak is more acuminated than in the former ;

and the area of the deltidium, which in B. Cnmingii and tulipa is excavately grooved, is

in B. fibula flat. In respect of the callous development of the interior, it is about inter-

mediate between the other two."

I may, however, observe that we are acquainted with only one specimen of the so-

termed T. fibula, purchased by the British Museum from Mr. Calvert, a dealer in objects

of natural history. It measm-es 7 lines in length by 6 in breadth, and is consequently

larger than M. Cumingi, which does not seem to exceed 5^ to 6 lines in length where

it is usually found. The area in M. Cumingi is, it is true, usually excavated or concave,

but in some examples it is almost flat, and upon that slight apparent difference it

would not be right, I think, to record it as a separate species. The difference of habitat

may perhaps have been more favovu'able to the development of the single example of

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 99

T. fibula hitherto discovered, whicli is said to have come from Bass's Strait, South

Australia. Those who differ fi-om mc in this identication will find T. fibula dcscril)cd

by Reeve in the following words : —

" Shell orhicularly ovate, solid, smooth, whitish, tinged with rose ; beak large, trian-

gularly acuminated, erect ; foramen small, terminal, deltidium obsolete, area very large,

flat ; valves nearly equally convex, sides callous within ; loop doubly attached, septum

callously anchor-shaped." [Conch. Icon. pi. viii.]

Uncertain Species.

55. ? Magasella patagonica, Gould, sp. (Plate XVII. figs. 12-13 a.)

Terebratula Patagonica, Gould, Proceed. Boston Soc. Nat. Hist. iii. p. 347, 1850, and United States

Exploring Expedition, Mollusca and Shells, p. 97, 1852.

Waldheimia Patagonica, Gould, Otia Conch. (Rectifications) p. 246, Index p. 236.

"i Magas patagonica, Dall, Amer. Jouru. of Coach, vol. vi. p. 133, 1870.

Magasella Patagonica, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 189.

Shell small, subpentagonal, slightly transverse or as wide as long, broadest near the

hinge-line. Dorsal valve very slightly convex, "oith a shallow depression along the middle

of the anterior half of the valve. Ventral valve deeper and more convex than the dorsal

one ; beak short, incurved, and truncated by an incomplete foramen, margined anteriorly

by a small jiortion of the umbo of the dorsal valve and by two small lateral deltidial

plates. Surface of valves smooth at the beak and umbo, the anterior and lateral two

thirds of the length of the valve being ornamented with about seventeen rounded

divaricating ribs of difierent lengths. In the interior the hinge-plate is wide and exca-

vated in the middle. The loop is doubly attached to the base of the hinge-plate, and to an

elevated mesial septum. Shell-punctures prominent and circular. Colour waxen white.

Length 6 lines, width 6, depth 3 lines.

Kab. Orange Harbour, Patagonia (United States Exploring Expedition).

Obs. This appears to be a doubtful species. Mr. Dall writes me that it may be a young

Terehratella dorsata, but he is not certain that it is so. The shell, he adds, is a typical

Magasella (which T. dorsuta is not). Mr. DaU describes the species at considerable length

on pp. 133, 13i of the ' American Journal of Conchology,' 1870 ; he says that the dorsal

valve is provided with an inconspicuous but acute apex, and small, moderately wide

cardinal process. " The hinge-plate is wide and excavated in the middle, or rather

there is no transverse lamina before the cardinal process and between the sockets. Instead,

two thin laminae are placed between the under side of the sockets, extending obliquely

inward for a short distance, and attached to the cavity of the apex, forming a triangular

ridge in the median hne, from which the septum takes its rise. The latter is broad

and biangulate at its nem-al extremity. Two haemal processes, provided witli short

pointed crura, proceed from the sockets and are attached, abovit midway between the

valve and the apex of the septum, to the latter. Erom the posterior apical angle of the

latter two broad, roundly-recurved processes arc extended posteriorly. The anterior

SECOND SERIES. — ZOOLOGY, VOL. IV. 14

100 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

apical angle of the septum is extended a sliort distance in front of tliem, and is somewhat

before the anterior front of the base."

As justly observed by Mr. Dall, this species must not be confounded with the fossU

Waldheimia patagonica, Sowerby, mentioned in Darwin's ' Geological Observations on

South America,' p, 252, pi. ii. figs. 26 & 27, 1846. More material is needed for comparison

before the specific value of this so-termed species can be definitely ascertained. I have

only seen one young example of the shell sent to me by Mr. Dall.

56. ? Magasella (? var.) l.evis, Dall. (Plate XVIII. fig. 4.)

Magasella (? var.) Icevis, Dall, A Revision of the Tcrcbratulidse, Amer. Journ. Couch, vol. vi. p. 136,

1870.

? Terebratula Malvince, d'Orbigny, Voy. Am. Merid. vol. v. p. 674. uo. 779, ix. pi. 85. figs. 27-29, 1847

(according to Dall) .

" Shell perfectly smooth except for the light, but beautifully regular, rounded, con-

centric lines of growth. Outline nearly circular, beak somewhat produced, slightly

recurved, with a large incomplete horse-shoe-shaped foramen. The false area sharply

carinate and separated from the deltidia by a deep groove. The deltidia are short, mode-

rately wide and widely separated. Shell not inflated, of a horn-colour, and conspicuously

punctate. Margin of the valves straight, without any indentation or flexure. Teeth and

sockets slender and weak, the whole texture of the shell being exceedingly delicate and

papyraceous.

The cardinal process is hardly perceptible. The hinge-plate is very thin, excavated,

and covers the posterior end of the mesial ridge which divides the cavity of the beak

below the hinge-plate into two parts. The crura are very short and delicate, the

hsemal processes at first slender, rapidly widen, throwing off a triangular lamina of sheUy

matter from the inner sides which reaches the septum and becomes consolidated with it

between the anterior and posterior edges, so that the posterior edge of the septum forms

a wall between the two triangular lamina3. In the last species \M. jlexuosa] the edge

does not project above the lozenge-shaped plate formed by the two laminae, and in

? Magas patagonica there is only a rounded ridge between them. The septum is broad,

arising close to the hinge-plate, obliquely forward, and is truncate at its extremity, which

touches the opposite valve. The reflected loop is broad and quite circular. The cardinal

muscles are attached in the apical cavity of the neural valve. The peduncle is short and

stout, the other muscles are very slender.

Length "34 in., breadth •32 in., diameter "16 in.

" A single specimen was found adhering by its peduncle to a large specimen of

Waldheimia venosa from Orange Harbor, Patagonia. ? ' Les isles Malouines,' D'Orb.

I.e.

" It is not unlike, in general appearance, a very minute specimen of W. [ Waldheimia']

venosa, except that the foramen is much larger, incomplete and of a different shape. It

may be identical with D'Orbigny 's species, of which the apophyses are not figured, but differs

in its small size and rounded form."

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 101

Obs. I have reproduced Mr. Ball's full description, as I have never seen the specimen

upon which the species (?) has been formed ; but I think its acceptance must be con-

sidered provisional.

57. Magasella. ? Halving, d'Orbigny, sp. (Plate XVIII. fig. 5.)

Terebratulal Malvince, d'Orbigny, Voyage Amerique IMeridionalCj vol. v. p. 674. uo. 779, ix. pi. 85.

figs. 27-29, 1846.

Shell small, ovate or longitudinally oval, broader than long ; valves evenly convex,

without fold or sinus ; beak short, pointed, slightly incurved ; foramen incomplete, mar-

gined anteriorly by a portion of the umbo of the opposite valve and by two lateral small

deltidial plates ; beak-ridges sharply defined, leaving between them and the hinge-line

a flattened space. Shell perforated by minute canals. Interior details not known.

Length 4 lines.

Sab. Obtained during soundings near the Isles Malouines by Dupetit Thouars.

Obs. I have never seen this so-termed species, and it was not to be found at the Jardin

des Plantes. It is in all probability a young and immature shell. It is described here

for the sake of reference, but cannot be admitted as a well made-out species.

58. Magasella incerta, Davidson. (Plate XVIII. figs. 2, 3 a.)

Magasella incerta, Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i.

p. 47, pi. iv. fig. 6 a, b, 1880.

Shell elongated, pear-shaped, broadest anteriorly, tapering posteriorly, very slightly

and evenly convex, somewhat flattened, without fold or sinus, smooth, nearly white. Beak

in ventral valve pointed, nearly straight, with a large incomplete foramen extending from

under the extremity of the beak to the hinge-line, and margined partly by the umbo of

the dorsal valve and by small lateral plates. In the interior of the dorsal valve a short,

elevated, vertical mesial septum almost reaches to the bottom and middle of the opposite

valve ; it extends along the middle portion of the bottom of the dorsal valve to about

haK the length of the shell ; to its sides and to the base of the hinge-plate are attached

the principal stems of the loop, the reflected portion being small. Length 2, breadth 1|,

depth 1 line.

Hah. Twelve examples of this small shell were dredged by the ' Challenger ' Expedition

west of St. Thomas, Danish West Indies, at a depth of 390 fathoms.

Obs. I have reproduced the description and figures of this small species from my

report on the Brachiopoda of the ' Challenger ' Expedition. None of the specimens

exceeded the proportions above given. They look as if they were young and immature

examples of some species at present unknown ; and I have given the shell a provisional

name for reference-purposes. The types are in the Zoological Department of the

British Museum of Natural History.

59. Magasella eadiata, Dall. (Plate XVIII. fig. 1.)

Magasella radiate, Dall; Report on the Brachiopoda of Alaska and adjacent shores of North-west

America, p. 49, 1877.

14*

102 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

Shell small, ovate, longer than wide, hroadest and rounded anteriorly, tapering

posteriorly. Dorsal valve very gently convex, somewhat compressed, with about 16 or

17 rounded radiating ribs of small elevation on both valves, commencing to rise at about

one third the length of the valves, the beak and umbo being smooth. Ventral valve a

little deeper than the dorsal one ; beak slightly incurved and truncated by a large incom-

plete foramen, margined posteriorly by the umbo of the dorsal valve, and laterally by

small deltidial plates. Shell-structure punctate. Colour waxy or ash-grey. Length

3 lines, breadth 2| hues.

Sab. PopoflF Strait, Shumagin Island ; one specimen, with Magasella aleutica, adhering

to stones at the lowest tides (Dall).

Ohs. In 1877 Mr. Dall did not figure his species, but subsequently, in 1885, he sent me

the enlarged figure, wliich I have much pleasure in reproducing, and writes : — " The inside

is like that of the ordinary Magasella form. I did not like to open my only specimen to

get it drawn. I have young Terehratella transversa {^caurina) less than half the size,

which show the imperfectly formed but still genuine Terehratella loop ; hence I cannot

ascribe this to the young state of that species, and as we have no other radiated form in

Alaska yet known, I am at a loss to name an adult form from it."

60. Magasella labkadoeensis, Sowerby, sp. (Plate XVI. figs. 18, 18 a.)

Terebratula Labrador ensis, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 95, and Thes. Concli. i. p. 362,

pi. 71. figs. 89, 90, 1846.

Terebratula {Terebratella) Labradorensis, Sowerby?, L. Reeve, Conch. Icon. Monogr. Ter. pi. v. fig. 19,

1860, and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 178, 1861.

Terebratella Labradorensis, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 185.

" Shell suborbicular, acuminated behind, obtuse, thickish, whitish ; valves very uueqiial,

obtusely radiately ribbed : marginal line somewhat flexuous ; dorsal valve rounded in

front, acuminated and obtuse behind ; perforations large, entire ; cardinal area large,

somewhat flattened ; deltidia rather large, united ; mesial ridge indistinct ; ventral valve

nearly orbicular, slightly acuminated behind : margin of valves crenulated. — In the

British Museum. Erom Labrador; C. Goodsir." (G. B. Sowerby.)

Obs. I know so little about this doubtful species, that I am obliged to content myself

by reproducing Sowerby's description, in the hope that a search for more specimens

may be effected in the locality whence the shell is said to have been obtained. In the

' Conch. Icon.' LoveU E-eeve figures another species from Cuming's collection, said to

agree with Sowerby's type ; but I cannot help regarding this statement as very uncer-

tain. The sheU is more circular than the specimen figured in the ' Thesaiu'us Conchy-

liorum,' and is stated to be " a rather depressed transparent white orbicular species, of

solid structure, ribbed with more strength and regularity than is common in the genus."

1 have written to gentlemen who have dredged in Canadian waters, but none of them

have ever met with the shell.

DH. T. DAVIDSON ON EECENT BRACHIOPODA. 103

Subfamily MEGEULiNiE.

Genus MEGERLIA, King-, 1850.

This excellent genus was proposed in 1850 by Prof. W. King, at page 145 of Ms

monograpli on the " Permian Fossils of England," published by the Palaiontograpliical

Society, with the following diagnosis : — " A transversely oblong, uni-areagerous Tere-

bratulidia. TJmhone very slightly projecting. Fissure or foramen large, emarginate,

and situated in the centre of the area. Cardinal muscular fulcrum excavated. Zoop

somewhat quadrate ; confined to the posterior half of the shell ; attached posteriorly to

the crural base, and anteriorly to the medio-longitudinal plate. Inner surface of valves

radiately pimpled. Punctures large. Type Anomia trimcata, Gmelin."

We are acquainted with two recognized and one uncertain recent species, viz. : —

Megerlia truncata, Linne, sp., = var. monstruosa, Scacchi.

Megei'lia (?) {Ismenia) sanguinea, Chemnitz, sp.

Megerlia Willemoesi, Davidson. Uncertain species.

As the generic characters have been fully given under Megerlia truncata, they need

not be here repeated.

Mr. Dall, in his Catalogue of the E-ecent Species of the Class Brachiopoda, published in

the Proceedings of the Academy of Natural Sciences of Philadelphia, pp. 186 and 187,

1873, groups the genus Megerlia into two sections : —

Section A (Megerlia). Lateral loops closed; shell transverse, sculptured.

1. Megerlia truncata, Linne.

Section B (Ismenia). Lateral loops open ; shell more or less swollen, ovate, smooth.

2. Megerlia Jeffreysi, Dall.*

3. Megerlia sanguinea, Chemnitz.

The loop, as shown by Prof. E. Deslongchamps, undergoes certain modifications during

its different stages of development. In 1870 Mr. Dall retained the Anomia sanguinea,

Chemnitz, as generically distinct from Megerlia truncata, and placed it in the genus

Ismenia, but in 1873 he regarded it as representing a section of Megerlia.

Section A.

61. Megerllv truncata, Linne, sp. (Plate XIX. figs. 11-20.)

Anomia truncata, Linne, Syst. Nat. ed. duodecima reformata, p. 11.52, 1767; Andrea, Lettres ecrites

de la Suisse, tab. 1. figs, d, e, 1763.

Anomia disculus, Pallas, Misc. Zool. p. 184, t. 14. fig. 1, 1766.

Anomie, fig. b, g, Davila, Cat. Syst. et Raisonne des Curiosites de la Nature, pi. xx. 1867.

Anomia truncata, Chemnitz, Neues syst. Conch.-Cab. vol. viii. p. 90, tab. 77. fig. 701, 1785 ; Born,

Mus. p. 118, tab. 6. fig. 14, 1778; Gmelin, ed. Linne's Syst. Nat. p. 3343, 1788.

* [See page 113 of this monograph, where Dr. Davidson is informed by Mr. Dall that the shell he first named

Frenula Jeffreysi, and afterwards described as Ismenia Jeffreysi, is^ the young of Laqueus californicus, var. van-

touverinds. — A. C]

104 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

Terebratula truncata, Briiguiere, Encycl. Meth. pi. 243. fig. 2, 1789.

Anomia truncata, Poli, Test. Sicil. p. 191, t. 30. figs. 16, 17, 1791-1795.

Terebratula truncata, Retzius, Nov. Gen. Testaceorum, p. 14, 1788.

Terebratula truncata, Dillwyn, A Descriptive Cat. of Recent Shells, p. 293, 1817; Lamarck, An.

sans Vert. vol. vi. p. 247, 1819; Sowerby, Cat. of the Shells of the Earl of Tankerville, p. 28, 1825;

Risso, Europe Mer. vol. iv. p. 387, fig. 174, 1826 ; Blainville, Diet. Sci. Nat. vol. liii. p. 159, 1828, and

= T. disculus on p. 138; Philippi, Enum. Moll. Sicilise, vol. i. p. 95, tab. vi. fig. 12,1834; Von Buch,

Ueber Terebrateln, p. 66, 1834; Scacchi, Cat. Conchyl. Regni Neapolitan!, p. 3, 1836.

Delthyris truncata, Anton, Verzeichniss der Conchylien, p. 22, 1839.

Terebratula truncata, Galvaui, lUust. delle Coq. Fossili, 1845 ; Kiister, Nov. ed. Chemnitz's Conch.-

Cab. p. 28, pi. 3. figs. 11, 12, 1843 ; E. Forbes, Report on the MoUusca of the ^gean Sea, p. 141,

1843; Philippi, En. Moll. Sicili®, vol. ii. p. 69, 1844; G. B. Sowerby, Thes. Conch, p. 354, pi. Ixxi.

figs. 64-67, 1846, and Ann. Sci. Nat. vol. viii. p. m, pl. vii. figs. 11, 12, 16, 37.

Terebratella truncata, A. d'Orbigny, Considerations zoologiques et geologiques sur les BrachiopodeSj

Ann. Sci. Nat. Zool. vol. viii. p. 268, pl. 7. figs. 11, 12, 16, 37, 1847.

Ort/iis oblita, Michelotti, Foss. Mioc. de I'ltalie, pl. i. fig. 21, 1847 ; Sismonda, Synopsis Methodica,

p. 11, 1847.

Orthis truncata, Aradas, Coq. Foss. di Gravitelli, p. 14, 1847.

Megerlia truncata, King, English Permian Foss. p. 140, 1851.

Megathyris oblita, d'Orbigny, Prodrome, p. 134, 1852.

Megerlia truncata, Davidson, Sketch of a Classification of Recent Brach., Ann. & Mag. Nat. Hist.

2nd ser. vol. ix. p. 369, 1852 ; Introduction to vol. i. Brit. Foss. Brach. p. 68. figs. 11, 12, 1853.

Terebratula truncata, Costa, Fauna del Regno di Napoli, p. 33, pl. i. figs. 4-6, 1851.

Megerlia truncata, Woodward and Gray, A Cat. of the Brach. in the Brit. Mus. p. 103, 1856.

Megerlia //-Mwca/a, S. P. Woodward, A Manual of the Mollusca, p. 219, fig. 122, 1856; H. & A.

Adams, Genera of Recent Mollusca, p. 578, pl. cxxx. fig. 3, 1858.

Terebratella truncata and T. oblita, Pictet, Traite de Pal. vol. iv. p. 22, 1857.

Megerlea truncata and M. oblita, E. Suess, Ueber die Wohnsitze der Brach., Sitzungsb. k. Akad.

Wissensch. Wien, Bd. xxxvii. pp. 208, 209, 1859.

Terebratula truncata, Verani, Zool. des Alpes Maritimes, 1862; Risso, Europ. Mer. vol. iv. p. 387,

fig. 174, 1862; Chemnitz, Man. de Conch, vol. ii. p. 205, figs. 1053-1055 (not 1052), 1862.

Megerlea truncata, E.-Deslongchamps, Recherches sur I'Organisation du Manteau chez les Brachio-

podes articules, p. 26, pl. iii. figs. 1-5, 1864.

Morrisia gigantea, Deshayes, Cat, des Mollusques de I'lle de la Reunion (Bourbon), Annexe E, p. 37,

pl. xxxii. figs. 9, 10, 1863.

Megerlia truncata, Seguenza, Pal. Mai. dei Terreni Terz. del distretto di Messina, Mem. Soc. Nat.

di Scienze Nat. vol. i. p. 63, pl. viii. fig. 4, 1865 ; Brusina, Moll. Dalmati, Real. Soc. Zool. Botanica di

Vienna, 1866.

Terebratula [Megerlia') truncata, L. Reeve, Conch. Icon. Monogr. pl. xi. fig. 47, 1861 ; Ann. & Mag.

Nat. Hist. 3rd ser. vol. vii. p. 180, 1861, and Journal de Conchyl. vol. ix. p. 133, 1861.

Megerlea truncata, Weinkaufl", Conchylien des Mettelmeeres, p. 287, 1867; Davidson, On Italian

Tertiary Brach., Geol. Mag. vol. vii. pl. xxi. figs. 1, 2, 1870.

Megerlia truncata, Dall, Amer. Jouru. of Conch, vol. vi. p. 129, fig. 14, 1870, and Proc. Acad. Sci.

Philadelphia, 1873, p. 186 ; Monterosato, Cat. Couch. Med. p. 7, 1875 ; Gwyn Jeffi-eys, On the Mollusca

of the ' Lightning ' and ' Porcupine ' Expeditions, Proc. Zool. Soc. 1878, p. 411 ; Zittel, Handb. der

Palaont. p. 707, fig. 556, 1880; Davidson, Report on the Brachiopoda, Voyage of H.M.S. 'Challenger,'

Zool. vol. i. p. 50, pl. iii. figs. 15-18, 1880 ; E.-Deslongchamps, Etudes critiques sur des Brachiopodes

nouveaux ou peu connus, p. 157, pl. xix. figs. 1 5, 1884.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 105

Shell transversely oval, semicircular or subquadrilateral, somewhat depressed, fulvous

white. Hinge-line nearly straight, nearly as long as the breadth of the shell, with acute

or rounded angles. Dorsal valve gently convex, sometimes much flattened, mesially

depressed longitudinally from the umbo to the front, more or less indented in front.

Ventral valve deeper than the dorsal one, and longitudinally keeled. Beak very little

inciu'ved, and truncated by a large circular incomplete foramen, margined anteriorly by

the umbo and by two small rudimentary lateral plates ; bcak-ridges sharply defined,

leaving between them and the hinge-line a flat area. Surface of valves marked with

numerous fine radiating riblets, increasing in number at variable distances from the

beaks by the interpolation of shorter riblets. Surface of valves crossed by concentiic

Lines of growth. Shell-structure perforated by minute canals. Loop extending to little

more than half the length of the valve, trebly attached, first to the base of the hinge-

plate, then to a short median septum, and again by lateral branches departing from the

reflected upper part of the loop to the upper anterior extremity of the septum. Brachial

or labial appendages consisting of two ear-shaped processes connected by a membrane

forming two large lateral lobes and a short median spiral one. Length 9 lines, breadth

10, depth 6 lines.

Sab. This species was dredged in great profusion by the ' Challenger ' Expedition off

Gomera, Tenerifi'e, in 70 or 75 fathoms. It is a common Mediterranean species, and

abounds on the Atlantic shores. Signer Costa obtained it from near the Island of Capri,

off Ischia, Palmieri, and in the Gulf of Taranto. Prof. E. Porbes states, in his Report on

the Mollusca of the ^gean Sea, 1844, that he found it living at from 60 to 105 fathoms.

It was also dredged off the coast of France, Morbihan, He de Noirmontier; Guetaria,

North Spain, off Marocco and the Canaries ('Talisman' Expedition), in from 50-65 fathoms.

The species has been quoted from New Soutli Wales, but I doubt the accuracy of this

statement, nor have I ever seen any specimens from Japanese waters. The habitat of

the Philippine Islands, given by Woodward, also requires corroboration. The specimen

figui-ed by Deshayes as having been di-edged off the Island of Bourbon (?) certainly belongs

to the species under description ; but it is erroneously named Morrisia gigantea, and its

habitat also requii-es confirmation.

Megerlia truncata is a common fossil in the Upper Tertiary formations of Sicily, Italy,

Nice, and elsewhere.

Ohs. This is an abundant and weU-known species, and the type of the genus Megerlia.

As may be seen from the long list of references, it has been often described, and very

generally so under the specific name of truncata. It bears a somewhat obscure external

resemblance to some forms of Orthis, but, although it has been several times referred to

that genus, it possesses none of its characters. In his admirable memoir entitled

' Recherches sur I'Organisation du Manteauchez les Brachiopodes articules," 1864, M. E.

Deslongchamps describes with minute detail the mantle of several forms, and especially

that of Megerlia truncata. He states that the microscopic flattened spicula of tlie mantle

are still more abundant than in TerebratuUna, have a very peculiar shape, and that the

calcified portions are well defined in both valves. The flattened spicula are wide and

nearly quadi'ilateral, with rounded extremities, the edges being festooned; they form

106

DE, T. DAVIDSON ON EECENT BEACHIOPODA.

Eia

denticulated calcareous plates, and vary suflBciently in arrangement in different genera of

Brachiopoda to serve as distinguishing characteristics (Plate XIX. figs. 18 & 19).

M. E. Deslongchamps describes with much care and detail, at page 117 of his valuable

memoir ' Notes sur les Modifications a apporter a la Classification des Terebratulidte,'

1884, the different stages in the development of Megerlia truncata. He says that

" the modifications the shell undergoes from the embryonic to the adult condition present

a special character, and constitute a rather peculiar type, at least so far as concerns the

brachial appendages. The shell assumes from the commencement a shape which is

but little modified by age. It is only more flattened and nearly circular in the youngest

individuals; ribs obscurely nodulous then mark the surface of the two valves. The

foramen is nearly triangular, but with an elliptic shape. In growing, the shell becomes

more and more transverse and sub quadrilateral, with a slight tendency to indentation in

front. The foramen enlarges posteriorly, but is never provided with more than two

rudimentary deltidial plates even in its most adult condition.

" Rather curious and much more accentuated changes take place in the brachial

appendages. We will examine them first in a shell two millimetres in length The

hinge-plate is very largely developed .... two small

projections, c, indicate the places whence the principal

stems of the loop will afterwards originate, but of which

there is as yet no indication. Towards the middle of

the bottom of the dorsal valve rises an apparatus

very different from that we have hitherto ob-

served, which first develops round the mouth.

Two smaU pillars, P, P, rise from the bottom

of the valve, then expand forward, forming two

thin lamellae, and expand in the shape of two half-

moons, I, I', furnished inside with small irregular

asperities, and miited at their two inner extremities,

leaving free a little triangular space, t. This small

space, to which we wiU apply the name ' escutcheon,'

is completed above by the borders of the semilunar

expansions just mentioned, and there constitutes tlie

deflected lamellae. These are united by a lamella in

the shape of a bridge, P*, which frames the escut-

cheon. The portion of the loop therefore that is first

formed is that in the region of the deflected ajiophysis,

and then no trace of the principal stems of the loop

■ P. I.e.

Young example of Majerlia truncata, 2

millimotres iu length (enlarged), after

M. E. Deslongchamps.

P.l.c, hinge-plate ; c, c, Ist indications of

the principal stems of loops forming two

smaU isolated projections ; P, P, small

pillars rising from the bottom of the

valve, expanding forward in the shape

of two half-moons, Z, l\ furnished with

points ; t, the escutcheon ; P*, united

lamellae in the shape of a bridge.

exists. This is contrary to what takes place in aU

the Brachiopoda we have hitherto recognized. (See woodcut, figure 9.)

" At the dimensions of 4 millimetres these two semilunar expansions, I, I', have become

elongated, and while becoming thinner have lost the small accessory projections of the

first stage. The Y-shaped apophysis that connects the deflected lamellae at the bottom of

the valve forms a process more or less analogous to the pillar of Platydia ; but their

DE. T. DAVIDSON OX EECEXT BEACHIOPODA. 107

development ends tliere, and ;i true median septum is not produced, uniting tlie piilai-

to tlie liinge-plate, as is the case \vitli Zeilleria or Terehratclla proper. The calcareous

appendage or loop oi" tlie genus Megerlia follows therefore, in this respect, the modi-

fications of the Terehralidce proper ; hut the analogy here ceases, for tlie observations

of M. Friele have shown that in these last there exists an entire series of transformations,

I'latkliJ'orm, Muijadifoivn, and TerehnUelliform, bearing no analogy with those of

Mec/erlia."

M. Deslongchamps then explains how in subsequent stages the principal laniellic or

stems of tlie loop become formed, and that this description of the modifications of the

loop must, for the present, l)e restricted to Megerlia trimcata, until those of the other

recent and fossil species referred to the genus have been examined. He states that

there arc four vascular sinuses in the dorsal valve.

M. Deslongchamps observes (Eecherchcs sur I'Organisation du Manteau chez les

Brachiopodes articules, ]>p. 27, 28) that " at the level of the bifurcation of the median

septum the mantle, always lined by tlie pallial apparatus, rises up to join the walls of the

visceral cavity, and thence is reflected throughout the length of the arms. Another part

passes over tlie lower portion of the median septum, covers the branches connecting this

septum to the principal and reflected branches soldered to the brachial appendage and to

the transverse basis which unites them, and afterwards forms one membrane in tlie shape

of an escutcheon, stretched like the skin of a drum between the free internal parts of

these various lamellar apophyses. It there forms the lips of the mouth and of the

interbrachial membrane, and is finally united to the corresponding portion of the mantle

in the large or ventral valve. Throughout this perambulation the mantle is effectually

protected by the pallial apparatus, the spicula of which are almost visible to the naked

eye, except on the different branches of the brachial apparatus where they are absent.

It results from this arrangement that the spicula form on the escutcheon a small area

independent of the rest of the pallial apparatus, and limited in all its circumference by

the laminae of the brachial apjiaratus [Plate XX. figs. 18, 19]. ... In the arms and their

cii'ri the shape of the spicula is entirely different ; they are arranged exactly like those of

the same parts in Terebnttulhia, only their branches are larger and their divisions less

numerous. These S2:)icules have almost the aspect of those on the borders of the

escutcheon, with this difference, that they are always more elongated in the transverse

direction, that is to say perpendicularly to the axis of the length of the canals, and are

much more cut out at their edges."

Dr. Gwyn Jeffreys, in the Ann. & Mag. Nat. Hist, for 1858, ii. pp. 123-4, in referring to

Megerlia triuicata, remarks that " Having examined Dr. Turton's specimen in my cabinet,

which he is said to have procured from Torbay, and which is referred to in the footnote,

p. 3G2, vol. ii. of the ' History of British MoUusca,' I am enabled to state confidently

that it belongs to the above species, and not to Terebratula detruncala or dccollata, as

therein supposed. M. Collard-Descherres records Terebratula truncata as having been

taken on the coast of Finisterrc (Journal de Couchyliologie, tome ii. j). 393), and there is

no reason to doubt the possibility of its being a British species."

Mr. Dall, at p. 130 of his memoir " On a Revision of the Terebratulidte," in the American

SECOND SERIES. — ZOOLOGY, VOL. IV. 15

108 DE. T. DAVIDSON OX EECENT BRACHIOPODA.

Journal of Conch, vol. vi. p. 130, 1870, says that " The [Smithsonian] collection includes

a specimen from New South Wales (coll. Angas), sent under the ahove name \_M. triincatct].

The shell and apophyses presented no constant difference from Mediterranean specimens.

The animal was in a perfect state of preservation in both, and I noticed the following

differences, of which only a much larger series would be sufficient to establish the constancy.

