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COMPARATIVE ZOOLOGY,

AT HARVARD COlLEfiE, CAJlBRIDfiE, 51ASS.

The gift of

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No. (oHiX n '

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THE

TRANSACTIONS

OF

THE LINNEAN SOCIETY

OF

LONDON.

SECOND SERIES— VOLUME III.

ZOOLOGY.

L O N DON:

PHINTED BY TAYLOR AM) FRANCIS. BED LION COURT. FLEET STREET:

SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-UOUSE;

AND BY LONGMANS, GHEEN, AND CO., PATEKNOSTER-ROAV.

M.DCCC.LXXXVIII.

a :

.'b^

CONTENTS.

A Revisional Monograph of Recent EphemeridcB or Ilaijflles. Bij Rev. A. E. Eaton, M.A.

{Communicated hij Sir JoHX Lubbock, Bart., F.R.S., ex-Presidenl of the Lhmean

Society.)

Issued in six parts as follows : —

Part I., pp. 1- 77, & Plates I -XXIV., loublished December 1883.

„ II., „ 77-152, „ XXV.-XLV., „ July 1884.

„ III., „ 153-230, „ XLVI.-LXIIL, „ April 1885.

„ IV., ., 229-281, „ December 1885.

„ v., „ 281-319, „ LXIV., LXV., „ December 1887.

„ VI., „ 320-352, with Index and Titlepage, „ February 1888.

TRANSACTIONS

OP

THE LINNEAN SOCIETY.

I. A Bevisional Monograj^h of decent Bpliemeridce or Ilayjllcs. By the Bev. A. E.

Eaton, M.A. {Commimicated by Sir John Lubbock, Bart,, F.B.S., Pres. Limi. Soc.)

(Plates I.-LXV.)

Part I. Read April 10th, 1883.

Inteoductort Eemaeks.

I HE present monograph is designed to facilitate the study of the Ephemeridte. On

many accounts these insects are very eligible subjects for scientific research ; but so long

as they are Ul known, and their exact identification a matter difficult of accomplish-

ment, their employment in any branch of zoological learning is surrounded with dis-

advantages too patent to need indication.

Many points in the classification of the Ephemeridaj formerly doubtful receive

elucidation in this work through the kind co-operation of entomologists of various

nationality. An unprecedented wealth of material, through their means, has been

avaUable for examination, every thing at their disposal likely to be in any way of

service to me having been most courteously given or lent by them. The chief con-

tributors of specimens have been Mr. E,. M^Lachlan, F.R.S., and Dr. H. A. Hagen, of

Cambridge, Mass. I am also under great obligations to Mr. H. Albarda of Leeuwarden,

Mr. C. Ritsema of Leyden, the Baron E. de Selys-Longchamps, M. Albert Mtiller of

Berne, M. A. E. Vayssiere of Marseilles, and Dr. E. Joly of Toulouse. My thanks are

also due respectively to the chief Entomologists or Directors of the British, Oxford,

Brussels, Paris (Jardin des Plautes), and other museums, for permitting valuable

specimens to be thoroughly examined by me. Many very choice Ephemerida; in the

Museum of Comparative Zoology, Cambridge, Mass., forwarded by Dr. Hagen, and some

remarkable species contributed by Mr. O. Salvin, demand particular acknowledgment.

At an initial stage in the preparation of the letterpress, having decided to write in

English, the question arose whether or not descriptions of the species should be given, or

should the text treat of genera only. The various tints of yellow, brown, grey, and, in a

lesser degree, of black, largely prevalent in the coloration of Ephemeridae, cannot be

precisely defined in common English entomological terms so well as in Latin ; and

SECOND SERIES. — ZOOLOGY, VOL. III. 1

2 EEV. A. E. EATON ON EECENT EPHEMERID.i: OR MATELIES.

kindred species are often so nearly alike in colour that terms of precision are indis-

pensable in describing the differences between them. When it was settled that the

work should be written in its present form, the exigencies of the case were met

by having recourse to a trade-colour pattern-book, as a standard of reference, sold by

one of the principal artists' colour merchants in London. The samples display three or

four gradations of each colour, — intense, medium, light, and sometimes very light. In

my descriptions, colours of medium gradation are usually quoted without any qualifying

adjective ; but in blacks, only the intense gradation is termed black, the medium being

designated greyish black, or blackish. The light gradation in blacks and browns, or

sometimes the lighter and lightest in a quadruple series of the latter, are referred to as

greys of such and such a tint. Very light gradations of red, orange, yellow, green, blue,

&c. are denoted as " extremely light," " the lightest possible tint," or " whitish,"

according to circumstances.

During the interval which will elapse between the issue of the successive parts of this

monograph, opportunities will doubtless occur of supplementing the illustrations of

species. A list of all additional tigures not cited in the text relating to the species

represented by them will therefore be given in the final part ; and references to them

can be made addenda.

Structure of the Ephemerid^e in General. — Adult.

The Ephemeridaj are insects with a long, soft, ten-jointed, sessile abdomen, furnished at

its hinder extremity with either two or three many-jointed setaceous or filiform tails

(caudal setae), and whose body is smooth and glabrous.

Head free, with atrophied mouth-organs, carinated epistoma, short subulate antennae,

composed of two short stout joints succeeded by a slender many-jointed setaceous awn,

three ocelli, and large oculi (compound eyes).

Thorax robust ; mesothorax predominant ; sternum well developed ; fore wings

ample, erect or spreading in repose, plaited lengthwise but not folded up (excepting

when a female happens to be ovipositing under water, and then they are reclinate and

compactly plicate like a closed fan) ; legs slender, femora strong, the fore coxre some-

what distant from, the others.

Abdomen armed with a pair of claspers (forceps), in the male placed ventrally at the

extremity of the penultimate segment ; the vasa deferentia have each of them a separate

iutromittent organ situated at the ventral joining of the ninth and tenth segments. In

the female the oviducts terminate separately in the joining of the seventh and eighth

segments ; there is no real ovipositor, but in some genera (e. g. Reptagenia) the apex of

the seventh segment is produced beneath into a short rounded flap, and in one

{Hagcmdus) this projection takes the form of a spout. In many genera there is a similar

extension uf the ninth segment in one or in both of the sexes. Alimentary canal capa-

cious, straight, filled with gas, and apparently destitute of salivary glands ; malpighian

tubules in most instances indefinitely numerous, capillary, very long and entangled ; but

in Prosoplstoma shorter, stouter in proportion, fewer in number, and combined into one

common duct on each side. Tracheae filameutose or capillary, not sacculated, furnished

EEV. A. E. EATON OK RECENT EPHEMEEID.E OR MAYFLIES. 3

with ten pairs of stigmata, two tlioracic and eight abdomiual. Ventral nervous tract

slightly abbreviated, and posteriorly somewhat concentrated, in P rosopistoma ex-

tremely so.

Peculiarities in structural detail are often noticeable in both or one of the sexes, and

are chiefly presented by the ocelli, wings, legs, and caudal setiB, and in the male by the

oculi and forceps.

The foremost ocellus is sometimes as large as the others, sometimes much smaller.

The oculi, always much larger in the male than in the other sex, are in him, in some

genera, divided each into two parts transversely ; the upper portion has larger facets

than the lower, and is sometimes coloured differently from it. The division between

these segments of the oculus may amount to nothing more than a mere superticial

furrow or impressed line traversing the faceted surface horizontally ; but when it is

deeper, the upper part of the oculus (always much the larger of the two) assumes a short,

subcylindrical or turbinate form, faceted only on its summit, and supports on its outer

base the smaller division, which is oval, and is faceted all over.

The fore wings, seldom ovate or oblong, are usually trilateral, ample, and rounded off

at the extremities. Their margins are unequal in extent, the costal or anterior margin

being slightly (sometimes not much) longer than the terminal or outer margin (measured

along the curve), and seldom less than double the length of the inner margin. The

costal margin is somewhat sinuous as a rule ; nearly straight at the base of the wing, it

generally presents a shallow sinus midway towards the apex, and then proceeds in a

gradual salient curve to its extremity. The terminal margin is arched ; its curvature is

sometimes stronger towards its extremities than in its midst, where it is occasionally

almost straight. In the greater part of its course the inner margin is usually straight or

incurved ; but there are cases in which it describes a salient curve continuous with that

of the terminal margin. The wings are relatively longer in the female than in the male.

The hind lobiys in some of the genera are not developed ; in others they are very

minute ; at the most they are not particularly large. Their usual form is triangular,

ovate, or oblong-ovate, with a salient prominence in front, either close to the wing-roots

or midway towards the apex, in which last case the prominence is sometimes {e. g. in

Rabr-ophlebia) followed by a deep sinus ; their neuration is fairly plentiful. When they

are very minute their nervures are very scanty, and their form is usually oblong or

linear-lanceolate.

The inner margin of the fore wing and the anterior margin of the hind wing hitch

together automatically to a larger or smaller extent when the wings are spread open.

The iciiig-rnembrane is usually glassy and iridescent in the adult. In OUgoneuria

and some other genera, however, the subimaginal pellicle of the wings is not shed, and

these are dim in consequence (viewed as transparencies) ; their reflection too differs from

that of the wings of other Mayflies in being either glossy instead of iridescent, or else (as

in Lachkmia &c.) of uniform azure glow. Pigment is often deposited in the marginal

and submarginal areas of the fore wings, and occasionally in all of the wings beside some

of the nervures and cross veinlets as well as at the wing-roots ; by the confluence of

1*

4 EEV. A. E, EATON ON EECENT EPHEMEEID.E OR MAYFLIES.

adjacent deposits blotches and fasciae are apt to be produced. The wing-membrane is

decvirrent along the sides of the peak of the mesonotum ; in OUgonetiria and some allied

forms it is there prolonged into short free subnlate tails, figured by Dr. Hagen in 1855.

In most of the Ephemeridse, during the subimaginal stage, the wings are fringed with

short cilise along the terminal margin. This fringe (excepting in Ccenis, Frosopistoma,

and Trycorytlms) is not retained by the adult fly.

JVing-neuration in the Ephemeridse is less complicated than it appears to be ; and

Avhere difficulty is experienced in ascertaining the homologies of nervures, it is more

likely to be occasioned by the suppression of some of them than from there being more

in the wing than can be reasonably accounted for. Unstable in minutiee, so closely is

the essential plan of the neuration adhered to by nearly related Mayflies, that the

general facies of the wings is an important aid to their classification, aff'ording charac-

teristics as easily recognizable as the style of branching in the case of trees. Its simplest

modifications are displayed in Oligoneurians (PI. III.), its most complex in PI. VI.

Throughout the whole series of figures illustrative of neuration, the special and serial

homologies of the main nervures of the fore wing and hind wing are indicated by

numerals (the same number being employed to denote the same nervure in every figure),

and these are placed at the distal extremities of the following nervures, excepting the

costa and the sutural nervures, whose numbers are not usually appended to tliem : —

1, the Costa, coincident with the anterior margin of the wing ; 2, the Subcosta ; 3, the

Eadius ; 4, the Sector ; 5, the Cubitus ; 6, the Prtebrachial ; 7, the Pobrachial ; 8, the

Anal ; 9\ 9- &c. Axillary nervures ; 10, the Sutural vein coincident with the inner

margin. Between these nervures others of an adventitious nature that issue from the

wing-margin in certain regions are often interpolated ; in many genera they do not

remain free, but annex themselves to the adjacent main nervures, often acquiring the

appearance and discharging the functions of branches of these. When necessary or

advisable for purposes of elucidation, the numeral of the nervure, dashed, is repeated at

the extremity of the hindermost adventitious branch.

At a meeting of the Entomological Society of London, in February 1879, I remarked

upon the tendency of the main nervures of the anterior wing in most of the Ephemeridse

to be segregated into three groups, of which the first communicates directly with the

thorax, the intermediate is either annexed to the first group, or terminates in the wino"-

membrane adjacent to it, close to the base of the wing, while the third is associated with

the prominent curved or augulated crease in the membrane which forms the boundary

of a depression posterior to the great cross vein and close to the wing-roots. I men-

tioned, further, that the anterior nervures of the hinder groups had a proneness to

secede from their own set, and transfer themselves to the hindermost nervure of the

grotip next in advance of them, so that in other orders of insects they are usually

reckoned as branches of the nervures to which they have strayed. An extreme instance

of such a transference is shown in the remarkable aberration floured in PI. VII. 11 c

where the sector (4), accompanied by most of the neighbouring adventitious nervures,

has usurped the trunk of the radius (3), so that this last nervure is not in direct con-

tinuation with its own basis, but simulates a branch.

EEV. A. E. EATON ON RECENT EPHE.MEEID^ OR MAYFLIES. 5

Nervures of the fore icing. First group. — The costa (1), the subcosta (2), and

radius (3), are strong simple nervures, nearly of the same length, and almost parallel

with one another. Close to the base of the wing they are all connected by the great

cross vein, and still nearer to the wing-roots the hinder two are again bound firmly

by another strong cross vein. In Fal'mgenia and some other genera the costa and

subcosta are liable to be folded back under the radius, so that this last appears to skirt

the edge of the membrane for a considerable distance. In Massoi/euria (PI. III. 3)

the subcosta is completely suppressed ; and in no case is the adventitious mediastinal

ever developed in the Ephemeridte.

Second group.— T\\q sector (4) and cubitus (5), the praebrachial (6) and pobrachial (7),

are the main nervures of the second group. The sector and cubitus (excepting in genera

allied to Oligoneuria, where one or both of them are suppressed) unite l)efore the middle

of the wing, and their common trunk joins the prsebrachial towards its termination.

The sector is usually reckoned as a branch of the cubitus by entomologists ; but it

constitutes a separate nervure in the hind wings of many Ephemeridse. Excepting in

wings very scantily nerved, the interval between tlie sector and cubitus is supplied with

adventitious nervures, usually five in number, but sometimes three or sis. "When there

are five of them, the fifth from the sector is the longest, the third the shortest of all, and

the first is longer than the second. In Cloeon and some other genera cross veinlets

afford the only communication between these and the main nervures ; but very fre-

quently most of them combine with the first or fourth, and that unites with the sector,

the fifth usually remaining alone. When the prsebrachial nervure is simple (excepting

in allies of Oligoneuria) two adventitious nervvires are always interposed between it and

the pobrachial nervure (PL XVI. & XVII.) ; when it is forked, its fork contains a single

adventitious nervure, and its hinder branch is followed by the pobrachial nervure imme-

diately Avithout the interpolation of any nervure whatever. The hinder branch of a

forked prsebrachial nervure is therefore evidently homologous with the second adven-

titious nervure, and should be accounted a false branch accordingly. The fork is ex-

tremely deep in (kmipsurus and Folymitarcys (PI. V. & VI.).

The pobrachial nervure, somewhat deserted by its fellows, is essentially a simple nervure,

any branches which it may appear to have being (like those of the priebrachial) virtually

adventitious nervures introduced between it and the anal nervure. Because in this

as in the last instance referred to, when the pobrachial nervure is obviously simple

(PI. XVI. & XVII.), two adventitious nervures intervene between it and the anal

nervure (8), which sometimes annex themselves to the latter (PI. l.ll),\c); and when

the second of them simulates a branch of the pobrachial, the fork thus formed contains

a single adventitious nervure within it, and is follo^ved immediately by the anal.

Sometimes each of them unites with the nervure to which it is nearest (PL V. 8«);

in short, the combinations into which they enter with themselves and the adjoining

nervures are almost as many as are possible. In Palingenia lonylcauda (PL I. 1 a), pro-

vision seems to be made for the origination of several other adventitious nervures.

Third G^-owj).— The anal (8) and the axillary' nervures (9', 9% &c.) complete the series

of main nervures in the disk of the wing. The former, as a rule, subtends the anal

6 EEV. A. E. EATON ON RECENT EPHEMEEID^ OE MAYFLIES.

angle directly, receiving some or all of the adventitious nervures that may happen to

orio-inate in the interval between itself and the first axillary nervure. But there are

many deviations from this rule. In genera related to Folymitm-cys and in Falingenia

(PI. I., II., V. & VI.), from one to five adventitious nervures come between the anal

nervure and the anal angle ; while in Bcetisca (PL XXL), where no nervure worthy of

mention intervenes before the asillarics, the first and second nervures of this last group

extend to the terminal margin between the said angle and the anal nervure. The usual

interj)olated nervures in other instances are occasionally intercej)ted by the first axillary

instead of by the anal nervure (PI. XI. 18, &c.). In several genera the last of these

adventitious nervures sometimes assumes the aspect of a main branch of the anal nervure

(PI. I.-III. &c.).

The axillary nervures seldom extend beyond the middle of the inner margin ; but in

Cloeon and its allies (PI. XVI. & XVII.) the first of them reaches to where the anal angle

would be in wings of a more distinctly trilateral form, and in Bcetisca (as has been

stated just above) both it and the second axillary nervure terminate beyond this angle.

In OUffoneiiria and kindred genera the axillary nervures are either suppressed, or are

represented only by a very few short obsolescent rudiments at the commencement of

the inner margin.

• By careful inspection of the third group of nervures, observing especially the disposi-

tion of the proximal extremities of the main nervures along the prominent curved fold

of the membrane, the form of the area contained by the fii-st axillarv nervure and the

inner margin, or of that enclosed between the first and the second of the axillary nervures,

and lastly, the general aspect of the adventitious and other nervures, the approximate

afiinities of Ephemeridae to one another can be ascertained very easily.

Cross veinlets, speaking generally, are of very small account in classification, though

the contrary was formerly supposd. Their relative abundance or scarcity in the marginal

area used to be considered as an item of prime importance ; but the sexes of the same

species sometimes {e. g. certain species of Cloeon) difi'er from one another, in respect of

this very particular, more than, in other instances, the species of different genera. They

occasionally are serviceable in the distinction of species, more especially the veinlets in

the pterostigmatic portion of the marginal area : in some genera these are indifferently

simple or branched in individual examples of the same species, and their branches are

apt to anastomose with one another. The nature of the series of anastomosing branches

is obvious enough in actual specimens of the insects, but in figures of wings it is liable

to be mistaken for an adventitious longitudinal nervure, as has recently been done by a

distinguished entomologist. Several of the genera related to OUgoneuria have a peculiar

arrangement of elevated folds and cross veinlets forming communications between the

main nervures close to their proximal extremities, to which attention was first directed

by Dr. Hagen in 1855. They are indicated in only one of my figures (PI. III. 2 o, ? ).

Nervures of the Hind IFing. First Group. — A noticeable dillerence is perceptible in

the composition of the first group of nervures in the hind wing, compared with the corre-

sponding group in the other wing, because the cubitus (5) is transferred to it from the

second group, and is annexed to the radius (3) either near the base (PI. I. 1 a), or

EEV. A. E. EATOX ON EECENT EPHEMERID^ OR MAYFLIES. 7

nearer the middle of the wing (PL XII.), the sector and the adjacent adventitious nervures

either remaining apart from both or forming a union with either of them. When the

costa is not rounded oif at the extreme base, it almost always describes a salient ana-le

in or before the middle of the anterior margin, after which it becomes approximated to

the subcosta (2) ; and this last, when not straight nor evenly curved, is strongly arched

towards its proximal extremity. The radius (3) takes a nearly direct course to "^he further

border of the wing, near the apex, so that a relatively wide space is left between it and

the subcosta : in Bcetisca it is interrupted, or obsolescent. The sector and adventitious

nervures (4-4^) are suppressed in scantily nerved wings, but vary in number and in their

combinations in other instances. The sector alone is present in some species of Campsurus

(PL V. 8 i) ; but in most genera there are at least two adventitious nervures associated

with it, the hinder oue of which visually unites with the sector, so as to form a fork,

including its fellow. Another arrangement occurs sometimes in Polijniitarct/s (PL VI.

10 a) where three such nervures are interposed; In. Palmgeiiia {^\. I.) and Bcetisca

(PL XXI.) there are perhaps five of them, whilst in most of the genera from Coloburus

onwards, although the number of the adventitious nervures appears at tirst to be two, it

seems reasonable upon closer inspection to recognize four of them, of which the third

unites with the cubitus (5) to form a fork enclosing the fourth (1^), in the same manner

as the second and sector enclose the tirst.

Second Group. — The defection of the cubitus and sector from this group is compen-

sated for by the transference of the anal (8) nervure to it. When adventitious nervures

are interposed between the prgebrachial and the pobrachial (they are absent in Habro-

phlebia, PL XIII.), they are more frequently associated with the former than with the

latter nervure ; and it sometimes happens that the hindermost adventitious nervure (6')

in genera related to Siphlurus, assumes equality with, or even predominates over, the

prtebrachial (6). The adventitious ueuration intervening between the pobrachial (7)

and anal (8) is of meagre extent when it is not suppressed.

Third Group.— The axillary nervures (9), usually left behind by the anal (8), gene-

rally occupy a very limited space in the hind wing ; they attain their highest develop-

ment in Cliirotonetes and Oniscigaster (PL XIX. & XXI.).

TJie legs present great diiferences in their condition, in the relative lengths of the

several pairs, and in the proportions of the component parts of corresponding pairs. Some

of these differences are sexuaL others are generical. Sometimes all of the legs are fuuc-

tionless, — flaccid, filamentary rudiments of the tibiae and tarsi, or else atrophied miniatures

of the same, definitely shaped, but thoroughly infirm, remaining attached to the femora ;

in other instances such is the condition of only the two hinder pairs, and then the anterior

pair may be either stout and short, or slender and long in either the male only, or in both

sexes. The fore legs are always longer in the male than in tne female (usually very

much so), and are generally longer than either of the hinder pairs ; but in the male of

OUgonenria the fore leg is shorter than the intermediate. The hind legs are usually as

long as, or shorter than, the intermediate ; but in Adeiiophlebia the middle pair is the

shortest of all. The prolongation of the fore leg is chiefly due to the lengthening eitlier of

8 EEV. A. E. EATON ON EECENT EPIIEMEEID^ OE MAYFLIES.

the tarsus, or of the tibia, or of both of them ; but in the other legs it is generally brought

about by extension of the tibia and femur. The fore tarsus is often as long as the tibia ;

indeed in the male it frequently is much longer than it : the hinder tarsi are usually

shorter, and only in a very few forms are they longer than it (e. cj. in Batisca, where the

proximal joint of the tarsus by itself is as long as the tibia). The maximum number of

tarsal joints is 5 ; the apical projection of the tibia which, in some genera, forms a basis

for the insertion of the fore tarsus of the male, resembles at first sight a sixth joint, but

it conforms in colour to the tibia and not to the tarsus. All of the tarsi may alike have

five joints, or the fore tarsus may be five-jointed, while the others have only four distinct

joints, and a very ill-defined trace of the fifth ; or all of them may have only four joints :

in atrophied legs, however, the tarsi of the hinder legs may be two-jointed, or even

jointless. The ungues of the fore tarsus are sometimes both alike in form and size ; bu.t

this is often not the case : the same may be said of the ungues of the hinder tarsi, which

further may resemble or differ from the ungues of the fore tarsus in form.

The forceps of the male (specialized legs of the ninth abdominal segment) are seldom

jointless (Ccenis, Campsurus, &c.), but are usually two-, three-, or four-jointed, with the

basal joint or the next the longest. In some genera they afford good distinctive cha-

racters of species.

Much diversity is exhibited in the number and relative proportions of the caudal setse.

They are often all of one length ; but the median seta is occasionally a little longer or a

little shorter than the others, sometimes considerably shorter, frequently atrophied to a

mere rudiment, and in many instances altogether cast off. The outer setae are always

persistent (in the absence of accident), and either many times exceed, or else equal or

fall short of, the body in length, according to sex or genus. The setse are commonly

glabrous, or almost so, seldom pilose or plumose : their component joints, transverse in

the basal portion, assume a more elongated form in the distal portion of the seta, where

in some cases they attain rather attenuated dimensions.

Habits of the Plies.

The popular supposition, that Mayflies are strictly ephemeral, is fallacious in most

instances. It is true that the adult insect cannot eat, owing to atrophy of its mouth-organs

and to the condition of its alimentary canal ; but, provided that the air be not too dry,

the imagines of many genera can live without food several days. Tradition states that

Curtis kept a female Cloeon alive three weeks ; this is an exceptionally long period, for in

general an individual in confinement becomes perceptibly shrunken within three days,

and is dead by the fourth day, if not before. Apparently there is some correspondence

between the length of time spent in the subimago stage and the duration of the life of

the imago : when the former amounts to twelve or twenty-four hours and upwards, the

latter lasts more than a day ; but when the change into imago takes place within a few

minutes of the insect's quitting the nymph skin, its life is fugitive, passing away in the

course of the evening or early morning. In some genera of sliort-lived Ephemerida3 the

subimago skin is partially or altogether persistent in one or other of the sexes ; and such

EEV. A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES. 9

portions of it as may be shed are moulted while the insect is in full flight. Thus the

males of Oligoneurla retain the pellicle in question u.pon their wings (the slough that

may often he seen still dangling from their tails comprises exuviae of the body, legs, and

setae only), whilst the females of Palu?ffenla, Campsurus, and some others, seem to throw

off none of it at all. The males of these restless creatures have their hinder legs either

atrophied or too feeble to support the body, and in most of the females the fore legs also

are equally infirm and functionless. The longer-lived flies issue from the nymph-skin in

a rather less matured condition than the others : then' legs are alwavs serviceable in both

of the sexes ; and the subimago skin is always completely cast. The change from nymph

to subimago is effected while the insect is floating at the surface of the water, buoyed up by

gas which has accumulated wdthin the alimentary canal and between the new and the old

integuments of the body. The moult having been transacted in the ordinary manner, the

subimago, standing upon the water with the wings erect, awaits a favourable moment for

flying to shelter. Fluttering steadily upwards it mounts aloft, sometimes to a considerable

elevation, presently making its way to trees, walls, or herbage, &c., likely to afford it a

suitable resting-place. There it assumes the posture characteristic of its genus during

repose. It uiay stand either upon all of its feet, or upon only the two hinder pairs ; and

the fore legs extended in advance, off the ground, may in this last case be held either

close together or else apart from each other. The caudal setaj, in most instances diver-

gent, are sometimes placed alongside of one another horizontally, or slanting upwards.

Adult diurnal Ephemeridre, in hot weather, seek repose during the heat of the day,

limiting their flight to the cooler hours of sunlight, or, at most, extending it later in the

evening till just after sunset. In cold disagreeable weather they seldom fly at all, but

remain under shelter. Many persons are familiar with the mode of flying habitual to

some of the more conspicuous Mayflies (especially the males), which, by tlie intermittent

action of the wings, results in a dance-like motion almost vertically up and down, — a

fluttering swift ascent, and tlien a passive leisurely fall, many times repeated. The body

during the rise is carried in a position very little out of the perpendicular, with the legs

extended upwards in advance, and the setas trailed behind; and this is thepostm-e main-

tained by Septa rjenia and its allies (only their sette are divergent) whilst hovering head to

windward, which has led to their being locally designated in the valley of the Axe (Devon)

"Yellow Uprights." During the descent, the body, less steeply inclined, is steadied by

the half-spread motionless wings and the outstretched setae and legs. The males of Ccenis

sometimes jerk themselves downwards impetuously in their dance, instead of subsiding

without effort ; and the females of Ephemerella, while flying horizontally onwards, have

a haliit of dipping frequently in their flight. Conspicuous objects near water, such as

roads, hedges, and shrubs, as well as the streams inhabited by the nymphs, are favourite

rendezvous of the dancers, and therefore good sites for collecting the adult flies. In

mountain-glens and wooded ravines prominent light-coloured rocks often serve to attract

them ; but frequently in such situations their diversions proceed beyond the range of the

net. When this is so, it is advisable to watch for subimagines rising frona the water, and

carry them home alive in bottles, to undergo their moult. The bottles must be kept cool,

and neither very dry inside nor visibly damp ; and it is sometimes necessary to place

SECOND SERIES. — ZOOLOGY, VOL. III. 2

10 REV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

within the bottle a piece of paper, secured from shaking about, to afford foothold to the

captives. A woollen wrapper round the bottle, and three or four drops of water upon the

paper, meet these requirements ; and in very warm weather the bottles can be carried in

a mat basket. Subimagines of certain genera issue only at particular times of the day ;

as a rule, the afternoon and evening are the best periods for collecting them. In the

morning specimens harbouring amidst branches of shrubs and trees overhanging streams

can be procured by beating into the net. Nocturnal species may advantageously be

looked for in spiders' webs, and on lamps, adjacent to rivers ; and wherever such lamps

happen to be close to white walls or placarded hoardings, numbers of specimens are apt

to be attracted by the illuminated surfaces. Subimagines of Bmtis and sundry other

genera may frequently be found clinging to Sparganium and grass at the borders of

streams, a few inches above the level of tlie water.

Many species tliat fly by night appear on the wing before dark. They are most of

them short-lived. The ordinary flight of Oligoneuria is rapid, the insects sweeping

swiftly to and fro, far up and down the stream, with flurried bustling movements, very

similar, indeed, to those of LeptoceridjB, the females for the most part close to the surface,

and the males a few feet above it, while now and again a female hurries aloft pursued by

a jostling throng of admirers amidst whom she very soon sinks down again encumbered

towards the water. Upon occasion, however, they behave differently. During one or

two nights only in the course of the season, in favourable weather, innumerable multi-

tudes of these flics issue after sundown from the river, filling the air, like snowflakes in a

storm, to a very considerable height (M. Albert Miiller observed some at an altitude of

500 feet above the E,hine at Basle), and advancing steadily in one direction. Species of

other genera, such as Falingenia and Polymitarcys, have a similar habit of swarming, and

so also have certain kinds of Ephemera and Hexagenia. Ccenis has been observed in

East Central Africa flying in dense clouds that resembled smoke in the distance.

Most of the Ephemeridte couple during flight, the male lowermost. Darting at his mate

from below, and clasping her prothorax with his eloutjated fore tarsi (whose articulation

with the tibia is so constructed as to admit of supination of the tarsus) he bends the

extremity of his body forwards over his back, grasps with his forceps the hinder part of

her seventh ventral segment, and with his outer caudal setse embraces her sixth segment.

These two setae exhibit near their origin a strongly marked articulation, where they can

be deflected abruptly so as to lie forwards over the back of the female parallel with one

another betvt^een her wings. Meanwhile the couple gradually sink, the female not being

quite able to support herself and mate ; and by the time they reach the ground, if not

before, their connexion is usually terminated, although a pair of Ecdyurus has been seen

by me to maintain union effectively as long as six or seven minutes after they had come

to rest. Soon after their disengagement the male flies away to resume his interrupted

gambols (being prone to polygamy), and the female after resting awhile repairs to the

water to lay her eggs. Many of the females are polyandrous.

The male of PaUngeuia has very short fore legs ; and he is mated, not in mid air, but

upon the river amidst crowds of rivals, who pile themselves up upon him and his sur-

roundings until he is overwhelmed by a large struggling mass of them floating dowji the

REV. A. E. EATON ON RECENT EP1IEMERID.E OR MAYFLIES. 11

stream like a heap of foam, whose resting-place (in New Guinea, at least) is generally

found in the mouth of a big fish. [See below, under Palingcnia ixipuana.']

OVIPOSITION AND THE EgG.

Oviposition is usually performed in fresh water; a Cingalese Palmffenia, howeyer,

inhabits an estuary where the water occasionally must be brackish. Some short-lived

species discharge the contents of their ovaries completely en masse, and the pair of fusi-

form or subcylindrical egg-clusters laid upon the water rapidly disintegrate, so as to let

the eggs sink broad-cast upon the river-bed. The less perishable species extrude their

eggs gradually, part at a time, and deposit them in one or other of the following manners : —

either the mother alights upon the water at intervals to wash off the eggs that have issued

from the mouths of the oviducts during her flight; or else (Eaton, Trans. Ent. Soc,

London, 1873, p. 401) she creeps down into the water — enclosed within a film of air, with

her wings collapsed so as to overlie the abdomen in tlie form of an acute narrowly linear

bundle, and with her setfe closed together — to lay her eggs upon the underside of stones,

disposing them in rounded patches, in a single layer evenly spread, and in mutual con-

tiguity. This has been witnessed by me several times, and in the case of several species

of Baetis. The female on the completion of her labour usually floats up to the surface

of the water, ineffectively swimming with her legs, and, on emerging, her wings all at

once are suddenly unfolded and erected ; she then either flies away, or (as often happens)

if her seta? have chanced to liecome wet and cannot ])e extricated from tlic water, she is

detained by them until she is drowned. In some instances, however, the female dies

under water beside her eggs.

The eggs, indefinitely numerous, are diversiform according to the genus, some being

subrotund, others elliptical. An appendage of various relative size is in certain cases

present at one end of the c^g ; for example, in Ccenis it is narrowly crescentic, but

in FyphemereUa it nearly equals the yolk itself in size, and forms in combination with it a

somewhat figure-of-8-shaped mass.

The dixration of the egg-stage varies with the temperature to which the eggs are

exposed. Some of Folijmitarcijs virgo, kept in Dr. N. Joly's laboratory at Toulouse, were

hatched about six or seven months after they were laid.

Professor L. Calori (1848) and Dr. E. Joly (1877) have recorded instances of larvi-

parition observed by them in Cloeon diptermn. Although they supposed that the young

were produced from impregnated eggs retained within the mother, perhaps for some

weeks, it may be conjectured, with equal if not greater probability, that these were the

produce of unfertilized ova advanced to maturity within the nymph and hatched as soon

as she became an imago.

In the absence of elaborate contrivances, many Ephemeridse can be bred in captivity

if confined in flower-pot saucers, or other wide vessels, containing very little water, duly

protected from extremes of temperature. If the bottom be glazed inside, it should be

thoroughly strewn over with sand or fine river-gravel, that the insects need not die of

fatigue in struggling to maintain their footing upon it. Banunculus should not be

2*

12 EEV. A. E. EATON ON RECENT EPIIEMEEIDiE OE MAYFLIES,

planted in the pans, because the sap exuding from its broken stems appears to be

poisonous to these animals.

The Young of the Ephemerid^.

The term "nymph" is employed in this work to designate all the subaqueous stages

in the development of the young after it is hatched. The old-fashioned usage of " larva "

and " pupa," borrowed from the terminology of other Orders to denote respectively the

wingless and wing-budding grades of the nymph, seem scarcely worth retention ; for they

do not indicate precisely any definite epochs of particular importance in the life-history

of these animals. Nymphs are young which lead an active life, quitting the egg at a

tolerably advanced stage of morphological development, and having the mouth-parts

formed after the same main type of construction as those of the adult insect.

Mayfly nymphs mostly feed upon either mud or minute aqviatic vegetation, such as

covers stones and the larger plants ; but (judging by tlieir mandibles and maxilla?) some

must be predacious. Many of them live in concealment in the banks or under stones

in the bed of streams, rivers, and lakes ; others ramble openly amongst water-weeds and

swim with celerity. Certain genera are restricted exclusively to large rivers ; and one of

these {Palingenia) is said to remain a nymph three years. Gloeon {teste Sir John

Lubbock) moults twenty-three times, and is probably bred much more expeditiously than

Palingenia ; it is one of the genera found in streams, ditches, and ponds, or the shallow

parts of lakes.

Besides the influence of flood and drought, or constancy of supply, the climate of the

water is largely concerned in determining the fitness or unsuitability of a particular site

for particiflar kinds of Ephemeridae. A knowledge of the water-climate needed by a

species renders intelligible the limitations of its geographical and local distribution.

The temperature of the ordinary land-springs in a district enables the climate of other

water iu that neighbourhood to be ascertained readily by comparison with it. If the

water of a given site exhibits marked difi'erences in temperature from the standard of the

neighbourhood, according to the season or the time of day, its climate is extreme, and

the site cannot be inhabited by species which require relatively cold water.

The newly hatched nymphs are destitute of any visible muscular, nervous, circulatory,

or reproductive system ; their alimentary canal is incomplete ; and, being too small to

requii-e sjiecial breathing-apparatus, they respire through the integument at large. The

abdomen is 9-jointed, and the anteunaj and caudal seta^ have likewise fewer articulations,

and are less hairy than those of more advanced nymphs. Pohjmitarcys possesses the

third caudal seta even before it is hatched ; but Clocon is born without any trace of

it, and developes it gradually at a later period (Joly and Lubbock).