The central spiral lobe of the brachia, prominent in the European species, seemed to be

nearly wanting in the Australian shell. The fringes in the former were nearly twice as

long, the individual filaments much more slender, and five or sis times as numerous

as in the latter."

Megerlia truncata, var. monstruosa, Scacchi. (Plate XIX. figs. 21, 22 «.)

Terehratula monstruosa, Scacclii, Osserv. Zool. no. 2, p. 17, 1838, aud Cat. Coiichyl. Regui Neapolitani,

p. 8, 1836.

Terebrutula monstruosa, Costa, Fauna del Regno di Napoli, p. 43, pi. ix. figs. 4, 5, 1851.

Megerlia truiicata, var. monstruosa, Monterosato, Poche note sulla Conch. Med. p. 4, 1875.

When describing this shell, Scacchi observes that he suspects it might be a malforma-

tion of Terehratula truncata, a view reciprocated by Costa and by several other malaco-

logists, and it is very probable that they are correct in their expression of opinion. Having

had a number of s])ecimens through my hands presenting the same peculiarities, I have

preferred to retain for it the varietal name of monstruosa. In shape it is either circular

or transversely oval, and usually smaller than Megerlia truncata proper. The dorsal

valve is much flattened, and occasionally even somewhat concave and marked with ruts

and irregularities dvie to the olyect upon which it lay closely impressed. There generally

exists at the umbo a semicircular aperture or foramen, somewhat similar to that oiFlati/dla,

which affords passage, in part, to the short thick peduncle. The ventral valve is evenly

convex ; beak very short, with its extremity sometimes i^artly overlying the semicircular

aperture in the umbo of the dorsal valve ; foramen semicircular, completing that in the

dorsal valve. Surface of ventral valve faintly marked by fine radiating raised lines or

I'iblets, that of the dorsal valve with concentric lines. In the interior of the dorsal valve

the loop is exactly similar to that of the typical Megerlia truncata. Colour yellowish.

Length 0 lines, l)readtli 6, depth 2| lines.

Sab. Dredged alive near the Island of Corsica (Scacchi) ; also in the Bay of Naples.

0/js. Were it not for the loop many specimens of this variety or malformation might be

taken for JPlatydice.

Section B.

62. Megerlia sangtjixea, Chemnitz, sp. (Plate XX. figs. 1-8.)

Anomia sanx/vinca, Chemnitz, Neues syst. Conch. -Cabinet, vol. viii. p. 9G, pi. 78. fig. 706, 1785.

Anomia sanguinolenta, Gmelin, ed. Linne's Syst. Nat. p. 3347, 1788; Dillwyn, Cat. of Kecent Shells,

p. 293, 1817 (not of Solandcr).

Terehratula sangulnea, Kiister, Nov. ed. Chemnitz's Conch.-Cab. p. 33, pi. ii. figs. 9, 10, 1843.

Terebrutula cruenta, E. Donovan (not of Dillwyn), The Naturalist's Repository, vol. ii. pi. Ivi. fig. 1^

1824 (according to Donovan tliis is the Anomia cruenta of Solandcr, MS.).

Terehratula sanguinolenta, Blainville, Diet, des Sci. Nat. vol. liii. p. 142, 1828.

DE. T. DAVIDSON OX EECEXT BRACHIOPODA. 109

Terebratula erylhroleuca, Quoy & Gaimard, Voyage de I'Astrolabc, vol. iii. p. j J7, j)l. Ixsxv. figs. 8, 9,

183J?; Deshayes, Nov. cd. Lamarck, Au. sans A^eit. vol. vii. p. 3JU, 18:3(].

Terebratula sanyuinca, G. B. Sowerby, Thes. Couch, vol. i. p. 357, pi. Ixxi. figs. "1-73, 1846.

Terebratula pulchella, G. B. Sowerby, ibid. p. 3G0, pi. Ixxi. figs. 105-107, 18 Ki.

TerehrateUa sanijuiiwa, Davidson, Auu. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 3G8, 1852.

Mvgerl'ia pulchella, Davidson, ibid. p. 369, 1852.

TerehrateUa xanijuhiea. Woodward & Gray, Cat. of Bracli. in Brit. Mus. p. 90, 1853.

Meijerleu yukhella, Woodward & Gray, ibid. p. 90, 1853.

Terebratella sanyuinea, E. Suess, Ueber die Wohnsitze dor Braehiopodcn, Sitzungsb. k. Akad. dcr

Wisscnsch. Wien, Bd. xxxvii. p. 205, 1859.

Terebratula {Terebratella) sanyuineu, lleeve, Conch. Icon. pl. vii. fig. 25 «, Z), c, and Ann. & ISIag. Nat.

Hist. 3rd scr. vol. vii. p. 178, 1861.

Ismenia saiir/uinea, Adams, Ann. & Mag. Nat. Hist. 3rd scr. vol. xi. p. 99, 1863; Dall, .Vmcr. .Jouni.

Conch, vol. vi. p. 127, 1870.

Megerlia sanyuinva, Davidson, Proc. Zool. Soe. 1871, p. 308, pl. xxxi. figs. 1, 2.

Megerlia samjuinea, var. lleevei, Davidson, ibid. 1871, p. 308, pl. xxxi. fig. 3.

Megerlea sanguinea, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 187, 1873; Davidson, Report on the

Brachioijoda, Voyage of II. M.S. 'Challenger,' Zool. vol. i. p. 52, pl. iii. fig. 14, 1880.

Frenulu sanguinea, Zittel, Ilaudbuch der Paliiontologic, p. 708, 1880.

Megerlea sanguinea, G. Dunker, Index [Mollusc, maris Japouici, p. 353, 1882.

Terebratella sanguinea, E. Deslongehamps, Etudes critiques sur des Brachiopodcs nouveaux ou peu

connus, p. 102, jil. xvii. figs. 1-4, 1884.

Shell thin, small, somewhat transversely oval, and quite regular, or almost circular,

as broad as long, smooth, almost polished, with faintly marked concentric lines of

growth. From white or yellow to a livid red, marked with brownish or reddish streaks,

freckled with bright blood-red blotches, bounded on each side by white and yellowish

streaks and patches or spots of red, which radiate towards the margin. Dorsal valve

moderately convex, with a more or less defined mesial dejoression, commencing at about half

the length of the valve and extending to the front. Ventral valve rather deeper than the

dorsal one, uniformly convex, sometimes either slightly keeled or flattened along tlie

middle. Beak moderately incm-ved and truncated by a circular foramen, very slightly

separated from the hinge-line by a small deltidium ; beak-ridges well defined, leaving a

flattened space or area between them and the hinge-line. Shell perforated by canals.

In the interior of the dorsal valve the loop does not extend much further than to about

two tliirds of the length of the valve ; it is three times attached— first to the hinge-plate,

then before attaining half its length to a longitudinal septum, and a third time by

vertical lamina?, which connect the lateral reflected extremities of the loop with the

median septum. Length 7 lines, width 7, depth 3i lines.

Eab. Dredged by the ' Challenger ' Expedition on the reefs of Zamboanga, at 10 fathoms

depth. One example was obtained by the * Astrolabe ' Expedition at Tongatabu. I

have very fine and large examples from off" the Island of Zebu, in the Philippines, and off

Honolulu, in the Sandwich Islands, attached to corals and stones. The Eev. J. Tenisou

Woods sent me specimens of the shell, both white and coloured, from uear Bird's Island,

North Australia. Mr. Adams dredged it at Mino-Sima, in 63 fathoms, and at Gotto in

48 fathoms. It was also obtained by Mr. E. Deplanclie not far from llie coast of

Tahiti, and recently off Phare, jS^ew Caledonia. The variety T. jndchella is stated by

110 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

G. B. Sowerby to liaAe been found by Mv. Cuming attached to corals at Calapan, Isle of

Mindoro, also off the Island of Cocos (Lieut. Swainson). The shell has been dredged

by Mr. J. Brazier oif the Bottle and Glass rocks, Port Jackson, Australia, and at other

places in the same region. (PL XX. figs. 9-11.)

Obs. Mr. E. Donovan, in vol. ii. (1824), of his ' Naturalist's Ptepository,' tells us that

*' this elegant little testaceous body is eminently entitled to the consideration of the

naturalist, being no other than the true Anomia Criienta of Dr. Solander's manuscripts,

preserved in the Banksian library, and of the Portland Museum to which the Solandrian

manuscripts refer ; it is consequently the shell which has been so uniformly mistaken for

and confounded with the Anomia sangiiiuea of the same author, and not unfrequently

with his Anomia rvhicunda also." Such may perhaps be the case ; but as Solander did

not publish a description of his shell, Ave are bound to take the name of the Anomia

sangitinea described and figured by Chemnitz in 1785. To a bleached specimen from

Japan, A. Adams, in 1863, gave the name of Ismenia JReevei (PI. XX. figs. 12, 12 b of this

work), and Mr. L. Eeeve states, in his description of T. sanguinea, that " An examination

of more than a dozen specimens of this charming species, most of them with the soft

parts macerated, so as to afford excellent comparisons of the loops, has convinced me

that Mr. Sowerby's T. ^yvlcheUa {Megerlia irnlcheUa, Davidson) is merely a variety of the

old Anomia sanguinea of Chemnitz." If only Sowerby's figures of T. sanguinea and T.pul-

chella are compared, one might perhaps feel disposed to conclude that they represented

different species ; but when one examines, as I have done, a large number of individuals,

it is soon found otxt that the two extreme forms are connected by intermediate or passage

ones. The red spots on the shell also vary much in extent, and even shaj)e, sometimes

forming a longitudinal and rather wide mesial band with a small yellow band on each side,

on Avhich none are visible, and in some examples short ribs are also observable near the

margin in both valves.

M. E. Deslongchamps, in his paper already referred to (p. 102), classes T. sanguinea with

Terebratella, and describes some of the changes it undergoes from the youngest stage up

to the adult condition. He says " that the brachial apparatus or loop is more comj)licated

than that of true Terehratellce , and very similar to what we observe in the IlegerJiforni

stage of Waldheimia septigera, but with an additional complication." In my opinion

T. sanguinea is not a true Terebratella, and, if not a Megerlia, would require to be left

with Ismenia or some other genus. In plate xvii. of the work just quoted, Deslongchamps

figures the passages of T. sanguinea from the Platydiform into the Magadiform stage at

the dimensions of 4 millimetres, the commencement of the Megerllform stage at 8

millimetres, and the Megerliform stage of the species at the dimensions of 10 millimetres

(see our PI. XX. figs. 4, 5, 6, 7, 8 ; and the corresponding explanations).

Mr. Ball, in his paper in the Amer. Journ. of Conch, vol. vi. p. 128, 1870, when

describing Ismenia sanguinea, mentions that "There is some variation in tlie obliquity

and breadth of the apophyses in different individuals, but the essential characters remain

the same. The punctures in the shell are larger and more conspicuous than in any

species of the group with which I am acquainted. The imbricating prisms of which the

shelly structure is composed are beautifully conspicuous with a very low power, inside;

and even the apojohyses seem to exhibit the same or a similar structure, though impunc-

DE. T. DAYIDSOX ON EECEXT BEACHIOPODA. Ill

tate In general, the foramen is moderate and the (k'ltidia are united, but in many-

cases the foramen is large and the deltidia are more or less widely sejiai'ated, and the a2)ex

is produced. I cannot doubt the identity of T. iJulchella, Sby., Avith T. sangidnca of

Davidson and Chemnitz."

JJncertcdii Species.

03. Megerlia Willemoesi, Davidson. (Plate XIX. tigs. 23-2(5.)

M(>(/erlia Jll/Zemocsi, Davidson, Proc. of the Koyal Soc. vol. xxvii. p. 438, 1878.

Merc/eVut ii-il/cinik'si, Report on the Braeliiopoda, Vojage of H.INI.S. 'Challenger,' Zoology, vol. i. p. 51,

pi. iv. figs. 1-3, 1880 (erroneously labelled on plate Muyasella Willemoesl).

Shell ovate, or longitudinally oval, broadest anteriorly, tapering posteriorlv. Valves

moderately convex, surface smooth, white. Dorsal valve moderately convex, not quite

so deep as the ventral one, and somewhat flattened anteriorly so that the front line is

slightly depressed. Yentral valve very convex, slightly flattened along the middle and

especially so anteriorly. Beak produced, comparatively large and truncated by a circular

foramen, separated from the hinge-line by a rather wide and high deltidium. In the

interior of the dorsal valve tlie loop is three times attached — first to the hinge-plate, ao-ain

to a median si^ptum, and thirdly by perpendicular lamellye which connect the lateral

reflected extremities of the loop with the median septum. Length 7 lines, width 5, depth

4 lines.

Hub. rive examples of this interesting species, attached to branched Polyzoa, were

dredged in company with Terehratula ihva by the 'Challenger' Expedition, off Twofold

Bay, South Australia, or between Sydney and Melbourne, in 120 fathoms.

Ohs. I can add nothing Avith respect to this species to the description here reproduced

from my ' Challenger ' report. The discovery of more specimens would be desirable

before the species is definitely admitted.

Subgenus Laqueus, Dall, 1870.

Type Laqueus californiciis, Koch, sp.

When proposing this subgenus, Mr. Dall published th(> following diagnosis : —

" Shell with the reflected portion of the loop attached by slender processes, on each

side, to the luunial processes, at or near the points where the two septal jn-ocesses branch

off to the septum. Foramen complete. It will be observed that the reflected part of

the loop is attached by the two (lateral) processes, not to the septum nor to tlie septal

processes, but to the hapmal portions of the loop (which I have termed haimal processes) ;

thus the two septal processes, the two lateral processes, and the 'bight' of tlie neural

loop, form a somewhat sinuous ring, intersected by the point of the septum, the lucmal

processes and the two sides of the neural loop." (Eevision of the Terebratulidic, 1870,

p. 123.)

This is a very good subgenus and has been generally accepted. We are acquainted

with tliree recent species and a named variety *, viz. : —

Laqueus californiais, Koeli.

californiciis, var. vancouveriensis, Davidson.

haqums pictus, Chemnitz.

ruhellus, Sowerby.

* \_Laqueus siiffmus, Dall, is figured on PI. XIX. figs. 0, 7 h. It was subsequently placed as a synonym of L. rubcUus,

by Dall, but was considered by Davidson tu be the young of L. ijiciics (p. 114). — A. C]

112 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

64. Laqueus califoknicus, Koch, sp. (Plate XVIII. figs. 6-9.)

Terebratula califonuca, Kocli, Kiister, nov. ed. Chemnitz, Couch. -Cabinet, vol. viii. pi. 2 b. figs. 21-23,

1843.

Terebratula Kochi, Kiister, ibid. vol. viii. pi. 2d. figs. 1-3, 1843.

Terebratula Ca/ifornica, G. B. Sowerby, Thes. Conch, i. p. 352, pi. Ixx. figs. 50-52, 1846.

Terebratula Californiana, Davidson, Sketch of a Classification of Recent Brachiopoda, Ann. & Mag.

Nat. Hist. 2nd ser. vol. i.K. p. 3G4, 1852.

Waldheimia Californica, Woodward & Gray, Cat. of Brach. in Brit. Mus. p. 60, 1853; V. Carpenter,

Rep. Brit. Assoc. 1856, p. 298; Cooper, Geogr. Cat. p. 3. no. 5.

Waldheimia californiana, E. Suess, Ueber die Wohnsitze der Brach. Sitzungsb. k. Akad. der Wissensch.

Wien, Bd. xxxvii. p. 202, 1859.

Terebratula [Waldheimia) globosa, L. Reeve (not of Lamarck), Icon. Conch. Monogr. Ter. pi. ii. fig. 3,

18C0.

Laqueus californicus, Dall, Amer. Jouru. Conch, vol. vi. p. 123, 1870, L. Californica, Proc. Acad. Sci.

Philadelphia, 1873, p. 186 ; E. E. Deslongchani])s, Etudes critiques sur des Brachiopodes nouveaux ou

l^eu connus, p. 202, 1884; Zittel, Handbuch der Palaontologie, p. 706, 1880.

Shell large, longitudinally oval, inflated ; margins slightly sinuous. Dorsal valve uni-

formly convex, with occasionally a very slight tendency to depression close to the frontal

margin. Ventral valve a little deeper than the dorsal one, with sometimes a slight indi-

cation of a mesial longitudinal elevation or flattened fold ; beak incurved, truncated by

a small circular foramen, margined anteriorly by two wide deltidial plates ; beak-ridges

sharply defined, leaving between them and the hinge-line a flattened space. Surface of

valves smooth, with concentric lines of growth, shell-perforations rather large. Colour

livid yellowish brown or light reddish brown. Length 2 inches 6 lines ; breadth 1 inch

11 lines ; depth 1 iucli. In the interior of the dorsal valve the hinge-plate is bifid ; car-

dinal process inconspicuous. The septum, of small elevation, extends from under the

middle of the hinge-plate to a little more than a third of the length of the shell ; the

principal lamella} of the loop, after having been attached to the angles of the hinge-plate

and giving off short curved crura, proceed a short distance, when they again give off two

slightly oblique laminte, which become attached to the anterior edge of the mesial septum.

The principal stems of the loop then extend to witliin a short distance of the frontal

margin, Avhcre they become deflected in the shape of a horse-shoe, giving ofi' on each side

a short lamella near their upper extremity, thus connecting the reflected portion with

the principal stems of the loop close to the point where the two oblique lamellte leave for

their attachment to the mesial septum.

Ilah. Coast of Barbara County, California, in 90 fathoms (Dall).

Ohs. This fine species, little inferior in size to Waldheimia venosa, Solander, has

often been confovmded with it on account of its similarity in external shape. The two

species are, however, perfectly distinct. The small foramen, w^idely separated from the

hinge-plate in Laqueus californicus, at once distinguishes it from IP'uhlheimia venosa,

which possesses a much larger foramen but little separated from the hinge-line. The

absence of a defined cardinal process in the interior of the shell and a very different

arrangement of the loop further distinguish the two species.

The Terebratula Kochi, Kiister, is only a smaller specimen of Laqueus californicus.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 113

Go. LAQUErS CALIFOENICUS, vav. VAXCOTJVERIENSrS. (Plate XYITT. figs. 10-13 Ij.)

Off Vancouver Island we find in large numbers a smaller race or northern form

which Mr. Dall considers to be Laqucus californicus. The shell has also been quoted by-

Mr. J. F. Wliiteaves from off Metla-katla, Queen Charlotte Islands, and from between

Ilacc Island Lighthouse and Victoria lIarl)our, in from 30 to 70 fathoms, as well as ofi' the

N.W. end of Texada Island, in 40 to 70 fathoms, west coast of North America. I have

examined a number of specimens of this shell, some quite circular, others ovate and

truncate anteriorly with a slight depression on the anterior third of tbe lengtli of both

valves. Tlie foramen is also comparatively larger than in typical Californian examples of

LaqHens californicus. Interiorly the loop and its attachments are similar to tliose of the

Californian shell. It is decidedly of a livid yellowish-brown colour. After consulting

with Mr. Dall upon the subject, he wrote me back, on the I7th of December 1884 : — " The

shells from Vancouver which I referred to L. californicus are, I am quite confident, a

northern form of that species, less briglitly coloured, thicker, and ruddier. I have northern

specimens fully as large as the southern ones, and I believe my Mcgerlia Jeff'reijsi to be the

young stage of it. The northern form might perhaps have a varietal name; but if Ave

had plenty of specimens, I think they would be found to intergrade."

I had always felt much uncertainty with respect to tlic specific value of the so-termed

Megevlia Jeffreysi, and was therefore pleased to hear Mr. Dall adniit that it miglit prove

to be a young stage of the northern form of Laqneus californicus. In 1871 it was In-iefly

noticed by Dall in the 'American Naturalist,' vol. v. p. 55, under the name of

Frenula Jeff'rcijsii ; in the same year in tlie ' American Journal of Conch.' vol. vii. p. 65,

pi. ii. figs. 7-10, by the name of Ismenia Jeffreijsl ; and in the ' Proc. Acad. Nat. Sciences

of Philadelphia,' 1873, p. 187, under tlie name of Megerlia Jcffreysi. It was dredged by

Dall at Port Etches, Alaska Territory, in 14 fatlioms chalky mud, as well as alive off the

Semidi Islands. It is also said to have been obtained iu the North Atlantic Ocean ; but

this statement needs confirmation.

G6. Laqueus kubellus, G. B. Soworby, sp. (Plate XIX. figs. 1-5.)

Terebrutula riibvUa, G. B. Sowerby, Proc. Zool. Soc. 184Gj p. 94, ; Tlies. Conch, i. p. 330, pi. Ixix.

figs. 40-12, 1840.

Terehratella rubella, Davidson, A Sketch of a Classification of Recent Bracliiopoda, Ann. & ^lag.

Nat. Hist. 2ud ser. vol. ix. p. 368, 18o2 ; Woodward & Gray, Cat. of Brach. in tlic Brit. ]\Ius. p. 90,

1853 ; L. V. Schrenck, Reiscn imd Forschungen im Amnr-Lande, p. 4GG, 1831-56; E. Sucss, Ueber die

Wohnsitze der Brachiopodcu, Sitzungsb. k. Akad. der Wisscusch. Wien, Bd. xxxvii. p. 205, 1859.

IValdheimia craniutii, A. Adams (not of Miillcr), Recent Brachiopoda I'ound in the Seas of Japan,

Ann. Mag. Nat. Hist. 3rd ser. vol. xi. p. 98, 1863.

? Laqueus siiffiisufi, Dall, Amcr. Jonrn. of Conch, vol. vi. p. 125, pi. vii. tig. h, 1870.

Laqueus rubella, Davidson, Proc. Zool. Soc. 1871, p. 306, pi. xxx. tigs. 18-22; Dall, Proc. Acad. Nat.

Sci. Philadelphia, 1873, p. 186; (>. Danker, Index ^lollusc. maris Japonici, p. 252, 1882.

Shell longitudinally nearly oval or ovate, longer than wide, straight or indented in

front, lateral margins very gently sinuated. Dorsal valve uniformly convex to within a

Ill DE. T. DAVIDSON ON EECENT BEACHIOPODA.

third or fourth of its length, when a flatfish mesial depression, about four lines in brcadtli,

commences and extends to the front. Ventral valve deeper and more convex than the

dorsal valve, keeled along its posterior half, gently depressed mesially along its anterior

half. Beak incurved, truncated by a small circular foramen, margined anteriorly by two

small narrow deltidial plates ; beak-ridges well defined, leaving between them and the

hinge-line a narrow flattened false area. Colour yellowish red, varying in intensity or

more vividly coloured at the concentric lines of growth, and sometimes rayed with

bright red. Length 1 inch 8 lines, breadth 1 inch, depth 7 lines.

In the interior of the dorsal valve the loop is long, the hinge-plate divided along the

middle. Mesial septum, not very prominent, extends from between the hinge-plates to

rather less than half the length of the valve.

The principal lamellse forming the loop after having become attached to the base of

the hinge-plate soon give off a horizontal lamina which attaches itself to the anterior

edge of the mesial septum, and after having attained its greatest length again becomes

reflected, the upper lateral portions of the deflected loop l)ecoming connected to the

principal stems by an oblique lamella, close to the point where the horizontal lamella

leaves for its attachment to the mesial septum.

Hah. Dredged by A. Adams, from a clear stony bottom off the small island of

Kuro-Sima, at a depth of 35 fathoms, Japan; by Prof. R. Plumpelly at the wharf at

Yokohama, Japan ; and by Capt. St. John in the Strait of Corea, in from 23 to 35 fathoms.

Ohs. Since Sowerby described this pretty shell in 1846, many much larger and finer

examples have been obtained from Japanese waters. The shell does not appear to vary

much in shape, and is distinguished from Laqueus 2^ict/(S by its straight or slightly

indented front. In 1870 Dall proposed a new species under the name of Laqueus suffusus

(PL XIX. figs. 6, 7 h), but this he relioquished in 1873, locating his so-termed species as

a synonym of L. ruheUvs ; but I am myself more inclined to regard it as a young

condition of Laqneus jjiclns. In colour L. rnbell as \a.vies considerably, some sjjecimeus

are ashy white, others are of a general salmon-colour, which deepens into orange-red near

the lines of growth or margins of the shell. In some examples, besides a general reddish

tint, a few rays mark the lateral portions of the shell, but these are rarely so strongly

defined as in Sowerby's figure, in which the coloration is exaggerated.

G7. Laqueus pictus, Chemnitz, sp. (Plate XVIII. figs. 14-18.)

Anomia pida, Chemnitz, Concli. -Cabinet, vol. xi. p. 247, pi. 203. figs. 2011, 2012, 1785 ? ; Anton, Yer-

zcicluiiss der Couch, p. 23, 1839.

Terebratula picta, G. B. Sowerby, Thes. Conch, i. p. 351, pi. kx. figs. 43, 44, 1846; Kiister, ed.

Martini & Chemnitz, Conch. -Cabinet, pi. ii e. figs. 8, 9, 1813; Davidson, A Sketch of a Classification

of Eecent Terebmtuhe, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 304, 1852.

fVa/dkeimia picta, Wood\var(i & Gray, Catalogue of Brachiopoda in the Brit. Mus. ]). 59, 1853;

A. Adams, The Genera of Recent Mollusca, p. 575, 1858 ; E. Suess, Ueber die Wohnsitze der Brachiopodcn,

Sitzungsb. k. Akad. der Wisscnsch. Wien, Bd. xxxvii. p. 201, 1859.

Terebraiu/a [IVuldhehiiia) picta, L. Reeve, Conch. Icon., Monogr. Terebratula, pi. iii. figs. 9 «, b, 18G0;

Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 175, I8G0.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 115

Waldheimia p'lcla, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 99, 1863 ; Dal), Amer.

Journ. of Cuucb. vol. vi. p. 112, 1870.

Laqueus pictus, Davidson, Proc. Zool. Soc. 1871, p. 301, pi. xxxi. fig. 10; G. Dunker, Index Moll,

maris Japonici, p. 252, 1882.

Shell ovate, longitudinally oval, broadest about the middle, somewhat acuminated or

rounded anteriorly. Dorsal valve uniformly convex, no fold or sinus. Ventral valve

rather deejier than the dorsal one, beak incurved, slightly overlying tin; mnbo of the dorsal

valve, and truncated by a small circular foramen sHghtly se})arated form the hinge-line

by a deltidium in two pieces ; beak-ridges sharply defiued, leaving between them and the

hinge-line a narrow flattened false area ; marginal line almost straight. Colour yellowish

red, sometimes bright red and marked in an irregular manner with zigzag light-yellowish

ramifying spots. Length 1 inch 4* lines, breadth 1 inch, depth 8 lines.

In the interior of the dorsal valve the hinge-plate is well defined and notched along

the middle ; no distinct cardinal process. A slightly raised mesial septum extends along

the bottom of the valve from the middle of the hinge-i^late to less than half its length ;

the loop is long ; the principal stems, after having become attached to the base of the

hinge-plate, soon give off a horizontal lamella, which become attached to the anterior

edge of the mesial septum, and again extends until it reaches its greatest length, when it

is deflected to form the loop ; before the reflected part has attained its terminations it

gives off on each side an oblique lamella which becomes attached to the principal

stems of the loop, close to the point whence the horizontal lamella leaves for its attach-

ment to the mesial septum.

Hab. Dredged by A. Adams, in 55 fathoms, off Satanomosaki, Japan, and by Capt.

St. John, in 23 and 24 fathoms, in the Corea Strait.

Ohs. This is a fine shell, much sought after by collectors. Its red colour is rarely as

bright as it is sometimes represented to be, the shell being generally of a dull yellow-red

with radially interrupted spots of light yellow. Young sjjecimens tajier considerably

anteriorly, are broader posteriorly, and of a salmon-colour. L. pictus has been successively

placed in the genera Terebratula, Terebratella, and Waldheimia ; but I Avas at last able

to ascertain that its loop was positively that of a Laqueus. L. Reeve gives Terebratula

erythroleuca, Quoy, as a synonym of the species under description ; but this is a mistake,

for it is really a synonym of the Anomia sanguinea of Chemnitz. He also quotes Java

as the habitat of Laqueus pictus, but I have never seen any specimen from that locality.

Subfamily MAGASlNiE.

Genus BOUCHARDIA, Davidson, 1849.

Of tliis genus only one species has hitherto been discovered ; its generic characters

have been described under Bouchardia rosea and need not be repeated here.

68. Bouchardia rosea, Mawe, sp. (Plate XX. figs. 13-18.)

Anomia rosea, Mawe, Intr. to Conch, tab. iv. fig. -l-, 1823.

SECOND SEBIES. — ZOOLOGY, VOL. IV. 16

116 DK. T. DAVIDSON ON RECENT BEACHIOPODA.

Terehratula rosea, G. B. Sowcrby, Cat. of Shells of the late Earl of Tankerville, p. 28, 1825.

Terehratula tulipa, Blaiuville, Diet. So. Nat. liii. p. 144, 1828.

Terehratula rosea, Sander Rang, Manuel de THistoire naturelle des Mollusques, pi. 8. figs. 1-3,

18.29; Deshayes, ed. Lamarek, An. sans Vert. vol. vii. p. 350, 1836.

Terehratula unguis, Kiister, ed. Martini & Chemnitz, Conch. -Cab. p. 35, pi. 2 b. figs. 8-10, 1843.

Terehratula rosea, d'Orbigny, Voyage dans I'Amerique Meridionale, vol. v. p. G74, 1847.

Bouchardia rosea, Davidson, Bull. Soc. Geol. de France, 2" sir. vol. vii. p. 62, pi. i. figs. 1-6, 1849 ;

Classification of Recent Brachiopoda, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 372, 1852.

Pachyrhynchus roseus. King, A Monograph of English Permian Fossils, Pal. Soc. p. 70, 1850.

Bouchardia tulipa, Woodward & Gray, Catalogue of the Brach. in the Brit. Mus. p. 100, 1853;

S. W^oodward, A Manual of the MoUusca, p. 218, 1856.

Terehratula rosea, Hanley, Recent Shells, p. 322, 1856.

Terehratula (Bouchardia) tulipa, L. Reeve, Conch. Icon. pi. mi. fig. 33, 1861.

Bouchardia tulipa, Adams, The Genei'a of Recent Mollusca, vol. ii. p. 577, 1858 ; E. Sucss, Ueber

die W^ohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch. W^ien, Bd. xxxvii. p. 210, 1859;

Dall, Eevision of the Terebratulidse, Amer. Journ. of Conch, vol. vi. p. 141, 1870.

Bouchardia rosea, Dall, Proc. Acad. Nat. vSci. Philadelphia, 1873, p. 191.

Shell thick, with a nearly straight heak, longitudinally oval or spindle-shaped, longer

than wide ; surface smooth, marked here and there with concentric lines of growth.