During the first few days after their birth the young cast their skin several times, the

intervals between the moultings lengthening by degrees (Lubbock). Blood-globules and

rudiments of the tracheal branchitc begin to appear simultaneously when the insect is

eight or ten days old ; the latter bud forth from th.e hinder lateral angles of some of the

abdominal segments, and (like the parts of the mouth) are modified considerably in

detail before they acquire their ultimate shapes (Joly).

EEV. A. E. EATON ON RECENT EPHEMERID^ OR MAYFLIES. 13

Adolescence is evidenced by the advancement towards maturity of the reproductive

organs internally, and externally by the outgrowth of rudimentary wings from the hind

borders of the proper segments. The forceps of the male also begin to bud forth, and in

certain genera an extension of the apical integument of the penultimate ventral segment

becomes perceptible in the female.

Characters and FeettUarities of the Nymjih. — In their general form most nymphs nearly

resemble the adult. Prosopistoma is exceptional in having the body oval in outline,

convex above and flattened beneath ; and it possesses the faculty of adhering firmly by

suction, like a limpet, to stones. A N. -American ally of Ephcmcrella (PL XXXIX.),

longer in the body than Prosopistoma, is furnished with concavities on the pectus and

venter that are densely pilose, which appear to aiTord it a similar power. Many other

genera have the body of the nymph dilated and flattened beneath more than it is in the

imago, but not Avith any view to its employment as a means of adhesion.

Head diversiform, prominent, usually about as wide as the thorax, vertical or else

pretense; cranial sutures mostly distinct. Labrum (when present) transverse, emar-

ginate in front, and rounded off at the anterior corners ; when it is absent, a velvety fold

of the palate-membrane completes the enclosure of the mouth opening immediately

above the mandibles at a distance from the edge of the epistoma. Frons usually even,

but sometimes (e. g. in Ephemera) produced into short projecting points. Ocelli three,

small. Oculi moderate, becoming large in the adolescent male. Antenna! slender and

tapering (their first two joints the stoutest), usually many-jointed and long, but some-

times few-jointed, very short and subulate; in many genera the joints are nearly bald,

whilst in others (e. g. Epihemera) they arc Ijcset near their tips each with a whorl of long

spreading hair. Mandibles strong, with more or less asymmetrical dentition, which com-

prises usually a molar surface in addition to fang-like lobes ; but in some predatory

genera (Pis. XLIII. & LIII.) the molar region is wanting. The cndopodite is often

represented by a slender jointless movable appendage attached to the inner base of the

inferior lobe (as in Sii)]ilurii.s, PI. L.), or sometimes by a tuft of hair [Ecdijurus,

PI. LXIL). The lobes are remarkably abrupt in Bactls (PI. XLIV.). The outer lateral

region of the mandible in a Palinfjeuia from Ceylon (PL XXV.) is produced into a

massive enlargement continuous with the crown ; in Potamanthus it is armed with a

tooth-like tubercle (PI. XXXI.); in Polijmitarcijs, Ephemera, &c. it is extended into a

strong tapering tusk, distinct from the crown, variously furnished outside with tubercles

(Pis. XXVIII. & XXX.); this prolongation is more slender in Euthi/plocia and densely

hairy (PI. XXIX.). First maxilla unaccompanied by a galea, its inner edge generally

either hairy or rigidly setulose, but sometimes spinose, the point often pungent, the

crown variously armed, sometimes with long fine hair distributed evenly upon it

(Oliffoiwuria, Poli/mitarci/s, Pis. XXVI.-XXVIII.), sometimes with a dense beard of

harsh hair, as in Ealrophlehia (PL XXXVL), at other times with pectinate spinules, as

in Chirotonetes, MhUhrogena, &c. (Pis. XLIX., LIV., &c.). Palpus of first maxilla

usually 2-, 3-, or 4.-jointed, according to the affinities of the genus [but in one instance

multi-articulate (PL LIII.)], and of various relative length,— extremely long in Eiithj-

plocia (PL XXIX.), very short in Ep)hemerella and its kindred (Pis. XXXVII.-XL.).

14 HEV. A. E. EATON ON liECENT EPIIEMERID.E OE MAYPLIES.

Second raaxillsc, when present (in OUgoneuria they are either suppressed, or else are

reduced to the condition of raised folds traversing- the upper surface of the lahium,

PL XXVI.), simple and usually flattened ; palpus 2-jointed in allies of Palingenia and

Ecdyurus (though in this latter group of genera the last joint may essentially be

compounded of two), 3-jointed in most other instances, but in one remarkable case

(PI. LIV.) multiarticulate ; it usually tapers towards its extremity, but is sometimes

enlarged or expanded, whilst in BcBtisca (PL LII.) it is actually forcipate. Labium

in the large majority of genera plane and bipartite, with lobes as large as, or smaller

than, the lacinise of the second maxillae. In a few cases it is undivided, and is then

either plane and creased lengthwise through the raxMlQ {Oligonenr'm, PL XXVI. ), or

else is conduplicate {FaUngenia, PL XXV. ; ToJumltareys, PL XXVIIL). Tongue

(glossa) and paraglossa? membranous or pergamentose, the former usually inflated and

often concave in the middle, generally broad, and citlicr as long as or shorter than the

paraglossse. The following are their leading modifications : — paraglossse broad ; tongue

ovate (Pis. XXV. & XXVI. , Pctllngenia ani OUgoneuria), subrotund (PL XXVII. JoUa),

oblong and entire (PL XXXIII. Bla'sturus), emarginate (Pis. XXIX. & XXX., Eiifhy-

plocia and Ephemera), obcordate (PL XXXI. Poiamanthns), retuse, with claw-like lateral

projections (Pis. XXXIV. & XXXV., Ghorotcrpes and Thraiilus), raucrouate, and in

combination with the paraglosste rather like a mitre or a birctta seen broad-wise

(Pis. XLV.-XLVII., Bai'tis and allies) : — paraglossaj narrow and recurved, tongue

broad and bifid (PL XXXVI. , Habropldebia). In some genera both glossa and para-

glossa) appear to be absent ; Prosopistoma seems to have none.

Thorax compact or subcompact, rigid ; pectus rather broad ; prothorax usually well

developed and more distinct than the metathorax from the mesothorax ; but in Baitisca

and some few other genera (Pis. XLIIL, LII.) the pronotum is intimately blended with

the mesonotum. Ecdyurus and many of its kindred have the head and pronotum bordered

at the sides with a membranous expansion seemingly subservient to the oxygenation of

intratracheal air. The winglets of advanced nymphs are united by their inner margins

to the apical borders of their proper segments, and overlie the base of the abdomen. In

nearly mature nymphs of OUgoneuria (PL XXVI.), and in even less aged specimens

of genera related to EphemereUa (Pis. XXXVII.-XL.), the space included between

the terminal margins of the fore wings and the peak of the mesonotum becomes closed

over by a membrane in continuity with the same, extending almost up to the extre-

mities of the wings. This membrane is produced backwards still farther in Prosopistoma

and Bcetisca (Pis. XLIII. & LII.), so as to form in combination with the wings a

hood which completely roofs over the tracheal branchiaj and the segments that bear

them. Pormerly the construction of this shield was not quite understood, the whole of

it being attributed to hypertrophy of the mesonotum ; but one of Dr. Hagen's gifts of

specimens furnished the means of explaining its composition rightly. Coxa) usually

prominent, but not so in Prosojnstoma (I. <?.). Trochanter short and strong. Femora

moderately or very stout, sometimes much compressed. Tibia) spurless, though in a few

instances terminating in a point or spine ; often apparently compound owing to the

distinctness of an oblique line of muscular insertion perceptible below the knee. Tarsi

liEY. A. E EATON ON RECENT EPIIEMERID^ OR MAYFLIES, 15

2-joiuted, the termiual joint claw-shapod. The legs, as a whole, are modified to suit the

habits of tlie nymph: the hinder pairs of burrowing nymphs are often short and weak,

whilst their fore legs are strong (e. g. Polymitarcijs, PI. XXVIII.) ; the fore tibite and

femora of many such nymphs also are often strongly bearded with long stiff hair. In

Prosopisioma the corresponding armature is a row of minute pectinate spinules. Dif-

ferent nymphs have different manners of disposing their legs Avhilst swimming, according

to their kindred : those which swim laboriously and slowly keep theirs at work as if

they were running, without much effect. Rcptagenia and its allies employ their

flattened femora to some advantage; others, such as Cloeoii and its associates, trail

their legs at length through the water, darting swiftly about, propelled solely by their

caudal setaj ; but the legs of Prosopistoma (which is just as nimble as the nymphs last

referred to) are folded up closely beneath the thorax, which is grooved for their recep-

tion. The legs of dead specimens in fluid are often set out in the postures appropriate

to them during natation.

Abdomen sessile, differing considerably in length relatively to the head and thorax,

according as the anterior segments are or are not abbreviated in comparison witli the

hinder ones ; in cross-section it is either sul)circular, or arched above and flattened

beneath. The hinder lateral angles of some of the segments are in many genera pro-

longed backwards into acute teeth of diverse dimensions. Erom the last segment just

Ijelo'iV the tergum issue two or three many-jointed caudal setae of various lengths in pro-

portion to the body ; sometimes they are much longer than it {Heptagenia &c.), at

others unequal to it, while in a Palingenia from Ceylon and a few other genera they are

many times shorter than it. The median seta is in some instances the shortest or even

abortive, and in many more is eventually deciduous at the jienultimate moult through

atrophy. Throughout more or less of their extent, on one or on both sides, their hair is

usually lengthened so as to feather them and render them fit to serve as organs of

propulsion. Tiie outer tails can be moved at will towards or away from the median

tail ; and the amount of their natural divergence from it during repose is an item of

importance in classification. In Prosopisioma the sette can be simultaneously retracted

into the abdomen so as to be entirely hidden.

Tracheal branchiae are movable, membranaceous, or filamcntose appendages to the

integuments, enclosing branching tracheae, which are deciduous witli the epidermis, and

are media for the oxygenation of the systemic air distributed throughout the body. It

is usual to assert that the insect employs them as fins ; but however rapidly it may

agitate them to and fro, they do not seem to increase its rate of progression. They are

principally outgrowths of some or all of the first seven abdominal segments, and arise

from only one region of the same segment at a time ; but the point of origin need not be

the same in consecutive segments. In the large majority of genera their places of

attachment are latero-dorsal, and then either well in advance of the posterior angle of

the segment {Paliiif/etiia, Lcp)top)hlebia, &:e.), or at the apex of the angle, or else at the

hinder border of the segment, within a sinus at the base of the lateral tooth-like pro-

longation of the same. The first abdominal pair in Olkjoneuria and RhUhroc/ena is

latero-ventral instead of dorsal ; and in the former genus, as well as in Jolia, one pair is

16 EEV, A. E. EATON ON EECENT EPIIEMEEID^ OE MATELIES.

cephalic, issuing from tlie basal joinings of the upper maxillfe. Jolia, in addition, has a

branchial tuft at the insertion of each of the fore legs. The abdominal pairs are usually-

all exposed, and are carried diversely in different genera ; their form, proportions, and

substance likewise vary more or less, not only with their serial position in the same

insect, but also with the genus. In Bcetisca and Frosopistoma all of them are concealed

by the shield already described in connexion with the thorax ; in other cases one pair is

enlarged and thickened so as to resemble elytra covering the pairs posterior to it

(Pis. XL.-XLII.). Several fossorial nymphs dispose their tracheal branchiae in an

arch over their backs ; in other kinds they are decumbent upon the dorsum ; in others

they are directed outwards and backwards from, or are held at right angles with, the

sides of the body ; in Uliithrogena some are deflected, and two pairs underlie the venter.

As to their forms, when foliaceous they may be subquadrangular, subrotund, oval,

ovate, sj)atnlatc, lanceolate, or linear, with tlieir margin entire or fringed, or in part

eroso-creuate ; they may be digitate, pinnatisect, laciuiate, or dissecto-fimlnnate ; and in

many of these alternatives they may be single or binate, plane or conduplicate. Some-

times they are compounded of dissimilar elements, as when a tracheal branchia consists

of a foliaceous membrane, furnished at its base with an exjilanate or fasciculated tuft of

simple or branched filaments (Pis. LIV.-LXII.); or as in Ephcmerella and its kindred,

where each is composed of a coriaceous lamina sheltering a binate appendage of imbri-

cate lamellfie disposed in the form of the letter V ; or again, as in what may be Trlco-

rythus (PI. XLI.). In the matter of proportional size, the tracheal branchia; of the first

abdominal segment (when they are developed at all) are frequently minute {e. g. in Ccenis

and Ephemera) ; the last pair is visually small ; the second pair is the largest in Ccenis,

the third or the fourth pair in many others ; but very often all of tliem are much alike

in size. The substance of tracheal branchiaj with the margin entire is stronger than

that of others whose form is less simple, being usually more or less coriaceous or

corneous. When they are unusually stout their hinder or under surface is lined with

delicate membrane, upon which the trachea? are distributed. Most of the tracheal

branchiae are kept in rapid agitation ; but the first and the last pairs, and in Ccenis the

elytroid pair, are usually held almost motionless.

The branchial trachea? branch in a manner very similar to that of the ribs and veins of

dicotyledonous leaves of like form. They should be examined (when this is possible)

while the insect is yet alive, because very soon after death endosmosis drives the air out

of their ultimate subdivisions, which cannot then be seen. More than one skilled ana-

tomist, trusting to inspection of cabinet examples placed in preservative fluid, has

denied the existence of tracheae within filamcntose tracheal branchiae, being unaware of

the rapidity and completeness of their obliteration in the dead insect under ordinary

circumstances.

Tracheal respiration is apparently carried on to some little extent by means of other

organs than the regular tracheal branchite in certain instances. The rectum, the

expanded borders of the head and front portion of the thorax in Ecclyurus and its allies,

the hinder surface of the femur in these and some other genera, and perhaps the caudal

setae, may be taken as examples of such accessory organs.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 17

In some genera the body and limbs are partially clothed with hair. This is generally

simple ; but EphemereUa and some kindred nymphs have clavate hairs in certain regions,

closely resembling in theii- spinnlose structure the thickened hairs of simdry Trombidiufe ;

and some of the pubescence on the head of a Cingalese PaUngenia is microscopically

plumose. The figure of the mandible of Frosojnsfomn (PI. XLIII.) is not on a scale of

enlargement sufficient to show the plumose structure of the bristles adjacent to the

endopodite.

The term ' Subimago ' is used to denote the penultimate stage in the life of such of the

Ephemeridse (the large majority of them) as moult once after direct respiration through

the stigmata has been established, and their wings have become fully expanded. The

chief points whereby insects in this condition can generally be distinguished from adult

examples are — the duluess of the integuments, especially that of the wings ; the ciliolate

terminal margin of the wings in many genera ; the brevity of the fore legs ; the greater

hairiness and shortness of the caudal seta?; the less protuberant and less brightly

coloured oculi ; and, in the male, the marked shortness and stoutness of the limbs of the

foi'ceps. Where (as in Caads and Trlcorytlms) the wings are ciliolate both in the

subimago and in the adult, and where (as in Polynutarcys) the wings are opaque in both

stages, account has to be taken of the remaining criteria. In some genera the thorax of

the subimago differs in its markings from that of the adult fly, and the wings undergo

changes in their coloration before the last moult. "When the subimaginal slough is

retained vxpon the wings of the adult fly (as in OUgoneurla) they remain dull and

subopaque during life.

The term ' Pseudimago,' employed by a few authors instead of Subimago, is an

etymological solecism derived from two words belonging to different languages. ' Pseud-

idolum,' or ' Proidolum,' would be the Latinized Greek equivalent of the Latin Sub-

imago, if any were needed.

Characters which have been used as Bases of Classification, but which

ARE NOT FUNDxVMENTAL.

Many of the characters upon which the classification of the Ephemeridaj was formerly

based have proved to be unsuitable for the purpose. Originally the number of the caudal

setcB was deemed a matter of primary importance ; and when forms were discovered with

the median seta abbreviated, they were ranked between those with three long equal setaj

and those with two only. Subsequently, in addition to the setse, the number of the wings

was employed as a leading clue to the arrangement of the genera. But it is now well

known that these criteria are serviceable at the most for nothing more than the distin-

guishing of genera very intimately related to each other, belonging to various subordinate

alliances comprised within the family; while one of them, (the number of the setre) is

not always available for even this purpose, varying as it does in some forms with the sex

[Polymitarcys), or with the individual {Atalophlebia australasica). In more modern times

the comparatice scarcity or abundance of cross veinlets in the wings, and especially in the

marginal area of the anterior wing before the nodus, has been supposed to furnish a trust-

SECOND SERIES. — ZOOLOGY, VOL. IIJ 3

18 EEV. A. E. EATON ON RECENT EPHEMEEIDJi OE MATELIES.

worthy guide to the succession of the genera ; but it is unequal to the actual requirements

of the case ; compare, for example, the fore wing of Baetis Salvini (PL XVI. 29 a) with

that of Cosmetogenia (PI. XXIII. 42). The most recent suggestion as to the classitication

of the genera was to group them according to the structure of the tracheal branches of

the nymphs. According to this scheme Haljrojihlchia (PI. XXXVI.) and Thraulus

(PI. XXXV.) would fail to come into the same group as Choroterpes (PI. XXXIV.) and

Blasturus (PL XXXIII.). Indeed if dependence be placed implicitly upon the modifica-

tions to which this organ or that is subjected in the adult, or in the junior conditions of

the insect, the scheme of classification arrived at can hardly fail to be unnatural and

arbitrary. It is only by taking cognisance of points of difference and agreement in many

details, in the anatomy and the mode of development and the habit, of leading repre-

sentatives of the various alliances of genera, at different periods of their lives, before and

after their exclusion from the egg, that the mutual affinities of the several associations

of genera to one another can be demonstrated adequately. Until such comparisons can

be and shall have been carried out, the whole question of their arrangement can only be

dealt with in a tentative and experimental manner ; and it will be fortunate if error be

avoided in the necessary grouping of the genera into provisional alliances of apparently

kiucked forms, preparatory to the study of their affinities. It is far more easy to demon-

strate defects in proposed methods of classification than to devise a trustworthy system

in their stead ; and possibly extended observation in the futu.re may eventually show that

some of the bases of arrangement adopted in this present work are mere temporary

expedients worthy of mention in this paragraph.