Colour yellowish red, pink throughout or sparingly rayed with bright crimson. Length

9 lines, breadth 5i liaes, depth 4 lines. Dorsal valve very gently and uniformly convex

posteriorly, anteriorly more or less depressed along the middle. Ventral valve slightly

deeper than the dorsal one, longitudinally keeled ; beak triangularly acuminated, almost

erect, very little incurved, and truncated by a small terminal circular foramen widely

separated from the hinge-line by a concave false area, with two narrow grooves along the

middle ; deltidium blended with the shell. Interior of the valves much thickened

posteriorly. The interior of the dorsal valve is unusually thickened posteriorly, to about

one third of its length ; hinge-plate large and solid, provided with V-shaped diverging

grooved ridges, and much elevated above the other portions of the shell, especially

anteriorly. These long scooped-out ridges probably served for the attachment of the

cardinal muscles. On each side, on a lower level, are the lateral portions of the hinge-

plate, and close to the hinge-line on each side the dental sockets. No cavity exists under

the hinge-plate, which is massive ; but from its sunken base a mesial septum of about one

third the length of the valve extends, this gradually rises until it becomes abruptly

elevated anteriorly in the shape of a wide perj^endicular plate, and to the posterior laljial

slopes of which are fixed anchor-shaped disconnected curved lamellae, broad at their

attachment to the sides of the septum and gradually tapering to a point At the bottom

of the valve on each side of the septum are faintly impressed muscular scars. In the

interior of the ventral valve the shell is much thickened at and near to the beak, as well

as longitudinally ; along its centre extends a wide sliglitly raised ridge with two oval-

shaped muscular impressions on each side ; two deviating massive ridges, deeply excavated

along the middle, extend from under the beak to about one third of the posterior length

of the valve. Teeth for the interlocking of valves strong. The positions of the occlusorj

DE. T. DAVIDSON ON KECENT BRACHIOPODA. 117

divaricator, and ventral adjusters in the ventral valve have been well defined by Wood-

ward, at page 218, fig. 118, of his 'Manual of the MoUusea.'

Hah. Rio de Janeiro, 13 fathoms (Macgillivray) ; bleached dead shells can be picked up

on the beach on the open coast just outside the mouth of the Bay of Rio, but generally

much worn and imperfect (Derby).

Ohs. The animal of this beautiful small species has not been hitherto examined. The

shell varies very little in shape and character ; its internal details are difiicidt to describe

in words, but a glance at the figures will make all clear. The shell has been described

under the specific names of Terehratula rosea, T. tulijM, T. unyuls, and, I believe, T. ttdipa

rosea. Some uncertainty has also prevailed with respect to the name first published.

The form was well figured in 1823 by Mawe under the appropriate specific name of

rosea, some years before that of tuUpa, given to it by Blainville in 1828. Mawe

appears to have adopted names chiefly from the manuscripts of Ilumphrey, Da Costa,

and Solander, and several authors have taken the name rosea from Humphrey.

In 1849, noticing the great dissimilarities the species presented in its internal structure

from other Terebratulida^, I proposed to create a distinct genus for its reception, and gave

it the name of Bouchardia, which has been very generally adopted since that period.

Lovell Reeve, in his monograph on Terehratula, expresses himself to the efi'ect that

T. Cnmhiffi, T. fihda, and T. rosea are distinguished from all other Terebratulae by the

structure of the beak of the shell.

At my request INIr. John Yomig, of the Hvinterian Museum, Glasgow, carefully

examined the shell-structure of Bouchardia rosea and Magasella Cumingi ; he wrote me

on the 20th of April, 1885 :—

" I have carefully etched the valves of both sj)ecies, so as to reveal more clearly the

nature of these perforations. Both species have their shell-structure perforated after the

same manner ; but there are some differences in the perforations and in th(> shell-structure

between the pores, which I will notice further on. Before etching, I examined both the

outer and inner surface of the valves, to see what was revealed, and noted what I saw.

In Bouchardia rosea the outer surface showed numerous minute oval punctures. The

inner surface showed only punctures on the thinner portions of the valve near the margin,

more towards the beak.

" In Macjasella Cnm/i/r/l the outer surface on both valves showed numerous minute oval

pores. These were most distinctly seen around the margin of the valves. On the inner

surface of the ventral valve the punctures are only faintly seen. On the inner surface of

the dorsal valve the punctures are not visible except by transmitted light ; they can be seen

passing downward through the shell-structure. After etching the shells to a greater trans-

parency the perforations become much more distinctly seen on the outer surfaces of both the

valves. In Bouchardia rosea they appear to be smaller and a little more numerous than

in M. Cmninffi. The tubes in their upward passage through the structure of the shell are

seen to be always inclined and directed towards the beak, and these tubes increase in

diameter as they open on the surface, agreeing in this resjject with what has been already

recorded. With a 1-inch or i-inch power of the microscope, imder a strong beam of

16*

118 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

transmitted liglit, the inwardly inclined tubes are very distinctly visible, especially on that

portion of the shell nearest the beak. The tubes are more depressed in £. rosea than in 31.

Cimingi. Another distinction which I notice between the two shells is that B. rosea, when

examined under a hig-her power of the microscope by transmitted light, shows a more dis-

tinctly marked imbricated structure than is seen in M. Cumingi. In the latter species the

prismatic structure is seen to be bent around the tubes in a manner not observable in the

former. I have noticed this bending of the prismatic structure around the tubes both in

Froductm and Chonetes. The real appearance of the perforations as they are seen on the

surface of the shell appears to be due to the angle at which the round tubes reach the

surface, — the more slanting the tubes within the shell the more oval will be the openings

of the perforations. Another point I notice in connection with these perforations

is, that from the middle of the valve, on each side, the tubes or canals incline outward

and upward towards the beak, and where there is a tendency to any folding of the

shell the tubes diverge on each side of the fold."

Subfamily Kraussinin^.

Genus KRAUSSINA, Davidson, 1859.

In 1852, while examining the interior of the valves of Terebratula rubra, Pallas, I was

struck with the marked differences and peculiarities they presented, and in vol. ix. 2nd

ser. of the 'Annals and Magazine of Natural History' I proposed a genus Kraussia,

subsequently (1861) altered to Kramsina, for the reception of T. rubra and four recent

species. The shells are subcircular, with a nearly straight hinge-liue ; beak truncated ;

foramen large and round ; deltidial plates small, not united ; beak-ridges well defined,

leaving a flattened space or false area between them and the hinge-line. In the interior

of the dorsal valve there are two wide, eye-shaped muscular impressions close to the hinge-

line, with a small cardinal process between them. A mesial septum of small elevation

extends to half the length of the valve, from the anterior extremity of which rise t\^"o

oblique or deviating lamellse, laterally expanded ; no other apophysary system for the

support of the labial appendages is present. The ciliated arms are unusually small, their

fringes not extending to more than halfway towards the border of the shell ; in the first

part of their course, from the mouth forwards, the cirri are few or wanting, the whole

brachial apparatus being supported by the small forked process above described, no other

part of the apophysary system being calcified. This genus has been generally adopted.

I have included in it Kruussma rubra, Pallas, K. cognata, Sowerby, K. Deshayesi,

Davidson, K. pismn, Lamarck, K. Lamarckiana ^ Davidson, K. JDavklsoni, Velain, and K.

Atkinsoiri, Tenison-Woods.

In 1884 Prof. E. Deslongchamps (Etudes critiques sur des Brachiopodes nouveaux

ou peu connus, pp. 120-124) proposed to remove the last two species from Kraussina

proper, and to jolace them in a small subgenus Megerliua, on accoimt of two additional

short, projecting, curved, rudimentary lamellte attached to each side of the septum, under

the central deviating forked lamella3 characteristic of Kmusslim. Full details having

been given in the description of the species, it will not be necessary to repeat them here.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 119

A glance at the figiu-cs will likewise assist in understanding the characters often hetter

than verbal description.

69. Kratjssina etjbra, Pallas, sp. (Plate XX. figs. 19-23.)

Anomia Rubicunda, Solander, MS. (accordiug to Donovan, Naturahst's Repository, ii. pi. Ivi., not of

Sowerby) .

Anomia rubra, Pallas, IMisc. Zool. p. 183, pi. xiv. figs. 2-11, 1766.

Anomia striata promontorii bona: spei, Chemnitz, Ncucs systematisehes Conchylien-Cabinet, vol. viii.

p. 94, tab. Ixx^-ii. fig. 103 b, c, 178.5.

Anomia capensis, Gmclin, ed. Linne's Syst. Nat. vol. i. p. .3347, 1788.

Terebratula capensis, Bruguiere, Encycl. Meth. pi. 243. figs. 4-9, 1789; Dillwyn, A Dcser. Cat. of

Recent Shells, p. 292, 1817.

Terebratula ruhicunda, Donovan (not of Sowerby), The Naturalist's Repository, vol. ii. pi. Ivi. figs. 2,

3,4,1824.

Terebratula rubra, Blainville, Diet. Sci. Nat. vol. liii. p. 138, 1828.

Terebratula capensis, Kiister, Martini & Chemnitz, Coneh.-Cab. p. 32, pi. 3. figs. 15-17, 1813; Krauss,

Siidafr. Moll. p. 32, pi. ii. fig. 10, 1848 (not T. capensis, Adams & Reeve, Voy. H.IM.S. ' Samarang,'

p. 71, pi. xxi. fig. 4, 1850).

Kraiissia rubra, Davidson, Sketch of a Classification of the Recent Brachiopoda, Ann. & Mag. Nat.

Hist. 2nd ser. vol. ix. p. 370, 1852 ; Woodward & Gray, Cat. of the Brachiopoda iu the Brit. Mus.

p. 109, 1853; Davidson, Brit. Foss. Brach. vol. i. Introduction, p. 09, pi. vi. fig. 28, 1853; Woodward,

A Manual of Mollusca, p. 219, 1856.

Kraussina rubra, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch.

Wien, Bd. xxvii. p. 210, 1859 ; Davidson, Ann. & Mag. Nat. Hist. 3rd ser. vol. viii. p. 39, 1861.

Terebratula {Kraussia) rubra. Reeve, Conch. Icon., Monogr. Tereb. pi. ix. fig. 37, 1861, and Ann. &

Mag. Nat. Hist. 3rd ser. vol. vii. p. 181, 1861.

Kraussia rubra, Chem. Man. de Conchyl. vol. ii. p. 2056, 1862.

Kraussina rubra, Dall, Amer. Journ. of Conch, vol. vi. p. 138, 1870 ; Proc. Acad. Nat. Sci. Phila-

delphia, p. 190, 1873; Zittel, Handbuch der Palaontologie, p. 708, 1880; E. E. Deslongchamps,

fitudes critiques sur des Brachiopodes nouveaux ou peu connus, pp. 121, 259, pi. xix. fig. 7, 1884.

Shell subch-cular, either as broad as long or a little broader than long ; hinge-line

nearly straight, rather shorter than the breadth of the shell, with rounded corners.

Dorsal valve semicii'cnlar, uniformly convex, with or without an extremely slight

depression near the front. Ventral valve deeper and more convex than the dorsal

one; beak slightly incurved, and truncated by a very large, incomplete foramen,

margined anteriorly by the umbo of the opposite valve, and by two very small deltidial

plates ; beak-ridges sharply defined, leaving between them and the hinge-line a flattened

false area. External surface of valves marked with numerous radiating ribs, increasing

in number by bifurcation and by the interpolation of shorter ones. Surface of valves

crossed by concentric lines of growth. Shell-structui'e punctate. Colour yellowish red,

more intense coral- red mainly on the radiating riljs and at the concentric lines of

growth. Length 1 inch, breadth 1 inch 1 line, depth 7 lines.

In the interior of the dorsal valve the hinge-plate is widely divided, and between the

lateral portions are two large eye-shaped depressions due to the peduncle-muscles ; between

these last a slightly raised mesial septum begins, and extends to about half the length of

120 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

the valve. Prom its anterior extremity arise two short, deviating, flattened and forked

lamellae, expanded at their extremities. The cirrated labial appendages are unusually

small, the spiral lobe diminutive ; these fringes do not extend to more than halfway

towards the border of the shell. In the first part of thek com-se, from the mouth forward,

the cirri are few or wanting, the whole brachial apparatus being supported by the small

forked process above described, no other part of the apophysary system being calcified.

Cardinal process very small. Margin internally, sometimes sharply, spinously toothed.

Mah. Port Elizabeth, near the Cape of Good Hope, South Africa. Some small speci-

mens were erroneously described by Dr. J. E. Gray, in the ' Annals and Magazine of

Natural History ' for 1872, under the mistaken name of T. tnmcata. They were found

attached to Ascidia, and to the stems of large Alga?, off^ the coast of Natal.

Obs. Donovan states, in his ' Naturalist's depository ' for 182i, that Solander had

given the MS. name of T. rubicunda to examples of the shell under description in the

Portland Museum ; but as manuscript names cannot claim priority over published ones,

that of rubra, Pallas, must be adopted. It is also somewhat singular, as observed

by Lovell Reeve, that the shell was not known to Valenciennes when preparing his

monograph of the Terebratulidse for Lamarck's ' Animaux sans Vertebres,' or to

G. B. Sowerby when publishing his ' Thesaurus Conchyliorum ;' for therein he figures a

specimen of T. cruenta with the mistaken name of T. rubra, Pallas. Reeve states

likewise that Sowerby's Terebratula algoensis is a blackened fragmentary valve of

Kraussina rubra. Krauss, on the contrary, says, in ' Die siidafrikanischen MoUusken,'

p. 32, that he looks upon T. algoensis as a synonym of his Terebratula natalensis —

the Kraussina pisum of Lamarck ; and this view may perhaps be the more correct one.

The specimen, which consists of a single ventral valve, is in the Zoological Department

of the British Museum.

In his ' Rechcrchcs sur I'Organisation du Manteau chez les Brachiopodes Articules,'

Caen, 1864, M. E. Deslongchamps' observations (p. 25) are to the effect that the vascular

sinuses are composed of two large trunks, which commence close to the hinge-plate, and

extend by a large curve parallel to the edges of the valves, and end anteriorly close to the

median line, each of these branches, on the sides facing the lateral edges of the valves,

giving forth six or seven branches, which bifurcate as they reach the edges of the shell.

The spicula are very numerous in Kraussina rubra, but they are so small and disunited

that they cannot be seen, except under an enlargement of about 40 or 60 diameters.

At p. 121 of his 'Etudes critiques sur des Brachiopodes nouveaux,' 1884, the same

authority states that he has been able to convince himself that in this species (K. rubra)

the mantle was furnished with spicula of a very special shape, and much smaller than in

the other Brachiopoda provided with these calcareous elements ; that, thanks to the tenuity

of these spicules and to their elongate shape, he has been able, from investigating them

in the genus Kruussina, to recognize their function, which is that of protecting the organs

of circulation. One system of spicula was destined to protect the venous sinuses of

the mantle, a second that of the arterial organs.

M. Deslongchamps further states that he has only been able to examine adult

DR. T. DAVIDSON OX RECENT BRACHIOPODA. 121

examples of Kyaussina rubra, and consequently can say nothing with respect to the

modifications through which the young shell passes previous to attaining its fullest

development, but that the disposition of this appendage in young K. Davidsoni establishes

points of transition so complete between the genera 3Iefferlia and K^^missina tliat there

is not the slightest doubt in his mind as to the position of these genera in the zoological

series, and that they certainly belong to one group. The analogy becomes apparent

when the details of the adult Kranss'ma Lamarckiana and the transitory state of Megerlla

trimcata are considered.

I have never seen any very young examples of K. rubra ; the smallest I have examined

measured 4 lines in length, the largest 12, and no material difference could be perceived

in tbe forked deviating lamellae. I do not see that 3Icgerlia trnncata and Kraussina

rubra are more nearly related than are Terebratella, Laquens, and several others.

We must value the characters of the genus or subgenus and species from the adult and

full-grown condition, and not from that of the early stages of growth ; for many

specimens prior to attaining their adult condition and characters pass through several

metamorphoses or modifications in shape, as has been so admirably demonstrated by

Herman Eriele, E. Deslongchamps, and others. There are also notable differences

between Megerlia and Kraussina in the shape of the hinge-plate, muscular scars, and

labial appendages, which must be taken into consideration.

70. Kraussina cognata, Sowerby*, sp. (Plate XX. figs. 24-26, var. ? 27-30.)

Terebratula cognata, Sowerby (not of Chemnitz) , Thes. Conch, i. p. 346, pi. 68. figs. 12-1 1, 1846.

Kraussia cognata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. i.x. p. 370, 1852.

Terebratula {Kraussia) cognata, L. Reeve, Conch. Icon. pi. is. fig. 38, o, 6, 1861.

Kraussina cognata, Dall, Amer. Joum. of Conch, vi. p. 140, 1870.

Shell somewhat sulitrapezoidal or elongated, semicircular ; hinge-line nearly straight,

almost as long as the width of the shell, with slightly rounded or angular extremities.

Dorsal valve semicircular, rounded in front, with or without a slight longitudinal median

depression along the anterior half of the valve. Ventral valve deep, and much more

convex than the dorsal one. Beak short, very little incurved, foramen large and incom-

plete, margined anteriorly by the umbo of the dorsal valve, and by two small lateral

deltidial plates ; beak-ridges sharply defined, leaving between them and the hinge-line

a triangular area. Surface of the valves radially marked by fine radiating ribs, increasing

in number at various distances from the beak and umbo by the interpolation of shorter

riblets, which are more sharply defined in some specimens than in others. Colour

* [No one can tell from Chemnitz's description and figures what reaUy constitutes his Cocjnata Anomue craniohris

basi perforata (Neues syst. Conchylien-Cabinet, vol. viii. p. 78, tab. 76. fig. 088 a, b, 1785). That author's unsatis-

factory description and illustrations in no way resemble those of the specimen described and figured by G. B. Sowerby

in his 'Thesaurus Conchyhorum ' (vol. i. p. 346, pi. 68. figs. 12-14, 1846). The Anomia cognata of Sowerby (not

of Chemnitz) is now in the British Museum. Chemnitz's figure represents a smooth shell, ovate in form, and with a

rounded hinge-lino. Sowerby 's T. lorjnata is squarely suborbicular, with a long, nearly straight, hinge-line, the

external surface being covered with numerous small radiating ribs. Chemnitz's species is unidentifiable and should

therefore be expunged, and the TerehraUda mrjnata, Sowerby, retained as the type of the species. — T. D.]

122 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

pale yellow. Two specimens measured — length 11 lines, breadth 8 lines ; length

9 lines, breadth 8 lines, depth 4 lines.

In the interior of the dorsal valve the hinge-plate is widely divided, and between the

lateral portions are two large eye-shaped depressions left by the peduncle-muscles,

between which a slightly raised mesial septum begins and extends to about half the

length of the valve. From its anterior extremity arise low, short, deviating, flattened,

and forked lamellae expanded at then* extremities.

Hab. South Africa, near the Cape of Good Hope.

Ohs. This species is distinguished from Krcmssina rubra by its general shape, the

flatness of its dorsal valve, and its colour. In some specimens, such as in Sowerby's type,

the ribs are very little marked and obliterated near the margin, but in others they are

sharply defined ; the mesial depression is, at times, also scarcely perceptible. Both

K. cognata and K. rubra are, however, much more nearly related to each other than to

other species of the genus. Mr. Lovell Reeve alludes to the spine-like projections

round the inner margin of Kraussina cognata, a character common to several, if not

all, the species of the genus. I have noticed them in Kraussina rubra as well as in

K. Lamarckiana. At one time I was under the impression that the Terebratula cognata

of Sowerby might be an unusually large specimen of Kraussina pisum, but I am now

very doubtful whether such is the case.

71. Kraussina Deshayesi, Davidson. (Plate XX. figs. 31-31 b.)

Terebratula capensis, Adams & Reeve (uot of Gmelin), Voyage of H.M.S. ' Samarang,' p. 71, pi. xxi.

fig. 4, 1850.

Kraussia Desliayesii, Davidson, Proc. Zool. See. p. 6, pi. xiv. figs. 20, 21, 1852 ; and Ann. & Mag. Nat.

Hist. vol. ix. p. 270, 1852; Woodward & Gray, Cat. of the Brachiopoda in the Brit. Mus. p. Ill, 1853;

E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch. Wien, Bd. xxxvii.

p. 211, 1859.

Terebratula {Kraussia) Desliayesii, L. Reeve, Conch. Icon. Monogr. of Tereb. pi. ix. fig. 35, 18G1.

Kraussina capensis, Adams & Reeve (not of Gmelin), Dall, Amer. Journ. of Couch, vol. vi. p. 140, 1870.

Shell orbicular, subovate, about as long as wide, valves nearly equally deep or convex.

In the dorsal valve a deep longitudinal depression or sinus extends from the umbo to the

front, with a corresponding elevation or fold in the ventral one ; beak short, incurved,

and truncated by an incomplete foramen, margined anteriorly by the umbo of the dorsal

valve and by two small lateral deltidial plates; beak-ridges sharply marked, leaving

between them and the hinge-line a flattened space. Surface of valves marked with

numerous fine radiating riblets, increasing in number by the interpolation of shorter ones,

the whole surface of the valves being crossed by concentric lines of growth. Shell-structure

largely punctate. In the interior of the dorsal valve two deviating central lamella? rise

from the anterior extremity of the very slightly raised mesial septum. Colour light

yellow, marked with crimson rays. Length 5J lines, breadth 5 lines, depth 2 lines.

Bah. Dredged by Sir Edward Belcher ofi" the Cape of Good Hope, in a depth of

120 fathoms.

DR. T. DAVIDSON ON EECEXT BRACHIOPODA. 123

Obs. This pretty little species is nearly related to KraiisHina pimm, but is distinguish-

able from it by its more orbicular shape and crimson rays. The Kraussina capensis

(Gmelin) being a synonym of K. rubra, Pallas, I proposed in 1852 to alter its name

to K. Deshayesi. I regret not being able to agree with Mr. Ball's suggestion that the

name capensis can be retained for this form, as it is a synonym of another species

of the same genus. It is. moreover, well distinguished from Kraussina rubra.

73. Kraussina pistjm, Valenciennes, apud Lamarck, sp. (Plate XXI. figs. 1-4..)

Terebratula pisum, Valenciennes, apud Lam. Animaux sans Vert. vol. vi. p. 330, 1819.

Ter ebr atula Natalensis, Kuster, Martini & Chemnitz, Conch. -Cab. vol. vii. p. 3G, pi. 2h. fio-s. 4-7

1843.

Terebratula Alt/oensis, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 95 ; and Thes. Conch, p. 302,

pi. Ixxi. figs. 91, 92, 184G.

Terebratula Nataleiisis, Krauss, Sudafrikanischen Mollusken, p. 33, pl. ii. fig. 11, 1848.

Terebratula piston, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 370, 1852.

Kraussia pisum, H. & A. Adams, The Genera of Recent Mollusca, vol. ii. p. 579, pl. cxxxi. figs. 4«, A, 1858.

Kraussina pisum, E. Suess, Ueber die Wohusitze der Brachiopoden, Sitzuugsb. k. Akad. der Wisseiisch.

Wien, Bd. xxxvii. p. 211, 1859.

Terebratula [Kraussia) pisum, Lovell Reeve, Conch. Icon., Monogr. Tereb. pl. is. fig. 36, a, b, 1861.

Kraussina pisum, Uall, Amer. Jom-n. of Couch, vol. vi. p. 140, 1870; Davidson, Report on the

Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 54, pl. iv. figs. 7, 8, 1880.

Shell suborbicular or oval, often rather wider than long, light yellowish white. Dorsal

valve very slightly convex, with a groove-like central longitudinal depression extending

from the umbo to the front. Hinge-line nearly straight, and rather more than half as

long as the breadth of the shell. Ventral valve deeper than the dorsal one, longitudinally

keeled, beak slightly incurved, with a rather large incomplete foramen, and two small

lateral deltidial plates ; beak-ridges sharply defined, leaving a flattened area between

them and the hinge-line. Surface of valves covered with numerous small radiating ribs,

which increase in number at variable distances from the beak and umbo, owing to the

bifurcation of many of the ribs and the interpolation of shorter ones. Valves crossed

at variable intervals by fine concentric lines of growth. In the interior of the dorsal

valve the hinge-plate is narrowed, a very slightly raised mesial septum extending from

the middle of the hinge-plate to about half the length of the valve. From the anterior

extremity arise two short, deviating, flattened, and forked lamellge, expanded at their

extremities ; two eye-shaped depressions due to peduncular muscles He on each side of

the posterior extremity of the hinge-plate. The brachial a])pendages are small, and do

not occupy a space larger than about half the length of the valve ; central spiral lobe

very small. Length 8 lines, breadth 8 lines, depth 3 lines.

Hab. This species was dredged by the ' Challenger ' Expedition off" the Cape of Good

Hope, at a depth of 150 fathoms. It has also been obtained near Natal, and by Sir E.

Belcher in the same localities.

Obs. This species is well distinguished from Kraussina Lamarchiana by its numerous

delicate raised strife, but it is scarcely distinguishable from Kraussina Deshayesi, except

second series. — ZOOLOGY, VOL. IV. 17

124 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

by its colour, the last-named species beinsj rather more triangular in form and marked

with deep crimson rays. Krcmssina Lamarckiana is also a much smaller species than

Kraussina pisum. At p. 33 of his ' Siidafrikanischen Mollusken,' Dr. F. Krauss expresses

the opinion that the Terehratula Algoensis of Sowerby is a synonym of the species under

description : this is very probably the case, and not of K. rubra as was supposed by Lovell

B-eeve.

73. Keaussina (Megeklina) Lamakckiana, Davidson. (Plate XXI. figs. 7-11.)

•

Kraussia Lamarckiana, Davidson, Proc. Zool. Soc. 1852, p. 80, pi. xiv. figs. 23, 23; Ann. & Mag.

Nat. Hist. 2nd ser. vol. ix. p. 370, 1852; lutr. to vol. i. of Brit. Foss. Brach. p. 69, 1853; Woodward

& Gray, Cat. of Brachiopoda in the British Museum, p. Ill, 1853; H. & A. Adams, The Genera of

Recent Mollusca, vol. ii. p. 579, 1858; S. P. Woodward, A Manual of Mollusca, p. 218, fig. 120, 1858.

Kraussina Lamarckiana, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungb. k. Akad. der

Wissensch. Wien, Bd. xxxvii. p. 21], 1859.

Terehratula {Kraussia) Lamarckiana, Lovell Reeve, Conch. Icon., Monogr. Ter. pi. ix. fig. 34', 1861 ;

Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 182, 1861.

Kraussina Lamarckiana, Chemnitz, Man. de Conch, vol. ii. p. 206, fig. 1057, 1862; Dall, Amer.

Journ. of Conch, vol. vi. p. 139, 1870; Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 190; Hutton, Cat.

of the Marine Mollusca of New Zealand ; Tenison Woods, Census of the Marine Shells of Tasmania, Proc.

Roy. Soc. of Tasmania, p. 34, 1877; Davidson, Report on the Brachiopoda, Voyage of H.M.S. 'Chal-

lenger,' Zool. vol. i. p. 53, pi. iv. fig. 9, 1880.

Megerlina Lamarckiana, E. Deslongchamps, Etudes critiques sur des Brachiopodes nouveaux ou peu

connus, p. 159, pi. xix. fig. 11, 1884.

Shell small, somewhat subquadri lateral, about as wide as long, flexuous, fulvous

white or light brown. Dorsal valve slightly convex, with a rather deep longi-

tudinal mesial depression. Hinge-line straight, and rounded at its angles. Ventral

valve deeper and more convex than the dorsal one, longitudinally keeled along the

middle. Beak slightly incurved, and truncated by a large incomplete foramen, laterally

margined by two rudimentary deltidial plates ; beak-ridges sharply defined, leaving a

false areal space l)etween them and the hinge-line. Surface of both valves ornamented

by a number of small radiating costse, increasing in number by the interpolation of

shorter ribs. Length 4 lines, breadth 4i lines, depth 2 lines.

In the interior of the dorsal valve the hinge-plate is wide and concave, with two eye-

shaped rudimentary scars between its outer margins. Under the middle of this plate a

slightly raised mesial septum, thickened, and most elevated near its anterior extremity,

extends to less than half the length of the shell ; close to its anterior extremity arise two

deviating, ^ -shaped, broad lamellae, slightly expanded and curved at their extremities ;

under these, on each side of the septum, are attached two slightly projecting, wide,

curved rudimentary lamellae, which simulate the part of the principal lamella? attached,

in other genera, to the sides of the septum. The bottom of the valve is costated and

faintly tuberculated ; a row of short, erect spine-like asperities rising perpendicularly

close to and all round the inner margin. Brachial appendages small, the central lobe

being the least. Shell perforated by small canals.

Sab. Dredged in great abundance by Mr. Brazier in Double Bay, Port Jackson, New

DE. T. DAVIDSON OX RECENT BEACHIOPODA. 125

South Wales ; and l)y the ' Challenger ' Expedition near Sydney, attached to specimens of

JT'aldheimia Jlavescens, fonnd close to the shore. The Rev. Teuison Woods states

that the shell occurs in ahundance under stones at low water at Tamai Heads, also

oflP the south-east coast of Australia and New Zealand, and occasionally at Long Bay.

I have never seen any New-Zealand examples.

Obs. — This small species is distinguishahle from Kraussina 2>isum by its much

smaller dimensions and comparatively stronger ril)s, as well as by some interior details.

It has been fortunate in retaining its specific name unchanged since first described. I

have through the liberality of Mr. Brazier been able to examine an extensive series of

specimens from half a line up to four lines in length. When very young the shell is

quite circular, with very few ribs, and these commence only at al)out half its length,

and extend to the lateral and frontal margins. On account of the shortness of its

peduncles the beak and umbo are often eroded and worn. In very young specimens

the septum and deviating lamellae are rudimentary and undeveloped. We are indcl)ted to

M. E. Deslougchamps for the discovery of the short accessory rudimentary lamellae that are

attached to the anterior lateral sides of the septum under the Y-shaped deviating lamellae.

M. E. Deslongcliamps describes the interior characters of this and its allied forms

with considerable care and minuteness at p. 122 of his 'Etudes critiques.' He remarks,

that having been able to observe the calcareous appendages in adult examples only of

lLraussi)/a rubra, he can affirm nothing positive as to the manner in which they have

been produced, but that the disposition of these appendages — first in Kraussina

Davidsoni, and, secondly, in K. Lamarchiana — establishes points of transition so complete

between the genera Megerlta and Kraussina that he feels no uncertainty respecting

the position of these two genera in the zoological series, and that they certainly belong to a

single group. He states that the differences between the adult conditions of Kraussina

rubra and 3IegerUa truncata, although seeming at first sight very striking, disappear

or become much less conspicuous Avhen an adult Kraussina Lamarckiana is compared

\^'ith the transition-stages of Megerlia truncata, traces being found in K. Lamarckiana

of all the parts that constitute the calcareous processes in Megerlia [truncata).

M. Deslongchamps would therefore propose a subgenus Megerlina for the reception of

K Lamarckiana and K. Davidsoni, which, according to his views, constitute the passage-

forms between Kraussina rubra and Megerlia truncata.

In his figure of K. Lamarckiana, M. Deslongchamps draws the hinge-plate simple

and concave ; but in my specimens it is quite similar to that of Kraussina rubra, with the

two eye-shaped scars due to the peduncular muscles ; and the only essential difference

that I can see is the presence of the short, broad, curved lamellaj that are attached to

the mesial septum under the upper forked deviating appendages.