History of the Classification of the EPHEMERiDiE.

The species of Ephemeridae known to Linn6 were arranged by him in two sections of

one genus Ephemera, according to the number of their caudal setae — species with three,

and with two sette, respectively.

No further subdivision of the family was attempted until the year 1815, when Leach

separated the latter of Linne's sections into two genera, Baetis with four wings, and

Cloeoii with two. In the hands of subsequent entomologists these two genera became

' obscured by the interpolation of extraneous forms. To Baetis, Say referred sundry species

of Hexagenia and ILeptageiiia, as well as a Bwtisca ; and eventually this name was

diverted altogether from the original type, and was misapplied by general consent to

species of Heptagenia and Siphlurus.

Curtis, in 1834, proposed another genus named Brachycercus, like Cloeon deficient in

hind wings, but distinguishable from it by its having three setae. This name was suitable

for the female insect only, with which sex alone he was acquainted.

Stephens, in 1835-6, possessing males of Brachycercus, finding them differ in very

obvious particulars from Curtis's definition of the genus, and failing to perceive that their

points of difference were of merely sexual character, established a genus Ccenis with two

sections, species with three long setse, and species with three short setse, a section for

each sex. He also transferred the genus from the position after Cloeon previously

assi-^ned to it, to the end of the section of Ephemeridae with three setse.

EEV. A. E. EATON OX RECENT EPHEMEEID.E Oil MAYFLIES. 19

Burmeister, in 1839, l»sed his arrangement of the genera primarily upon the compara-

tive scarcity or abundance of cross veiulets in the wings, and employed as secondary

characters the conditions of the oculi, ocelli, tarsi, and setse. He, too, renamed the

genus Bracliycercns of Curtis, calling it Oxijcypha. Merging Leach's Cloeon and Baetis

together vinder the shorter form of the first name (C'loe) he regarded them as mere

sections of this. The appellation Baetis was misapplied by him, the first of the two series

of species designated by it being equivalent to the unrestricted Potamanthus of Pictet

(probably his materials were dried specimens defective in setoe), the second series (with

one exception) to Heptagenia. He founded a new genus {Ballngenia) for the reception

of some species of the comprehensive Ephemera of early authors, distinguished by their

possessing a distinct median ocellus and four-jointed tarsi, in lieu of an obsolescent

median ocellus and tarsi almost five-jointed (the fifth or basal joint being intimately

adnate to the tibia and ill-defined). These genera were arranged by him in the same

sequence as that in which they are mentioned in this paragraph.

Professor Westwood, in 1840, established a genus Leptophlehla for some small species

of the " Ephemera cauda triseta " series of early authors, and unknowingly revived the real

genus Baetis of Leach, under the name Braclnjiildehia. From allusions to Burmeister's

genera in the Addenda to the Generical Synopsis, he appears to have become acquainted

with the ' Handbuch ' while the ' Introduction ' was in the press, too late for a place to be

assigned to Puliucjeiiia. From consideration of the number of the wings and seta?, and

the structure of the nymph, he drew up the following arrangement of the genera : —

Ephemera, Leptophlehla, % Baetis (= Heptayenia), Ccenis, Cloeod, and BrachijphJehia.

The scheme propounded by Pictet (1843-5) was constructed to a large extent with

reference to the abundance or the paucity of cross veiulets in the anterior wings, the

condition of the oculi in the male, and the number or tbe relative proportions of the

caudal setre. In the main the order of succession deduced from these data agrees with

that which is arrived at Avhen the genera are grouped according to the general habit of

their nymphs (so far, at least, as he had been able to ascertain this), viz. : — Burrowing

nymphs, creeping nymphs, and nymphs that swim with agility. The sequence of the ^

genera is : — Ei>heia.era, Balingenia (= Bolymitarcys, Hexagenia, Campsurus, and the

restricted Palingenia), % Baetis (= Ueptagenia, and a species of Atalophlehia), Pota-

manthus {= the restricted Potamanthus, LeptoiMebia, Kabrophleltia, and Ephemerella),

Clo'e (= Baetis, Centroptilum, Callibcetis, and Cloeon), Ccenis, and Oligonenria. Pictet

foresaw that some of the species referred by him to the genera Palingenia and Pota-

manthus Avould probably prove to be incongruous, but was precluded by lack of materials

from verifying his suspicions. He also surmised correctly that the neuratiou of the

anterior wings in detail would furnish characters towards their discrimination, adding: —

*' Mais j'ai repugne a entrer pour cela dans une analyse aride, longue et minuticuse ; j'ai

craint de rendre plus diflicile encore riutelligence des descriptions;" but he did not attach

much importance to the tarsal characters. If he had known of the name of LeptophJehia

in time he would have used it instead of Potamanthus, although, as he remarks, this last

is more comprehensive in its application than the former.

In 18G2 an account of some Illinois species of Ephemerida? was published by the late

3*

20 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

Mr. B. D. Walsh. The classification of the genera was determined by an application of

almost the same principles as were adopted by Burmeister, and is as follows : — J Ba'etis,

comprising three sections (Sect. A = Siphlurus ; Sect. B = Chirotonetes ; Sect. C = Bhi-

tlirogena) ; Fotamantlms (= Blasturus) ; FaUngenia with three sections (named by him

in the following year : A, Pentagenia ; B, Hexagenia ; C, Reptagenia) ; Ephemera,

Ephemerella, Bcetisca; Clo'e containing three sections (A = CaUibcetis ; B = species of

Callihcetis and Baetis ; C = Cloeoii) ; and Ccenis.

Dr. Hagen, in 1863, used Pictet's genera in a revised order, alluding only incidentally

to forms foreign to Great Britain : — Oligoneuriu, Cceiiis, PaUngenia, Ephemera, Pota-

manthus, % Baetis, and Cloeoii (= Cloe).

In 1868 a systematic catalogue of genera with named types, and with notes on their

geographical distribution, was published by me in the 'Entomologist's Monthly Magazine.'

My attempts to describe the wings in an intelligible manner, in the absence of illustra-

tions, were, to say the least, abortive. The genera stood thus : — Ccenis, Tricorythus, Oli-

gonetiria (with three sections), Campsurns (with two unreal sections), Polymitarcys,

PaUngenia, Pentagenia, Hexagenia, Ephemera, Poto^nanthus, Leptophlehia (with two

sections), Bcetisca, Colohurus, Siphlurus, and Reptagenia (with two sections).

In the same year, while describing the nymph of Cainis, I adduced reasons for trans-

ferring this genus from the position near Baetis and Clo'eon, assigned to it by Pictet (on

account of the simplicity of its wing-neuration), to the neighbourhood of Leptophlehia,

series 2 (= Rabrophlehia), and likewise for the removal of Oligoneuriu, ranked next after

Ccenis by Pictet, to the vicinage of PaUngenia, changes that were carried out in my

work on the Ephemeridne in 1871, when a few minor alterations involving no principle

in the successiou of genera were also made.

The structure of the tracheal branchiae of the nymph was taken as the basis of classi-

fication of Ephemeridae by Dr. A. Vayssi^re in his ' Thesis ' presented to the Paculte des

Sciences de Paris, and published in the ' Annales des Sciences Naturelles ' in 1882. He

arranged the genera in five groups : — 1, those having fringed branchial laminae, Lepto-

phlehia (= Hahrophlebia), Ephemera, Potamanthus, and Polymitarcys ; 2, those with

laminae devoid of fringes, Oniscigaster, Cloeopsis (= Cloeon), % Cloeon (= — — ?), f Cen-

troptihim (= Baetis); 3, those with simple laminae furnished at the base with either a

tuft of fibrils, Reptagenia (= Ecdyurus), Oligonetiria, Jolia, or a bifid appendage bearing-

very delicate imbricated lamellae, Ephemerella ; 4, those whose second jjair of brauchia

afford protection to the following pairs, Tricorythus and Ccenis; 5, "les larves dont

I'appareil respiratoire est completement cache ct protege par des jirolongements mesotho-

raciques dans I'epaisseur desquels naitront j)lus tard les ailes superieures," Bcetisca and

Prosopistoma. I examined and named the type specimens of this Thesis at Avignon in

August 1880 ; but the indications affixed to the phials appear to have become confused.

To the best of my recollection the specimens representing % Cloeon were junior examples

of something which I suspected might be Centrojytilum or Ba'etis ; but I did not ascertain

which.

The additional knowledge of Ephemeridas gained since 1871 has not yet necessitated

any material departure from the sequence of the genera which I adopted. A few minor

EEV. A. E. EATOX OX EECEXT EPHEMEEID.E OR MAYFLIES. 21

alterations have been made (such as the establishment of genera in place of provisional

sections) and a remarshalling of the members of certain alUances ; and besides this, some

genera, then isolated, have become rallying-points of new alliances ; but these changes

have not disturbed the scheme as a whole. The plan upon which it has been drawn up

may be described as based upon conclusions derived from comparisons of adult insects

checked and modified by others educed from the study of younger specimens. The o-eneral

effect of this plan has been to bring into the middle of the series genera of hardy habit

that moult completely at the last ecdysis, that have functional legs with four distinct

tarsal joints, and have the oculi of the adult male either bipartite or ascalaphoid. The

ends of the series are occupied by genera that have the oculi of the d furrowless and

undivided, those having weak or functionalless hinder legs with at most four distinct

joints to the tarsus, whose eggs are discharged in bulk, and whose Life is truly ephemeral,

commencing the series ; and those whose legs are all efficient with five distinct joints to

the tarsus, whose oviposition is gradual, whose life in the adult condition is measured bv

days, if it attain its full natural term, and whose last moult is complete, bringing the

series to its close. The scheme is open to objections attendant upon all linear arrano-e-

ments in zoology, individual genera here and there having to be ranked in groups with

whose formulated definitions they are largely at variance during some portion of their

existence. The subjoined Table exhibits the system of classification ; generical details of

the adult flies are illustrated in the first 24 plates, and the numbering of the genera

quoted in the Table accords with the numerals assigned to them in the writing of those

plates.

Table of the Classificatiox of Genera of the Ephehered^

NUMBERED AS IN PlATES I.-XXIV.

Family EPHEMERID^.

Group I.

Series I.

Section 1 of Palingenia Genera 1-6.

„ 2 oi Polymitarcys „ 7-10.

Series II.

Section 3 of Ephemera Genera 11-13.

Group II.

Series I.

Section 4 of Potamanthus Genera IJ^IS.

Series II.

Section 5 oi Leptophlebia... Genera 16-2S.

,, 6 oi Ephemerella „ 24, 24- dis &c.

Series III.

Section 7 oi Ctenis Genera 25, 25 ii«, 26.

„ 8 of Prosopistoma

27.

Serie IV.

Section Q oi Baetis Genera 28-31.

22 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

Group III.

Series I.

Section 10 of Siphlurus Genera 32-36.

„ 11 oi Btetisca » 37.

Series II. (provisional).

Section 12 (provisional) Gemis Plate LII.

Series III.

Section 13 of Atopopus Genera 38-10.

,, \-i oi Ecihjurus „ 41-46.

It may be noted of tlie foregoing Table that the composition of the section of Folymt-

tarcys is not altogether homogeneous. Genus 7, Ei(thi/plocia, may eventually have to

rank as a separate section, on account of its triarticulate palpi.

Section 8 is associated in the same series as section 7, because the adult Prosopistoma ? ,

in the construction of its head and thorax, is, according to M. Vayssiere's representation,

very similar to Ccenis. This last genus, ' in some particulars, resembles insects of the

Folymitarciis section ; but, on account of the formation of the nymph, it appears to be

more nearly related to the section of Ephemerella than to the genera of section 2.

The provisional section 12 is classed in Group III. on account of the nymph having

some resemblance to genera of section 10 in the form of the laciniae of its lower maxillae

and the lobes of the labium. On the other hand, its hinder tracheal-branchiaj are con-

structed after the same plan as those of the genera in section 14. As a matter of pure

conjecture, it may be suspected of belonging to section 13, of which no nymphs have

hitherto been seen ; only if such were the case, it is probable that the tibiae would be

somewhat shorter than they are in comparison with the tarsi.

Systematic Description,

group i. of the genera.

Adult. — At the fore-wing roots the anal nervure (8) meets the pobrachial nervure (7) ;

the hinder tarsi, when not atrophied, have four distinct joints, and sometimes an ill-

defined fifth joint intimately concrete Avith the tibia ; 6 oculi evenly contoured.

Nijmxjli. — Palpi of the 2nd maxillae (" labial palpi ") 2-jointed (except Euthyplooiu,

3-jointed).

First Series of Group I.

Legs of the adult ? short in proportion to the body, and feeble, when not functional-

less, through atrophy of the tibia and tarsus ; the fore legs in both sexes of the subimago

extremely short, and transversely rugose ; hind legs of adult 5 the longest pair. Nymph.

Palpi of 1st maxillEe very stout, 2-jointed (excej)t Euthyplocia 3-jointed) and curved.

Section 1 of the Genera. — Type of Faliugenia. — Subcosta of the fore wing, when de-

veloped, retired within a fold of the membrane somewhat beneath the radius. In many

genera the subimaginal pellicle of the wings is not shed at the last moult. Nymjjh fos-

sorial or predatory ; in those that are known the median lobe of the tongue is pointed.

Subsection A. Wing-neuration complete and plentiful ; anal nervure (8) of the fore

wing either sinuous, or else from the wing-roots to its fork nearly straight, and afterwards

gently arched; axillary nervures short but strong; the first (9') annexed to the anal

EEV. A. E. EATO^S' ON RECENT EPHEMEEID^ OR MATPLIES. 23

nerviu'e (8) at tlie wing-roots, the second (9-) ending apart from it in the regular raised

axillary fold or vessel ; wiug-membrane translucent and dull. Pronotum large, trans-

verse, broader than the head, tumescent, arched behind. Setae pubescent or minutely

pilose, short in ? , very long and divaricate in d . Forceps borne upon a deflexible

laminar lobe prolonged from the distal ventral margin of the 9th segment, which is not

represented in the ? , the proximal joints of the limbs the longest. Lobes of the penis

unarmed ; orifice of the seminal duct subapical, and on the inner side of the lobe. Eyes

of the 6 large, oval, narrowly separated from each other ; anterior ocellus much smaller

than the hinder two. Pore tibia and tarsus densely rugose transversely ; ungues in

each tarsus unequal, and not quite alike. Nymph fossorial ; the labium concave, its

sides approximated to each other above ; the tracheal branchiae borne upon protuberances

armed with single minute spinules, situated in or near the middle of the sides of their

respective segments, and arched upwards over the dorsum ; the hinder lateral angles of

the segments not produced backwards. Pore legs stout, densely bearded with long hair

on the femur and tibia ; the tibia and tarsus compressed, the former oblique at the tip.

Terminal margin of the fore wings free.

The single genus contained in this subsection is a composite one ; but further materials

are needed to enable the incongruous species to be completely dissociated from the type.

They may be referred provisionally to three subgenera: — JPalingenia (typical), Burmeister,

containing European and Western Asiatic species ; Anagenesia, containing Indo-Malay,

and a Siberian species ; and a nameless subgenus containing Brazilian species.

PALINGENIA, Burm. 1839; restricted Eaton, 1868.

Illustrations. Adult (details) PI. I. & III. 1 «-!/ (whole figures), see citations under

P. longicauda. Nymph PI. XXV., see also citations of Swam., Gorove, and especially

Corn. (18-18) under P. longicauda (whole figures and details).

Subgenus Palingexia (typical).

Adult.— Vrcohv^chivil nervure (6) of the fore wing forked beyond the middle ; two con-

spicuous sets of longitudinal nervures proceed in pairs to the terminal margin (at 4<\ and

at 5 & 6). Pore tarsus of 6 about twice and a half (2f ) as long as the femur. Seta3 2,

in the 6 upwards of three times as long as the body, in ? about the same length as

the body. Anterior thoracic spiracle gaping, large ; aperture bivalvular, the lower

valve the smaller, with concave margin ; the upper valve sinuous, having a large salient

obtusely rounded lobe projecting inwards in front of the tegulae. Orifice of the posterior

thoracic spiracle gaping, irregularly reniform with the siniis in front.

Nymph, [after Cornelius].— Six pairs of abdominal tracheal branchiae, each lamina

fringed with short simple fibrils, and perhaps folded together lengthwise. Seta? about I

as long as the body in the female.

DistriJjut/ou. Eastern N. temperate region.

Tyjye. P. longicauda (in Ephemera), 01.

Etymology, TraXiyyeveu, in allusion to its annual swarming.

24 REV. A. E. EATON ON EECENT EPHE-AIEEID^ OE MAYELIES.

Palingenia longicauda, Oliv. Plate I. 1 « (wings, legs, d 2 , head and forceps,

6 adnlt).

Hemerobius, Clutius, Opusc. 2, cap. viii. (frontispiece), p. 100 (1634).

Ephemerum, Swam., Epliem. vita (1675) ; idem, ed. Tyson, p. 44, pis. i.-iv. and v. 2 (young) ; pi. v.

1, 3, &c., viii. [adult] (1681); SchiefFer, Ic. iii. tab. cciv. 3 (1776). Ladislaus Gorove, alias Stefan

Goseve, in Tudomanyos gyiij tem^ny, viii. [Egy kulonos tiinemenynek, az ugynevezett Tisza viragzas

nach leiraza], pp. 22, tab. 1, a-c (young), e (last moult), f (slough), g c?, d $ im. [A very full account]

(1819) . Reprinted by Mocsary, in Rev. d. Inhaltes der Termeszetrajze Furzetek, ii. 124-5, and (German-

text) natiir. historische. Heft ii. Bd. ii. u. iii. 181-2) (1878).

Ephemera longicauda, Oliv., Euc. Meth. vi. 418 (1791) ; Latreille, H. N. xiii. 96 (1805) ; Lamarck, H. N.

ed. i. iv. 221 (1817) ; ! Ramb., Nevropt. 295 (1842). E.flos-acjiue, Illiger, Mag. f. Ins. i. 187-8, no. 17

(1802); Treipke, Stet. ent. Zeit. i. 54-8 (1840). E. Sivammerdiana, ! Lat., H. N. xiii. 96 (1805) ;

idem, Gen. iii. 184 (1807) ; Cmder, R. A. ed. I. iii. 430 (1817) ; ditto, ed. II. v. 244 (1829); Lamarck, H. N.

ed. I. iv. 221 (1817) ; Blancbard, H. N. Ins. iii. 54 (1840) ; idem, in Cuv., R. A., ed. Crochard, xiii. 91

(1848). E. Swammerdamiana, Sliaw, Gen. Zool. vi. part 2, pi. Ixxxii. (1806).

X Semblis marginata, Panzer, in Explic. Scbajf. Ic. cciv. (1804).

Palingenia longicauda, Burmeister, Haudb. ii. 803 (1839) ; H.-Schtef., Fn. Ratisb. 346 (1840) ; Pictet.

Nat. Hist. Ndwopt. ii. Epbem. 155, pis. xiv. xiv bis, xvi. (1843-45) ; Cornelius^ Beitr. z. Kenntu. d.

P. lofigicauda, pp. 38, pis. i.-iv. (1848) ; Walker, Cat. 549 (1853) ; Hagen, Stet. ent. Zeit. xv. 316-19

(1854); Perty, Die Zool., Th. ii. 344-45 (1855) ; Hag., Stet. ent. Zeit. xx. 431 (1859); Loew, Verb,

zool.-bot. Ges. Wien, xi. 409-10 (1861) ; Corn., Stet. ent. Zeit. xxiii. 465-66 (1862) ; Gerstacker,

Handb. d. Zoologie, ii. 59-61 (1863) ; Karsch, Die Insectenwelt, v. 400-2 (1863) ; Eaton, Trans.

Ent. Soc. Lond. 1871, p. 62, pis. 17-17 a (1871); Joly, Mem. Soc. d. Sc. Nat. Cherbourg, xvi.

pi. i. 2 [after Swammerd.] (1872) ; Hag., Trans. Ent. Soc. Lond. 1873, pp. 385-86 and 392 (1873) ;

N. & E. Joly, Rev. Sc. Nat. v. 10, and pp. 324-26, pis. vi. 2, ix. 39-41 (1876) ; Mocsary [vide

Ephemerum, Swam. &c. supra] (1878) ; Rostock, Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 82

(1878).

Adult {dried) 6 . — Wings dull translucent brownish, of a tint intermediate between

medium sepia and medium Cologne-earth, with opaque ncuration and slightly yellowish

wing-roots. The first of the subsidiary nervurcs contained within the fork of the anal

nervure (8) is rather unstable in its arrangement. Setae, venter, legs, and underside of the

thorax light bright yellow, excepting the tibice and tarsi, which are very light brownish ;

the pronotum dull light waxy-yellow, the mesonotum slightly browner. Head pitch-

black. Dorsum of abdomen intense sepia.

S . Wings very slightly lighter than in the 6 . Pronotum, meso- and metanotum of

a medium Cologne-earth brown, which colour borders the occipital margin of the

vertex. Seta? light brownish yellow. Length of body, d 23-25, $ 27*5-29; wing,

6 24-26, $ 31 ; setaj, 6 70-74 & 1-5, 2 26-27-5 mm.

Mab. The large rivers of middle Europe from Rotterdam to Hungary, also near Cette.

This last locality is quoted on account of a nyiuph in the Museum of Comparative

Zoology, Cambridge, Mass. According to Mr. Snellen of Rotterdam, Swammerdam's

statement that this species appears in vast multitudes during one or two evenings only

every year, " on or about the Peast of St. John," is generally correct, but the date of

the swarm is liable to be earlier in warm seasons, sometimes as early as the 10th

of June.

EEV. A. E. EATON ON EECENT EPHE]\rEEID.E OR MAYFLIES. 25

Palingbnia ftjliginosa, Georgi.

Ephemera fuliginos a, Georgi, Geogr.-physik. u. naturhist. Beschr. d. russischen Reichsj Th. iii. vi. p. 324

(1802).

Palingenia fuliginosa, ! Hag., Trans. Ent. Soc. London (1873), p. 392.

Adult {(hied) 6 . — Wiugs deep raw-umber brown, translucent, dull. Compared witli

P. lonrticanda, the sinuous first axillary nervure (9') of the fore wing is more strongly

arched towards the inner margin ; and the first of the subsidiary nervures enclosed by

the fork of the anal nervure (8), instead of being diffuse, imitates on a small scale with

its branches the same main nervure and its branches in an appreciable manner. Pro-

thorax above somewhat pale ochreous, the remainder of the thorax chiefly brown-ochre.

Ab iomen above rather darker than the wings ; the pleura and venter, forceps and sette,

pale yellow-ochre. Sides and underside of thorax and the femora slightly deeper in tint

than the venter, the tibire and tarsi tinged with ashy-grey ; vertex of head brown-ochre,

with the orbits of the ocelli blackened. Approximote admeasurements : — length of

body 25, wing 25, setae upwards of 55 mm.

Hah. The Caucasus.

Subgenus Anagenesia.

Adult. — Prsebrachial nervure (6) of the fore wing forked before the middle ; three

conspicuous sets of longitudinal nervures proceed in pairs to the terminal margin (at i',

5 & 6, and 6^). Pore tarsus of d shorter than the femur. Setae 2, in 6 upwards of

three times as long as the body, in ? about half as long as it.

Nym])h. — Divisions of the abdominal tracheal branchite, of uniform shape, unequal;

each division is a narrow membranous lamina folded length-wise, fringed with short

simple fibrils, to which are distributed colourless air-vessels from a dark median trunk.

In a nymph from Ceylon the clypeus has a globular tubercle in the middle of its

front edge ; there is a triangular tubercle above the insertion of the antenna, and

one in a line with the eye on each side of the jirothorax. The bearding of the

fore femur is restricted to a rounded patch at the base beneath, and is almost erect ;

that of the tibia is spreading, and clothes the sides and the front, and in the latter

position a scanty series of long tactile hairs stands erect. In the hinder legs the femoral

patches are insignificant, the tibia and tarsus are ciliated outside, and the tibia is shortly

and densely pilose on its distal border, and towards its extremity beneath. Antennae

setaceous, shorter than the head; the first three joints longer than any of the othei-s,

which are almost nude ; the second joint furnished with a dense patch of hair outside.

Labrum small. Mandibles short and stout, distally pilose, and with a curved patch of

long spreading hair near the base on the outside ; the crown, somewhat wedge-shaped

and irregularly dentate, is remote from the molar protuberance. Lacinia of the upper

maxilla flattened and ol)liquely truncate, pungent, and crowned with a dense beard, also

bearded within below the point, the last line of hair shortly and obliquely decurrent upon

the outside; first joint of the palpus nude; second joint much the longer, slightly

incurved towards its acute extremity, and densely pilose nearly all over. Labium and

SECOND SEKIBS. — ZOOLOGY, VOL. III. 4

26 EEV. A. E. EATON ON EECENT EPHEMEEID.5: OE MATELIES.

lower maxillse as in the typical form. Lingua acutely ovate ; the paraglossae rather

narrow, connivent. Setae about J as long as the body.

DistribiUion. Indo-Malay region and Irkutzk.

Ti/pe. F. lata, "Walker.

Etymology . dvayeveala, regeneration.

Palingenia sibirica, jVPLach.

Palingenia sibirica, \ M'^Lacb., Ann. Soc. Ent. Belg. xv. 50, jil. i. 1-lffl (1872).

Adult 6 {dried). — Pore wings pale yellowish-brown, darkening gradually towards the

tip ; neuration for the most part pale, but some of the veinlets in the marginal and sub-

marginal areas are blackish. Hinder tarsi with one claw each ; legs whitish. Head

pale yellowish ; a black spot at the base of each antenna, a subtriangular blackish spot

contiguous with the oculus on each side of the vertex, the sutures of the cranium

blackish, and two brownish occipital clouds. Notum blackish ; the borders and median

stripe of the prouotum pale. Abdomen above blackish ; the segments pale at the sides,

and very narrowly so at the tips ; venter pale. Setae pale, with fine sliort pubescence.

Length of body 21 mm.

Hab. Irkutzk, 20th of May (M'Lach. Mus.). There is a specimen in Baron de Selys-

Longchamps's collection.

Palingenia lata, Walk. Plate I. 1 6 (wing).

Palingenia lata, ! Walk., List Neiiropt. Brit. Mus. iii. 550 (1853) ; Etn., Trans. Ent. Soc. Lond. (1871),

p. 63, pi. iii. 18-18 6 (1871). P. amjAa, M<-Lach., Ann. Soc. Ent. Belg. xv. 50 (1873) [nominal

reference — part] .

Adult {dried) 6 . — Wings and thorax light Vandyke-brown ; the longitudinal neuration

of the former, the cross veinlets in the basal half of the disk of the fore wing, and also

those contained within the narrow interspaces of the nervures, distributed in pairs to the

terminal margin, opaque and dark Vandyke-brown; the fork of the anal nervure (8)

encloses a single longitudinal nervure. Femora nearly concolorous with the wings ; the

fore femur dark above, the hinder tibiae and tarsi greyer, and transversely rugose. In

dried examples the ungues of the hinder tarsi appear to be single. Abdomen faded,

fuscous above. Setae very light dull brownish yellow, pilose with uniform hair. Length

of body, d , 22, wing 23, setae about 70 mm.

Eah. Silhet.

Palingenia ampla, sp. nov, Plate I. Ic (wing).

Adult {dried) 6 . — Wings (as opaque objects) uniformly deep warm sepia-grey,

modified in transmitted light with light sepia-brown, their neui-ation for the most part

opaque; in the fore wing, the fork of the anal nervure (8) encloses a single longitudinal

nervure. Venter very light bistre-grey modified with equally light Vandyke-grey;

hinder femora nearly of the same colour beneath as the venter, but Vandyke-brown

above ; fore femora faded ; all the tibiae and tarsi (probably faded) extremely light

Vandyke-grey, transversely rugose; the hinder ungues darker and single. Setae light

EEV. A. E. EATON OX EECEXT EPHEMERLD.E OR MATELIES. 27

warm sepia-brown, with opaque joiiiing-s, and pubescent, with a few hairs at the joinings

longer than the others. Length of body, 2 , 17, wing 18 mm.

JSuh. Sarawak.

Palixgenia javaxica, sp. nov. Plates I. & II. 1 d (forceps, 6 , legs, fore wing, and

parts of setse).

Adult (dried) d . — Wings dark subtestaceo-cervinous, with opaque neuration ; the

veinlets along the terminal margin of the fore wing less sparse and better defined than in

the wing of P. tenera. Body faded above ; venter and setse subtestaceous, the genitalia

luteo-testaceous ; the setoe for some distance in the middle portion of their length are

furnished at the joinings with a few spreading hairs, longer and stronger than the hairs

of the universal pubescence. The fore legs and the hinder tibire and tarsi opaque

whitish ; hinder femora testaceo-lutescent ; fore tibia on the inner side at the tip armed

with a small more or less acute tubercle ; intermediate legs the shortest pair, hind legs

the longest, and more than half as long as the abdomen ; luigues of the hinder tarsi very

unequal, the lesser hardly visible ; those of the fore tarsus more nearly alike, and well

developed. The last two joints of each forceps-limb are together very nearly half as

long as the antepenultimate joint. Length of body, 6 , 19, wing 22-23"5, setoe about

60-70 mm.

Sab. Orawang (Java occid.). Five examjjles in Leyden Mus. communicated to me in

1876 by Mhr. C. Eitsema. The MS. name by Van A'oUenhoven attached to one of them

(No. 50), being preoccupied in Ephemeridas, is not adopted.

Palixgenia texera, sp. nov. Plate II. 1 e (wing and part of setae).

Adult {dried) 6 . — TMngs dark cinereous, with the longitudinal nervures and the

coarser of the cross veinlets subpiceous or fuscous, and with the finer of these whitish or

edged with whitish when viewed obliquely so as to reflect light. Body discoloured,

genitalia pale testaceous, setae almost concolorous with the wings. Legs very short in

comparison with those of P. y««;a?i/(?«, the posterior femur not extending to beyond the

second abdominal segment ; fore legs faded (whitish ?), posterior femur subochraceous.

Pubescence of setaj composed of uniform hairs. Length of body 17, setai circ. 55 mm.

Sab. Ardjoeno (Java orient.). One example in the Leyden Museum. A smaller

insect than P. javanica, having wings free from the least tint of testaceous, and with

more delicate neuration.

Palixgexia papijaxa, Etn. Plate II. \f (wing and forceps, 6 adult).

Palingenia papuana,\ Etn., Annal. Mus. Civ. di Stor. Nat. di Geneva, xiv. 398, woodcut a-f

(1879).

Adult {dried and in spirits). — Wings in the 6 white with light yellowish nem-ation,

the membrane during life somewhat creamy-white : in the 2 the wings are spotted with

black. The fork of the anal nervure of the fore wing contains a single longitudinal

nervure. Sette pubescent with uniform hair. Fore femur in the 6 not much shorter

than the fore tibia ; intermediate tarsus about as long as the intermediate tibia ; hinder

4*

28 EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

tarsi biunguiculate, the ungues very vinequal (/. c. woodcut h, c). Forceps sliort and

stout, their last two joints very short. Length of body, d 36, ? (after oviposition) 32 ;

wing, c? and ? , 27 ; seta?, 6 50, ? 17 mm.

Hab. Near tlie island of EUangowan, in December 1875, in insignificant numbers ;

and on Fly river, New Guinea, on the 2nd of July, 1876, in extreme profusion (Signor

L. M. d'Albertis). Specimens in fluid are in Mus. Civ. di Stor. Nat. di Genova, and in

M'Lach. Mus., and some remnants of a pinned 6 example in Brit. Mus.

The ' Annali ' above cited, after my diagnosis of the species, quote a passage from Signor

d'Albertis's travels relating to this insect, whose purport may be thus freely summarized.

On the 2nd of July, 1876, a few hours before sunset, wo witnessed a strange and magni-

ficent sight produced by an abundance of a species of Mayfly, actively pursued by the

following birds: — Calornis metalUca, Artamus cucopifgkdis, a Graculus, a Eurystomtis,

and the commonest Whiteheaded Osprey, HaUastur (jirrenera. Simultaneously the

insects were being preyed upon by thousands of fishes, who rushed up to seize them

whenever they touched the water with their delicate wiugs. But so profuse was the

abundance of the flies, that the ravages of all their destroyers caused no appreciable

diminution in their numbers. Mile after mile, from bank to bank, the river seemed

covered with them, when all at once, as if by signal, the whole of them rose up

confusedly, flying aloft in a thousand different directions, producing an eff'ect in the air

like that of a heavy fall of snow ; then they descended again, and the snow seemed to

cover the river with a white layer. The males very largely outnumbered the females.

Subgenus

? Palingenia atrostoma, Weber.

Ephemera atrostoma, Weber, Obs. Ent. 99 (1801).

Palingenia atrostoma, Pict., Hist. Nat. Nevroiit. ii. Epliem. 1.^)7 (1843-5) ; Walk., List of Neuropt.

Ins. in Brit. Mus. part iii. 550 (1853).

1 He.ru genia atrostoma, Etn., Trans. Ent. Soc. London (1871), G5.

Wings fuscous. Body yellow; mouth black; dorsum of abdomen fuscous ; setce fuscous.

Hah. Brazil. In 1871 I ranked this species conjecturally with Hexagenia. At that

time the genus Palingenia was not positively known to be represented in America ; but

now that a species of this group (represented by the nymph in the Museum of Com-

parative Zoology, Cambridge (Mass.), figured in PL XXV. of the present work) has

been ascertained to occur in the Amazons, Weber's description of the species atrostoma

as " Gigas in hoc geuere ; thorax marginatus canaliculatusque ; cauda biscta, setis

longissimis," taken in connexion with the (iolours of the wings and body, lends proba-

bility to the supposition of its being a Palingenia. Pictet was disposed to refer it to

what is now known as Gampsurus. The furrows of the thorax are adverse to its being

considered to be a Euthi/plocia.

Subsection B of Section 1. — Wing-neuration scanty ; anal nervure (8) of the fore wing

curved ; axillary nervures either rudimentary or obsolete, or represented by a branch

of the anal nervure (8) that meets the terminal margin ; wing-membrane transparent ;

REV. A. E. EATON ON EECENT EPHEMEEIDiE Oil MAYFLIES. 29

recurrent membi^ane at the fore-wing roots often prolonged into a narrow free-pointed

appendage beyond the peak of the naesonotum ; hind wing traversed lengthwise by a con-

tracted fold. Pronotuni compact, transverse, arched behind. Setce in $ short, smooth,

and usually glabrous ; in d very long, and more or less pilose. Forceps — limbs inserted

upon the sides of a laminar lobe extending from the distal ventral margin of the 9th

segment, which lobe is probably not deflexible, but is sometimes represented in the $ ;

their proximal joints the longest. Penis exposed, the lobes unarmed (excepting perhaps

in Lachlania) ; but stimuli capable of extrusion are in some genera concealed in the

9th segment. Proportions of eyes and ocelli vary with the genus. Fore legs of 6 short

and slender ; the tibia and tarsus often transversely rugose, the femur nearly as long as

the tibia, the ungues usually alike, the tarsus shorter than the femur; hind legs usually

the longest pair, the ungues subequal, broad, sometimes dissimilar, commonly flaccid.

Nymi)h {OUgoneurla oulj). — Labium flat; abdominal tracheal branchia3 inserted in

the axils of notches in the posterior margins of the segments close to the lateral angles,

which angles are prolonged backwards. Pore legs strong, the femur and tibia densely

bearded beneath or behind with long hair, the tibia and tarsus slender in comparison

with the femur. The terminal margins of the fore wings are united by membrane

forming a hood. [I believe these characteristics are common to all the nymphs of this

alliance, judging from the structure of the adult flies.]

{a.) Wing-membrane dull or satin-like ; fore wing with the anal nervure (8) forked,

and \\ith a free epinotal appendage ; 3 caudal setae.