The diflerences and resemblances between the diff'ereut forms here alluded to will be

better understood by a glance at the figures in Pis. XX. and XXI. The brachial

aj^pendages in very young specimens of K. Lamarckiana are extremely small, as well as

the calcareous appendages for their support.

M. Deslongchamps informs us, moreover [loc. cit.), that in Kraussina the spicula are

17*

126 DE. T. DAVIDSON ON EECEXT BRACHIOPODA,

very thiu, detached, and elongated, but in Megerlina they are more or less thick, and

approach more to those of Megerlla.

So far back as 1852 (Proc. Zool. Soc.) I stated in my paper, " Descriptions of a few

New Species of Recent Brachiopoda," that K. Lamarckiana "is distinct from K. pisum

and K. Deshayesii by its somewhat tetragonal shape, stronger and fewer costae, as well

as by the details of its loop, relating it more than any of the other species of Kraussia to

the section Megerlia," and 1 am glad to find that in 1884 M. Deslongchamps has con-

firmed the opinion I expressed in 1852.

74. Kraussina (Megerlina) Davidsoni, Velain. (Plate XXI. figs. 12-14.)

Kraussina Davidsoni, Velain, Archiv de Zoologie Experiraentale, 1877, p. 139, pi. v. figs. 23, 24 ; and

Malacologie de I'lle de St. Pavil ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challenger,'

Zool. vol. i. p. 21, 1880.

Megerlina Davidsoni, E. Deslongchamps, Etudes critiques sur des Brachiopodes nouveaux ou peu

connus, p. 159, pi. xix. figs. 9, 10, 1884.

Shell small, rather thick, globose, variable in form, pouch-shaped, longer than wide,

or slightly transverse and suborbicular. Dorsal valve convex, with a mesial depression

or groove of greater or lesser depth. Ventral valve rather deeper than the dorsal one,

longitudinally keeled ; beak short, slightly incurved, and truncated by a large incomplete

foramen, margined anteriorly by the umbo of the dorsal valve, and laterally by two

small deltidial plates. Surface either partially smooth or radiately ribbed, ribs increasing

in number by the interpolation of shorter riblets. Surface crossed by strongly marked con-

centric lines of growth. Colour darkish brown, verging on black. Length 4 lines, breadth

3 or 3| lines. In the intei'ior of the dorsal valve the hinge-plate is comparatively large and

concave, with two eye-shaped peduncular scars between its lateral portions. Septum of

very small elevation, extending from the middle of the base of the hinge-plate to about

half the length of the valve ; from its anterior extremity arise two deviating Y-shaped

lamellee, slightly curved at their extremities ; under these and also attached to the

septum are two small rudimentary plates. The bottom of the valves is covered with large

projecting tubercles, which are most prominent close to the margin of the shell.

Mab. This species was collected by M. C. Velain in large numbers at the Island of St.

Paul, in 1874, during the Prench expedition to observe the transit of Venus. M. Velain

states that these Brachiopoda live in abundance in the interior crater of the island, on its

littoral side open to the sea ; that during the ordinary low tides they are scarcely covered

by water, and are alternately covered and left bare by the ebb and flow of the tide. They

occur in an area of a few yards width, and, consequently, at shallow depths, doubtless

because they find those conditions to which they are accustomed in other localities. M.

Velain informs me that during his lengthened stay at the Island of St. Paul no other

species of Brachiopod was found ; that the shell referred to by Mr. Dall as Kraussina

picta, Val., Verb, zool.-bot. Ges. Wien, p. 894, 1865, as from the Island of St. Paul, has

been nowhere described, and that the name must be attributed to an incorrect citation.

This has subsequently been admitted by Mr. Dall.

DE. T. DAVIDSON ON KECENT BRACHIOPODA. 127

Obs. This small species is nearly related to Krcntssina Lamarckiana, but it is more pouch-

shaped, and differs from it in several exterior and interior details. From the shortness

of its peduncle, the beak and umbo are generally much worn from friction. Some

specimens are ribbed only on the posterior half of the valves, while on others the surface

is regularly ribbed throughout. The interior details have been described under Kraussina

{MegerUna) Lamarckiana, and need not therefore be repeated.

75. Kraussina Atkinsoni, Tenison Woods, sp. (Plate XXI. figs. 5, G.)

Kraussia Atkinsoni, Tenison Woods, Census, with brief deseriptions, of tlie Marine Shells of Tasmania,

Proc. Koy. Soc. Tasmania, 1878, p. 57.

Shell small, somewhat subpeutagonal, widest about the middle, indented iu front.

Marginal line Hexuous. Dorsal valve gently convex, divided longitudinally into two

lobes by a deep, wide, angular sinus ; lateral sides of the umbo auriculate. Ventral

valve deeper than the dorsal one, with a longitudinal mesial elevation or fold ; beak very

slightly incurved, pointed, with a rather large incomplete foramen, margined anteriorly

by a portion of the umbo of the opposite A^alve and by narrow elongated lateral deltidial

plates ; margin-line in front angular. Surface of valves smooth, marked by tine concen-

tric lines of growth. Colour light greyish yellow. Length 3 lines by 2^ in breadth and

Ij in depth. In the interior of the dorsal valve the hinge-plate is excavated along tlie

middle ; septum very slightly elevated, extending from the middle of the base of the hinge-

plate to about half the length of the valve. From the anterior extremity of the septara

rise two deviating folded lamellse.

Hub. Dredged at Long Bay, South Tasmania, by the Eev. IL. D. Atkinson, iu 10

fathoms water.

Obs. I am indebted to the Eev. Tenison Woods for my knowledge of tliis well-marked

small species. It can hardly be said to have been described, for all that Woods says is

that " This is a shell about the size of the last {K. Lamarckiana), but more depressed, with

a smooth valve." Kraussijui Atkinsoni is at once distinguished from its congeners by

being the only smooth species of the genus with which we are acquainted, and also by

the shape of its shell.

Subfamily ARGioPiNiE.

In this subfamily we would include the genus Argiope, Deslongchamps, lSi2

(=Megathi/ris, d'Orbigny, 1847), and the subgenus Cistella, (iray, 1853, both being

closely related to the Terebratulidse, of whicli they form a part, and distinct from the

Thecidiidae, which the larger number of zoologists and palaeontologists would form

into a separate family.

W^e are well aware that the name Argiope was j^roposed in 1827 by Savigny and

Audouin (Descr. de I'Egypte, ed. 2, xxii. p. 334, pi. ii. fig. 6) for a genus of Egyptian

Spiders ; but as tlie name Argiope has been very generally adopted for a genus of Bra-

chiopods, I am disposed to retain it for that purpose.

In Argiope proper there are three or five prominent submarginal septa, the lamella

128

DE. T. DAVIDSON ON EEUENT BRACHIOPODA.

forming the loop being four-lobed, adhering to the septa, and more or less confluent with

the valve.

In CisteUa there is but one prominent submarginal septum, the loop, or semicircular

lamella, being two-lobed. In the first the labial appendages are folded into four lobes,

in the second into two.

The animal and its embryology have been carefully studied, described, and illustrated

by such excellent observers as W. Dall, Kowalevsky, A. E. Shipley, M. A. Schulgin, and

S. P. Woodward, as well as by myself and others, and these investigations will be fully

alluded to in the description of the species.

We know with certainty of but one species of At^giope in the recent condition, the

Argiope decollata of Chemnitz. To this section Schulgin would add the A. Barroisi

Shnd A. globuliformis; hut as I have never seen those two species or their interiors, I

cannot feel certain whether they should be classed with Argiope or with Clstella.

We are acquainted with the following eight or nine recent species of the genus CisteUa,

viz. : —

1. CisteUa neapolitana, Scacchi, 1833.

2. ■ Koivalevskii, Schulgin, 1884.

3. cisteliula, S. Wood, 1840.

4. IVoodwardiana, Davidson, 1866.

5. cuneata, Risso, 1826.

6. CisteUa Barrettiana, Davidson, 1866.

7. Schrammi, Crosse, 1866.

8.

9.

liitea, Dall, 1870.

lunifera, Philippi, 1836.

76. Argiope decollata, Chemnitz, sp. (Plate XXI. figs. 30-35.)

Anomia decollata, Chemnitz, Conch.-Cab. vol. viii. p. 96, pi. Ixxviii. fig. 70.5, 1785.

Anomia detruncata, Gmelin, Syst. Nat. p. 3347, 1788.

Terebratula ungula, Retzius, Nov. Gen. Test. 1788.

Terebratula detruncata, Bruguiere, Encycl. Meth. tab. 243, fig. 10, 1789.

Anomia detruncata, Dillwyu, A Descrip. Cat. of Shells, p. 292, 1817.

Terebratula detruncata, Blainville, Diet. Sc. Nat. vol. liii. p. 141, 1828.

Terebratula aperta, Blainville, Diet. Sc. Nat. vol. liii. p. 144, 1828.

Terebratula decollata, Deshayes, Encycl. tab. ccxliii. fig. 10, 1830; Cantraine, Bull. Acad. R. des

Sciences de Bruxelles, 1835.

Terebratula dimidiata, Scacchi, Osserv. Zool. p. 17, 1833, and Cat. Conch. Regni Neapolitani, p. 8, 1836.

Terebratula detruncata, Scacchi, Cat. Conch. Regni Neapolitani, p. 8, 1836.

Terebratula urna antiqua and T. cardita, Risso, Fauna Europ. Mer. vol. iv. pp. 387, 389, pi. xii.

figs. 177, 180, 1826.

Terebratula decollata, Lamarck, An. sans Vert. ed. 2, vol. vii. p. 350, 1836.

Terebratula detruncata, Philippi, En. Moll. Sicilije, vol. i. p. 96, tab. vi, fig. 14, 1836.

Arr/iope decollata, E. Dcslongchamps, Mem. Soc. Linn, de Normandie, vol. vii. p. 9, 1842.

Orthis detruncata, Philippi, En. Moll. Siciiise, vol. ii. p. 69, 1844.

Terebratula detruncata, Forbes, Rep. on the Moll, of the ^gean Sea, p. 141, 1844; D. Galvani, 111,

delle Couch, fossili, 1845.

Terebratula decollata, G. B. Sowerby, Thes. Conch, i. p. 355, pi. Ixxi. figs. 68-70, 1846.

Megathyris detruncata, A. d'Orbigny, Comptes Rendus Acad, des Sciences, 1847; Annales des

Sciences Nat. Zool. 3'' ser. vol. viii. p. 341, 1847; Paleontologie Fraufaise, Ter. Cret. vol. iv. p. 146.

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 129

Ortltis detruncaia, G. Michelotti, Descr. des Foss. Jliocenes, p. 78, 181"; A. Aradas, Descr. delle

Conch. Foss. di Gravitelli, p. 14, 18-17.

Terebratula pectiniformis, Costa, Mem. Reale Accad. delle Scienze di Nap. vol. v. p. 39, pi. i. fig. G.

Orthis di'lrancata, Costa, Fauua del Regno di Napoli, pi. ii. figs. 6-7, 18."j1.

Aryiope dccollata, Davidson, Ann. & Mag. Nat. Hist. vol. ix. p. 373, 1852; "Woodward & (Jniy, Cat.

of the Brachiopoda in the Brit. Mus. p. 113, 1853; Davidson, Brit. Foss. Bracli. vol. i. Introduction,

p. 73, figs. 22-23, and pi. vi. figs. 32-33, 1853 ; S. P. Woodward, A Manual of the Mollusca, p. 220, 1856.

Jrt/iojje detrmicata and A. dccollata, Pictet, Traite do Pal. vol. iv. p. 27, 1857.

Aryiope decollala, A. Adams, The Genera of Recent Mollusca, vol. ii. pi. exxxi. fig. 6, 1858; Deslong-

champs. Bull. Soc. Linn, de Normandie, vol. iii. p. 122, 1858.

Orihis decoUata, Requiem, Coq. de la Corse, p. 35.

Artjiope decoUata, Gwyu Jeffreys, Ann. & Mag. Nat. Hist. 3rd ser. vol. ii. p. 124, 1858; E. Suess,

Ueber die Wohnsitzc der Brach. Acad, der Wissenscli. Wien, Bd. xxxvii. p. 213, 1859.

Terebratula {Arglope) decollata, Lovell Reeve, Conch. Icon., Monogr. of Ter. pi. x. fig. 43, 18G1 ; and

Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 185, 1801.

Argiope decollata, Chemnitz, Man. de Conch, ii. p. 209, figs. 1067-1069, 1862; E. Deslongchamps,

Recherchcs sur I'Organisation du Manteau chez les Brachiopodes, p. 291, pi. iii. figs. 8, 9, 1864-

Gwyn Jefi"reys, Brit. Conch, vol. ii. p. 18, 1863, and vol. v. p. 164, pi. xix. fig. 3, 1869; Davidson,

Brachiopoda of the jMaltese Islands, Ann. & Mag. Nat. Hist. 3rd ser. vol. xiv. p. 9, pi. i. figs. 11, 12,

1864; Seguenza, Mem. Soe. Ital. di Scienze Nat. vol. i. p. 69, 1865 ; S. Brusina, Moll. Dalmati, p. 47,

1866 ; C. WeinkaufF, Die Conch, des Mittelmeeres, p. 288, 1867 ; Davidson, Ital. Tert. Brach., Gcol.

Mag. vol. vii. pi. xxi. figs. 5-8, 1870.

Megathyris decollata, Dall, Amer. Journ. of Conch, vol. vi. p. 145, 1870, and Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 193.

xirgiope decollata, P. Fischer, Brachiopodes des Cotes Oceaniques de France, Journ. de Conch, vol. viii.

p. 377, 1870, and Conchyl. dc la Gironde, Soc. Linn, de Bordeaux, p. 172, 1874; Gwyn Jeffreys, Proc.

Zool. Soc. 1878, p. 409; Zittel, Handbueh der Palaontologie, p. 697, 1880; Davidson, Report on

the Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. i. p. 57, pi. iv. figs. 12, 13, 1880.

Megathyrh decollata, J. de IMorgan, Bull. Soc. G(iol. de France, vol. viii. 1883.

Argiope decollata, Schulgin, Zeitschrift fiir wissensch. Zool. Band xli. pi. viii. figs. 1-11, 1884.

Shell small, variable in shape, generally semioval or obscurely subpentagonal, rounded,

laterally and in front, obtusely angular posteriorly. Hinge-line nearly straight, as long

as the greatest breadth of the shell, with generally acute cardinal extremities. Dorsal

valve semicircular, gently convex. Ventral valve rather deeper than the opposite one ;

beak prominent, nearly straight ; foramen large, incomplete, margined anteriorly by a

considerable portion of the umbo, laterally by very small rudimentary deltidial plates ;

beak-ridges sharply defined, leaving between them and the hiuge-line a wide triangular,

flattened area. Surface of valves ornamented with from ten to fourteen rounded cori-e-

sponding ribs, the two central ones generally deviating so as to admit one or two shorter

ribs between them. Surface of both valves crossed by equidistant, slightly projecting

lines. Teeth short, sockets broad and deep. In the interior of the dorsal vahe the

hinge-plate is long, narrow, and concave, without any defined or prominent cardinal

process. Three or five submarginal septa, most elevated anteriorly ; the three central

ones the largest and most prominent. The loop, composed of a ril^and-shaped lamella,

is first attached to the hinge-plate, then cvu'ved to fit into the hollows between the

130 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

septa, which adhere to the sides of the hinge-plate, and are more or less confluent with the

valve. Labial processes folded into four lobes, united by a membrane, forming a

brachial disk with long cirri. Mantle extending to the margin of the valves, and

closely adherent. A tu.berculated flattened margin surrounds the valves. In the

interior of the ventral valve a triangular plate occupies the posterior portion of the inside

of the fissure, and from under the centre of which extends a short mesial septum. Shell-

structure punctate. Colour dull yellow or white. Length 3 lines, width 4 lines, depth

2 lines.

Hab. Mediterranean Sea ; J]]gean Sea, at a depth of from 27 to 100 fathoms (Forbes) ;

Straits of Samos ; Atlantic coast of Spain and of France, off Cape Breton, in upwards

of 45 fathoms, two miles east of Guernsey, 18 fathoms ; off Madeira in 20 fathoms

(M° Andrew) ; Canary Islands ; Rhodes (Fischer) ; Guetaria in 80 fathoms (Hidalgo). Costa

informs us that Argiope decollata occurs plentifully near the islands of Capri, Ischia,

Palmieri, and in the Gulf of Taranto. The 'Challenger' Expedition obtained it in great

abundance at Gomera, off Teneriffe, in 73 or 75 fathoms.

It is a common fossil in the Upjier Tertiaries of Italy, Sicily, Malta, and is found at

Nice and elsewhere ; also in rocks of Miocene age.

Ohs. Dr. S. P. Woodward and myself were able to give the first description and illus-

trations of the manner in which the loop and brachial appendages are arranged in this

important genus and species (Ann. & Mag. Nat. Hist. vol. ix. May 1852). Since then

Dr. Gray proposed to separate from the genus Argiope all those forms with a single

submarginal septum, uniting them into the subgenus Cistella. Up to the present time

we are acquainted with only a single recent species of Argiope, but there are several

fossil species referable to the genus.

In his admirable memoir ' Eecherches sur I'Organisation du Manteau chez les Brachio-

podes articules,' p. 29, 1864, M. E. Deslongchamps asserts that, properly speaking,

no pallial apparatus (of spicula) exists in the genus Argiope. The whole of the mantle,

which is stretched like the skin of a drum between the arched branches of the dorsal

valve, is pervaded merely by an amorj)hous calcareous substance, the presence of which

is indicated by a slight effervescence when the mantle is submitted to the action of dilute

acid. The labial appendages and their cirri are equally devoid of definite calcareous

structures, although their yellowish aspect in dried specimens might lead at first sight

to a contrary supposition. If, however, the raised up j)ortion of tlie mantle in the larger

valve be examined at tlie place wliere it forms the walls of the visceral cavity, a con-

centric line of detached spicula may be seen when sufficiently magnified, elongated

perpendicularly to the direction of the front, and nearly similar in aspect to those of

Kraussina. Some small calcareous particles of an angular and irregular shape may also

be seen. The genus Argiope thus shows a manifest passage from a mantle entirely

destitute of calcareous bodies to one where spicula are more or less numerous, as

in Terebratulina, Terehratula, Kraussina, Megerlia, and Ilorrisia.

In his "Note sur quelques especes nouveUes de Megathi/rides," Bull. Soc. Zool. de France,

vol. viii. 1883, M. J. de Morgan strongly advocates the adoption of A. d'Orbigny's generic

DR. T. DAVIDSON ON EECENT EEACIIIOPODA. 131

name Ilegathyris, 1817, in preference to that of Argiopc, proposed in 1817 by E. Deslong-

champs. He also describes, with considerable detail, the aniiual and its shell. He gives the

follow ing diagnosis of the animal: — ^" Oval, fixed, provided with a mantle disunited at the

edges, thickened and ciliated, cut out into four lobes like clover ; gills formed of a ramified

vascular net-work. Body small, uii[)r()vided with arms ; peduncle short, tendinous, issuing

from a cardinal foramen in tlie upper or ventral valve." The peduncle is, indeed, so

short that the beak is often much yfovw from friction, due to its close contact with

the objects to which the shell is attached.

Tlie species of Cistella are more numerous, both in the recent and fossil conditions,

than are those of Argiope.

In 1790, AVulfen published some good figures of ^. decollata, as well as of T. seminula.

77. Cistella Is"eapolitana, Scacchi, sp. (Plate XXII. figs. 8-21.)

Terebratula neapoUtana, Scacclii, Osserv. Zoologiclic, ii. p. 18^ 1833, aud Cat. Conch. Rcgni Xcap. p. 8,

1836; Kustcr, New ed. Chemnitz, Concli.-Cab. p. 32, 1813.

Orthis necqjoUtana, Philippi, En. IMoll. Sic. ii. p. 69, 1811; Costa, Fauna del Regno di Napoli, p. 37,

pi. iii. figs. 1, 3, 5, 1851.

Argiope neapoUtana, Davidson, Proc. Zool. Soc. 185.2, p. 81, pi. xiv. figs. 21, 25, and Ann. & ilag.

Nat. Hist. 3rd scr. vol. viii. p. 40, 1861.

Argiope Forbesii, Davidson, Ann. & Mag. Nat. Hist. 2nd scr. vol. ix. p. 373, 1852.

Argiope neapoUtana, S. P. Woodward, A ^Manual of the ^MoUusca, p. 220, fig. 125, 1856; E. Sncss,

Uebcr die Wolmsitze der Brachiopodcn, Sitzungsb. k. Alcad. Wissenscli. Wien, p. 213, 1859; Davidson,

Brit. Foss. Brachiopoda, Introduction to vol. i. p. 73, fig. 21, 1853.

Terebratula [Argiope) neapohtana, Lovcll Rccvc, Conch. Icon. Mouogr. Ter. pi. x. fig. 15, 1861, and

Ann. & Mag. Nat. Hist. 3rd scr. vol. vii. p. 180, 1861.

Argiope neapoUtana, Chemnitz, Man. de Conch, ii. p. 209, figs. 107-1, 1075, 1862; H. C. Wcinkauft",

Conch, dcs Mittelmeeres, p. 290, 1867.

Cistella neapoUtana, Dall, Amor. .Journ. of Conch, vol. vi. p. 146, 1870, and Philadelphia Acad. Nat.

Sciences, 1873, p. 194.

Argiope neajiuUtana, Kowalcvsky (in Rnss. INIoscow, 1874), Observations sur le Developpcmcnt dcs Bra-

chiopodes. Analyse par !MM. Oehlert and Dcniker, in Archives de Zool. Experim. 2" scr. tom. 1. pp. 57-76,

1883; Gwyn Jeffreys, Proc. Zool. Soc. 1878, p. 409; S. Brusiua, MoUuschi Dalmati, p. 47, 1866.

Argiope biplicata, Scgueuza, Rendiconto Accad. dclle Scienze Fisiche ct Matcmat. Napoli, xv.

pp. 123, 124, 1876.

Argiope neapoUtana, A. E. Shipley, On the Structure and Devclopmcut of Argiope, Mitthcil. a. d.

Zool. Station zu Ncapcl, Bd. iv. p. 494, 1883.

Shell small, somewhat triangularly orbicular, broadest anteriorly, obtusely angular

posteriorly, plicalely indented at the margin and especially in front. Dorsal valve very

moderately convex and flattened, with a mesial longitudinal depression commencing at a

short distance from the umbo and extending to the front ; hinge-line obtusely angular,

nearly straight, and rather more than half the lengtb of the breadth of the shell ; lateral

sides of the umbo auricular. Ventral valve very moderately or tumidly convex, with a

longitudinal mesial depression (as in the dorsal valve) commencing near the extremity of

the beak and extending to the front. Beak short, slightly incurved and truncated by an

SECOND SERIES. — ZOOLOGY, VOL. IV. 18

132

DR. T. DAVIDSOX OX EECENT BEACHIOPODA.

Fiff. 10.

incomplete foramen, marp^ined anteriorly by the umbo of tlie opposite valve, and laterally

by two small deltidial plates ; beak-ridges sharply defined, leaving between them and

the hinge-line a small triangular flattened space. Surface of valves smooth, or Avitli from

two to six rounded ribs, more or less defined in different specimens. Sliell semitrans-

parent, white or yellowish brown. Shell-structure punctate.

Length 2^ lines, breadth 2 lines, depth 1 line. In the inte-

rior of the dorsal valve the hinge-plate is long and narrow,

without any defined cardinal process. Under its centre a

triangular-shaped j)late or septum gradually rises, and extends

to four fifths of the length of the valve, being most

elevated near to its anterior extremity. Loop two-lobed,

attached to the base of the hinge-plate and again to the

anterior extremity of the submarginal sejjtum, and more or

less confluent with the valve. Labial processes folded into

two lol)es, united by a membrane forming a brachial disk

fringed with long cilia. Mantle extending to the margin,

closely adherent. In the interior of the ventral valve a small

septum extends from under the beak to about half the

length of the shell ; margins of the valves much thickened

within.

Bah. Mediterranean, at depths of from CO to 100 fathoms ;

Bay of Naples, off the islauds of Capri and Ponza ; J^gean

Sea.

Obs. Some malacologists have expressed the opinion that

Terehratula semhiula, Philippi, is a synonym of C. neapoli-

tana ; but the foraminal umbo of the dorsal valve in the

first-named shell would render that view doubtful.

Exteriorly Cistella neapoUtana is a well-marked species,

although it varies a good deal in shape, being also either

quite smooth or obscurely ribbed.

Kowalevsky has described and illustrated in great detail

the development of C. neapoUtana. MM. Oehlert and Deniker

have published an excellent summary of this memoir, most

useful to those who are unable to read the Russian language.

Kowalevsky states that the eggs, after they are detached

from the ovary, fall into the general cavity of the body,

enter the oviducts by the funnel-shaped opening of these

organs, and pass into the incubatory pouches, situated on the

ventral lobe of the female individual, where they are deve-

loped. He is of opinion that fecundation must, without

doubt, be accomplished either during the passage of the egg

along the oviduct or in the general cavity.

Argiope neapoUtana (after

Kowalevsky).

A. Egg after the invagination of

a part of the blastoderm :

d, cavity formed by the in-

vagination ; a, orifice of the

cavity ; o, exterior layer (up-

per) ; V, interior layer.

E. The embryo divided into two

segments.

C. Embryo, in which the folding

of the mantle already covers

a part of the caudal seg-

ment : rt, cephalic segment;

6, thoracic segment ; c, cau-

dal segment ; s, bundles of

bristles.

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

133

First Period. — From the Commencement of the Development of the Egg up to the

moment toheii the Larva fixes itself

In the least advanced state, as observed by Kowalcvsky, the egg presents the aspect

of a vesicle, the sides of which are composed of little cylindrical cells surrounding a

small cavity. Soon after a portion of a blastoderm becomes invaginated (woodcut,

fig. 10, A) the extremities of the gastrula approach each other, and leave between them

only the place of an opening. At tliis moment the embryo presents two layers of small

cells ; one of them is the outer layer of tlie blastodenn, the other the inner layer; and

it is at the expense of this last that tlie middle segment, as well as all subsequent modi-

fications, are formed.

In the next stage the cavity divides itself into three lobes (one median and two lateral),

which communicate at the part nearest to the orifice.

This orifice is conuectcd with the median lobe by

means of a narrow canal, the walls of which present

two small prominences formed of small cells distinctly

differentiated. Soon after the embiyo divides itself

transversely into two segments, the one upper and

large (cephalic segment), the other narrower and more

conical (caudal segment). (Woodcut, fig. 10, B.)

At this period tlie three lobes of tlie internal

cavity become separated from one another, and form

three isolated cavities. The median cavity presents

at its posterior portion so great an approximation to

its walls that these last appear as partitions. At the

lower part the median cavity is surrounded, in addi-

tion to its own walls, wliich are formed of cylindrical

cells like the envelopes of the other cavity, l)y a

second layer of small pale-coloured hexagonal cells,

which for some distance are in direct relation with

the external layei'. (Kowalevsky is unable to explain

either the origin or the signification of this laver.)

Afterwards the median cavity is transformed into

a digestive tulie : perhaps these walls form the intes-

tino-glandular layer. The lateral cavities constitute

the general cavity of the body ; the interior part of

their walls jn-oduces the mesentery and perhaps some

muscular fibres (intestino-muscular layer of the

middle layer) ; the outer part mainly contributes to

the principal muscles.

Kext follows a stage wherein the embryo is divided

into three segments (woodcut, fig. 10, C), the last

Adult larva of Argiope neapolitana

(alter Kowalevsky).

Swimming freely, y, eyes ; r, edge of the

cephalic segment ; », cylindrical part re-

uniting the cephalic segment to the tho-

racic segment ; m, mantle ; i, rudiment

of the iute.-tiue ; e, mesentery (a part of

the mantle covering over the caudal

segment) ; a, muscles going from the

dorsal pait to the ventral part of the

valve ; h, abdominal muscles ; c, muscles

of the cephalic segment ; s, bristles.

18*

134 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

segment to appear being tlie median or tlioracic segment, wliicli lias probably been

formed by a division of the caudal segment.

The thoracic segment carries four bundles of bristles, of which two are median and

two lateral ; each bundle is composed of four or five immovable cylindrical and blunt

bristles (woodcut, fig. 10, C).

At the succeeding stage the mantle commences to appear under the form of two

folds covered with cilia, which rise from the ventral and dorsal sides of the thoracic

segment.

This folding of the skin (future mantle) soon becomes developed and partly covers the

caudal segment. The bristles, which are then situated on this fold, become larger and

pass beyond the caudal segment. At the same time two pigmentary spots appear on the

dorsal side of the cephalic segment.

The author was not able to observe the intermediate j^hases between this stage

and that where the larva issues from the incubatory pouch and swims freely. At that

period of the larval development the mantle covers all the caudal segment, whilst

the cephalic segment, which is covered with vibratile cilia, assumes an umbrella-shape,

at the summit of which may be distinguished a portion more or less separated from the

rest (head), which carries four eyes (woodcut, fig. 11, y) : this head corresponds to that

which M. Lacaze-Duthiers has described in Thecidium.

The digestive tube is almost entirely confined to the thoracic segment ; its anterior

portion, however, pentrates a little into the cephalic segment. This last is connected

slightly with the adjoining segment by means of an organ of cylindrical shape.

Kowalevsky could not detect any traces of the nervous system.

The muscular system of the larva is represented by delicate fibres, which pass from

the posterior portion of the intestine to the lateral walls of the thoracic segment.

The mantle is composed of two layers — one external, formed of pavement-epithelium,

the other internal, and consisting of small cylindrical cells. Between these two layers there

are very delicate muscular fibres. The edges of the mantle always carry, on the ventral

side, four bundles of bristles, which, already existing in the preceding stages, have grown

and increased in length.

At this stage the larva swims freely by the help of its vibratile cilia and by slight

movements of the head. At the approach of danger it vigorously contracts itself, and

erects its bristles in all directions. The larva, after swimming for some time, fixes

itself, and then the second stage of its development commences.

Second Period.

The attachment of the larva is effected by means of a sticky substance exuded

by the caudal segment ; as soon as fixed, the larva begins to turn up its mantle

and to raise it above its head, so that in a little time the mantle envelopes the whole of

the cephalic segment. On account of this foldiug-over of the mantle, the external part

of each lobe becomes internal, and the bristles which were on the exterior surface,

being thus carried inside, become unnecessary, and drop off in a few days' time. It

DR. T. DAVIDSON OX EECEXT BEACHIOPODA.

135

is thus seen that it is not these hristles which produce those that horder the mantle

of the adult animal. Argiope, it is true, is not provided with marginal bristles or

setae, but in species wherein they occur they are the result of a new formation of a

Pis. 1-'.

£z^n.

Argiope {CisicUa) nerqjolitanu (after Kowalevskv).

Immediately after it lias become fixed. (The tlioraeio segment lias four bundles of bristles, of which two are

median, and two lateral.) s, bristles ; ij, ej-es ; m, muscles going to the basis of the bristles ; md, adductor

muscles ; 7np, ventral peduncular muscles.

much later period. The lobes of the mantle gradually become invested with a thick

and ridged cuticle, which permits theni to move only in a vertical direction. At tiie

same time the caudal segment is transformed into a peduncle, and the muscles that

proceeded from this last segment to the thoracic segment become ventral peduncular

muscles, the middle pair of muscles changing into divaricators. The head assumes

a spherical shape, and the eyes remain.

At the next stage the thoracic segment grows smaller in size, the digestive canal

becomes round, and a funnel-shaped pit which descends towards the canal is produced

on the cephalic segment. This depression is, in all likelihood, the oesophagus

(gullet). It should be observed that the characteristic feature of this period consists

in the appearance of the brancliias ; these come into existence in the shape of four

nipples directed inwardly and situated on the thickening, of the dorsal lobe near its

border.

The dorsal thickening soon assumes the form of an almost circular swollen ring, and

136

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Fiff. 13.

tlie number of the brancliise amounts to ton (woodcut, fig. 13, b). In the interior of

the swollen ring there exists a cutaneous layer which seems to support all the hrauchia

apparatus, and is pierced by a hole opposite each

of the branchiiie. The branchiae, which are only

prolongations of the swollen ring, are covered with

Tibratile cilia, are provided with flexiljle muscles,

and become erected through their owu elasticity.

The extremities of the branchiae converge towards

the opening of the mouth.

In the following stage twelve tentacles are present,

and at the same time the shell is formed ; but no

tubular perforations are yet seen. Of the following

stases Kowalevsky has been able to trace but oue,

that of the gradual foruiatiou of the shell.

In 187G Signor Seguenza described a small Cistella

under the name Aryiope bipUcata. Dr. Gwyn Jeffreys

considered it to be an abnormal form of C. cuneata, but

I would be more inclined to refer it to A. ncapoUtana ;

only one example was collected.

In his valuable paper on the structure and de-

velopment of Argiope or Cistella neapolllana and C.

cuneata, Mr. A. E. Shipley* observes that " The body

of Argiope lies almost entirely in the dorsal shell,

whose internal skeleton consists of three triangular

plates : one median, the other two lateral and paired."

I find myself, in the specimens of those species, that there is present in the dorsal

valve one prominent submarginal septum only, the loop being two-lobed, adhering to

the septum, and more or less confluent \\\i\\ the valve. The shell is sometimes, when

fresh, sli"litly subtransparent, showing the outline of the lophophore and the red colour

of the egf^s and larvaj. Mr. Shipley describes with much care and detail the minute

structure of the shell; he says (p. 496 et seq.) that it " consists of a number of very-

fine calcareous spicules supported by an organic network On the outer side of

the shell is a layer, in thickness about one eighth of the whole shell, where the

proportion of calcareous matter to organic is enormously increased. The spicules

are here nearly square, and packed against one another like bricks Outside

this is a third layer or periostracum. This is a thick structureless cuticle ; it completely

covers the whole shell, and in the fresh state adheres very closely to it The shell

is pierced by very numerous canals which run completely through the calcareous part,

but their outer end is covered by the cuticle. They are of uniform diameter in the first

part of their course through the first layer, but when they reach the second layer of King,

thev expand and end in funnel shaped mouths They are, as a rule, single but

in the posterior part of the perforate shell, Avhere it is unusually thick, I have seen

* Mitthcilungeu a. d. Zool. Station zu Neapol, Bd. iv. p. 494. 1SS3.

Larva of Ari/iope nenpolitana (after

Xowalevsky).

Condition previous to the formation of the

shell. 6, branchial' ; /, muscular bundle

of the branchiie of the inner side ; Z, head

of oesophagus ; z, divaricator muscles ; i,

stomach ; in.p^ ventral muscles of the

peduncle ; mi, muscles going from the

ventral valve to the upper part of the

dorsal valve ; el, internal envelope ; p,

peduncle.

DK. T. DAYIDSOX OX EECENT BRACHIOPODA. 137

branched canals The minute structure of the internal skcletou is like that of the

inner layer of the shell, there are no canals present The mantle which lines the

internal surface of each shell is formed hy two evaginations of the body-wall On

the outer surface the mantle is in direct communication with the organic basis of the

shell. No setse occur in the mantle of Argiope. Into each of the canals which pierce

the shell, the mantle sends a diverticulum. This is a hollow tube which fits exactly into

the calcareous canal, but, unlike that, is closed at its outer end." ]\Ir. Shipley then

describes at some length the papilte and their supposed functions; but space will not

aUow us to transcribe his account of them, my object being merely to give a few extracts

from his valual)le paper, which should l)e read in its entirety.

"The lophophore [p. 499] lies entirely in the dorsal shell, it forms a great part of the

body wall of the animal. The shape is an oval, the border running parallel with the margin

of the shell, except at the anterior median portion Mliere there is a narrow deep indentation

dividing the lophophore nearly into two equal halves ; this is caused by the triangular

septum mentioned above. These halves correspoiul with the two arms of other Brachio-

pods. The lophophore [p. 500] is attached anteriorly and anterio-laterally to the mantle

lining the shell, postero-laterally it is attached to the free edge of the triangular plates ; in

the median postcn-ior portion it is continuous with the remaining body wall. In the median

line it is attached on each side to the free edge of the septum. The lophophore carries

round its margin a number of tentacles ; the number increases with the age, but is usually

from 70 to 100. "Within the bases of the tentacles a lip runs entirely round the lopho-

phore, forming a groove ; the mouth lies in the posterior median portion of this groove.

The remainder of the lophophore is composed of a membrane which covers some of the

viscera ; the centre of each half of this membrane is rather thickened and presents in

the fresh state an ill defined whitish patch. The tentacles usually lie ])ointing towards

the centre of each half, but they are often curved and sometimes coiled like a cork-

screw Around the edge of the lophophore, between the base of the tentacles and the

origin of the lip, there runs a canal in the substance of the lophophore . . . Thus the cavity

in the lophophore communicates with part of the body cavity. . . . The protrusion of the

tentacles [p. 501] is probably brought about by forcing in a perivisceral fluid, but their

retraction and coiling movements are probably occasioned by tlie muscular fibres which

lie in their interior.

" The mouth [p. 502] is a transverse slit in the median posterior part of the ciliated

groove ; it leads into a somewhat narrow oesophagus which lies against the posterior

curved border of the triangular septum. At the bottom of this border, the oesophagus

turns towards the posterior end of the animal and immediately enlarges into the stomach.

This is globular in shape and receives upon each side the opening of the liver. The

stomach narrows posteriorly and passes into a conical intestine which bends towards

the ventral shell between the two brood pouches, and ends between the occlusor muscles.

There is no anus.

" The liver [p. 503] consists of two branched glands lying one on each side of the

alimentary canal The blood is contained in a number of vessels which run iri'egu-

larly in the tissues of the body, but which chiefly lie in the mantle and that part of the

body wall lining the shell."

138

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

Diagrammatic view of

the muscles of Argiope

(after A. E. Shipley).

" The muscles [p. 504] of Av^\o\)q {ClsteJla) consist of four pairs ; of these two pairs are

connected with tlie movement of tlie shell upon the stalk, tlie other two with closing and

opening the shell. Each of these last is composed of two parts

and is usually considered to rej)resent two distinct muscles, thus '"'

making the number six Of the two pairs of adjusters, which

are both inserted into the peduncle, one pair arises from each shell

(A'alve) (woodcut, fig. 14, d.ad and v.acl). The pair arising from the

dorsal shell has its origin opposite the commencement of the intes-

tine, and tlie muscles of this pair are close to each other, one on each

side of the median line ; they pass down and are inserted by a tendi-

nous cord which passes directly into the substance of the stalk. The

adjusters of the other shell have their point of origin a little nearer

the posterior border of the shell, and are rather larger, they also are

inserted into the stalk in a similar manner. The principal function

of tliese muscles is without doubt to raise and lower the animal upon

its stalk The occlusor muscles [p. 505] have two points of origin

upon each side of the m.edian line of the dorsal shell, one in front of

the other. They correspond with the two parts of the muscle which

were termed by Hancock the occlusor anterior and posterior. Their origin is external to

that of the adjustor muscles, and their anterior limit passes far into the two anterior lateral

divisions of the body cavity formed by the septum (woodcut, fig. 14, oc.m). The muscles

of each side which are at first quite distinct soon unite into a common tendon which takes

an obliquely downward direction, passing close vmder the central nervous system; and here

it is connected with the homogeneous substance supporting the chief ganglion on each

side of the oesophagus, and is inserted by an expanded extremity in the ventral shell just

to one side of the median ridge. The insertion is a little anterior to the posterior limit

of the intestine which lies between the two tendons. The division into two parts, of

the divaricators, is much less marked than is the ease with the occlusors. These

muscles arise, one upon each side of the median line in the posterior part of the ventral

shell, a little behind the insertion of the occlusors, they pass straight across and their

tendons are inserted into the most posterior part of the dorsal valve in the middle line

(woodcut, fig. 14, d.m). The axis upon which the shell turns joasses through the teeth

and sockets mentioned in the description of the shell, and this lies in front of the

insertion of the divaricator muscles ; hence a contraction of these muscles has the effect

of opening the shell- In Argiope [Cistella) all the muscles are unstriated.

" The peduncle of Argiope [p. 506] appears to be an unusually large development of the

homogeneous supporting substance which occurs so frequently in the body of Brachio-

poda The ovaries of Argiope p. 507] are of a bright brick red color, resembling

the red rays on the shell of Argiope cuneata Each ovary [p. 508] appears to be

foi'med of a membrane continuous with the body-wall When the eggs are ripe they

drop off into the body cavity, the capsule apparently bursting. In the body cavity they

are taken by the inner end of the oviduct and thus pass into the brood pouch."

DE. T. DAVIDSON OX EECENT BRACHIOPODA. 139

Mr. A. E. Shipley then goes on to describe and illustrate the diU'ercut stages of

embryonic development, and his descriptions agree Avith those given by Kowalevsky.

The few preceding extracts from Shipley's very instructive paper will enable the reader

to form a good idea of the character of the shell and the animal of Cistella neapolitana.

Subsequently to the publication of Mr. Shipley's researches, another able memoir

on a closely allied species was puljlished by M. A. Schulgin, to which Ave shall shortly

refer. As this Avriter confirms, in all essential points, the details given by Shipley,

Ave may consider the animal of Cistella to have been thoroughly and ably worked out.

78. Cistella cistellula, Searles Wood, sp. (I'late XXII. iigs. 1- 1.)

Tcrebrutula cisteUula, Scai-les Wood, Auu. & Mag. Nat. Hist. 1st ser. vol. vi. \\. 2."j,'J, 1811.

Aryiope cistcUula, Searles Wood, Suppl. to the Crag Mollusca, Pal. Soc. p. 170, pi. xi. figs, i u-il, 187 t.

Mciiathijiis clslcllula, Forbes & Hauley, Brit. Moll. vol. ii. p. 361, pi. ivii. fig. 9, 1850.

Argiope cistdlulu, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 373, 18,"i2; i'roc. Zool. Soc.

1852, pi. xiv. fig. 28; Monogr. Brit. Tert. Brack, i., Pal. Soc. p. 10, pi. i. fig. 13, 18."')3; Ann. & Mag.

Nat. Ilist. ord ser. vol. viii. p. 40, 18G1 ; Tort. Suppl. Brit. Foss. Bracli. vol. iv. p. (!, (il. i. fig. 2, 1874;

E. Deslongclianips, Bull. Soc. Linu. Normaudie, vol. iii. p. 120, 1858.

Cistella cistellula, Woodward & Ciray, Cat. of Brachiopoda iu the Brit. ^lus. p. Ill, 1853 ; 11. & A.

Adams, Genera of Recent Mollusca, vol. ii. p. 581, 1858.

Argiope cisiellida, E. Suess, Ueber die Wohnsitze der Bracliiopodeu, Siizuiigsb. k. Akad. Wisseu^cli.

Wien, Bd. xxxvii. p. 215, 185!) ; Gwyn JeftVeys, Brit. Couch, vol. ii. p. 19, pi. i. fig. 2, 18G3, and vol. v.

p. 1G4, pi. xix. fig. 4, 18G9; Further Cleaniugs of Brit. Couch., xVnu. & Mag. Nat. Hist. 3rd ser. vol. iii.

p. 43, pi. ii. fig. 8, 1859 ; Proe. Zool. Soc. 1878, p. 410.

Cistella cistellula, Dull, Aiuor. Jouru. Conch, vol. vi. p. 14G, 1870; Proe. Acad. Nat. Sci. Phila-

delphia, 1873, p. 191.

Terebratulu [Aryoipe] cistellula, Lovell lleevc. Couch. Icon., jMouogr. Ter. pi. x. fig. 46, 18G1 ; Ann.

& Mag. Nat. Hist. 3rd ser. vol. vii. p. 18G, 18G1.

Argiope cistellula, P. Fischer, Brachiopodes des Cotes oc(5aniques de France, Jouru. dc Couch, vol. xix.

p. 104, 1871 ; and Actes Soc. Liun. Bordeaux, vol. xxix. p. 173, 1874.

Shell very small, variable in shape, often squarely transversely oblong, broader than

long, or subpeutagoual and as long as wide ; hinge-line nearly straight, and often as

Ions as the 2:reatest breadth of the shell : cardinal extremities rounded or more often

extended into sharp angular extremities ; lateral margins rounded, front gently indented.

Dorsal valve semicircular, moderately convex, lateral sides of umbo auricular, longitu-

dinally divided by a mesial depression commencing at a short distance from the umbo

and extending to the front. Ventral valve deeper than the dorsal one; beak. slightly

incurved, often worn by attrition ; foramen large, incomplete, margined anteriorly by the

umbo of the opposite valve, and laterally by small deltidial plates ; beak-ridges sharply

defined, leaving between them and the hinge-line a flattened triangular area. Colour dull

tawny yellow or light yellowish brown. Surface smooth, marked with line concentric

lines of growth. Shell-perforations rather large. In the interior the teetli are strong,

sockets not very deep. Hinge-plate long, not very wide. Septum submarginal, promi-

nent anteriorly ; loop formed of two semicircular lamellae, attached first to the base of

the hinge-plate and then to the anterior extremity of tlie septum, and more or less

confluent with the valve. Brachial appendages yellowish brown. Cirri few and thick ;

SECOND SERIES. — ZOOLOGY, VOL. IV. 19

140 DE, T. DAVIDSON ON RECENT BEACHIOPODA.

occlusor and retractor muscles very large and powerful. Length 1 line, breadth Ij line,

depth 1 line.

Hub. East Shetland, Skye, County Antrim (Gwyn Jeffreys) ; Moray Firth (Dawson) ;

Dublin Bay (Walker), Belfast Bay ; Exmouth (Barlee and Clark) ; off Guernsey (where

Dr. Leskis found more than 200 specimens on a single stone brought up from a depth of

20 fathoms); off Weymouth (Damon) ; Sardinia (Verany) ; Etretat, Normandy ; S.W. coast

of Erance, Cape Breton (Landcs), Hendage, Basses-Pyrenees, in 32 to 45 fathoms

(P. Eischer).

Fossil. Kirkoen, near Christiania (Sars) ; Coralline Crag, Sutton (Searles Wood), not

abundant.

Obs. The discovery of this interesting little Brachiopod is due to Mr. Searles Wood, who

mentioned it under the name of Terebr^atuJa cistellula in his ' Catalogue of the Crag Mol-

lusca ' in 1841, and it was dredged in the living state by Dr. Gwyn Jeffreys seven years

later. Eorbes and Hanley give a good description of this shell as found in the recent state

in their valuable work on ' British Mollusca.' It is there stated that a few specimens

had been found in 40 fathoms of water by Mr. Jeffreys and Mr. Barlee while dredging off

Skye ; also in 30 fathoms off Croulin Island, near Skye, by Mr. MacAndrew ; and on the

Haaf, or deep-Avater fislung-grounds of Zetland, by Mr. Barlee. Dr. Gwyn Jeffreys

observes, in his ' British Conchology,' p. 21, that this shell may be easily distinguished

from Argiope iieapolitana " in being only half the size and more convex, in the foramen

being much larger, and in the inside margin of the upper valve being slightly and closely

crenulated, instead of having rather strong and distant tooth-like notches, which is the

case in A. neapolitana.'"

To this species several malacologists have referred the Terebratula lunifera of Philippi,

while others have referred that shell to the Plati/dia anomioides. As much uncei'-

tainty prevails about the matter, I have preferred, provisionally, to leave T. lunifera

among the doubtful species of Plafi/dia{?). In 1852 I published a figure showing the

labial appendages and muscles from a dried specimen, as well as the two-lobed loop.

79. CiSTELLA WooDTVARDiANA, Davidson, sp. (Plate XXII. figs. 7, 7c.)

Arg'wpv IJoodwardimin, Davidson, Proc. Zool. Soc. 18G6, p. 103, pi. xii. fig. 4.

Cistella IJ^oodicardiana, Dall, Amer. Journ. of Conch, vol. vi. p. 146, 1870; and Proc. Acad. Nat.

Sci. Philadelphia, 1873, p. 195.

Shell very small, somewhat pentagonal, indented in front. Dorsal valve semicircular;

hinge-line straight, as long as the width of the shell, moderately convex, but divided

into two lobes by a deep median sulcus. Ventral valve deeper and more convex than the

opposite one, and with a longitudinal groove along the middle ; beak very prominent ;

area acutely triangular ; foramen large and incomplete, margined by the umbo of the

opposite valve and laterally by small rudimentary deltidial plates. External surface

smooth, whitish yellow, with a few red patches arranged in interrupted lines radiating

from the beak. The shell is also marked with numerous concentric lines of growth.

In the interior of the dorsal valve the loop is two-lobed, adhering to a central sub-

DE. T. DAVIDSON ON EECEXT BEACHIOPODA, 141

marginal elevated septum. Sliell-structure i:)unctate. Propoi-tions variable ; the largest

specimen measured — length 2.j lines, breadth 2 lines, depth If lines.

Hab. This species Avas obtained at a depth of GO fathoms, off the north-east coast of

Jamaica, by Lucas Barrett.

Ohs. I published this description in 1SG6, and have never seen any specimens besides

those obtained by Mr. Barrett. Cistella JFoodicurdiaiia is a stout little shell, and

differs from its congeners in shape as weU as in its smooth and spotted surface.

80. Cistella cuneata, Eisso, sp. (Plate XXII. figs. 30-31.)

Terebratiila ciineata, llisso, Hist. Nat. Europe meridionale, t. iv. p. 388, pi. 4. fig. 179, 1826.

Terebratulu Solduniana, Eisso, Hist. Nat. Europe meridiouale, t. iv. p. 389, pi. 4. fig. 178, 182(5.

Terebratula cuneata, de Blainville, Diet. Sci. Nat. t. liii. p. 143, 1828.

Anomia Peru, ]\Iuhlfcld, A^erhandl. d. Gesellscli. naturforsch. Frcunde, Berlin, i. p. 205, 1829.

Terebratula cinxuitii, Pliilippi, Enum. Moll. Sicilise, vol. i. p. 90, pi. vi. fig. l;5, 183G ; E. Forbes,

Eeport ou the ^lollusca of ^Egean Sea, Brit. Assoc. Report for 1843, p. 1G5.

Terebratula pera, Kiister, Conch. -Cab. vol. vii. p. 30, pi. 2 b. figs. 14-17, 1843.

Orthis Peru, Pliilippi, Euum. Moll. Siciliie, vol. ii. p. 69, 1844.

Terebratula cuneata, G. B. Sowerby, Thes. Concli. i. p. 355, pi. Ixxi. figs. 83 & 84, 184G.

Ortliis Pera, O. G. Costa, Fauna del regno di Napoli, p. 37, pi. iii. bis, fig. 1, 1851.

Argiope cuneutu, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 373, 1852; and Proc. Zool.

Soc. 1852, pi. xiv. fig. 27 ; Woodward[& Gray, Catalogue of BracLiopoda in Brit. Mus. p. 114, 1853 ; E.

Suess, Ueber die Wolinsitze der Bracbiopoden, Sitzungsb. k. Akad. Wissenseh. Wien, p. 21 1, 1859.

Terebratula [Argiope) cuneata, Lovell Eceve, Concb. Icon. pi. x. fig. 44, 1801 ; Ann. & Mag. Nat.

Hist. 3rd ser. vol. vii. p. 185, 1861.

Terebratulu cuneata, Verany, Zool. des Alpes Maritimes, 1862.

Arr/iope cuneata, H. C. Weinkauff, Die Coneb. des Mittelmccres, vol. i. p. 288, 1867.

Aryiope Peru, S. Brusina, Moll. Dalmati, p. 47, 1800.

Terebratula cuneata and T. Soldaniana, Davidson, Notes on some Recent Mediterranean Species,

Ann. & Mag. Nat. Hist. 4tb ser. vol. iii. p. 374, 1809.

Orthis pera, Terquem, Coquilles de Corse, p. 99.

Aryiope cuneata, Montcrosato, Cat. delle Coq. Mediterranea, 1875; G-nyn Jeffreys, Proc. Zool.

Soc. 1878, p. 410; Sdmlgin, Zeitschrift i'iir wissenseh. Zool. Bd. xli. p. 121, pi. viii. fig. 3, 1885;

A. E. Shipley, On the Structure and Development of Aryiope, Mittheilungen a. d. Zool. Station zu

Ncapcl, Bd. iv. p. 495, 1883.

Shell very small, somewhat transversely semicircular, obtuse posteriorly, slightly

indented in front, rounded laterally, wider than long. Iliuge-line straight, about as long

as the greatest breadth of the shell; cardinal angles gently rounded. Dorsal valve semi-

circular and very gently convex. Ventral valve deeper and more convex than the dorsal

one ; beak tumidly produced, slightly incurved and truncated l)y a very large, broad,

incomplete foramen, thickened posteriorly, anteriorly margined by the umbo of the

dorsal valve, and laterally by small rudimentary deltidial plates ; beak-ridges sharply

defined, leaving betAveen them and the hinge-line a widish triangidar flattened space.

Surface of valves marked with from six to eight simple, rather flat, rounded radiating ribs,

with interspaces of nearly equal breadtli, three or four on each side of a rather wide

median groove ; ribs corresponding in both valves. Colour white, or bright yellow, tinted

19*

142 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

with light-brick or rose-red between the ribs ; shell-structure punctate. Length a little over

1 line, breadth 2 lines, and less than 1 line in depth. In the interior of the dorsal valve

the hinge-plate is very broad and narrow ; from under its centre a long narrow mesial

septum proceeds to within a short distance of the front margin, which acquires height as

it nears its anterior extremity. The principal lamellse of the loop, first attached to the

base of the hinge-plate by a half-circle, afterwards attach themselves to tlie sides of the

anterior extremity of the septum. Margins of the shell crenulated. In the interior of the

ventral valve a short mesial ridije extends to half the leno>th of the valve under the

posterior thickened edge of the foramen.

Hah. Cistella ciineata occurs in different j)laces in the Mediterranean. In the Bay of

Naples ; iEgean Sea at a depth of from 28 to 69 fathoms (Forbes) ; near Villafranca. To

a white variety found near the coast of Sicily Dr. Gwyn Jeffreys has given the varietal

name oipentalaria. It has been found off the Canaries in 28 to 200 fathoms ( MacAndrew) ;

off Corsica (Terquem), Sardinia (Cantraiue), Dalmatia (Brusina).

Philippi mentions it as fossil at Tarent.

Obs. In the ' Proceedings of the Zoological Society of London ' for 1852 I gave an

enlai'ged figure, showing the interior of both valves in a dried specimen given to me by

Prof. E. Porbes in 18.51. It shows the fringed labial appendages of a yellow colour, the

position of the mouth, and of the adductor, cardinal and pedicle muscles.

Cistella cimeata bears some external resemblance to Argiope decollata, but differs from

it generically, on account of its bilobed loop which is attached to a single submarginal

septum. It is also a much smaller shell, with fewer and simple ribs tinted with red

in their interspaces.

In his paper on the Mollusca procured during the ' Lightning' and ' Porcupine ' Expe-

ditions (Proc. Zool. Soc. of London, 1878, p. 410), Dr. Gwyn Jeffreys says : — " I have

been favoured by Prof. Seguenza with an opportunity of examining his unique specimen

of Argiope biplicata from the Straits of Messina, and of comparing it with an extensive

series of A. cimeata and its colourless variety. The result of such examination and com-

parison, as regards both the outside and inside, compels me to consider the specimen an

abnormal form of A. cuneata!'

I would, however, have almost considered it a malformation of Cistella neapolttana, for

some specimens of the last-named shell sometimes possess four rounded ribs with a Avide

mesial interspace, as in Seguenza's specimen. Cistella cimeata has received three or four

specific names, but that of cimeata seems to be the oldest. While at Nice, in 1869, I

was able to examine llisso's types of Terebratula cimeata and T. Soldaniana, and found

them referable to a single species, and this view was subsequently confirmed by Dr. Gwyn

Jeffreys.

81. Cistella lutea, Dall. (Plate XXTII. figs. 5 & 6.)

Cistella Barrettiana, Dall, Amer. Jouni. of Condi, vol. vi. p. 1-16, 1870.

Cistella {1 Barretti(t)ia var.) lutea, Dall, Report on the Brach. dredged by the United States Coast

Survey Exped., Bull. :\Ius. Comp. Zool. vol. iii. p. 20, pi. i. figs. 5 & 6, 1871.

Cistella lutea, Dall, Moll, of the ' Blake ' Exped., Bull. Mus. Comp. Zool. vol. xii. p. 203, 1886.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 143

Shell small, transversely oval, wider than long- ; hinge-line straight, rather less than the

breadth of the shell, sides and front rounded. Dorsal valve semicircular, very little

convex, somewhat flattened. Ventral valve deeper than the dorsal one, Avith a slightly

marked depression extending from the beak to the anterior margin ; beak bent backwards

and truncated by a large incomplete foramen, xxsually much eroded, margined ante-

riorly by the umbo and laterally by very small rudimentary dcltidial plates ; area

triangular, flat, and smooth. Colour light brownish white, with about twelve radiating

ribs in each valve, of which five or six are smaller and interpolated between the longer

ones. In the interior of the dorsal valve a large, much elevated mesial septum is

present, denticulated anteriorly, forming nodules and iiotches on its upper edge, the

whole having a subtriangular form, somcAvhat resembling an open fan. The loop consists

of tAvo bands, or lamella?, attached to the hinge-margin and afterAvards to the sejitura on

each side about its middle and close to the shell. Cardinal plate, or hinge-plate, absent ;

area behind the muscular disk somcAvhat excavated. Length 3 lines by 3J in breadth.

Hah. Tortugas, in a depth of 30 to 43 fathoms (Pourtales). Ofl^ Havana, 80 to 127

fathoms (Sigsbee) ; Barbados, 100 fathoms, ' Blake ' Exped. (Dall).

Obs. We are indebted to Mr. TTilliam H. Dall for the first description of the animal of

Cistella (C. litlea), Avhich he published in 1871, prior to Ivowalevsky's admirable

description of the animal of Cistella NeapoUtana in 1873, and that of C. KoicalevsJdi by

Schulgin in 18S4. Dall says (/. e. p. 20) : — " Muscular impressions much thickened,

forming two rather concave disks. . . . The anterior portion of the apophyses is

more posterior than in C. NeapoUtana, and the margin is not granulated as in that

species. It Avould seem from Mr. Davidson's figures that the loop of Cistella Barrettiana,

Dav., is more anterior than in this species ; the latter being also unprovided with the

posterior extension of the septum seen in the figure of the former, and being, moreoA'er,

entirely destitute of the red markings between the ribs ..... It is possible that the

present species, C. Anfillartim and C. Barrettkma, are forms of one species, in which case

the last name has priority."

[_L. c. p. 22.] " I have not met Avith much success among these small species in the use

of acid in dissolving away the shell from the animal. . . . The brachia in this and the other

species oi" the genus are arranged around the edge of a broad membrane, Avhich covers the

concavity of the shell, like a drumhead. The loop of the drum is represented by the apo-

physes. The brachia diS"er from the same organs in the Terebnitulina; in being arranged

in a single series instead of a double one. Of this there can be no doulit, it is very evident

upon a casual inspection, and is entirely confirmed by careful dissections. In this species

the drumhead membrane is divided into two lobes by the septum. The edges of these lobes

are fringed Avith the brachia. . . . They are usually curled up in front and on each side,

Avhile those Avhich are situated behind the mouth are longer than the others, and usually

lie smoothly over them, extending forward without any marked curve, pointing toAvards

the anterior margin of the shell, and extending clear over the central membrane, even

beyond the posterior edge of the septum. The brachia are covered Avith an epithelium

furnished Avith cilia, are tubular, and communicate Avith a series of brachial channels,

144 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

which did not appear to differ from those of Waldheimia as described by Hancock,

as far as I was able to discover. The great brachial canal was rendered conspicuous by

a band of cartilaginous substance which seemed to form its external covering, or rather

beneath which it was situated, and Avhich was longitudinally striated. The external

edge of the membranes, between which the apophyses were formed, was directly attached

to the pallial lobes at the points where the apophyses are attached to the muscular disks

of attacliment already described. On either side of this attachment, however, was a

kind of pocket, opening externally, where the brachial and pallial membranes did not

coalesce ; and, there being one on each side of the point of union, there were conse-

quently four in all, two on each side of the septum. Tiie drumhead membrane, covering

the space inside of the brachia, was translucent white or opalescent, and quite thick and

tough towards the middle of each lobe."

[i. c. p. 23.] " I am inclined to think that an eri'or has been perpetuated in regard to

the position of the mouth of Megathyris decollata. It has been figured and described by

Woodward as being of a circular form, and situated in the midst of the drumhead membrane.

It is certainly not so situated in Cintella ; and I do not believe that it is in Megathyris,

though I have only seen dry specimens. In the present species it is placed, as in all the

TerehratuUdcs, at the back of this nieml)rane, just in front of the posterior junction of the

brachia, and at the bottom of a deep transverse groove which is of a stout membranous con.

sistency, and the two sides of which, for convenience' sake, I have called the lips {labia). In

the present species the oral groove is situated far back and close to the brachia, which are

exceptionally long behind it, as already described. It is, in fact, entirely hidden by them

until they are laid back. The groove is very long and quite deej), the entrance to the

oesophagus being trumpet-shaped and flattened transversely. Were the brachia disposed

as in Woodward's figure, the oral groove would be hidden. I am disposed to think that

this was really the case in the specimen figured, and that the extraordinary circular

motith there figured was an accidental lesion of the dry tissues, which might easily be

taken for a mouth of so small an animal. The labia, in all the Brachiopods I have

examined so far, have invariably exhibited a tinge of darker colour than the surrounding

tissues. The present case forms no exception. The posterior lip presents a small promi-

nence in the median line, and the anterior lip a small emargination or concavity below

this prominence. This structure is also common to all the Brachiopods I have examined.