OLIGONEURIA, Pict. 1815.

Illustrations. Adult (details) PL III. 2 a-6 ; (whole figures,) see citations of Costa,

Pictet, and Hagen (1855), under O. rhenana and O. anomala. Nymph, PL XXVI. ; see

also citations of Joly and Vayssiere (O. garumnlca), under O. rhenana.

Adult. — Pore wing with 5 longitudinal nervures, beside the costa and subcosta (this

last concealed), and with several series of cross veiulets in the fore part of the wing.

Setae subequal in length to one another ; in 6 about 1^ as long as the body, and pilose

at the joinings ; in $ at most §, and at least \, as long as it. Eyes in s somewhat

reniform, and approximated to each other above ; in $ oval and remote ; anterior

ocellus not much smaller than the others. Spinose prolongations of the posterior lateral

angles of the abdominal segments slender, those of the 8th and 9th segments the

strongest. Thoracic spiracles open in the dried insect ; aperture of the anterior trian-

gular, that of the posterior ovate, narrowed below.

Ni/mjjh [O. rlienana). — Six dorsal pairs of tracheal branchiiE, borne upon segments

2-7, and a ventral pair on segment 1, all alike composed of a small, thick, coriaceous,

subrotuud lamina, with a tuft of fibrils at its point of attachment. Divisions of the

labium intimately colierent : 1st maxilke furnished with a tuft of fibrillose tracheal

branchia; at the ouler base of the palpus. — In the nymph of O. rhenana, the bearding

of the fore leg is restricted to well-defined patches on the inner (or hinder) side of the

tibia and femur, the rest of the legs being almost quite glabrous ; the intermediate

30 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

tarsus is minutely spinulose beneath ; the hind tibia is similarly spinulose behind dis-

tally ; the tibia and tarsi are all slender, and the femora distally somewhat enlarged ;

the tracheal laminae are spinulose also. Head semielliptical, arched above from side to

side, and shelving from behind, so as to be wedge-like in vertical section, the underside

being flattened. Antennae glabrous, setaceous, the first two joints the largest. Labrum

sbghtly retuse in front, and diffusely pilose along its anterior border. Mandibles distally

enlarged, the molar tuberosity continuous with the crown, compact, and relatively large ;

the three fangs slender and small, the innermost appendiculated. Lacinia of 1st maxillaj

small, ovate lanceolate, pungent, densely bearded inside, pubescent outside ; the palpus

very large and stout, the first joint minute, pubescent outside ; the second joint rela-

tively enormous, finger-like, curved, tapering distally, within and without at the tip

densely hairy above, more sparsely pubescent beneath ; the stipes closely associated with

the fan-like branchial tuft of fibrils, which passes backwards above and beyond the

hinder border of the labium, and underlies the prosternuni. Lacinige of the 2nd maxillae

(if developed at all) adherent to the labium in the form of two elevated folds of mem-

brane ; palpus strong and finger-like, the first joint short, pilose ; second joint pubescent,

long, and stout. Lingua somewhat broadly cordate ; the paraglosste well developed and

somewhat rounded. Outer seta? less than half as long as the body.

Distribution. Europe, middle and south, and Brazil.

Ti/pe. 0. anomala, Pict.

Mijmology . oXlyoc and vevglov, from the paucity of cross veinlets in the wings.

The following differences between the adult European and Brazilian species may here

be noted, because they may be accompanied by unconformity in the nymphs, and be of

more than specific value. O. anomala, ? , has the setae equal to each other in length,

and sparingly pilose. The d has the fore tibia relatively shorter in proportion to the

femur than 0. rhenana, and the proximal joint in all the tarsi longer than the second

joint. In O. rhenana, ? , the intermediate seta is slightly shorter than the outer setae,

and all are glabrous. The 6 fore tibia is about 1-| (instead of only 1^) as long as the

femur, and the proximal joint in all the tarsi is shorter than the second joint.

Oligoneubia anomala, Pict. Plate III. 2 i ( d , wings, legs, and forceps, $ , legs).

Oligoneuria [type] anomala, Pict., Hist. Nat. Nevropt. ii. Epli^m. 290, pi. xlvii. (1843-5) ; Walk.,

List Neuropt. in Brit. Mus. part iii. 585 (1853) ; Hag., Stct. ent. Zeit. xvi. 269, pi. i. (1855) ; Etn., Ent.

Mo. Mag. V. 83 (1868); id., Trans. Ent. Soc. London (1871), 55.

Adult {dried) <s . — Wings transparent light sepia-grey, with opaque light pitch-brown

longitudinal neuration, the membrane giving a dull light purple-grey reflection. Thorax

pitch-brown. Abdomen in segments 8-10 and in the distal halves of segments 2-7

pitch-brown, the anterior halves of these being pellucid white. Setae warm sepia-grey,

with alternately wide and narrow light pitch-brown annulations at the joinings. Legs

subpiceous, the hinder tarsi with their terminal joint white, and ungues piceous.

? (after Ilagen). Body fuscous or brown. Wings light grey, the fore wings with

about six cross veinlets [in the space beliind nervure uo. 3j. Length of body, 6 , about 7,

$ (Hagen) 13 ; wing, cJ 8, ? 15 ; setae, ? 8 mm.

EEV. A. E. EATON ON EECENT EPHEJMERIDiE OR MAYFLIES. 31

nab. Brazil {Pict.), Rio Mauhes, "at light," 5tli May, 1874, and Rio Jutahi, "at

light," 1st to 5th Fehruary, 1875 {Trail) ; both sexes ia M^Lach. Mus. The cross veinlets

in the marginal area of the fore wing are not easily discovered in a dried wing ; and those

in the space behind the nervure numbered 3 in my figure vary within two or three of the

number (six) quoted. The dimensions of the ? in M°Lach. Mus. are identical with

those stated by Hagen.

Oligonetjria rhenana, Pict. Plate III. 2 a (wings, s and ? , head, s , 3 views, legs, c^ ,

and forceps, tip of a forceps-limb and penis). Nt/atph, PI. XXVI. (whole figure and

details).

[Nameless^, Costa, Fn. di Aspromonte, pi. i. 2.

Oligoneuria % anomala (part), Pict., Nat. Hist. Nevropt. ii. EpLem. pi. xlvi. (143-5) ; Kirsclib., Jahresb.

Vereins f. Naturk. Nassau, Heft ix. 44-5 (1853). 0. rhenana, Imh., Bericht iiber Verhandl. d. naturf.

Gesellscb. Basel, x. 177-180 (1852); Hag., Stet. ent. Zeit. xvi. 267, pi. i. (1855) ; Brau., Neur. Aust. 25.

(1857) ; Rogenhofer, Verb, zool.-bot. Ver. Wien, vii. 130 (1857) ; Mtil., Ent. Mo. Mag. i. 262 (1865),

and ii. 182 (1866); Etu., op. cit. v. 83 (1868), and Trans. Ent. Soc. London (1871), p. 55, pis. i. 2,

and iii. 7-7 a- Hag., o/j. cit. (1873), p. 390-1 ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 307 (1874); trans-

lation of Imboff, 1852, by Joly, Bull. Soc. d'Etud. Sc. Angers, Ann. 4-5™f, pp. 37-4-0 (1876). O. pal-

lida {0. rhenana, var.?), ! Hag., Stet. ent. Zeit. xvi. 268, pi. i. (1855); ! Etn., Trans. Ent. Soc. London

(1871), p. 56. Nymph. — 0. Gurumnica,\ Joly, Zoologist (1873, Aug.) 36555-7, figs, a, b; idem, I'roc.

Ent. Soc. London (1873), p. xx. figs, a, b ; ditto. Bull. Soc. d'Etud. &c. Angers, pp. 37-9 & 46, figs, a, b

(1876); ditto, Rev. d. Sc. Nat. Montpellier, r. 9 (1876, Dec); ditto. Bull. Soc. d'Et. des Sc. Nat.

Nimes, Ann. 6*, no. 4 (separate pgs. 8), figs, a, b [inferior to tbe earlier figures] (1878, April) ; idem,

Compt. Rend. Soc. d'Et. des Sc. Nat. Nimes, 1878, pp. 64-9; Vayssiere !, Ann. Sc. Nat. (6) Zool. xiii.

54, figs. 52, 58-65 [whole figure and details] (1882). O. rhenana, \ Mill., Mittb. scbweiz. ent.

Gesellseb. v. 384-6 (1878).

Suhimago. — Body much browner than that of the adult fly.

Imago, living, c? . — Head and thorax brown-ochreoiis, eyes black. Abdomen white, the

segments pellucid in their basal halves and opaque behind, their distal dorsal borders

narrowly edged with greyish ; in the dried insect the opaque portions of the segments

become lutesceut or ochreous ; in the 9th ventral segment (prior to their extrusion) are

visible through the integument the light yellowish chitinous mandibuliform appendages

to the penis. Setoe and forceps white. Fore legs from the coxa to the base of the

femur whitish, and from thence sepia-brown ; hinder legs white, with yellowish white

femora and dark ungues : when dried, the fore legs and hinder femora become light

yellowish brown. Wings greyish with opaque neuration, the stronger nervures sepia -

grev.

$ . Abdomen previous to the extrusion of the eggs bistre-brown, and opaque when

dried, afterwards very light brownish-ochreous ; eggs lutescent. Thorax brown-ochreous,

head rather browner in front, leers when dried licyht bistre-brown or brown-ochreous.

Length of body, d 9-13, 2 12-15 ; Aving, ^ 11-14<, $ 11-16 ; setai, 6 im. 12-13, subim.

(slough) 4; 2 im. 3-4, subim. 25-3 mm.

Hab. The Rhine, Cologne to Basel ; the mill-stream at Versoix, Geneva ; France,

Brive (Haute Loire), Toulouse (Haute Garonne), and Taraseon (Arifege) ; Portugal,

32 EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

Ponte de Morcellos (Beira Baixa) ; Italy, Turin, and Breno (Val Oamonica, Brescia to

the Neapolitan territory (locality — ? fide Costa) ; Hungary (var. ? pallida, Hag.) ;

Galicia, Stry (fide~E. Brauer). The terminal small joints of the forceps-limbs appear to

be variable in number, and the specimens from France, Geneva, and Italy are much

lighter in colour than some of older date from the Rhine with which I have compared

them. This difference in colour may be due to my specimens having been killed with

fumes of prussic acid (Potassium-cyanide bottle) ; and the variation in number of the

forceps-joints is probably of common occurrence. In the absence of examples in spirits,

I failed to arrive at any decision as to the rank of O. ixdlida, Hag., as a var. of

0. rhenana or a separate species.

ELASSONEURIA, Etn. 1881.

Illustrations. Adult (details) PI. III. 3; also Trans. Ent. Soc. London (1871),

p. iii. 9, 9 a.

Adult 2 . — Fore wing with only three longitudinal nervures, besides the costa and con-

cealed subcosta, of which the hinder two are forked ; cross veinlets more restricted in

their range than those in the fore wing of Oligoneuria. Pronotum transverse, prolonged

on each side into a deflected oblong lobe. Aperture of the anterior thoracic spiracle trian-

gular, its upper edge straight, that of the posterior spiracle oval. Setoe nearly coequal

in length, about \ as long as the body, the intermediate seta rather slender, all of them

glabrous excepting towards their tips, where for a short distance they are sparingly

pilose. Eyes oval and remote ; anterior ocellus not much smaller than the others. In

other points very like Oligoneuria.

Distribution. Natal.

Type. E. Trimeniana (in OUgoucuria), M°Lach.

Etymology. eXdaawv and vev^'iov, from the greater paucity of the neuration in comparison,

with that of Oligoneuria.

Elassoneuma Trimeniana, M"Lach. Plate III. 3 (wings, ? ).

Oligoneuria Trimemana,\ M<^Lacli., Ent. Mo. Mag. iv. 177-8 (1868); ! Etn., op. cit. v. 83 (1868); id.,

Trans. Ent. Soc. London (1871), 56, pi. iii. 9-9 a [penult, veutr. process ? ] ; Joly, Sur une Nouv. Esp.

d. Gen. d'Eplie'm. Oligoneuria &c. Nimes (1877), 6 figs. 8vo. [transl. of M^Lachl. 1868].

Elassonewia [type] Trmemawa, ! Etn., Ent. Mo. Mag. xvii. 191 (1881).

Adult {dried) ? . — Head and thorax brown-ochreous aljove, liditer beneath. Abdomen

discoloured; eggs formerly green, now brown-ochreous. Sette opaque-whitish. Wings

transparent, very slightly tinted with light smoke-grey, giving a faint very light cobalt

or ultra ash-blue glance, soft as the gloss of satin ; neuration opaque, light smoky-grey.

Length of body, ? , 12, wing 22-5, seta? 4 mm.

Sab. IVIapumulo IMission Station, Umvoti District, Natal. Captured " at light " on

3rd of March, 18C7 (M^Lach. ]\Ius.).

{b.) Wing-membrane " shot " with blue or purple ; the free epinotal appendage of the

membrane decurreut from the wing-roots is easily broken off, but may be regarded as

probably absent in LacJilania and Eomoeoneuria.

REV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 33

SPANIOPHLEBIA, Etu. 1881.

Illustrations. Adult (details), PI. III. 4.

Adult. — Anal nervure of the fore wing forked ; the membrane decvirrent from the

wing-roots terminated by a free epinotal appendage ; cross veiulets comparatively nume-

rous in the anterior portion of the wing ; the nervure next in advance to the anal (8)

deeply forked. Aperture of the anterior thoracic spiracle fissure-like and gaping in

front (in the dried insect), closed by a single, large, arched, dorsal valve rounded at the

edge ; the anterior and lower margins of the orifice meeting in front at an angle, without

valves ; that of the posterior spiracle is large, roundly subti-iangular, and valveless, with

a small salient lobule projecting from its front edge. Setai 2. Hinder lateral angles

of the intermediate abdominal segments shortly prolonged into slender projections that

are easily broken off. Fore tibia of 6 about as long as the femur ; the proximal joint

in every tarsus longer than the second joint. Eyes of d hemispherical, relatively small,

remote from each other above ; the foremost ocellus rather smaller than the others.

Distribution. Tropical South America.

Type. S. Trailice.

Etymology , a-aavwc and ^\ki^wv, from the scanty cross neuration.

Differences in the neuration of the fore wings of the two species provisionally placed

in this genus are specified in the descriptions. There ai'e other incongruities between

them. The s Brazilian species has pilose seta) about as long as the body ; those of the

Ecuador d are pubescent, and about 2^ as long as the body. The latter certainly

possesses the epinotal appendages mentioned above ; but these are not so surely ju'escnt

in the Brazilian.

Spaniophlebia Traili^, Etn. Plate III. 4 (wings, legs, and forceps, d ).

Spaniophlebia [type] Trailhe,\ Etn., Ent. Mo. Mag. xvii. 191 0881).

Imago (dried and in alcohol), d . — Body pitch-brown, the thorax darker than the

abdomen ; the latter with the tenth dorsal segment, and the lateral borders of the other

segments above the spiracular margin as dark as the thorax, but with the joinings of the

segments pale. Setie, in the dried specimen pitch-black, with testaceous pilosity ; but in

the specimen in fluid both are testaceous ; forceps whitish. Legs pitch-black, the ungues

of the hinder tarsi whitish : in alcohol the legs from the coxa to the knee are light pitch-

brown, and the rest of the tibia with the tarsus dirty white. Wings transparent, tinted

throughout, very faintly indeed, with smoky-grey, so as scarcely to diminish their lim-

pidity, and giving a light blue-purple or (in other positions) a mauve reflection ;

neuration piceous, the quasi-subcosta (no. 3) of the fore wing, distaUy, and the cross

veinlets that join it, margined for some distance with intense warm sepia-brown, which

colouring occupies the pterostigmatic space, and imparts a slight tint to the rest of the

marginal area. The nervure (pobrachial ?) in front of the anal (8) of the fore wing, is

forked before the middle, at about the same distance from the wing-roots as the anal

ner^oxre, and is met nearer the base of the wing by one of two simple nervures interposed

SECOND SERIES. — ZOOLOGY, VOL. III. ^

34 KEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

between it and the quasi-subcosta (3). This simple nervure (prsebrachial ?) forms the

posterior limit of the region provided with cross veinlets ; of these there are about 25 in

the marginal area, from 2 to 5 in the next area, and one or two in the area next to that.

Length of body 9, wing 10, setae 8 mm.

Hab. Sao Paulo, Rio Solimoes, October 18, 14, and November 26th, 1874 [Trail,

M-^Lach. Mus.), " at light."

Spaniophlbbia pallipes, sp. nov.

Adult {dried), 6 . — Pronotum, sides and underside of the thorax, the hinder border

of the mesonotum, and the metauotum, light Vandyke-brown ; the mesonotum in

advance of the peak, darker or dull black. Abdomen discoloured, lighter beueath than

above ; the dorsum nearly concolorous with the metanotum. Setse white, pubescent

throughout. Pore femur in opaque view very light dull brownish-yellow, changing in

transmitted light to light yellowish-amber ; the tibia in opaque view nearly of the same

colour as the femur, but light brown at the tip ; the short joints, the ungues and the tip

of the terminal joint of the tarsus light brown, the rest of the terminal joint whitish

brown. Hinder legs very similar but a little lighter. Wings transparent, tinted, very

faintly indeed, with extremely light Vandyke- or sepia-grey, -changing in some positions

to a like shade of Roman sepia-grey, and " shot" with a rather dull intense blue ; their

nem'ation in a large extent light pitch-brown, growing paler towards the wing-roots,

changing in some lights to light Vandyke- or warm sepia-brown. The nervure in front

of the anal (8) of the fore wing is joined by a weak and flexuous branch nearly in the

middle of the wing, at a point further from the wing-roots than the fork of the anal

nervure, and shortly before the great cross vein, is joined also by the longer of the two

nervures interposed between it and the radius (3) ; the shorter of these interposed

nervures meets the radius a little beyond the middle ; the subcosta is visible at the bottom

of a deep fold of the membrane when the wing is viewed edgeways from in front, but is

concealed by the radius when the wing is viewed from above ; the anal nervure bounds

posteriorly the portion of the wing traversed by cross veinlets ; the number of these in the

marginal and submarginal areas (if any exist there) cannot be ascertained ; but in the

area between the radius (3) and the shorter of the interposed nervures are 6-8, which are

thickened towards their junction with the radius ; in the next area are 5 or 6 cross

veinlets ; within the fork of the next nervure 2 or 3 ; and between this nervure and the

anal, from 2 to 4 cross veinlets. Length of body, 6 , about 11 (not allowing for shrinkage) ;

wing 16-17 ; seta? 40 (or more) mm.