"The oesophagus is wide, transversely flattened, with thin walls, and of an orange

color. It enters the stomach nearly at a right angle, without much dilation. The

stomach is oval with thicker and firmer walls ; the inner lining appearing slightly villous

and rugose. The intestine is not diiferentiated from the stomach on the lower side, but

on the upper side a deep groove occurs at the juncture. The canal is stout and thick at

its lower extremity, tapers slightly, and terminates in a somewhat bulbous, Init pointed

csccal extremity, attached to the perivisceral membrane. The various membranous bands

which support the alimentary system present no differences from the homologous struc-

tures in other species of TerehratuUdce. The stomach was filled in each case with a

yellowish flocculent matter. The hepatic lobules resembled those of other species, entering

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 145

tljc stomach by two ducts on each side, of which the anterior were the larger. They

did not extend over or cover the sides of the intestine."

[L. c. p. 2jf.] "The licart is extremely small and difficult to find. It is situated lower

down than in most species, and between and hidden by the hepatic lobules. It is nearly

spherical. No accessory pulsatile vesicles were found, after close scrutiny.

" The ovaries differ in appearance from those of JFaldhelmia and Terebmlnllna. They

hang like a frill or puckered ribbon-like lamina from the pallial membranes, and form a

simple loop on each side of each valve. Those of the hgemal (dorsal) valve Avere most

developed. The ends of the loops extended into the great pallial sinuses. The rounded

granules which studded the frills were of two kinds. Those at or near the extreme edge

were of a pellucid deep brown hue, while those closer to the pallial membrane were mostly

of a pale yellowish color, and quite opaque. The oviducts are very inconspicuous and

not easily found. They are situated in the usual position, but exhibit only a very few

short folds, and the external opening directly in the midst of them, instead of being at

the end of a rather long duct, as in other forms. There are only two of them. They do

not appear to be attached to the intestine or mesenteries, but lie flatly upon the parietes.

The pallial sinuses are comparatively insignificant in this species, being very narrow,

almost linear, channels with few branches. A few spicula3 were observed in some of them.

The margin of the mantle is perfectly plain, without seta3, and adhering closely to the

shell. Yet the circumpallial muscular band is m;ich broader than usual, and strongly

marked. When torn from the shell, the csecal prolongations of the mantle were beautifully

shown. They wei'e often bifurcate and occasionally had three or even four branches.

" The punctate structure of the shell was very coarse. Even the crura and laminae

of the apophyses were punctate. The nervous system was not traced out ; but the

oesophageal ganglia presented no special peculiarities.

"The border of the mantle appeared to be ciliated. The peduncle, so wide and short

as to resemble a mere muscvilar disk, was strongly attached to the shell by the peduncular

muscle, beside which a broad tendinous band appeared to pass entirely across, in front

of the dorsal adjustors (posterior retractors of Owen), giving an additional solidity and

firmness to the attachments of the peduncle. The extremities of all the muscles were

very much enlarged and thickened, while their median portions were slender and

tendinous. No striated fibres were observed."

82. CiSTELLA Bakrettiaxa, Davidson, sp. (Plate XXIII. figs. 1 & 2.)

Argiope Bmrettiana, Davidson, Proc. Zool. Soc. 1866, p. 103, pi. xii. fig. .3.

Argiope Antillarum, Crosse & Fischer, Journ. de Conch, vol. xiv. p. 270, pi. viii. fig. 7, 1866.

Cistella Barrettiana, Dall, Amer. Journ. of Conch, vol. vi. p. 14G, 1870; and Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 193.

Cistella [1 Schrammi, var.) ruhrotincta, Dall, Bull. Mus. Comp. Zool. vol. iii. p. 19, pi. i. fig. 6, 1871.

Cistella Barrettiana, Davidsou, var. rvbrotincta, Dall, ]\Ioll. 'Blake' Exped., Bull. Mus. Comp. Zoiil.

vol. xii. p. 203, 1886.

Shell small, somewhat subpentagonal, wider than long; dorsal valve semicircular.

146 DK- T. DAVIDSON ON RECENT BRACHIOPODA.

slio-litly indented in front ; liinge-line straight, as long as the hreadth of the shell, forming

acute angles at its junction with the labial margins of the valves. Valves vmequally

convex. Dorsal valve very gently convex, rather flat, with a shallow longitudinal depres-

sion along the middle. Ventral valve convex, with a rather deep mesial sinus, correspond-

in"- to the one in the dorsal valve; beak and area sloping backwards, forming an obtuse

anc-le with the plane of the dorsal valve. Foramen very large, incomplete, margined

anteriorly by the umbo of the dorsal valve, and laterally by rudimentary deltidial plates.

Surface of valves traversed with from eight to tAvelve rounded ribs, corresponding in

both valves, with interspaces between them of almost equal breadth. Colour pale yellow,

with scarlet interspaces ; surface marked with punctuations clearly visible to the eye in

a o-ood lia'ht. In the interior of the dorsal valve the apoj)hysary system consists of a

bilobed ribbon-shaped lamella, originating at the base of the sockets, which after forming

half a circle on each side, adheres to a central prominent submarginal septum, the

lamellae forming the loop being also partly confluent with the valve. Proportions

variable. Length 3 lines, by a little more than 1 lines in breadth.

Hah. North-east coast of Jamaica in a depth of 150 fathoms (Barrett). At Guada-

loupe in from 200 to 250 fathoms (Crosse). Dredged in 70 fathoms off E,io de Janeiro,

Brazil, by the captain of the English steamer ' Norseman,' in lat. 21° J^S' S., long. 40° 3' W.

These specimens were obtained attached to corals brought up by the grappling-irons, and

sent to me by Mr. E.. Ptathbun. Dredged also by M. de Pourtales west of Tortugas in

30 to 43 fathoms ; Sand Key, 80 fathoms ; St. Vincent, 95 fathoms ; Tortugas, 43

fathoms ; otf Grenada, 115 fathoms ; Barbados, 100 fathoms ; off Havana, 450 fathoms

(Sigsbee), Yucatan Strait, 641 fathoms, ' Blake' Exped. (Dall).

Obs. This fine species of Clstella approaches most nearly in general appearance to the

Cistella cnneata, Eisso, but is a much larger species and possesses, when full-grown, a

o-reater numl)er of ribs. In external shape it bears likewise some resemblance to Arglope

decollata, from which, however, it can Ije at once distinguished by its two-lobed loop and

single submarginal septum. It varies someAvhat also in shape as well as in the number

of its ribs, some specimens being as long as wide when quite young. In a letter dated the

22nd of March, 1870, Mr. Crosse writes me that in all probability his Argiope antillarum

is a synonym of Cistella Barrettiana, but that he considers his C. Schrajnud to be a dis-

tinct species. I have also, through the kindness of Mr. Dall, been able to examine the

lype of his O. ruhrotincta, and I believe it to be a synonym of C. Barrettiana. Erom

Mr. Dall's description it would seem that it is of a pale yellow colour, with brilliant

scarlet interspaces, and agrees in shape and character with typical examples of C.

Barrettiana. " Septum triangular, extending from the hinge margin to the anterior

border of the shell. Most elevated point, forming the apex of the triangle in the middle

of the valve, rather bulbous and of a red colour. Anterior slope of the septum to the

border of the sheU, straight without nodules ; this part of the septum is thin and even.

Posterior slope of the septum irregularly concave, tliick, and nodulous, tapering to a

point at the hinge-margin." The size and extent of the transverse plate of the septum

varied in different specimens.

DR. T. DAVIDSON OX EECENT BEACHIOPODA. 147

Uncertain Species.

83. ARGiorK GLOBULiFOEMis, Scliulgiii. (Plate XXII. fig. 28.)

Argiope globuliformis, Scliulgin, Zeitscbr. f. wiss. Zool. Bd. xli. p. 1:21, pi. viii. fig. 2, 188 i.

Shell small, ellipsoid, globular ; valves smooth, inflated, of a yellowish colour ; beak

not very projecting, wide ; foramen incomplete, transversely oval. In the interior of the

dorsal valve there are three submarginal ^epta. In the ventral valve one low median

septum. Diameter 7 millim.

Ilab. Obtained by Sehulgiu on stones off Sardinia, and near the islands of Ilyeres ;

it was not found at Villafranea.

Obs. I have never seen this shell and have no further knowledge of it tliau Schulgin's

very brief description and figure affords. It is said to have tlu-ee submarginal septa in

the dorsal valve, and must consequently be placed in the genus Ai'giope.

81. Argiope Barroisi, Schulgin. (Plate XXII. fig. 29.)

Argiope Barroisi, Schulgin, Zeitschr. f. wiss. Zool. Bd. xli. j). 1:2"J, pi. vii. fig. 4, 1884.

Shell small, squarely transversely oblong, wider than long ; hinge-line straight, less

than the breadth of the shell. Valves moderately convex, ornamented with from eight

to eleven rounded ribs. Colour light yellowish orange ; interspaces between ribs bright

red. Beak moderately produced ; foramen large, circular, incomplete, margined ante-

riorly by a part of the umbo of the dorsal valve. In the interior of the dorsal valve there

are three high submarginal septa, and a single low one in the ventral valve. Breadth

3 "6 millim. ; length 3 millim.

Hub. It oecui's frequently on Posidonia and upon stones at Villafranea, along

w'ith Cistclla Kowalevskii at a depth of 30 metres ; also off Sardinia, Xaples, and tlie

islands of Hyeres.

Obs. I have never seen this shell, and know nothing more of it than is contained in

Schulgin's brief description. Ilis figure does not quite satisfy me. As it is said that

three septa exist in the dorsal valve, it is an Argiope.

85. CiSTELLA Kowalevskii, Schulgin, sp. (Plate XXII. figs. 26 & 27.)

Argiope Koti-alevskii, Schulgin, Zeitschr. f. wiss. Zool. Bd. xli. p. \2\l, pi. viii. figs. 5-9 & 12, pi. ix.

figs. 14-18, 188L

Shell very small, from 3 to 8 millim. in length by 3 millim. in breadth, heart-shaped,

broadest and rounded anteriorly, tapering somewhat posteriorly. Valves gently convex,

thin, shining, and sharp at their edges, marked with a few concentric lines of growth and

widely separated punctures ; beak short, triangular, both it and the umbonc of the opposite

valve excavated for the passage of the cyUndrical-shaped pedimcle. In the interior of the

dorsal valve one short thick submarginal septum ; in the ventral valve a thin, low, long

septum. Colour yellow,

SECOND series. — ZOOLOGY, VOL. IV. 20

148

DR. T. DAVIDSON OX EECENT BRACHIOPODA.

FiK. 15.

ILah. Foimd by Herr M. A. Scliulgin alone or in groups on Posklonia ; off Sardinia,

Villafranca, and off the islands of Hyeres.

Obs. I have never seen this small shell. Schulgin

gives two figures which seem to me rather dissimilar ;

we will, however, take the illustration in his pi. viii.

fig. 5 as his type, as it differs in several particulars

from Cistella neapoUtana. Schulgin describes and illus-

trates the shell and its animal with much care and minute-

ness in the memoir above quoted ; but his description

agrees so nearly witli that of Cistella neapolitana, pub-

lislied one year before by Mr. Shipley, that I must

refer the reader to Herr Schulgin's memoir, and content

myself by reproducing in PL XXII. fig. 26 one of the

author's most instructive illustrations. Schulgin seems to

have discovered the presence of some sense-organs situated

in the body-wall just behind the chief or suboesophageal

nerve-ganglion ; but this requires confirmation, for A. E. Muscular arrangement in Cistella

Shipley saw notliing of them in the allied species he studied Sowalevskii (after ScMgin).

in Naples. The arrangement of the muscles in C. Ko- rtc^.", adjuvator ventralis ; rfv.i', di-

loalevskii is quite similar, as might be expected, to that varicator ventralis ; oc.6, ocelu-

described by Mr. Shipley in Cistella neapolitana.

sor biceps ; ad.d, adjuvator dor-

salis ; </v.d, divaricator dor-

salis.

86. Cistella Schkammi, Crosse, sp. (Plate XXIII. figs. 3 & 4.)

Argiope Sclirammi, Crosse & Fischer, Journal dc Concli. vol. xiv. p. 269, pi. viii. fig. 6, 1806.

Cistella Schrammi, Dall, Amer. Journ. of Conch, vol. vi. p. 146, 1871, aud Proe. Acad. Nat.

Sci. Philadelphia, 1873, p. 194.

Shell very small, transversely subpentagoual, wider than long, indented in front ;

hinge-line straight, as long as the greatest breadth of the shell, cardinal extremity

prolonged and acutely angular. Dorsal valve very gently convex, with eight rounded

ribs, and a very broad median depression between the two central pairs. Ventral valve

rather deeper than the dorsal valve, with a similar number of corresponding ribs, and

wide depressions between the central ones ; beak bent backwards, almost straight, area

triangular, foramen large and incomplete, margined anteriorly by the umbo, and by two

small lateral deltidial plates. Colour yellowish or pale orange, sometimes tinted with

red. Length 1 line, lu'eadth 1^ line.

Sab. Dredged, associated with Cistella Barrettiana (C. antiUariim, Crosse), off Guada-

loupe, at a depth of from 200 to 250 metres, by the Italian brig ' Icilia.'

Obs. Thanks to the kindness of M. Crosse, I have been able to examine and draw his

type. I have also a rather larger specimen from Tortugas. The matei-ial at hand has,

however, been so small that I can say nothing j)ositive with respect to the specific

claims of Cistella Schrammi.

DE. T. DAVIDSON ON EECENT BRACHfOPODA. 149

87. CiSTEi.LA (?) LUNIFERA, Pliilippi, sp. (Plate XXII. figs. 5 & 6.)

Terebratulu Imi'iferu, Pliilippi, Eiium. Mollusc. Siciiiaj, vol. i. p. '.)", tab. vi. figs. IG a~f, 1<S36.

Orthis luuifera, Costa, Faima del regno di Napoli, p. 40, tav. iii. bis, figs. 3 a, b, & I, 1851.

Morrisia luniftra, E. Suess, Uchor die Wolinsitze der Bracliiopodcn, Sitzuugsb. k. Akad. Wisscnseli.

Wien, 13d. xxxvii. p. 212, 1859.

Aryiope [Tcrebratula) lunifera=T. fw/eZ/M/tt, Montcrosato, Nuova Ku vista dellc Conchy. Med., Atti del

Aecad. Palerruitaua di Scieiize, 1875.

Terebratula (Morrisia) lunifera, L. Reeve, Couch. Icon. pi. x. fig. II, 18()1.

Morrisia Ituiifera, Weiukauft', Die Couch, des Mittclmecres, vol. i. p. 288, 18G7.

Aryiope liotiferu, Gwyn Jeti'reys, Mediterranean iloUusea { = A. cislcllulu), Ann. & Mag. Nat. Hist.

4th ser. vol. vi. p. G7, 1870.

Shell small, length aud breadth half a line, thin, hyaline, somewhat orhicular, broadest

anteriorly. Dorsal valve very gently and uniformly convex, somewhat compressed, very

slightly indented at the umbo and at the frontal margin. Ventral valve gently convex ;

beak short, slightly incurved and truncated by a rather large incomplete foramen ; beak-

ridges sharply defined, leaving between them and the hinge-line a narrow triangular space.

Surface smooth, puckered near the margin, and traversed by fine concentric lines of

growth. Colour light yellowish white. A small submarginal septum rises in the

interior of the dorsal valve. On each side of the mouth the labial appendages form a half-

circle and do not apparently occupy much more than a third of the interior of the shell.

Sab. Mediterranean Sea, off the African coast,

Obs. Much uncertainty has prevailed Avith respect to the genus to which this so-termed

species should be referred. It was described and figured in 1836 by Pliilippi as

follows : —

" T. testa minima ; subcordata, compressa, punctata, margine frontali subemarginato,

foramine incomplete, sceleto interne e lamella semilunata obliqua versus frontem aperta

constante. Specimina duo zoophytis inhaerentia inveni. Testa minima f'" louga, V"

lata, •!'" alta, cordata subpentagona, margiue frontali emarginata, parum convexa, con-

vexitate maxima in cardinis regionc, v. fig. c. Sub lente fortiori superficies punctis

minutis elevatis per series radiantes dispositis, aliisque minimis, impressis, densissimis

obsita. Area angusta satis elevata, foramen magnum iucompletum. Dcltidium distin-

guere non potui. Sceleton internum lamina obliqua semilunaris ad frontem prona et

aperta, v. fig. IG a et e. Color testae albidus." Philippi gives six figures of his little

shell ; in fig. a he draws a submarginal single septum as in Cistella, and he speaks of

a loop in the shape of a half-circular lamella.

The form is, therefore, as the Marquis of Monterosato and Dr. Gwyn Jeffreys suggest,

more nearly related to Cistella than to Flatijdia. Costa, in his ' Fauna del regno di

Napoli,' describes and figures some of the soft parts of the animal, from a specimen which

he says belonged to Philippi's species, which occurs off the shore of Trapani, as well as

near the coast of Africa. He points out the differences between it and Flatydla anomi-

oides. The hinge-line in the dorsal valve is entire and not scooped out, as in the last-

named species, for the passage of the peduncle, and its interior is quite difierent from

that of Platydia.

20*

150 DE. T. DAVIDSOX ON RECENT BRACHIOPODA.

The Marquis of Monterosato and Dr. Gwyn Jeffreys would consider the Cistella

cistellula of Wood to he a synonym of C. Inniferax hut this identification seems to he

lancertain, and new material must he examined and compared hefore the matter can he

regarded as definitely settled.

Uiicertam Genus and Sjwcies, 1859.

(The characters of the genus are given under Gioynia capsula. One species only known.)

88. GwYNiA CAPsULA, Gwyn Jeffreys, sp. (Plate XXI. figs. 28 a, b, c, & 29.)

Terebratula capsuhi, Jeffreys, Ann. & Mag. Nat. Hist. 3rd ser. vol. iii. p. 43, pi. ii. figs. 7(t, b, IS.jO.

Gwynia capsula, King, Proc. of the Dublin University Zool. & Bot, Assoc, vol. i. p. 258, -woodcuts,

figs. 1-5, 1859.

Arffiope capsula, Gwyn Jeffreys, Brit. Concli. vol. ii. p. 21, 1863, and vol. v. p. 164, pi. xix. fig. 5, 1869.

Gwynia capsula, M. Sars, Om de i Norge forckommende fossile Dyrlevninger fra Quartaerperioden,

Christiania, p. 96, pi. iv. figs. 121, 122, 1865 ; Davidson, Br. Foss. Bracb. vol. iv. p. 5, pi. i. figs. 3-4,

1874; H. Friele, Arcbiv for Mathematik og Naturvidenskab, Bd. ii. p. 385, pi. iii. figs. 7 « & 6, 1877.

Argtop)e capsula, Tei-quem, ' Essai sur le classeraent dcs animaux qui vivent sur la plage dans les

environs de Dunkerque,' 1879 ; Gwyn Jeffreys, Ann. & Mag. Nat. Hist. 5tb ser. vol. vi. p. 406, 1880,

audProc. Zool. Soc. 1881, p. 949.

Shell thin, minute, pouch-shaped, or slightly elongated oval, nearly equivalved, longer

than wide, hroadest anteriorly, rounded in front ; hinge-line nearly straight or very

ohtusely angular, margins rounded at the sides. Dorsal valve convex, most so at the umho,

slightly depressed anteriorly. Ventral valve uniformly convex ; heak slightly prominent

and incurved ; foramen incomplete, margined anteriorly hy the umho, and hy small

rudimentary deltidial plates. Interior without loop or septa (?). Surface of valves

smooth ; shell-perforations rather large and f:\r apart. Lines of growth slightly marked.

Colour nearly white, glossy. Length two thirds of a line hy half a line in hreath.

Salt. Off Plymouth, in 18-25 fathoms (Norman, from Wehster). On stones near

Guernsey, 8 to 20 fathoms (Lukis and Duprey). Duhlin Bay and off Portsmouth (Waller).

Belfast Bay, Larne, County Antrim (Hyndman and Gwyn Jeffreys). It occurs with

C. cistellula, nestling in hollows of old shells, Fectunculus glycymeris, and other hivalves.

Off Etretat, in Normandy, on stones which had heen taken up in trawl-nets at a distance of

ahout four leagues from land (Gwyn Jeffreys). Off Dunkerque (Terquem). M. Colheau

ohtained the shell from Sluys-Kill, Zeeland, near the Belgian frontier. Off Jersey, low

water (Duprey), where it adheres hy its short stout peduncle in an upright position to

the undersides of large stones which are sunk and partly buried in the sandy mud

(Gwyn Jeffreys).

It also occurs fossil iu the Post-tertiary clays at Kirkoeu, near Christiania (Sars).

Ohs. I have specimens of this minute shell, from the size of a microscopic dot up to

little more than half a line in length. I cannot, however, arrive at any other conclusion

than that it is the fry or young stage of some species not at present determined. The shell

has already heen referred to Terebratula, Arcj'wpe, and Gioynia. Dr. Gwyn Jeffreys and

Ilerr Herman Friele believe it to he referable to Argiope or Cistella, and in vol. ii. p. 22 of

his 'British Conchology,' Gwyn Jeffreys writes, " It may he the young of Argiope NeapoU-

DE. T. DAVIDSOX OX EECEXT BEACIIIOPODA. 151

tdtin (probably T. cordala of Risso) ; and I feel pretty confident that the last-named

species will be found on our own as well as the Mediterranean coasts." In 1859, Dr. S. P.

Woodward and myself spent a whole day at the British Museum in endeavouriii"-, with

tlie aid of a good microscope, to find some kind of calcareous support, or septum, l)ut could

tind none; nor has any other naturalist who has studied the shell been more successful.

In 1859, Prof. W. King proposed tlie generic name of Gwijnia for this form, statin"- at the

same time that "the principal generic character of Gwyuia is in the labial appenda"'es

being attached directly to the shell (first observed by Mr. Jeffreys), and not to a loop, as

in other genera of the family. The prominency of the umbonc of the small or receivin"-

valve, the form, position, and (considering the size of the species) the unusual develop,

ment of its teeth, also the large size of the perforations of its shell-tissue, form other

good distinguishing characters." We must, however, for the present, assume that no

calcareous support in reality exists.

In a note published in the 'Ann. and Mag. Nat. Hist.' for Xov. 1880 (p. 400), Dr. Gwvn

Jeffreys again returns to the subject, in referring to what he terms Arcjiope capsula, and

says :— "The specimens kindly sent me by Mr.Duprey are larger than any I had previously

seen ; and I was enabled to examine the inside of the shell by soaking them for some

days in dilute potash water, together with Argiojye clstellula of the same size. A. can-

sula has a thick hinge ; and the smaller (though scarcely smaller) valve has a sharp-edo-ed

and wavy crest or ridge lying a little within the margin, which is heart-shaped and con-

tinuous in front. The shell is strong for its size, and is nearly spherical and cquivalve, the

beaks of both valves being excavated to contain the b^ ssus. There is no trace of a septum

in either valve. The caecal tubercles are numerous, twice as many as in ^. cislellula of

the same size. The latter species is transversely oblong ; there is a distinct and promi-

nent septum in each valve ; and the laminar ridge in the smaller valve is much sli<'hter

and is interrupted by the septum to which it is attached. Both species occur too-ether

on the English and Irish coasts, and at Etretat in Normandy."

In his paper on the development of the skeleton in the genus Woldlieimia, Herman

Eriele says (p. 385), " Dr. Jeffreys has had the great kindness to send me his type-speci-

mens of Gwjjnia {Arfi'iope) copsiila, Jcffr., for comparison. My first glance at them sufficed

to convince me that there can be no question as to their [not *] being the fry of Wcddheimia

cranium, for not only are both valves of very nearly the same size, but the form, the

foramen, and the structi.u*e of the shell are essentially different."

Mr. Lovell Beeve writes, in his ' Geographical Distribution of the Terebratula; ' f , " Is

this very minute form, it has been asked, an adult shell, or the fry oi Arrjiope cistcllulum

or of some other Tevcbmtvla ? An Argiope it certainly is not ; and I am unable, after a

most tedious examination of specimens, to add anything to what is knoAvn on the subject."

The question being still involved in considerable uncertainty, it will be better, I

think, at any rate provisionally, to leave it under Gwrjnia, from which it may be

hereafter removed, if anything definite should be ascertained concerning it.

* [Hcrr Friclo writes Ai)ril lOtli, ISSO, tliat " by a printer's error the -svord ' not " was omitted here : " and Ihis

is evident from the rest of the passage quoted. — A. C]

t Ann. & ilajr. Nat. Hist. 3rd scr. vol vii. p. 1,^3.

152 DE. T. DAA'IDSON ON EECENT BEACHIOPODA.

Mr. W. H. Dall, iu liis Index to the names wliich have been applied to the subdivi-

sions of the class Brachiopoda (Smithsonian Miscell. Coll. vol. xiii., Bull. U. S. Nat.

Mus. vol. i. no. 8, p. 30, Washington, 1877), states, as many zoologists have done, that

the so-termed Gioijnia capsula is an immature form, and perhaps that of JFaldheimia

cranium.

Genus PLATYDIA, Costa.

The subfamily into which the genus J^latydia should be placed has not yet been

satisfactorily determined. It is thus characterized by Dall : — " Shell with the loop

attached, not reflected ; animal with sigmoid brachia meeting behind the mouth, without

any spiral median lobe or lateral loops. Cardinal process absent."

The genus FlatyiUa was proposed by Costa in January 1852, and by myself, entirely

independently, in May of the same year, under the name of Jjforrisia, which must now be

placed among the synonyms.

The animal of FlatycUa has not yet been anatomically examined.

89. Platydia anomioides (Scacchi), Philippi, sp. (Plate XXI. tigs. 15-19.)

Terebratuhi Seminuluni; Pliilippi, Eumn. Moll. Slcilite, vol. i. p. 97, pi. vi. fig. Ija-ff, 1836.

Orthis anoiiiioides (Scacchi, AIS.), Pliilippi, Fauua ]\Ioll. llegui iitriusquc SiciliiE, vol. ii. p. 69,

pi. xviii. fig. 9, 1844.

Terebratuhi appressa, E. Forbes, Report of the Mollusca of the ^Egean Sea, Report Brit. Assoc, for

1843, pp. 141, 167, 193, 1844.

Platidia anomioides, Costa, Fauna del regno di Napoli, p. 48, pi. iii. fig. 4, and pi. iii. bis. fig. 6, 1852.

Morrisia seniinulum, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 371, 1852.

Morrisia anomioides , Davidson, Proc. Zool. Soc. 1852, pi. xiv. fig. 29 ; Intr. to vol. i. Brit. Foss. Brach.

p. 71, pi. vi. figs. 30, 31, 1853; Woodward & Gray, Catalogue of Brachiopoda in the Brit. IMus. p. 108,

figs. 17, 18, 1853; S. P. Woodward, A Manual of the Mollusca, p. 218, 1856; H. & A. Adams, The

Genera of Recent Mollusca, vol. ii. p. 579, pi. cxxxi. figs. 5 a, b, 1858 ; E. Suess, Ueljcr die Wohnsitze

der Brachiopoden, Sitzungsb. k. Akad. Wissensch. Wien, p. 212, 1859.

Terebratula (^Morrisia) anomioides, L. Reeve, Conch. Icon. pi. x. fig. 40, 1861, Ann. & Mag. Nat. Hist.

3rd ser. vol. vii. p. 184, 1861 ; Chemnitz, Man. de Conch, p. 208, fig. 1064, 1862.

Morrisia anomioides, E. Dcslongchamps, Recherches sur I'Orgauisation du Alauteau chez les Brachio-

podes articules, Caen, p, 28, pi. iii. figs. 6, 7, 1864; Seguenza, Cat. Mai., Mem. Soc. Ital. Sci. Nat.

p. 66, pi. viii. fig. 6, 1865 ; H. C. Weinkauff, Die Conch, des Mittelmeeres, vol. i. p. 288, 1867.

Platidia [Morrisia) anomioides, Davidson, On Italian Tert. Brach., Geol. Mag. vol. vii. p. 405, pi. xxi.

figs. 15, 15 «, 1870; Dall, Amer. Journ. of Conch, vol. vi. p. 143, 1870, and Proc. Acad. Nat. Sci.

Philadelphia, 1873, p. 192; P. Fischer, Brachiopodes des cotes oceaniques de France, Journ. de Couch,

vol. XX. p. 162, 1872; Monterosato, Poche note sulla Conch. Meditcrranea, 1875.

Platidia seminulum, Monterosato, Journ. de Conch, vol. xxvii. p. 307, pi. 13. fig. 3, 1879.

Platidia anomioides, Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challengci-,' Zool-

vol. i. p. 55, pi. iv. figs. 10, 11, 1880; Zittel, Handbuch der Pal. Bd. ii. p. 708, 1880; E. Dcslongchamps,

Etudes critiques sur les Brachiopodes, p. 160, pi. xiii. fig. 19, 1884.

Shell small, transversely oval, or nearly circular, semitransparent, yellowish Avhite,

con.spicuously perforated by minute canals ; foramen large, encroaching nearly equally

DR. T. DAVIDSON ON EECENT ERAC'IIIOPOD.A. 153

on both valves. Dor.sal valve almost flat, and nicsially doprossod ; umbo nolchod by a

semicivcnlav foramen. Ventral valve convex, of moderate deptii, hinge-line straight,

area small. Beak very slightly incurved, foramen situated under its angular extremity,

margined liy narrow deltidial plates. Surface smooth, marked willi concentric lines of

growtli. In the interior of the dorsal valve the loop is not reflected. The converging

principal lamelhTB are found attached first to the hinge-plate, and then to a small pillar-

shaped median vertical septum. Peduncle very short ; animal possessed of sigmoid

vertical labial appendages. Length 2 lines, breadth 2 lines.

TIah. Dredged in the J<lgean Sea by Prof. E. Porbcs, under the names of Terehratula

semlmilum, Philippi, and T. appressa, Forbes, at depths varying from 45 to 105 fathoms; in

the Bay of Naples (Costa) ; off the Portuguese coast, near the mouth of theTagus, attached

to corals (W. S. Kent); Bay of Biscay and Sahara (' Travailleur ' Expedition), in 178 to 347

fathoms ; North of Stornoway (' Knight Errant ' cruise) ; off Cuba and AVest Indies

('Blake' Expedition), 88 to 615 fathoms; off Marion Island in 500 fathoms, and off

Prince Edward's Island close to Marion Island (' Challenger ' Expedition). Mr. W. H.

Dall records it from San Diego, California, and from Lodos, Santos Bay, south of the

United- States boundary in Lower California (Mexico).

It occurs in the fossil state in the Upper Pliocene rocks of Sicily.

Obs. As the specific name anomioides is now in general use, I do not feel inclined to

disturb it, although those of seiniimlnm and of appressa, Eorbes, seem to have priority.