Hub. Ecuador (M-^^Lach. Mus.).

LACHLANIA, Hag. 18(J8.

Illustrations. Adult (details), PI. III. 5 (whole figures), see citations of Hagen and

Packard under L. abnormis.

Adult. — Anal nervure of the fore wing forked ; no epinotal free appendage to the

membrane decurrent from the wing-roots ; cross veinlets, as a rule (with rare individual

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 35

exceptions), uuiserial in a transverse row extending to the uervure next in advance of the

anal ; that nervure is forked sliortly, or beyond the middle. Aperture of the anterior

thoracic spiracle triangnlar, with a salient angular valve above, its lower lip straight ;

that of the posterior spiracle small and round. Seta3 2, in d" (pilose ?) about 2^ as long

as the body, in ? glabrous, about ^ as long as it. Proportion of d legs not observed.

Eyes of ? large for the sex ; the anterior ocellns rather smaller than the others. Slender

projections, easily lost, are prolonged shortly from the hinder lateral angles of the inter-

mediate abdominal segments ; 9th ventral segment of ? hardly produced behind into a

lobe, but cleft in the middle.

Distribution. Cuba and Central America.

Tijpe. L. ahnormis. Hag.

Etymology . E.. M'^Lachlan, the British neuropterist.

Lachlania abnormis. Hag. Plate III. 5 (wings, $ ).

Lachlania abnormisl Hag., Proc. Boston Soc. Nat. Hist. (1868), 372-1, fi,<r. ; Packard, Guide to Study

of Ins. ed. i. 596, fig. 578 [after Hag.] (1870) ; Etu., Trans. Ent. Soc. Loudon (1871), 54, pi. i. 1 [after

Hag.].

Adult (dried), 2 . — Body above warm sepia-brown, beneath lighter; head, prothorax,

femora, and the spiracular border of the abdominal segment, piceous ; tibite and tarsi

lighter, especially the ungues ; setae whitish. Wings transparent sepia-grey, with an

intense blue-purple reflection, and light (Vandyke) brown neuration ; the finer of the

cross veinlets much lighter than the others. In the fore wing, a single series of cross

veinlets extends in a slight curve from the (functional) subcosta (no. 3) to the anterior

branch of the forked longitudinal nervure (pobrachial ?) next in advance of the anal (8) ;

the series is sometimes continuous, and sometimes broken by a slight displacement of

the second or third veinlet ; the posterior branch of the pobrachial is weak, and very

similar in colour and calibre to hindermost cross veinlet. Length of body, 2 , C-7 ; wing

9-10 ; seta; 5 mm.

Sab. Cuba (Hag. & M'Lach. Mus.).

Lachlania lucid a, sp. nov. Plate III. 5 (forceps).

Imago (dried), 6 . — Tliorax piceo-fuscous ; abdomen fuscous, broadly annulated with

white near the joinings : forceps and seta? whitish. Pore legs and posterior femora fus-

cescent, tarsi and posterior tibia? Avhite, with dark ungues. Wing-neuration subfuscescent.

? . Thorax luteo-piceous ; abdomen darker than in the c? ; in other details very

like the d . Wings tinted as in L. abnormis, the membrane rellecting bright (medium

smalt) blue. Length of body 11-12 ; wing, s 12, ? 11 ; seta;, 6 circ. 30, 2 7 mm.

Sal). Guatemala (6 2, Paris Mus. Jardin des Plantcs) ; Central America (2 2 , M'Lach.

Mus.).

HOMCEONEURIA, Etn. 1881.

Illnstratioiis. Adult (detail). PI. III. 6.

j^cluit. — All of the nervures of the fore wing simple ; membrane decurrent from the

wing-roots, apparently destitute of any free epinotal appendage; no cross veinlets.

36 REV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

Aperture of the anterior thoracic spiracle oblong, with a salient rounded drooping valve at

its upper border ; that of the posterior spiracle round. Setfe 3, in ? subequal, glabrous,

about J as long as the body. Hinder lateral angles of the intermediate abdominal

segments acute, but seemingly not prolonged into projections ; 9th ventral segment not

prolonged into a lobe behind, nor cleft, but entire.

Distribution. Central America.

Type. a. Salvinics.

Mymology, Ofioioc and vev^iov, from the mutual likeness of the wing-nervures.

HoMOEONEUBiA Salvini^, Etu. PI. III. 6 (wings, ? ).

HomcEoneuria [type] Salvinim\ Etu., Ent. Mo. Mag. xvii. 192 (1881).

Imago {dried), 2 . — Head and thorax pitch-black above ; abdomen dark warm sepia-

brown above, with the joinings either transparently whitish or opaque sepia-brown,

according as this region is distended or not ; belly warm sepia-grey, with the hindermost

3 or 4 segments warm sepia-brown; sette pitch-black. Legs concolorous with the

venter ; the fore legs darker than the hinder. Wings transparent, faintly smoky, with a

glowing purplish French ultra-blue reflection, changing (in a very oblique front view) to

very light purple-madder bronze ; neuration opaque, coloured and bordered narrowly

with very light bistre-brown. Length of l)ody, ? , 8-11 ; wing 8-12 ; setse 2-5-3-5 mm.

Hah. Guatemala ; Duenas, 4950 ft., and Accytuno, 5100 ft. alt. (Salvin, in M-^Lach.

Mus.). The specimens were secured early in the morning while floating dead upon the

surface of the stream, when the flash of the wings was very conspicuous. In some

examples, the thinner portions of the integument in the Iiinder parts of the notum are

whitish. .

Section 2 of the Genus, Type of Polymitai-cys. AdiM. — Subcosta of the fore wing

displayed (except in dried Campsurus, 2 ). Posterior margin of 9th ventral segment in

2 not extended into a lobe. Pronotum tumid ; its hinder border straight (excepting

perhaps in Jolia, c? , it may be sinuous behind).

Nymph fossorial or predatory ; in those that are known, the median lobe of the tongue

is obtuse.

EUTHYPLOCIA, Etn. 1871.

Illustrations. Adult (details), PI. IV. Nymph (whole figure and details), PL XXIX.,

see alsoPict., Hist. Nat. Nevropt. ii. Eph(^m. PL XV. 2-1 [with circumspection].

j^clult. — Discal cellules of the fore wing large, and in the vicinage of the terminal and

inner margins transversely elongated, especially those posterior to the sinuous anal

nervure, which are themselves sinuous. <s , fore leg about as long as the head and body

together : the tarsus longer than the femur, which is about f as long as the tibia. Tarsal

ungues equal and nearly alike. Aperture of the anterior thoracic spiracle elongate, or

oval, in the dried insect, with an arched upper valve ; that of the posterior spiracle

narrow, elongate and gaping. Setse 3, subequal, about 3f as long as the body in the 6 ;

in ? glabrous, but in c^ sparsely pubescent beyond the middle. ^ , eyes of moderate

proportions, mutually remote ; anterior ocellus the smallest. Porceps-limbs inserted at

EEV. A. E. EATON OX EECENT EPIIEMEEID.E OK MAYFLIES. 37

the sides of a short deflexible lobe prolonged from the hind margin of the ninth segment ;

their jn'oximal joint very short, the second much the longest. Penis extruded and rather

similar to that of Campsurus 4<-deiitatiis (PL V. 8 e), without apparent stimuli. No

projections at the hinder lateral angles of the abdominal segoiont.

Nymxili. — Raptorial, furtive ; mandibles tusked ; fore tibia spurred ; 6 pairs of abdominal

tracheal branchiae, inserted at the sides of segments 2-7, a little in front of the hinder

angles, and arched upwards over the back, each composed of a pair of narrow uniform

and subequal lanceolate membranous laminae, folded lengtliwise, and frin"'ed with

simple fibrils. Sette rather shorter than the body, pilose to beyond the middle, and then

tail-pointed. Palpi of both maxillae 3-jointed. — Head relatively small, narrower than the

thorax : pronotum subquadrate, the lateral borders narrowly dilated ; terminal margins

of the fore wings free ; body slender. Antennae setaceous, longer than the head. Labrum

emarginate, pubescent. Mandibles prolonged into a tusk on the outer side, about twice

as long as the head, densely hirsute outside and above with slightly spreading hair, and

half encii'cled at its junction with the crown of the mandible by an interrupted verticil

of widely spreading bail' ; the fangs are rather distant from the molar protuberance, and

are set almost at right angles with the task, which is curved gently and regularly

inwards, and tapers to a slightly oblique point ; stipes very short. First masillee weak ;

the lacinia small, pubescent externally, ciliated internally, crowned with a dense tuft of

short hair and terminated by a few (3 or 4) slender spines ; paljms upwards of four times

as long as the lacinia, rather slender, 3-jointed (exclusive of the pedicel) ; the tirst joiut

pubescent, the others pilose ; the third joint nearly as long as the other two together.

Second maxillse almost in the form of quadrants, densely pubescent; palpus 3-jointed,

geniculated at the penultimate joining, and pilose outside ; the distal moiety clavate and

truncate, the terminal disk hispid ; the proximal joiut pubescent within. Labium small,

the lobes narrow and acute. Tongue perhaps distorted ; medium lobe obcordate ; para-

glossia moderate in size and rounded. Legs pilose above and below, the tibiae obliquely

truncate, the fore tibia spurred with a long, slender, but strong apical spine ; the fore

tarsus very long. (Figured and described from a dried slough in the Mus. iioy. de

Bruxelles, measuring, — body (exclusive of mandibles) 30 ; setae 19 mm.)

Dlstrihution. Tropical America.

Type. E. Recuha (in Falhigeuia), Ilagen.

Etymology, evOvTrXoKia, from the evenness of the cross veinlets.

EuTHTPLOciA Hecuba, Hag. Plate IV. 7 a (wings 2 ).

Palingenia Hecuba \ Hag., Smithsoo. ]\Iiscell. Coll. (18G1), Synop. Ncuropt. N. Am. 40.

Eutlnjplocia [type] Hecuba\\ Etii., Trans. Eut. Soc. Londou (1871), 07; Hag. & Etu., op. cit. (1873), 392.

Imago (dried), ? . — Head blackish fuscous, antennae pale at the tip ; prothorax glossy,

fuscous ; the rest of the thorax with the coxae and trochanters luteous, the femora &c.

deficient. Abdomen above blackish fuscous, luteous beneath, the seta3 whitish sepia-

grey, with lighter joinings. Wings dull, transparent, tinted faintly with very light

warm sepia-grey (" grayish-rosy," Hag.), but rather darker along the anterior margin of

38 EEV. A. E. EATOjS' ON EECENT EPHEjMEEID.E OR MAYFLIES.

the fore wing, from the costa to the melius ; neuration opaque (" gray," Hag.), light

Trarm sepia-hrown. Length of body, $ 20-22 ; wing, 35-38 mm.

mth. Vera Cruz (Salle in De Selys-Longchamps Mus.), Veragua (M''Lach. Mus.).

Etjthtplocia anceps, sp. nov. Plate IV. 7 c (wings, legs, forceps from above).

Imago {dried), 6 . — Head and prothorax above light pitch-brown, the remainder of the

notum light testaceous or pale lutescent. Dorsum dark purplish grey ; venter whitish

ochreous : sets?, near their insertion, tinged faintly with light purplish grey and then be-

coming transparent white ; forceps white. Fore leg (as an opaque object) with the femur

pitch-black as well as the tibia, the tarsus greyish white ; in transmitted light the tibia

is piu'ple-grey, the tarsus purplish white. Hinder legs whitish yellow at the knee, light

pitch-brown or fuscous. TTings transparent, in tlie disk slightly smoky ; the fore wing

tinted more distinctly with pm-plish- or light Roman sepia-grey in the marginal and

submarginal areas, especially towards the base : neuration in great measure Eoman sepia-

or j)itch-brown, becoming lighter and translucent in its more attenuated portions. Length

of body, 6 , about 12 ; wing 13 ; setjE about 26 mm.

Eab. Eio Mauhes, Brazil (Trail, in M'Lach. Mus.).

CAMPSURUS, Etn. 1868.

ninstrotions. Adult, PI. V. 8 a-8/ (details) ; (whole figures) see citations of Percheron

and Pictet under C. albicans & dorsalis.

Adult. — Discal cellules of the fore wing large, nearly as wide as long ; the intercalated

nervures, constitutiug branches of the cubital (5), pra?brachial (6), and often of the anal (8)

nervxires, are convergent mutually into fascicles towards the base of the fore wing ; the

anal nervure is somewhat sinuous, and its course from the wing-roots is at first close

alongside of the first anal nerviu-e. Fore leg of 6 shorter than the head and body

together ; the tarsus longer than the femur, which is about ^ as long as the tibia ; the

ungues unequal, dissimilar, ligulate and flaccid, are unusually long. Aperture of the

anterior thoracic spiracle patulous, subtriangular, with the angles obtusely rounded, and

with the anterior border rovmdly salient ; that of the posterior spiracle very large,

exceeding the anterior in its dimensions, widely patulous, ovate, narrowed below.

Setse two ; in j about 3^ as long as the body, divaricate in di'ied examples, and glabrous

with the exception of a very few scattered hairs near the tips ; in $ about as long as

the body, smooth, and glabrous, d , eyes small, oval, mutuaUy remote ; foremost oceUus

much smaller than the others. Forceps-limbs inserted each upon a separate basis, above

and distinct from the posterior ventral margin of the 9th segment, and not upon a

deflexible lobe prolonged from the margin ; unless these bases be taken to represent

proximal joints, the limbs are jointless. Penis extruded, commonly decui'ved, sometimes

provided with well-developed stimuli. Xo prpjections usually at the hinder lateral angles

of the abdominal segments.

Nymph unknown.

Distribtdion. Texas to Brazil.

Type. C. latipennis (in Falingenia), Walker.

Etymology, ku/x-toj and ovoa, from the divarication of the d setae, after death.

EEV. A. E. EATOX OX EECEXT EPHEilEEIDJ: OR MAYFLIES. 39

Campsurus latipekxis, Walk. Plate V. 8 c (wiugs & forceps).

PaUngenia latipennisl "Walk., List of Neuropt. Inst, in Brit. Mus. part iii. 554 [escl. var.] (1853).

Campsurns [type] latipennis ! Etn., Ent. Mo. -Mag. v. 83 (1868) ; id.. Trans. Ent. Soc. London (1871),

57, pis. i. 4, & iii. 10, 10 a [details].

Imago {dried), s . — Thorax fusco-luteous (eaten out by Psocidce) ; abdomen above very

light Timber-grey, more distinctly so in segments 4r-10 than in the others, with the

joinings of the segments and the line of the dorsal vessel darker ; venter testaceous ; setae

pellucid white. Fore legs sepia-brown, with white ungues. In the fore wing the costa,

subcosta, and radius, from the wing-roots to a little beyond the middle, are warm sepia-

grey ; the adjacent part of the marginal area is tinged -n-ith the same colour, or

fuscescent.

Subimago. — Body very light brown-ochreous, with the setae white or yellowish white.

2 . Pronotum bistre-grey ; mesonotum brown-ochreous. Abdomen discoloured (largely

denuded by Psocidce) very light brown-ochreous beneath ; dorsttm carinated lengthwise

and perhaps bistre-grey in segments 2-9. About nineteen Hue, simple, almost straight

cross veinlets in the marginal area of the fore wing. Length of body, 6 S , 7 ; wings 8 ;

setse, 6 im. 22, subim. 15 mm.

Sab. Para; Toncantine (Wallace in Brit. Mits.) ; Santarem (Bates in M'Lach.

Mus.).

CAMPsmrs ALBLFiLrM. Walk. Plate Y. 8 a (adult 6 , head, wing, forceps, fore leg :

subim. c? , fore leg).

PaUngenia albifilum ! Walk., List of Xeuropt. Inst, in Brit. Mus. part iii. 554 [excl. rar.] (1853).

Campsurus albifilum ! Etu., Trans. Ent. Soc. London (1871), 57, pi. iii. 11 [details].

Imago (dried), 6 . — Pronotum very nearly light bistre-brown ; mesonotum in the type

discoloured by gum. Abdomen l)eneath light Boman-ochraceous ; dorsum lighter,

marked in segments 1-6 with light grey, but in segments 7-10 with light bistre-brown ;

the markings are : — in segment 1 a spot on each side ; in segments 2 & 3 a streak from

the base on each side of the middle curved outwards near the hind margin ; in segments

4-7 two marks, one on each side of the middle line resembling square vincula ] [ placed

back to back, whose extremities in the hinder segments tend to be conjoined by a narrow

baud of the same colour ; in segments 8 et 9 a large oblong blotch on each side of the

pale median dorsal line ; segment 10 is light brown-ochreous with a small spot on each

side. Setae white, faintly tinged at the base with pale ochreous. Forceps and penis pale

yellowish. Coxae testaceous ; fore femur and tibia deep sepia-brown, the tarsus and

ungues light sepia-grey. Costa, subcosta, and radius of the fore wing light brown-

ochreotts at the wing-roots, and then light sepia-grey. Length of body, d , 12 ; wing 13 ;

setae 10 mm.

Sab. Para (Brit. Mus.).

CAiiPsmrs ALBICANS, Perch.

Ephemera albicaiu^, Perch., in Guer. & Peich. Gen. d. Ins. &c. li^T. \i. pi. iv. 1 (1838).

PaUngenia albicans, Bui-m., Haudb. d. Ent. Bd. ii. Abth. ii. 803 (1839) ; Pict., Hist. Nat. NevTopt. ii.

4,0 -REV. A, E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

Eph(5in. 149, pi. xiii. 1-3 (1843-5) ; Walk., List of Nem-opt. lus. in Brit. Mus. part iii. 548 [excl.

exemplar] (1853).