Forbes neither described nor figured his species, and therefore it cannot be said to have

been published. The name anomioides is attributed to Scacchi, but he has neither

named, described, nor published it. It was a MS. name known to Philippi and to Costa,

and they both described and figured a shell in 1844 and 1852 under the name of Orthis

anomioides. As the Terehratula semiimlitm, Philippi, is evidently identical with the

so-termed Orthis anomioides, and was described and figured in 183G, the specific name

seminulum should in reality obtain priority over that given to the shell in MS. by Scacchi.

In May 1852 I proposed for T. seminulum anA. similar shells the generic name of Morrisia,

not being aware at the time that Costa on the 27th of January of the same year had

proposed that of Vlalijdia for the same shell.

The animal of this interesting and well-marked genus and species has not yet been

anatomically examined. The arrangements of its labial appendages are very remarkable.

They were briefly described and figured by Costa and by myself in 1852, but more particu-

larly by E. Deslongchamps in 1804, in his valuable memoir, ' Recherches sur I'Organi-

sation du Manteau chez Ics Brachiopodes articules.' His observations were, however,

like my own, nnfortunately founded on dried specimens. He states that the brachial

appendages are much more simple than in other genera of the Brachiopoda, and that

the two principal branches which lie close to each other at their origin and deviate by

a curve towards the centre of the shell, and, having made almost a complete circle, return

close to their origin, without forming a spiral. His most imponant observations, how-

ever, relate to the mantle, which he states to be so thickly coated with spicula that it is

impossible to separate it from the brachial appendages without injuring them; that

154 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

they are small, but exceedingly numerous, and yet so blended together that it becomes

at last very difficult to define their shape ; and that they appear to be a white spongeous

mass formed of an innumerable number of short lamellae, crossing each other in every

direction. In his paper " Brachiopodes des cotes oceaniques de France " (' Journal de

Couchyliologie,' vol. xx. p. 160, pi. vi. figs. 3-9, 1872), M. P. Fischer describes at

great length PlatycUa anomioides, and the characters that distinguish it from Flatijdia

Davidson i. He gives an enlarged sketch of the brachial appendages, Avhich he likcAvise

states to be extremely simple. " De chaque cote de la bouche part une portion hori-

zontale qui se coude eusuite et forme une premiere anse ou boucle buccale. EUe est

continuee de chaque c6t6 par la portion currente dirigee du crochet de la valve vers le

bord frontal et en rapport avec la valve inferieure ou dorsale ; cette portion currente se

coude, decrit un ccrcle complet (anse ou boucle laterale) et revient au-dessus de la portion

currente en etant en rapport avec la valve dorsale ; elle se termine enfin par une

sinuosite dirigee vers la bouche. C'est la le rudiment de la portion spirale, qui est

assez developpee chez les Megerlia et beaucoup plus marquee chez les Terebratula.

L'appareil brachial ressemble done a celui du Platidia anomioides ; mais la boucle

est moius large, par rappoi't aux boucles laterales. Les cirrhes des bras sont assez longs

et disposes par paires, ou plutot chaque cirrhe semble se diAdser en deux filaments egaux.

Ce caractere a etc represente, chez le Platidia anomioides par M. Davidson."

Owing to the extreme shortness of the peduncle, the ventral valve is kept so close to

the object to which it is attached that the asperities or irregularities of the rock or shell

are often reproduced upon it. This peculiarity is especially observable on the smaller

valve of PlMi/dia anomioides.

90. PLA.TYDIA Davidsoni, E. Deslougchamps, sp. (Plate XXI. figs. 23-27.)

Morrisia Davidsoni, E. Deslougcliamps, Ann. & INIag. Nat. Hist. 2ud ser. vol. xvi. p. 443, pi. x. figs.

20 a-d, 1855 ; Seguenza, Mem. Sue. Ital. Sci. Nat. vol. i. p. 07, pi. viii. fig. 5, 18G5 ; E. Suess, Ueber die

Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wisseusch. Wieu, p. 212, 1859.

Terebratula {Morrisia) Davidsoni, L. Reeve, Coucli. Icon. pi. x. fig. 42, 1861, and Ann. & Mag. Nat.

Hist. 3rd ser. vol. vii. p. 181, 18G1.

Platidia Davidsoni, Dall, Amer. Journ. of Coneli. vol. vi. p. 143, 1870, and Proc. Acad. Nat. Sci. Phila-

delphia, 1873, p. 192; P. Fischer, Brach. des cotes oceaniques de France, Journ. de Conch, vol. xx.

p. 163, pi. viii. figs. 8-9, 1872, and Etudes Couch. Slarines du Dep. de la Giroude, Soc. Linn.

Bordeaux, t. xxix. p. 170, 1874; Monterosato, Poche note suUa Conch. Mediterr. 1875, and Note sur les

esp^ces du genre Platidia, Journ. de Conch, vol. xvii. p. 300, 1879.

Shell small, semicircular or transversely oval, often irregular in shape and unequi-

lateral, wider than long, subpellucid, yellowish white. Dorsal valve flat and irregular,

assuming the shape of the objects upon which it lies in close contiguity ; concentrically

striated, and perforated by rather large canals ; deeply notched at the umbo by a large,

wide, semicircular aperture, which constitutes almost the entire foramen. Ilinge-line

straight, a little shorter than the breadth of the shell. Ventral valve uniformly convex,

cardinal angles rounded ; beak short, slightly incurved, beak-ridges sharply defined, with

a very narrow area or flattened space between them and the hinge-line, in the middle a

I)E. T. DAA'IDSON 0,\ EECE^"T BEACHIOPODA. 155

very Avidc, rudimentary, obtusely anyular lissurc represents the foramen, on each side of

which are two very narrow rudimentary deltidial plates. Shell irregularly concentrically

striated, Avith numerous small asperities rising- Irom its surface. Shell perforated hy

canals visible under feeble magnifying-power. Length 3 lines, breadth 5 lines. Valves

articulating by means of teeth and sockets. Interior of the dorsal valve not com-

pletely known. Short cylindrical processes project into the interior of the shell from a

little under each angle of the wide semicircular foramen, and from about the middle

of the bottom of the valve arises a thickened pillar-shaped process or septum, curved

towards the hinge, and forked at its extremity.

Rah. Found attached to large specimens of CaryophylUa ramosa from the coral-fisheries

near Tunis, and at other places in the Mediterranean (E. Deslongchamps and Fischer) ;

it was also dredged hy the Marquis de Folin at Cap Breton (Landes) in 25-70 fathoms.

OIjs. In exterior aspect this spegies quite resembles an Anomia. It is the largest form

of the genus 'Platijdia with which we are at present acquainted. It was well described

in 1855 by M. E. Deslongchamps, and subsequently with greater detail by Dr. Paul Fischer

in two memoirs already referred to. In his paper, M, E. Deslongchamps says : — The

dorsal valve is at times very irregular, owing chiefly to the shortness of the peduncle.

From a superficial examination of the animal in a dried condition my father and

myself were enabled to convince oui-selves that the labial appendages seem connected

with the apophysary system hy a kind of very delicate network, reminding one of the

descending apparatus in TheckUum, which in some species is formed in its upper portion

by a calcareous network freely suspended above the visceral cavity.

In his memoir on JPlutijdia, published in the ' Journal de Conchyliologie,' vol. xii.

p. 160, 1872, Dr. Paul Fischer describes and figures some good examples of Pluti/dla

Davidsoni dredged hy the Marquis de Folin from tlie Fosse du Cap Breton, which I have

also been able to examine through the liberality of the Marquis. In another paper,

issued in the Actes Soc. Linn. Bordeaux, t. xxix. 1874, Dr. P. Fischer says (p. 171) : —

The brachial apparatus is supported by a little calcareous forked pillar rising from

the middle of the dorsal valve. . . . The forked pillar is proportionally much longer

than in individuals of similar dimensions of IlegevUa tnmcatu. Mecjerlia tnmcata can

be so modified that the valves become moulded on their substratum ; this is occasioned

by the shortness of the peduncle, and therefore the peduncular aperture is found almost

completely transferred to the dorsal valve — a malformation raised to the rank of a

species by the name of J/<?i^er^i« mo«s^r«o«a, Scacchi ; but even in this case we recognize

the characters of the species at all ages, and at no stage do Ave find the rudimentary

apophysis of Flatydia Bacldsoni. Dr. Fischer proceeds [1. c.) : — The general arrangement

of the brachial appendage, in P. Duindsoni, is extremely simple. On each side of the

mouth proceeds a horizontal portion, which afterwards bends and forms an incurvature

(boucle). It is continued on each side by the running portion directed from tlu^

beak of the valve towards the frontal margin, and connected with the dorsal valve ;

this part (portion currente) bends, describes a complete circle, and returns above the

running portion, being in relation to the dorsal valve ; it ends at last l)y a sinuosity

SECOND SERIES. — ZOOLOGY, VOL. IV. 21

15G DR. T. DAVIDSON ON RECENT BRACHIOPODA.

directed towards the mouth. This is the rudiment of the spiral portion which is

moderately developed in Megerlia, and much more marked in Terehratula. The

brachial appendages (in Platydia Davidsoni) resemble therefore those of Platijdia

anomioides. The cii'ri of the arms are rather long, .... disposed in pairs, or rather

each cirrus seems to he divided into equal filaments. This character has been repre-

sented by Mr. Davidson in Platydia anomioides.

The characters of Tlatijdia Daridsoni are very remarkable. In Megerlia the

peduncvilar opening encroaches a little on the dorsal valve, more especially in the

variety monstruosa. In JPlatijdia anomioides the foramen is almost entirely on the

dorsal valve, and finally in JPlatydia Davidsoni the ventral valve is devoid of fissure,

and its beak forms a median projection. This remark, however, is scarcely correct,

for there exists under the beak an indication of a shallow fissure. There are,

continues Dr. Fischer, important exceptions among the articulated Brachiopoda, since

the perforated valve is not foraminated in 'Platydia Davidsoni. All these changes are

produced by the shortening of the peduncle, which obliges the Brachiopod to live in close

contiguity with a rock, and to rejiroduce the irregularity of the object upon which it is fixed.

Since the above was written, M. E. Deslongchamps has described the different stages

in the development of the loop in 3Iegerlia truncata, and points out that at one stage

the dissimilarity between it and Dlatydia, although apparent, is not so very great.

In Platydia anomioides the principal stems of tlie loop, after having become attached

to the base of the hinge-plate, become fixed to the central pillar-shaped process arising

from the bottom of the dorsal valve ; but in Platydia Davidsoni these principal stems,

in the specimens examined by M. E. Deslongchamps, Dr. Eischer, and myself, were

either broken or absent ; so that to ascertain tlicir real condition more specimens will

have to be examined hereafter.

Family THECIDIID^.

Genus THECIDIUM, Defrance, 1828.

We are acquainted with but two recent species of this genus, viz. Thecidium mediter-

raneum, Risso, 182(5, and Thecidium Barretti, Woodward, 1861.. The generic characters

have been fully described under Thecidium mediterraneum. The animal and embryology

of the bst-named species have been admirably described and illustrated by Lacaze-

Duthiers and otliers.

91. Theciditjm mediterraneum, Eisso. (Plate XXIII. figs. 12-22.)

Theddea mediterranea, Risso, Hist. Nat. des Priiicipales Prod, de TEurope meridionale, t. iv. p. 394,

pi. xii. fi-. 183, 1826; Blaiuville, Diet. Sc. Nat. t. liii. p. 434., 1828; Deshayes, Encycl. Meth., Vers,

t. iii. p. 135, 1830 ; Pliilippi, Emim. Moll. Sicilife, vol. i. p. 99, pi. vi. fig. 17, 1836, and vol. ii. p. 70, 1844.

Tliecidea? spondi/lea, ScaeeLi, Cat. Conch. Regni Neapolitani, p. 8, pi. ?, fi^s. 8-10, 1836.

Tliecidea mediterranea, Dcsh. cd. Lamarek's An. sans Vert. vol. vii. p. 346, 1836; Anton, Verzeichniss

Conch, p. 21, 1839 ; Kiister, nov. ed. Chemnitz's Couch.-Cah. pi. 2 c. figs. 22-25, 1843 ; G. B. Sowerby,

Thes. Conch, p. 371, pi. ixxiii. figs. 30-32, 1846.

Tliecidea testudinaria, Michelotti, Dese. des Foss. Jliocenes de PItalie Sept. p. 79, pi. ii. fig. 26, 1847.

DE. T. DAVIDSOIS' ON EECENT BRACHIOPODA. 157

Tlwcidea niediterraiica, O. (r. Costa, Fauna del Regno di Xajjoli, p. 19, pi. ix. figs. 1-3, 18.J2 ; David-

son, Ann. & Mag. Nat. Hist. 2nd scr. vol. ix. p. 374, 18r)2 ; A. Adams, The Genera of Recent MoUusca,

p. 581, pi. cxxxii. fig. 1, 18.")8.

Tlu'cidiuiii ijwditcrraneum, Davidson, Brit. Foss. Bracli. vol. i. Introduction, p. 77, fig. 2'.), 18.~>3 ;

Woodward and Gray, Catalogue of the Brachiopoda in the British Jluseum, p. 118, 1853; S. P.Wood-

ward, A Manual of the MoUusca, p. .'221, fig. 128, 185G; E. Sucss, Ueber die Wohnsitze dcr Brachio-

poden, Sitzungsb. k. Akad. dor Wissenseh. "Wien, Bd. xxxvii. p. 21G, 1859; Laeaze-Duthiers, His-

toirc de la Tlu'cidic mediterrancuin, Ann. des Sciences Nat. 4' ser. Zool. vol. xv. p. 259, pis. 1-5, 18G1.

Tenbrutula (Thec'nft'n) nicillh-rnitica, L. Reeve, Couch. Icon. pi. xi. fig. 48, 1861, and Ann. & Mag.

Nat. Hist. 3rd ser. vol. vii. p. 18G, 1861.

Tlwcidea mediterranea, Verani, Zool. dcs Alpes Maritimes, Nice, 1862 ; Chinu, Manuel de Conch,

vol. ii. p. 212, figs. 1087-1089, 1862.

Thi'c'idiiini iiicdikiraneinii, Davidson, Geol. Mag. vol. i. j). 11, pi. i. figs. 1-3, j)!. ii. figs. 5-10, 1864 j

E. Deslongehaiups, Rechcrchcssur I'orgauisationdu Manteau chcz Ics Brachioj)odcs Articuk's, p. 31, pi. iii.

figs. 10-12, Caen, 1861; 11. C. WeinkaufF, Die Conch, des Mittelmeercs, p. 291, 1867; Dall, Amer.

Journ. of Conch, vol. vi. p. 151, 1870, and Proc. Acad. Nat. Sci. Philadelphia, p. 195, 1873; Gwyn

.Icffrcys, Proc. Zool. Soc. 1878, p. 412, & 1881, p. 919.

Shell small, somewhat pyriformly ovate, variable in sliape, tliiciv, attached to laavinc

ohjects by a portion of the beak of the ventral valve. Colour dead white. Dorsal valve

thin, semicircular, sliglitly truncated in front ; hinge-line straight, shorter than the

breadth of the shell, gently convex, most so at the umbo, flattened near the margin.

Ventral valve more or less regularly pyriform, very convex, thickened, longitudinally

depressed along the middle ; beak callous, much produced, irregular on account of the

position and extent of its attached surf;xce ; area large, triangular. Hat, Avith a slightly

raised, flattened, triangular pseudo-deltidium ; no foramen ; shell-structure punctate.

Surface of valves smooth, marked with concentric lines of growth. In the interior of the

dorsal valve the hinge-plate is large, squarely oblong, prominent, and concave. There

exists outside each of the socket- depressions an oval muscular scar, attributed by Lacaze-

Duthiers to his " lateral adductor muscles " (adjustors of Hancock). A broad, thickened,

sloping, granulated margin encircles the valve, and forms a bridge (Plate XXIII. fig. 10,

h) over the small deep visceral cavity, and close to the basis of the hinge-plate, or cardinal

process. The granulations are larger and most prominent as they recede from the outer

margin. This inner denticulated or granvilated margin follows in a parallel manner the

margin of the shell from the In-idge-shaped process {h) until it nearly reaches the middle

of the frontal [c), where it suddenly stops and becomes inflected upwards. At the point

(c) the margin is again directed upwards, producing a second parallel curve, when at {e)

by another downward curve it forms a tliird short parallel concave curve, until it reaches

the point {f) near the centre of the valve, where it combines with the similar inflections

of the other lialf of tlie shell, so as to produce on tlie median line an upwardly produced

tongue-shaped process (/y), the angular extremity of which is directed towards the middle

of the bridge-shaped process {h). These four symmetrically bent ridges or lobes con-

stitute M. E. Dcslongchamps's " ascending apparatus," the central portions (/ and g)

are more elevated than the other parts, and overlie a portion of the visceral cavity.

The parallel grooves or spaces left between the ridges above described are partially

21*

158 DR. T. DAVIDSON OX EECEXT BRACHIOPODA.

occupied by a lamella in the shape of a double crescent {i and 1-), of which the larger

branches (i) partly occupy the large cavities left between the first and second ridges,

these being on their inner sides intimately united with the sides of the grooves ; while

the shorter branches {^■) are freely suspended over the visceral cavity, and occupy the

spaces left between the third and fourth ridges of the ascending apparatus. To these

crescent-shaped lamellae M. Deslougchamps has given the name of " descending appa-

ratus." The interior of the ventral valve is concave and deep, with a small longitudinal,

rounded, mesial elevation ; the hinge-line is straight, and on each side at the base of the

deltidium strong hinge-teeth for the articulation of the valves are situated. The beak is

hollow ; l)ut there exists on the median line, and far back in the cavity, a small elevated

septum, to each side of which is attached a very small thin concave plate (Plate XXIII.

fig. 15, b), to Avhich, according to M. Lacaze-Duthiers, the adductor muscle, or " occlusor "

of Hancock, was attached. On the bottom of the valve, a little low^er down, and on each

side of the mesial elevation, and partly under the cavity of the beak, a large pyriform scar

is observable, to which the " divaricator muscles " of Hancock were attached (c) ; and,

lastly, external to these, on the bottom of the valve, and near the angles of the hinge-line,

there exists a small oval scar (a), which is believed to have been produced by the "ven-

tral adjuster " of Hancock. The remaining surface of the shell is closely covered with

numerous granulations or asperities. Length 3 lines, breadth 2|, depth 2 lines.

Hab. Mediterranean, especially on the African coast, in from 30 to 300 fathoms.

Bay of Xaples ; off the coast of Sicily. Algerian coast, from Bone to near Cape Eosa.

Off Jamaica, 60 to 150 fathoms (L. Barrett). In the Gulf of Mexico (' Blake ' Expedi-

tion), 163 fathoms. It is also stated by Sir H. Barkly to occur off Mauritius ; but this

statement must be taken with reserve.

TheckUmn mediterraneum occurs fossil in the Miocene and Pliocene rocks of Italy.

Ohs. The animal and its embryology have been admirably described and illustrated by

M. Lacaze-Duthiers. We extract the following notes from his important paper : —

Belative to the muscles, M. Lacaze-Dvithiers states that there are three pairs, six in

all, possessing distinct directions and functions. Of these muscles, two (woodcuts, figs. 16,

17, 18, a) are lateral, short, wdde, easily observal^le, and serve without doubt for the

occlusion of the shell. These are M. Lacaze-Duthiers's " muscles adducteurs lateraux ou

externes," which, Mr. Hancock informs me, Avould represent his "adjustors," but that the

function of this pair of muscles does not appear to be exactly similar to the " adjustors "

of Waklheimia, in which they move the shell upon the pedicle ; in ThecicUum they

assist in closing the valves suddenly, and in preventing any irregular or lateral movements

W'hich, from the central position of the occlusors, might be liable to take place. In fact,

he believes that the function of the "adjustors " in ThecicUum is modified much as it is

in the same muscles of Linr/ida; and he is therefore inclined to conjecture that the two

valves of the former are not so firmly hinged as they are in the other articulated forms.

The second pair of muscles {h of woodcuts) are those nearest to the median line ; these

are termed " muscles adducteurs internes " h\ M. Lacaze-Duthiers, and correspond, or are

equivalent to, Mr. Hancock's anterior or posterior occlusors. In the central valve these

DE. T. DAVIDSOX OX EECEXT BRACIIIOPODA.

159

muscles would bo fixed to the bottom of tlic valve, nearly iiiider the extremity of the touguc-

shaped "ascending shelly process" already descril)ed (Plate XXIII. fig. IG, cj), and be again

attached to the two thin shelly processes (Plate XXIII. fig. 15, b) which we have described

Fkr. 10.

Fisr. 17.

V\<x. IS.

After Lacazc-Diithiors, ' Annalcs des Sciences Xaturollcs,' Zool. t. xv. pi. i. figs. 7, 8, 9.

Fig. K). Longitudinal section of TheckUum, to give an idea of the manner in which the median muscles act : n

curved lamelhr, which are supported by and attached to a small septum under the beak in the ventral

valve : h, median adductor muscle of Lacaze-Duthiers ( = occlusor of Hancock); c, adductor muscle of Lacaze-

Duthiers, which is attached by one extremity to tlu; bottom of the ventral valve, and by the other end to

the extremity of the quadrilateral cardinal process of the dorsal valve. 31. Laea/.e-Duthiers states that

the mechanism of the opening and occlusion of the shell can be thus formulated : when the animal

wishes to open its shell, the power, P, is represented by the muscle (c), its point of application being at

the extremity of the cardinal process of the ventral valve ; the resistance, E, is the weight of the valve

which has to be raised ; the point of support is found at A ; we have, thus represented, a lever of the

first kind. When the shell has to be closed, the same analysis would be applied to the lateral muscles,

reversing, however, the power and the resistance, the point of support being always at the articulation A.

Fig. 17. Animal, with the lobes of the mantle spread out, viewed from the side of the shell so as to exhibit M.

Lacaze-Duthiers's {a) muscles adducteiirs lateraux (Hancock's adjusters) ; J, Lacaze-Duthicrs's " muscles

abductours medians " Cllancock's occlusors), of which one extremity passes between the " muscles abduc-

teurs " (<■), and the other is directed outwardly to make room for the intestine ((7) which is the continua-

tion of the lobes of the liver (e) ; c is Hancock's divaricator.

Fig. IS. Animal, separated from the shell, and seen on the face which corresponds to the coTicavo valve : a. lateral

adductor muscle of Lacaze-Duthiers ; h, median adductor muscle, of which the extremity only can be

seen, which attaches itself to the bottom of the lamcllai under the beak of the ventral valve : c, adductor

muscle slightly curved, of which the two extremities can be seen.

as existing in the cavity of the beak. The function of these muscles (as stated by j\[.

Lacaze-Duthiers) would also be to effect a closing of the valves, but less efficaciously than

the preceding pair. The third pair, designated " muscles abducteurs " l)y the same author

(woodcuts, figs. IG, 17, 18, c), arc Mr. Hancock's " divaricators," and tlieir function Avoukl

be to open the valves. They form large impressions on tlie bottom of the ventral valve, on

IGO DR. T. DAVIDSON ON KECEXT BliACHIOPODA.

each side of the central septum (Plate XXIII. fig. 15, c) and Liave their outer end attached

to the extremity of the cardinal process of the dorsal valve. M. Lacaze-Duthiers has had

the opportunity of studying a vast numher of individuals of this species of Thecidiiiia in

the living state ; and he mentions that, contrary to what we find to be the case in Tei^e-

hraiula, the animal opens its shell very widely — the dorsal valve rising on its hinge at

right angles to the ventral valve, like the lid of a snuff-box (woodcut, fig. 16, c). The

animal is also sensible to light and darkness ; and it draws down its smaller valve with

the rapidity of lightning on the approach of danger.

M. Lacaze-Duthiers further observes that the mantle is exceedingly thin, and is not

famished round the margin with any of the long setse which exist in Terebratula and

L'mgida, and that the genital lobe (the one which corresponds to the concave or ventral

valve) differs much from the other, and is characterized in its thickest lobe, or central

portion (that is to say, towards the deep and concave j)ortion of the valve), by very thick

calcareous plates, the analogues of the plates and spicula occurring in the mantle of Tere-

hratula. Tiiese plates in Thecidium participate in the character of the shell itself, being

smooth on the under surface, and covered on the npperside with asperities similar to those

which cover the entire surface of the bottom of the valve. The plates are very thick, and

form a ceiling or vault over the cavity which contains the organs of reproduccion. Tliey

have been carefully described and figured by M. J. Bosquet, M. E. Deslongchamps, and

myself, as seen in several fossil species, and in particular in Thecidium cermlculare, from

the Upper Cretaceous beds of the Duchy of Limbourg.

M. E. Deslongchamps says, at pp. 30, 31 of his memoir on the Organization of the

Mantle in the Articulate Brachiopoda: — In short, the Thecidiidte possess an altogether

peculiar organization of the mantle. Calcareous spicules crowding the external laminae

are no longer present, but true calcareous plates which obliterate almost the whole

interior, and form, as it were, a second shell, line the interior of the valves, and

give them a most strange and elegant appearance. We will not now repeat the details

of the conformation of these curious lamina? constituting the pallial apparatus, which

can, it would seem, be better studied in the fossil than in the recent species, and of which

a large number of authors have given excellent descriptions. We will only mention that

this apparatus undergoes very great modifications in different species, being sometimes

excessively complicated, as in T. recurvlrostrls, whilst in others this apparatus is

reduced to an indistinctly marked single lamella, as in T. Perrleri

Another very striking peculiarity is revealed to us in the organization of the tissues of

Tliecidea medUerranea. We have seen hitherto, except hiArglope, which formed the ex-

ception, that it was in the arms and their cirri that the calcareous spicula wevQ especially

developed, and that it was in these organs that they began to appear in the earliest stages of

the shells, extending progressively on the two laminae of the mantle. We note that precisely

the contrary occurs among the Tliecididae. The majitle is no longer, so to say, merely a

calcareous mass, and the arms and their cirri do not show the smallest trace of spicula or

even of calcareous granulations It is apparent that the arms constitute a simple

diaphanous membrane, which is rather difficult to distinguish even by a feeble magnifying-

DR. T. DAYIDSOX ON EECEXT BRACIIIOPODA, Kil

power, as tlio walls avo so dcliratc; whilst the calcified portion of the mantle is very

thick, of a dull white colour, apparently of a spongy nature, and under the same

enlargement seems to us much nun-e compact than even the walls of tlio shell. In oi-dcr

to realize the diverse condition of the mantle thus calciGcd, we must call to our aid high

magnit'ying-])owcr.

]\I. Lacaze-Uuthiors states, in the work previously quoted, that the so-termed " oral

arms " or lal)ial appendages of Thocidium resemhle those of other Brachiopoda, except that

they are not free, hut adhere throughout their extent ; that the swollen basis certainly

presents a canal similar to that which exists in the other animals of the same group, and

that this longitudinal canal is present throughout their length, heing almost confounded

with the mantle, or with the margin of the body, and is even located in the insertion of the

arms. These "arms" are inserted by their basis, not on the intermediate or lateral

lamella, or external lamella (" descending crescent-shaped processes "), but on the edge

of the "ascending apparatus." Their direction is that of the lamina on which they are

supported ; and they reach, after having described the inflections already indicated, the

median point of the tongue-shaped process, where their two extremities arc located. This

arrangement is shown in PL XXIII. fig. lO, Avhich is copied from one I published first

in the 'Annals and Magazine of Nat. Hist.' for May 1852, and afterwards reproduced in

Dr. AVoodward's ' Manual of the Mollusca.' The cirri of the arms are long and flexible.

Space will not permit us to follow M. Lacaze-Duthiers in bis admirable observations in

connection with the anatomy of the animal, further than to say that he minutely describes

the position of the animal in the shell, the mantle, muscles, the organs of nutrition, the

arms and their cirri, the moutli and its lips, the liver, stomach, intestines, circvilation,

respiration, the special glands, nervous system, the male and female organs of repro-

duction, &c. He adds, that French zoologists consider, with some other naturalists,

that respiration is probably effected partly by the labial appendages, which bear a

great analogy to the gills of other Mollusca, and that he has not been able to discover

any anal aperture — a fact strongly urged by Messrs. Huxley, Hancock, Gratiolet,

and others for Terehratula and EliynclioneUa. M. Lacaze-Duthiers is of opinion that

the sexes are distinct, or, in other words, that there is a male and female animal; but

Mr. Hancock considers this to be uncertain, and is disposed to hold the opinion that the

sexes are combined in the same animal.

M. Lacaze-Duthiers concludes his elaborate series of anatomical observations with

many important details in connection wdth the embryonic condition of Thecklmm medi-

terraneuin, but states that it was not possible for him to follow out in a complete manner

every successive stage of its development. The youngest egg that he was able to

observe had already acquired a rather elongated pyriform shape, and what attracted

most notice was the large size of the cells of which it was composed, which also

contained a large quantity of granulations, of a comparatively enormous size.

The egg at this stage is very similar, at least in general appearance, to a mass of

vegetable cells full of feculse. Towards one of the extremities of the egg the connection

with the bourlet or cap of the suspensory filaments may be found, and however little

1G2 DE. T. DAVIDSOA^ ON EECENT BEACHIOPODA.

the glass slides are shaken between which the embryos are placed they become ruptured,

and the cells and granulations that they contain escape.

In the next stage which M. Lacaze-Duthiers found in the same group of young, the

embryo no longer presented a uniform mass, but was divided into two halves, one of

which, more voluminous than the other, Avas in every case found attached to the tipper

filament.

After many details which I have not space to reproduce, M. Lacaze-Duthiers con-

cludes by saying (p. 324) : — On the lower face, an embryo in the more advanced state

shoAvs four eye-shaped spots, visible in the thickness of its anterior intermediary lobe.

A distribution of yellowish matter recalls tolerably well the origin of the liver in the

Acephala or the Gasteropoda ; it is probably in the middle of these small agglome-

rations of yellowish matter that the stomach is excavated, and one may already recognize

in these series of little bundles the lobules and secretory glands of the liver of the adult

TheckUum. We have reproduced on Plate XXIII. a few of M. Lacaze-Duthiers's admir-

able illustrations of the embryo with two and four lobes.

92. Thecidium Baeeetti, Woodward, MS. (Plate XXIII. figs. 9-11.)

Thecidium Barretti, Davidson, Geol. Mag. vol. i. p. 17, pi. ii. figs. 1, 2, 3, 1864 ; Crosse, Journ. cle

Concli, 3" ser. t. vi. p. 272, 1866; Dall, Amer. Jouru. of Couch, vol. vi. p. 151, 1870, Bull. Mus. Comp.

Zool., Harvard, vol. iii. p. 42, 1871.

Shell small, somewhat pyriformly ovate, attached to marine ol)jects by a portion of the

back of its beak. Dorsal valve semicircular, flattened, and slightly convex at the umbo.

Ventral valve somewhat pyriform, very convex, deep, and thickened ; beak mode-

rately produced ; area triangular, but more or less irregular on account of the position

and extent of the attached surface. The interior of the dorsal valve is slightly concave'

with an oblong, square-shaped, prominent, cardinal process between the dental sockets.

A broad, thickened, raised, granulated margin encircles the valve, and forms a bridge

over the small, deep, visceral cavity, close to the basis of the cardinal process ; the gra-

nulations are larger and more prominent on the inner margin. On reaching the front,

near the middle, the margin suddenly cm-ves upwards on each side, and unites so as to

form a central A-shaped ascending process {[/), the attenuated extremity of which is direc-

ted towards the middle of the bridge- shaped process {h) already described in TheckUum

medUcrraneum (see PL XXIII. fig. IG). The descending apparatus (/, k) is united close

to the extremity of the central angular ascending process, and follows at a little distance

the curves of the inner margin of the same ascending process. Length and breadth

about 2 lines. Colour white.

Hah. This small and well-characterized species was obtained by Lucas Barrett at 60

fathoms off the north-east coast of Jamaica, and was found fossil by him in the newest

Pliocene beds of that island.

Ohs. In external shape Thecidium Barretti cannot be distinguished from the Mediter-

ranean species ; but its interior is very different, and resembles, in its simple arrange-

ment, that of several Jurassic forms, such as Thecidium Moorii, T. triaiKjulure, &c.

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 163

Family RHYNCHONELLIDyE.

The genus BhiinchoneUa, Fisclier, 1809, and the genus Atrctia, Gwyn Jeffreys, are the

only representatives of this family found in the recent state.

The genus Mhynchonella is one of the oldest types of life, and has heen largely repre-

sented since Silurian times. Sis species are still living in tlu^ present seas, viz. : —

1. RhjiichoncUa psittacea, Clicmiiitz, 1780.

2. 7ii(jncans, Sowerby, 184-6.

3. I u eld a, iio\\\ A, 1860.

4. Rhynchonella cornea, Fischer, 1885.

5. Gray}, Wocxhviu'd, 18").").

0. Dodo/cini, Davidson, 188u.

The first two species are very abundant, the others much less so. Of the spiny Ehyn-

chonella D'dtlerlehii four specimens have heen dredged, and we are only acquainted with a

single example of lUtynchonella Grayi. The shell in all is fibrous and impunctate.

The genus Rhynchonella is characterized by a very insignificant development of internal

septa. In the ventral valve generally only dental plates are present, which do not unite

in the middle line, and in the dorsal valve an inconspicuous median septum is developed.

The hinge-plate is deeply divided, supporting two slender curved lamelke. The animal

has elongated spiral labial appendages, directed imvard towards the concavity of the dorsal

valve. Mantle not adhering, its margin fringed with a few short seta;.

93. llHTNcnoNELLA PSITTACEA, Chemnitz, sp. (Plate XXIV. figs. 1-11.)

Anomia, Lister, Hist, sive Syu. methodicae Concliylioruiu, tab. 211. fig. 46, 1685.

Bee de per roquet, Davila, Cat. Syst. vol. i. pi. xx., 1767.

Anomia ?, Lister, Couch, tab. ccxi. fig. 16, 17(58; Favanne dc Moiitcervellc, La Conchy) iologie,

pi. xli. fig. 24, 1780.

Anomia rostrum psittacea, Chemnitz, Neues syst. Couch. -Cab. vol. viii. pi. Ixxviii. fig. 713, 1785.

Anomia uquilina, Solander, MS. no. 14, 1757.

Lampas psittacei, Calonnc, Catalogue of the various articles which compose the Coll. of ]\I. de

Calonne, 1797.

Anomia psittacea, Gmeliu, Linn. Syst. Nat. p. 3319, 1788.

Anomia , d'Argenville, Hist. Nat. Conchyliologie, etc. tab. 23.

Terebratula psittacea, Bruguierc, Encyclop. Meth. pi. ccxliv. figs. 3a, 3i, 1789; Klein, Tentamen

Methodi Ostracologica-, pi. xii. fig. 84, 1753.

Ano7nia psittacea, Dilhvyn, Descriptive Catalogue of Recent Shells, p. 293, 1817.

Terebratula psittacea, Lamarck, An. sans Vert. vol. vi. p. 248, 1819.

Anomia psittacea, Turton, A Conch. Dictionary of the British Islands, p. 5, figs. 42-44, 1819.

Terebratula psittacea, Fleming, Hist, of Br. An. vol. i. p. 368, 1828.

Gijjndia psittacea, ^Meuke, Syn. Meth. Moll. p. 96, 1828-30.

Terebratula psittacea, Blainville, Diet. Sci. Nat. t. liii. p. 140, 1828 ; Miiller, Index Moll. Gronlandiae,

Nat. Tidsskr. iv. p. 76 ; Owen, On the Anatomy of Terebratula, Trans. Zool. Soc. vol. i. p. 146, pi. xxii.,

1833 ; Quenstedt, Ueber das Oeffnen und Schliessen der Brachiopodeu, Wicgraann's Archiv, Bd. ii. p. 220,

pi. iv. figs. ,1 & 6, 1835; Davidson, Ann. & Mag. Nat. Hist. ;:nd ser. vol. xvi. p. 436, 1855; Lamarck,

An. sans Vert. vol. vii. p. 333, 1836 ; Anton, Verzeichniss der Conchylien, p. 23, 1839; G. B. Sowerby,

A Conch. Manual, p. 203, 1842; Kiister, Chemnitz's Conch.-Cub. vol. vii. pi. ii. figs. 18-20, 1813;

Sowerby, Thes. Conch, p. 342, pi. Ixxi. figs. 78 80, 1846.

Hiipothyris psittacea, King, Ann. & Mag. Nat. Hist. vol. xviii. p. 238, 1846.

Hemithyris psittacea, d'Orbiguy, Considerations Zool. sur Ics Brachiopodes, Comptes Rendus, t. xxv.

p. 268, 1847.

SECOND SEllIES. — ZOOLOGY, VOL. IV. 22

164 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

Hi/pothyrispsittacea,Fovhes8i}Iaji.\ej,A History of British Mollusca, vol. ii. p. 3 IG, pi. Ivii.figs. 1-3, 1849.

Rhyncho7iella psittacea, Quenstedt, Handbuch der Petrefakteukunde, pl. 35. fig. 44, 18.51 ; Davidson,

Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 374, 18.52 ; L. Barrett, Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi.

p. 259, 1855; S. P. Woodward, A Manual of the Mollusca, p. 225, figs. 138 & 189, 1856 ; A. Adams, The

Genera of Recent Mollusca, vol. ii. p. 582, pl. cxxxii. fig. 2, 1858; A. Hancock, On the Organization of the

Brachiopoda, Phil. Trans, vol. cxlviii., 1858 ; E. Sness, Ueber die Wolinsitze der Brachiopoden, Sitzungsb.

k. Akad. Wissensch. Wien, p. 218, 1859 ; L. Reeve, Monogr. of Rhynchonclla, pl. i. fig. 2, 1861.

Hemithyris psittacea, M'Coy, Synopsis of a Classification of the British Palaeozoic Fos.sils, p. 199, 1865.

Rhynchonella psittacea, Gwyn Jeffreys, British Conchology, vol. v. p. IGl, 1869, and Proc. Zool. Soc.

1878, p. 413 ; Gould, Report on the Terebratulce of Massachusetts, p. 210, fig. 501, 1870.

Hemithyris psittacea, Dall, Proc. Acad. Nat. Sci. Philadelpliia, 1873, p. 196.

Rliynchonella psittacea, Davidson, Brit. Foss. Brach. vol. iv. pp. 8 & 16, pl. ii. fig. 5, 1874 ; G. O. Sars,

Moll. Regionis Arcticse Norvegiee, p. 9, t. i. fig. 1, 1878; Whiteaves, Canadian Naturalist, vol. viii.

no. 8, 1878; G. Dunker, Index Mollusc, maris Japonici, p. 253, 1882; Davidson, Brit. Fossil Brach.

vol. v. p. 331 etc., 1884.

Shell somewhat triangular, globose, broadest anteriorly, tapering posteriorly, lateral

margins rounded. Dorsal valve inflated, especially at the umbo, more or less divided

into three lobes, of Avbich the central one forms a mesial fold, scarcely defined in some

specimens, much more so in others ; front line nearly straight or three-lobed. Ventral

valve much less convex than the dorsal one, rather flattened, with a broad, channelled,

flattened, longitudinal mesial sinus ; beak sharply pointed, incurved, under which is

situated an incomplete elongated foramen, margined anteriorly by the umbo, and

laterally by triangular deltidial plates ; beak-ridges not sharply defined ; lateral

margins of the valves sinuous, curved in front. Surface of valves radiately and

finely striated. Shell-structure fibrous. Valves strongly articulated by curved teeth

in the ventral valve, fitting into sockets in the dorsal one. Hinge-plate in the dorsal

valve deeply divided, supporting two short, flattened, grooved and curved lamellte. At

the bottom of the dorsal valve are seen the quadruple muscular impressions left by the

adductor or occlusor muscles, each pair beiug separated by a short medio-longitudinal

ridge. In the interior of the ventral valve the teeth are supported by dental plates

extending to tlie bottom of the valve, and at their base a semicircular ridge on either

side encloses a saucer-shaped depression in which are situated the muscular scars. Close

under the beak the peduncular muscles leave a small scar ; lower down and towards

the centre of the valve is situated a divided heart-shaped scar due to the adductor or

occlusor muscles ; and on each side of these are situated, one above the other, the divari-

cator and ventral adjuster muscular impressions. The animal is provided with elongated

spiral arms, directed inwards, towards the concavity of the dorsal valve ; alimentary

canal terminates behind the insertions of the adductor in the ventral valve ; mantle not

adhering, its margin fringed witli a few short setae. Colour bluish or a brown-black.

Length 1 inch 3 lines, width 1 inch 1 line, depth 9 lines.

Rab. Bhijnchonella psittncea is circumpolar in its distribution. It was dredged in

Eranklin-Pierce Bay, lat. 79° 25' N., in 15 fathoms, and at Cape Napoleon in 15 fathoms,

by Nares's Arctic Expedition in 1875, being in fact the only Brachiopod obtained

by the ' Alert ' and ' Discovery ' in those polar regions. R. psittacea abounds in the

DR. T. DAVIDSON ON EECENT BEACHIOPODA. 165

Norwogian Seas, from Drontheim to the North Cajie ; off Shetland ; Grand Greve, Gaspav

Bay, Canada East ; Unalashka to Shumagins in the Aleutian Chain (Dall) ; Banks of

St. Margaret Bay; Russian Lapland to Sitka; from Behring Strait to Japan in North

Pacific; in the Gulf of St. Lawrence, Canada, and in several other places.

Fossil. It occurs in the Upper Tertiaries of Great Britain, Ireland, Scandinavia, Canada,

Sicily, south of Spain, &c.

Obs. Until 1S()9, when Fischer de Waldheim proposed his excellent genus Ithijncho-

nella, the shell under description had been described under the fancy and generic names

of ''Bee de perroquet,'" Anomia and Terebratiila; since then sometimes by those of

Hemithyris, Hypothtjris, Lampas, and Gi/pidea ; but Fischer's name Rhynchonella is the

generic designation by which the shell has been generally known, and that which should

hold priority over all others.

Rhynchonella psUtacea does not vary very much in external shape ; young specimens

are, however, more triangular, less convex, and with a more elongated triangularly shaped

beak. The dorsal valve in some adult examples is uniformly convex, while others show

a well-defiued mesial fold. The intimate structure of the shell of Rhynchonella has been

carefully studied, described, and illustrated by Dr. W. B. Carpenter in various jiapers.

He says : — " No one who examines the shells of the Recent Rhynchonella psittacea and

Rh. nigricans, even in the most superficial manner, can have any hesitation in recognizing

the entire absence of the superficial ' punctuations ' which mark the orifices of the shell-

canals in the recent species of TevebratuUdce; and the most careful microscopic exami-

nation of these sections of the shell, taken from any part and in any direction, does but

confirm this conclusion. ... In all other respects the intimate structure of the shell cor-

responds precisely with that of Terebratulidce ; but it may be mentioned that the prismatic

laminoD are less adherent to each other than in the perforated shells, so that they are

readily split asunder." (' On the Intimate Structure of the Shells of Brachiopoda,'

Palseontological Society, p. 35, 1851.)

The animal of R. psittacea and its anatomical characters were carefully described

by Richard 0^ven in 1833, and especially by Albany Hancock, in his admirable

memoir " On the Organization of the Brachiopoda," in the Philosophical Transactions of

the Royal Society for 1858. 'Wq arc likewise indebted to Prof. T. H. Huxley for several

valuable anatomical details published in vol. vii. of the Proceedings of the Royal Society

for 1854, as well as to several other distinguished zoologists. In 1835 Quenstedt, in

Wiegmann's Archiv, Bd. ii. p, 220, founding his views on very precise reasons derived

from the mode of attachment of the valves in Rhynchonella psittacea, pointed out the

two orders of muscles, of which one closed, while the other opened the valves.

Mr. Lucas Barrett informs us that he found Rhynchonella psittacea A-ery difficult to

exaiuine, the animal being extremelv timid and closed its valves on the slightest move-

ment ; the coiled arms are extended, so that the cirri come as far as the margin of the

shell, but it never protruded its arms *.

In Rhynchonella psittacea, as well as in other species of the genus, the elongated spiral

appendages are supported at their origin only by two short, curved, projecting calcareous

* Annals & Mag. Nat. Hist. 2nd ser. vol. xvi. p. 259, 1855.

22*

166 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

jirocesses ; they can bo uurolled at the will of the auimal and protruded to some distance

beyond the margins of the valves, contrary to the statement made by Barrett. When

forci])ly stretched out they are said to be more than four times the length of the shell,

and support some 3000 cii'ri. In a note on the extension of the coiled arms in Rhyn-

chonella j:>si(tacea, published in the ' Amer. Journ. Sci. & Arts,' 3rd ser. vol. xvii. 1879,

p. 257, Prof. Morse says : — " Years ago von Buch recorded that Otto Erederic Miiller had

observed Rliijnclionella j^sittacea protrude its arms beyond the anterior borders of the

shell. This single observation was not widely accepted, and many doubted the possibility

of the arms being exerted in this manner. In the year 1872, Avhile studying living

Rliynchonella in the St. Lawrence, I observed a specimen protrude its arms to a distance of

four centimeters beyond the anterior borders of the shell, a distance nearly equaling twice

the length of the shell. This year I again had an opportunity of studying Rhynclionella in

Hakodate, Yesso, and again observed the same features. Specimens lying on the bottom of

a glass dish protruded their arms a short distance, and remained in this position for hours.

.... The movements of the arms were very sluggish, though the cirri were constantly

in motion. Sometimes the shells closed upon the arms before they were retracted."

In 1833 Owen [1. c.) gave a figure in illustration of the arms, one of which has been

artificially unfolded. Space will unfortunately not admit of my reproducing all the

admirable details in connection with the anatomy of R. j^s/ttacea so well described and

illustrated by A. Hancock ; we will, however, refer to the most important features.

" In Rhynchonella psittacea (p. 799, I. c.) the general disposition of the muscles is the

same as in W. mistralis, only they are longer and more slender, particularly the occlusors,

Avhich, with the exception of their extremities, are thin and tendinous. The surfaces of

attachment also vary a little in form, as can be readily seen on removing the shell. The

extremities of the muscles are then observed, as usual, at the ventral surface of the

animal, clustered together, a little in advance of the umbonal region. The occlusors are

almost colourless, narrow and elongated, and have their anterior margins united on the

median line ; posteriorly they diverge, leaving a space between them, in Avhich the

terminal extremity of the intestine is seen. The divaricators are very large, and are

placed external to, and in contact with, the occlusors ; they are broad and fan-like in front,

exhibiting radiating divisions, and meet on the median line, in advance of the occlusors.

Behind they are produced and pointed. The ventral adjuster muscles have their

extremities narrow and much elongated ; they rest agaiust the external margin of the

divaricators, are enlarged a little, and converge posteriorly. Unlike Waldheimia, there

is here a pair of peduncular muscles seen at the sides of the umbo, having between

them the accessory divaricators, which are of a somewhat triangular form. The dorsal

terminations of the occlusors present nothing remarkable in their appearance. All the

extremities of the muscles seen at the surface of the animal are of a yellowish-red coloux*,

except those of the peduncular muscles and the ventral terminations of the occlusors . . .

The muscles (l. c. p. 805) in the Terebratididce and RhynGlionellklce are peculiar for their

enlarged, fleshy extremities, and for the attenuated, tendinous character of their inter-

mediate portions . . .

*' The arms [p. 802] of R. psittacea are totally deprived of calcareous support except at

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 167

their origin, where they arc sustained by tlie two lunye-processes, or oral lamina.', the

points of which reach as far forward as their external margins. They fill up the greater

portion of the pallial chamber ; and in their arrangement accurately resemble the cal-

careous spirals of Atrijpa reticularis, a Silurian fossil, only their approximate sides are not

flattened. The arm throughout is composed of a slightly depressed tube or canal, carrying

along its outer margin the semi-cartilaginous grooved edge, bearing the fringe of cirri as

in W. auslrails. The brachial fold in front of the groove is largely developed, and com-

pletely overlaps it. The tube or the great brachial canal terminates at the side of the

oesophagus in a delicate membranous sac of no great extent, which projects into the

perivisceral chamber, as first noticed by Prof. Huxley . . .

" The parietes of the great canal are somewhat stouter than in W. australis ; the mus-

cular fibres, however, are arranged in the same manner as in it, but are more numerous,

particularly the longitudinal ones, which form a well-defined band towards the proximal

extremity of the arm .... A large development of the brachial apparatus seems

necessary in the economy of the animal, and the various ways in which it is folded up

and disposed within the pallial chamber are only so many methods of arranging within a

limited space the requisite extent of organ."

Mr. Hancock seems to doubt the unrolling and projection of the arms in Hhynchonella

or that the arms arc in any way instrumental in opening the valves.

" In H. psiltacea [p. 814] the disposition of the alimentary canal is the same as iu the

Terebratulida}. The oesophagus is, however, considerably longer than in Waldheimia, the

mouth approaching much nearer to the ventral valve. The liver is larger than usual,

and the hiliary secretion is conveyed through the lateral walls of the cardiac extremity

of the stomach by four short ducts, two at each side, one being placed a little in advance

of the other.

"The intestine is rallier long and gradually tapers downwards. On reaching the

ventral valve, directly behind the extremities of the occlusor muscles, it turns backw^ards

and upwards, and, detaching itself from the mesentery, advances a little, and ter-

minates in a much enlarged, rounded extremity, which inclines to the right or

left, varying in this respect in different individuals. The termination projects freely

into the centre of the perivisceral chamber, and here, as in the TerehralHlldoi, there

is no anus ; the bulbous enlargement is entire, exhibiting no opening whatever. . . .

In BhynchoHella the gastro-parietal and ilio-parietal hands, jiarticularly the latter, are

longer than in Wcddheimia .... The reproductive organs [p. 818] have much the same

disposition iu Rhi/nchonella psittacea [as in the other Terebratnlidce], but the dorsal

genital sinuses arc not connected with the so-called vascular trunks, while the ventral

are. The genital band, too, which is yellow, is much more closely convoluted, having

sometimes almost the appearance of being fused into one mass, the interstices being just

sutficient to permit the passage of the muscular ties, which are stout, and are arranged in

imperfect longitudinal and diagonal lines. These ties give a granulated or pitted

appearance to the ovarian impression in the shell, and are worthy of the attention of

the palaeontologist. . . .

" There are two of these oviducts In all the Brachiopods that have come under my

168 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

observation, except in Rhynchonella, in whicli there are four, as first pointed out by

Prof. Huxley two [p. 821] within the ventral, and two within the dorsal valve ;

both paii's are precisely similar, and are of a yellowish colour .... The central portion

of the blood-system in Rhynchonella is arranged much as in the Terchratulldce .... In

a. psittacea [p. 829] tlie setae are slender, short, and finely pointed ; they vary in length,

as they do indeed in all the species, and occasionally three or four issue out of one

follicle .... The great cavity [of the perivisceral chamber], placed close to the hinge of

the valves, in which the viscera are lodged, is limited above and below by the dorsal and

ventral walls of the body, and in front by the inflections of the inner laminae of the pallial

lobes." In conclusion, Mr. Hancock describes at great length the nervous sj^stem, to

which we cannot refer.

Rhynchonella psittacea, var. Woodwardi, A. Adams. (Plate XXIV. figs. 12-13.)

Rhynchonella Woodivardii, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 100, 1863.

Rhynchonella psittacea, var. Woodwardi, Davidson, Proc. Zool. Soc. 1871, p. 309, pi. xxxi. fig. 12.

Mr. Adams states in his paper that " this species differs from R. psittacea in being

concentrically striolate instead of radiately grooved ; the beak, moreover, is smaller and

less curved ; the foramen is more broadly triangular, and the ventral margin rounded and

produced in the middle. The young possess the same characters seen in more adult

specimens."

Hah. Gotto, 48 fathoms ; also off Ptifunsiri Islands, four miles from the shore, in

35 fathoms, from a bottom of coral, broken shells, and stones.

I have been able to examine two examples of this shell, given to me by Mr. Adams,

and could distinctly perceive faintly radiating striae, similar to those that cover the surface

of B,. psittacea. I cannot help thinking, and am confirmed in this opinion by Dr. Gwvn

Jeffreys, that thei?. Woodioardi of Adams is no more than a local variety of i?. psittacea.

The specimens obtained by Mr. Adams are of a less bluish tint than we find usually

in the shell last named, but some examples from the Northern European seas have also

assumed tliat colour.

94. Rhynchonella lucida, Gould. (Plate XXIV. figs. 14-15 h.)

Rhynchonella lucida, Gon]d,'Proc. Boston Soc. Nat. Hist. p. 323, 1800; Otia Concli. p. 120; and

Proc. Boston Soc. Nat. Hist. vol. vii. p. 323, 1871 ; E. Suess, Ueberdie Wolmsitze der Brachiopoden,

Sitzungsb. k. Akad. Wissensch. Wien, p. 219, 1859 ; A. Adams, Ann. & Mag. Nat. Hist. 3rd ser.

vol. xi. p. 100, 1863; Dall, Amer. Journ. of Conch, vol. vi. p. 153, 1870; Davidson, Proc. Zool. Soc.

p. 309, pi. xxxi. figs. 13-1 1, 1871.

Hemithyris lucida, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 196, 1873.

Rhynchonella lucida, G. Duuker, Index Moll, maris Japonici, p. 253, 1882.

Shell small, obtusely subrhomboidal or ovate, rather longer than wide. Dorsal valve

convex, almost gibbous ; mesial fold wide, commencing to rise at about half the Icns-th

of the valve. Ventral valve rather less convex, or deeper tlian the opposite one, and

scooped out near tlie front in the form of a rather deep sinus. Peak acute, sharply

incurved ; foramen beneath the angular extremity of the beak, completed by a deltidium.

Surface smooth ; shell-structure fibrous. Colour light glassy grey. Length 6 lines, width

5 lines, depth 3 lines.

DR. T. DAVIDSON ON EECEXT BRACHIOPODA. 169

Sab. Dr. Gould's specimens wcro tlrodyed off the coast of Japan, lat. 30° 35' N., loni?.

130° 40' E., in 100 fathoms, sand, by Capt. Stevens of the ' Hancock,' and by A. Adams

at Satanomosaki in 55 fathoms, and at Gotto in 48 fathoms.

Obs. This very interesting species was first discovered by Dr. Gouhl, liut ho does not

appear to have figured it. I did so, however, in 1871, from specimens given to me

by Mr. Adams. In his description. Dr. Gouhl observes that his shell, which might be

taken for a small Terebmtula citrea, is very thin and delicate, and further distinguished

by the absence of punctures.

95. RuYNCHONELLA Grayi, Woodvvard. (Plate XXV. figs. 1-1 c.)

Rhiinrhonella Grayii, S. P. Woodward, Ann. & Mag. Nat. Hist. 2nd scr. vol. xvi. p. 141', pi. x. figs. 16-

]()f;, 185"); E. Suess, Ueber die Wohnsitze der Brachiopodcii, Sitzuugsb. k. Akad. Wlsscusch. Wien,

Bd. xxxvii. p. 219, 1859; L. Reeve, Conch. Icon., Monogr. of Rhynchonc/la, pi. xi. fig. 3, 1861; Dall,

Amer. Joui-n. of Conch, vol. vi. p. 153, 1870.

Hcmitliyris Grayi, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 196, 1873.

" Shell light horn-colour, dull, trigonal, depressed ; sides rounded, front truncated ; beak

small, acute; valves smooth, obscurely marked by lines of gro^\-ih, and strongly plaited

near the margin with four central plaits and three or four on each side, the furrows

obscurely striated; margins of valves sinuated in front and strongly toothed; foramen

minvite, completely tubular. Length nearly 8 lines, by G^ in breadth and 4 in depth.

" This interesting and at present unique shell was sent, with other natural-history

objects, from the Feejee Islands by J. M'Gillivray, Esq., Xaturalist to the Surveying

Expedition under Capt. Deuham, of H.M.S. 'Herald.' No particulars as to its habitat

have been received. It differs from the known species of living Rhynchonella in its

lightness of colour, the others being black ; in the plication of the borders of its valves,

which reminds us of the fossil Bh. subplicata (Mantell), and Rh. lineata, Philippi, and

especially it differs in having a foramen quite separate from the hinge-line, by the deve-

lopment and union of the two elements of the deltidium, in this respect agreeing with the

ordinary adult condition of the fossil RhynchonelUe. Were it not for the remains of the

pedicle and traces of the mantle in its interior, we might have taken it for a pliocene fossil,

being exactly similar in its colour and dull transj)arency to the specimens of Rh. psittacea

found in the Crag at Norwich. The muscular impressions arc like those of the type, and

the interior has traces of unsymmetrical vascular markings."

The above description was sent to me for pul^lication in 1855 by my valued and

eminent friend Dr. S. P. "Woodward ; and I added figures of the shell to my paper " On

Brachiopoda " pubhshed in the Ann. & Mag. Nat. Hist, for 1855. Singularly enough, no

other example of the species has been discovered. The type forms part of the collection

of shells in the Zoological Department of the British Museum.

96. Rhynchonella nigricans, Sowerby. (Plate XXIV. figs. 10-19.)

Rhynchonella mgricans, G. B. Sowerby, Proc. Zool. Soc. 18 IG, p. 91, and Thesaurus Conchyliorum, i.

p. 342, pi. Isxi. figs. 81, 82, 18J.6; Davidson, Proc. Zool. Soc. 1852, p. 81, jjI. xiv. figs. 30, 31, and Ann.

& Mag. Nat. Hist. 2nd ser. vol. xvi. p. 415, pl. x. fig. 18, 1855 ; E. Sucss, Ucber die Wohnsitze dcr Bra-

chiopoden, Sitzungsb. k. Akad. der Wissensch. Wicn, p. 220, 1859 ; L. Reeve, Couch. Icon., Monogr. of

170 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

RhynchoneUa, pi. i. fig. 1, 1861 ; E. Sucss, Fossile Mollusken aus Ncu-Sielaiul, Novara Exped. Geol.

Theil, Bd. i. Abth. 2, p. 60, pi. xiv. fig. 6, 1864; Dall, Amer. Journ. of Conch, vol. vi. p. 152, 1870 ;

Hutton, Catalogue of the Marine Mollusea of New Zealand, 1873, p. 87.

Hemlthyris mgricans, Dall, Proe. Acad. Nat. Sci. Philadelpliia, 1873, p. 196.

RhynchoneUa nigricans, T. W. Kirk, List of Marine Mollusea found iu the neiglibourliood of Welling-

ton, Transactions New Zealand Institute, vol. xii. p. 303, 1880.

Shell somewhat tetrahedral, wider than loug. Hinge-line obtusely angular. Dorsal

valve convex, divided into three lobes, of wliich the central one forms a broad, slightly

raised mesial fold. Ventral valve rather less deep or convex than the dorsal one, with a

broad mesial sinus commencing at about a third of the length of the valve and extending

to the front; beak pointed and slightly incurved ; foramen longitndiually oval, incom-

plete, and situated under the extremity of the beak, margined anteriorly by a small

portion of the umbo and laterally by narrow deltidial plates ; beak-ridges tolerably well

defined, leaving between them and tlie hinge-line a narrow triangular flattened space.

Surface of valves ornamented by a variable nvimber of angular ribs, from twenty to

twenty-live on each valve, a few of which are due to interpolation, while from five to six

occupy the fold and sinus. Surface of valves crossed by numerous concentric lines, or

projecting ridges, of groAvth. Colour bluish or brownish black ; shell-structure fibrous,

impunctate. The apophysary system consists of two short curved lamellae. Length

11 lines, breadth 13 lines, depth 7 lines.

Hah. Five miles east of Ruapuke Island, New Zealand ; dredged by Mr. F. J. Evans,

R.N., in 19 fathoms, on rock and coral. Abundant at Faveau Strait, and not un-

common otr the south Chatham Islands (Hutton).

Fossil shells referred to this species have been found in New Zealand.

Ohs. Our first knowledge of this most interesting species is due to G. B. Sowerby,

Avho says that, at the time he was describing the shell, only one small young specimen,

without indication of locality, was known, wliich was found in the collection of the late

G. Humphrey. Since then a number of specimens of all ages have been dredged and may

be seen in many collections. In 1882 I I'eceived from New Zealand several examples, and

redescribed and figured the species.

When quite young, and up to a certain age, the shell is triangular and somewhat

compressed, and many adult examples are unsymmetrical, from the fold and sinus being

moved more to one side than the other. The yoving shells are often found attached in

groups to an adult example, or to a sponge or rock.

The striking resemblance presented to more than one Jurassic or Cretaceous species of

RhynchoneUa is very remarkable. Some fossil specimens of 11. nigricans described by Prof.

Suess from Kohuron in New Zealand measured 13 lines in length by 14 in breadth.

97. Rhynchonella nigricans, var. pyxidata, R. B.Watson, MS. (Plate XXIV. fig. 20.)

RhynchoneUa nigricans, var. jjixydata, Davidson, Report on tlie Bracliiopoda, Voyage of H.M.S.

' Cliallenger,' Zool. vol. i. p. 59, pi. iv. fig. 14, 1880.

Var. pyxidata. Shell transversely oval, widest anteriorly, tapering posteriorly, wider

than long. Dorsal valve uniformly convex to about half its length, where a broad mesial

DR. T. DAVIDSON ON KECENT BRACHIOPODA. 171

fold, scarc(;ly raised above the general convexity of the valve, occupies ihe anterior half

of the valve. Ventral valve rather less deep and convex than the opposite one, with a

broad well-defined mesial sinus, commencing at a short distance from the extremity of

the beak and extending to the front ; beak rather small, acute, and incurved ; foramen

incomplete, situated under its pointed extremity, laterally margined by narrow deltidial

plates ; surface of both valves ornamented Avith about forty to forty-six small, am^^ular,

radiating ri])s, closely intersected by equidistant, squamose, concentric I'idges of growth,

giving an imbricated appearance to the surface. Colour whitish, sometimes brownish,

especially at the beaks. Length 9 lines, breadth 10 lines, depth 0 lines.

Hah. Six examples were dredged by tlie ' Challenger ' Expedition south of Kerguelen