Campsurus albicans, Etn., Trans. Ent. Soc. London (1871), 58.

Imago (dried), d . — Protborax yellowish, violet-grey at the sides of the notum; meso-

and metathoi-ax broAvn-ochreous. Abdomen pale yellowish or brown oclireous towards

its hinder extremity. Legs whitish, the fore femur and tibia violet-grey. Wings

whitish, tinged towards the base with violet-grey, the stronger nervures of this same

colour. Length of body 10, exp. of wings 30 mm.

JIab. Brazil {Perch.}. The description is probably insufficient in the absence of

definite information of the precise locality where the type was captured. The details

figured by Pictet appear to have been drawn from the dried insect, and to be mis-

represented; Percheron's illustrations may have been delineated from an example in

spirits. The ? , doubtfully referred to this species by Walker (Brazil, J. P. G. Smith, in

Brit. Mus.), seems rather too small to be identical with it, but may possibly be

C. curtus, ? . It is well, however, not to attach much weight to mere possibilities in

matters of this nature.

Campsueus cuspid attjs, Etn. Plate V. 8 d (forceps).

Campsurus cuspidatus, ! Etn., Trans. Ent. Soc. Loudon (1871), 58, pi. iii. 12 [details].

Imago [dried], 6 . — Pronotum mouse-grey, tinged slightly with greenish. Abdomen

smoky-white above, yellowish- white beneath. Wings transparent, whitish throughout.

Length of body lO'u, wing 11 mm.

Hab. Guatemala (Be Selys-Longchamps Mus.). This species is easily recognizable by

the cuspidate outline of the subgenital plate.

Campstjiitis qtjadkidentatus, Etn. Plate V. 8 e (forceps).

Campsurus quadridentatus, ! Etn., Trans. Ent. Soc. Loudon (1871), 58, pi. iii. 13 [details].

Imago {dried), 6 . — Tliorax and legs pale testaceous. Abdomen light yellow-ochreous,

sbaded with black-grey, especially posteriorly ; the foremost six segments traversed

lengthwise by a median black line. Wings dull translucent whitish ; subcosta and

radius of the fore wing black-gi'ey or sepia-grey. Length of body 12, wing 13 mm.

Sab. Santarem, Brazil, June (Bates, in Dale Mus.). The subgenital plate of the 6 is

angularly excised behind on both sides of a large deep central su.bcircular sinus. The

name has reference to the tooth-like projections adjacent to the excisions.

Campsurus cubtus. Hag. MS. Plate V. 8 f.

Palingenia J albifilum, var. ! AValk., List of Neuropt. Ins. Brit. Mus. part iii. 554 (1853). — P. curta,

Hag. MS. (1861).

Campsurus [B] curtus, ! Etn., Ent. Mo. Mag. v. 84 (1868).

Asthenopus [type] curtus, ! Etn., Trans. Ent. Soc. Loudon (1871), 59, pis. i. 3, and iii. 14-14 b

[details] .

Imago (dried), d . — Pronotum piceous, the remainder of the notum (perhaps modified

by gum) luteous. Abdomen beneath and at the sides of the back light yellow-ochreous,

EEV. A. E. EATON ON RECENT EPHEMERED.E OR MAYFLIES. 41

becoming darker in segments 8-10 ; the remainder (midst) of the back chiefly blackish-

grey, having joinings 1-3, and a small elongated spot on each side in segments 4-8 pale ;

joinings 4-7 darker grey. The dark colour projects obliquely downwards as a line from

the hind border in segments 1 and 2, and as a short stripe bounded in front by a pale

line ascending from the spicular border in segments 3-5 or -6 ; the same dark colour, in

segments G- or 7-10, occupies nearly the whole dorsal surface, but the same pale lines

from the spicular border project upwards into it in segments 7-9. Seta; white, tinged

very faintly with light grey near the base. Eore legs blackish-grey, with pale joinings ;

hinder legs luteous. Wings transparent, their neuration pale distally, but nearer the base

(the costa, subcosta, and radius especially) tinged with violet-grey; the same colour

imparts a light tint in the fore wing to the proximal portion of the marginal and sub-

marginal areas, and also to the space enclosed by the first axillary and the inner margin.

Length of body 8, wing 10, setse 35 mm.

Bah. Para (Brit. Mus.).

Campsurus decoloratus. Hag.

Palingenia decolorata, ! Hag., Smithson. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 43..

Hexagenia decolorata, Etu., Trans. Eut. Soc. London (1871), 65.

Imago (in alcohol). — Luteous ; antennae pale ; mesothorax yellowish-fuscous ; abdomen

striped at the sides with obscure fuscous ; sette luteous. Tore legs blackish ; hinder

legs luteous. Wings transparent, yellowish ; neuration luteous, excepting the fuscous

subcosta of the fore Aving. Length of body 16, exp. of wings 30, setae about 30 mm.

Jlab. Mexico ; Matamoras, Tamaulipas, common (Mus. Comp. Zool. Cambridge,

Mass.). [After Hagen.] The specimen seen by me was a female. Specimens from the

same localities could be readily identified by the colour of the fore legs, and by the

dimensions &c. quoted. In M'Lach. Mus. are several ? examples of a Campsurus

taken by Belfrage in Bosque Co., Texas, which has the fore legs yellowish like the

hinder legs.

The fore wing of this Texan species is figured by me in Trans. Ent. Soc. London (1871),

pi. i. 3, the hind wing in the present work (PI. V. 8 b). In the absence of the 6 it is

well to leave it undescribed and nameless.

Campstjbus dorsalis, Burm.

Palingenia dorsalis, Burm., Haudb. d. Ent. Bd. ii. Abth. ii. 803, 1015 (1839) ; Pict., Hist. Nat.

Nevropt. ii. Epliem. 153, pi. xiii. 5 (1843-5); Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 549

(1853).

Asthenopus dorsalis, Etn., Trans. Eut. Soc. London (1871), 59.

Imago, ? [after Pict.].— Pronotum yellowish, with a violet line or spot in the middle ;

the rest of the thorax yellow-ochreous at the sides, violet above, with a pair of lutescent

lines in the middle. Abdomen ochraceous grey, with a median fuscous streak tapering

behind. Sette whitish. Pore legs black-grey. Wings almost colourless ; costal region

SECOND SERIES. — ZOOLOGY, VOL. III. 6

42 REV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES.

of the fore wing violet-fuscous, the nervures in other parts of the wing light fuscescent ;

neuration whitish in the hind wings. Length of body 11, exp. of wings 38 mm.

Hah. Brazil (Burm. ; Pict. in Vienna Mus.).

JOLIA, Etu. 1881.

nUtstrations. Alleged Adult, PI. II. 9 (details). Nijmph, PI. XXVII. (whole figure

and details) : see also citations of figures by Joly and Vayssifere under J. Boeseli.

AdulL—Discal cellules of the fore Aving moderately small, subquadrate ; neuration, as

a whole, very similar to that of Polymitarci/s. 6 , fore leg about as long as the head and

body together, the tarsus shorter than the femur, which is more than ^ as long as the

tibia; tarsal ungues iinequal, dissimilar, narrow, long and flaccid (probably subim.).

Spiracles mutilated in the types. Setoe 2 ; in ? about ^ or J as long as the body,

glabrous, excepting near the tips, and there minutely puberulous ; in d (subim. ?), nearly

as in Camps7iriis subim. Eyes of s (subim. ?) large, mutually approximated above,

rounded, excepting at the inner orbit, and there somewhat flattened or straight ; anterior

ocellus rather smaller than the others. Forceps-limbs sessile upon the distal border of

the 9th ventral segment ; the proximal joint (subim. ?) short and largely dilated (perhaps

= a divided ventral lobe), the 2nd joint the longest ; integument transversely rugose

and puberulose. Penis exposed, without apparent stimuli. Lateral margins of the

abdominal segments somewhat flattened out in a small degree ; the hinder lateral angles

of the 9th segment of the d produced into a short tooth-like spine, those of the other

segments acute or subrectangular, not produced. Duration of subimago stage {fide

Joly) about 30 minutes ; last moult complete. Nymph predatory, agile ; mandibles

tuskless ; fore tibia spurred, and strongly setose behind ; 7 pairs of abdominal tracheal

branchiae inserted in notches in the hind margins of the segments near their lateral

angles on the dorsum, all made alike but unequal in size, each one formed of a single

obovate membranous lamina, intersected obliquely by a fine crease or strengthening

rib, containing a pinnatcly branched trachea, and furnished at its hinder base with a

fascicle of filaments ; margin of the lamina minutely serrated. Seta3 about -^^ as long as

the body, the median plumose and the outer ciliated on their inner sides for upwards of

half their length, and then tail-pointed. Palpi of both maxilla) 2-jointed. — Head

relatively small, narrower than the thorax. Antennas long and slender, setaceous and

multiarticulate, the first two joints the stoutest. Labrum ciliate in front, hispid on the

outer surface. Mandibles broad, their two fangs slender and acute, the innermost

appendaged, and distant from the molar protuberance. Laciuia of 1st maxilla rounded

and pilose externally, subtruncate and ciliate within, acutely pungent ; stipes furnished

with a small fascicle of tracheo-branchial filaments at the base outside ; palpus stout, the

second joint enlarged and densely pilose, the first joint glabrous. Lacinia of second maxilla

semiovate, densely pilose, excepting towards the pubescent apex; palpus stout, the

second joint enlarged, densely pilose, and about thrice as long as the first joint. Lobes of

the labium well defined, Imt seemingly coherent, smaller than the lacinia? of the maxillce.

Median lobe of the tongue subrotund; paraglossaj rounded, pilose. Body proportioned

REV. A. E. EATON OX EECENT EPHE5IEEID.E OE MAYFLIES. 43

as in Cloeon or Siphlurus ; the legs slender, trailed in the act of natation, whicli is

eflPected by the sette onl3^ Fore femur and tibia bearded behind with long stiff hairs,

which on the tibia are disposed in two rows longitudinally, and spread divergently ; the

tibial spur nearly as long as the tarsus, the shin or front of the tibia spiuulose; the

tarsus slender, bearded beneath. Prosternum at the joining of the head furnished on

each side with a tuft of fibrillose tracheal branchite.

Distribution. South of France, the Garonne at Toulouse ; also N. America, at Niagara.

Type. J. Boeselii (in Paliiir/ema), Joly MS.

Etymology. Dr. E. Joly of Toulouse, who first discovered the animal,

JOLIA RcESELii, Joly. Plate II. 9 ( d , wings [part], legs, forceps [subim. ?]).

Palingenia tolosana, Joly, IMS. (1870). P. Rwselii, ! Joly, INIem. See. d. Sc. Nat. Cherbourg, xvi.

67, pi. i. 1 [excl. citations] (1872); idem, Bull. Soe. d'Etud. Sc. d' Augers, ann. 4-5'', p. 42, Note C

[cited as P. longicauda, var.] (1876); idem. Rev. Sc. Nat. MontpeUier, v. 309, 314, pi. vi. 3 (1876).

Julia [type] Resell, Etu., Ent. Mo. Mag. xvii. 192 (1881). /. Rrsdii, ! Vayssiere, Ann. Sc. Nat. (6),

Zool. xiii. 59, figs. 69-73 [nymph details] (1882).

Imago undescribed. — The 6 specimen given me by Dr. E. Joly, for the British Museum,

is in pieces preserved in alcohol. He considers it to be an imago ; but the condition of

the legs, forceps, and setae is so nearly identical with that of the corresponding parts in

subimagines of Campsuriis and Folymitarcys, that I am not yet convinced of its being

the adult fly.

Nymxih- — Length of body about 11, setae 6 and 4 mm.

Hah. The Garonne near Toulouse. The njmiph harbours under large stones in swift

parts of the river : I have obtained it just below the railway-bridge (pont d'Empalot) above

the town. The fly was reared by Dr. E. Joly on 1st September, 1868, who named the

nymph Palingenia tolosana in a paper read at a meeting of the Soc. d'Hist. Nat. de

Toulouse, on the 15th July, 1870, and who altered the name to P. Hosselii the next year

in another paper communicated to the Cherbourg society, cited above. In the plate

illustrative of this later paper Dr. Joly reproduced four figures from older authors, which

he tabulated as nymphs congeneric with Jolia, and in one instance identical with the

French nymph. These are respectively, fig. 2 (after Swammerdam), Palingenia longi-

cauda; fig. 3 (after Pteaumur), Cloeon rnfidum; fig. 4 (after Ptoesel), a Siphlurus; and

fig. 5 (after De Geer), a Siplihims. Of these figures, nos. 3-5 had never before been

supposed to represent any thing akin to Palingenia, and their citation as illustrative of

species near of kin to Jolia is not only misleading, but also very depreciatory of the

novelty of Dr. Joly's discovery. Reaumur's figure of the Cloeon and Rffisel's of the

Siphlurus are not quite accurate, so far as they go ; but their general effect is charac-

teristic, and the accompanying letter-press affords additional means of ascertaining what

were the subjects intended to be represented by them. De Geer's description is also

conclusive.

FOLYMITARCYS, Etn. 1868.

Illustrations. Adult (details), PI. VI. 10 a -c; (whole figures) see citations under

P. Virgo and the other species, especially Palingenia virgo, Pict., Hist. Nat. Nevropt. ii.

6*

44 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

Ephem. pi. xi. Kymph, PI. XXVIII. (whole figure and details) ; see also citations tinder

P. virgo, especially of Reaumur (1742), Joly (Sept. 1876 and 1878), and Vayssifere

(1882).

Adult. — Discal cellules of the fore wing small and subquadrate ; in the vicinage of

the terminal margin the axillary nervures and the proximal branch of the anal nervure

are strong, but in the neighbourhood of the fork of the anal nervure the neuration often

assumes a feebler and rather closely reticulated texture ; the nervures interposed between

the anal (8) and pobrachial (7), or some of them, are liable to lose themselves in this

reticulation on approaching the basis of the anal nervure, and nowhere in the wing are

the nervures especially fasciculated. Pore leg of 6 about as long as the head and body

together, the tarsus much (3-5 times) longer than the femur, which is not \ as long as

the tibia ; the ungues nearly coequal, narrow, long, and flaccid. Aperture of the anterior

thoracic spiracle ovate, narrowed below ; that of the posterior spiracle ovate, narrow and

elongate. Setae in d 2, in $ 3, equal ; in the former sex about three times as long as

the body, glabrous from the base nearly to the tip, and divaricate in the dried insect ;

in ? about f as long as the body, and pubescent. Eyes of s relatively small, oval,

mutually remote ; anterior ocellus much smaller than the others, which are unusually

large in comparison with the eyes. Eorceps-limbs sessile upon the border of the seg-

ment ; the proximal joint short, somewhat compressed ; second joint the longest. Penis

exposed, the lobes straight, unarmed. Hinder lateral angles of the abdominal segments

subrectangular. Isymph fossorial ; mandibles tusked ; fore tibia strongly bearded and mi-

nutely tuberculated behind, spurless ; seven pairs of abdominal tracheal branchiaj inserted

each on a lateral protuberance, armed with a minute tooth-like tubercle, situated a little

in advance of the hinder lateral angle of the segment, arched upwards over the back ; the

first of the series different from the rest, being single, spathulate, and fringeless ; the

others mutually alike, double, with uniform unequal divisions, — each moiety a rather

narrow, blunt, membranous lamina, folded together lengthwise once, and fringed with

short simple fibrils. Setse about \ as long as the body, plumose in the greater part of

their length, and then tail-2:)ointcd. Palpi of both maxilla; 2-jointed. — Head hard, about

as broad as the thorax ; pronotum quadrangular ; terminal margins of the fore wings

free ; body soft and tender. Antennas setaceous, many -jointed, the first 2 joints stouter

than the others. Labrum well developed, subquadrangular, rounded in front. Tusks of

mandibles about twice as long as the head, echinate iipon the upper surface, slightly

connivent distally, each with a well-defined ensheathing beard of long spreading hair

inserted in a curve on the outer base, also with a dense patch of shorter hair just at

the commencement of the tubercles, and with some sparse pilosity over the rest of the

upper side ; the crown and lobes (or fangs) nearly at right angles with the tusk.

Lacinia of first maxilla subquadrangular, widened from the base to the obliquely truncate

crown, acvitely pungent, ciliate at the inner margin, and crowned with a dense long

beard : palpus stout and long ; the first joint nude, and about \ as long as the second ;

second joint externally pilose, on the inner side strongly bearded, tapering from the middle

to a point, and slightly curved. Lacinia of second maxilla broadly ovate, oblique, densely

pilose : palpus stout ; first joint nearly § as long as the other, pilose outside in the

EEV. A. E. EATOX ON EECENT EPHEMEEID.E OR MAYFLIES. 45

middle ; second joint compressed, dilated distally, pilose outside, and on the inner side

strongly bearded before the tip. Lobes of labium small, approximated to each other

above. Tongue small, the median lobe subquadrate, obtusely prominent in the middle

of its front edge ; paraglossa> rounded, pilose. Fore leg short and strong, bearded and

minutely tuberculated beneath the femur at the base, and at the back of the tibia; tlie

tibia with a strongly circumscribed line of oblique spreading beard near its base outside,

two rows of tubercles behind, and a single series of erect tactile hairs in front. Hinder

legs slightly pubescent, but shortly pilose at the upper extremity of the femur, in front

of the tibia, and on the dorsum of the tarsus. The nymph sometimes divaricates the

outer setae, and then their tips are bent so as to point behind. When the subimago

alights to moult, the slough is cast off completely in about | of a minute, the insect

standing upon its four hinder legs, holding its fore legs apart off the ground, and its setjB

a little apart from one another.

Distribution. Middle continental Europe southwards to N. Africa; In do-Malay

Eegion ; S. Africa ; N. America, from Canada (Niagara) to New Orleans.

Type. P. virgo (in EpI/emera), 01.

Etymolor/y. ttoXv^htoc and apKvc, from the closeness of the reticulation of the wings.

PoLYMiTARCTS VIRGO, 01. Plate VI. 10 a ( c? , head, legs, forceps, wings adult ; fore leg

subim.).

Hemerobius, Epheinerum, S^c; Glut., Opusc. ii. title-page (woodcut) and pp. 61, 87, 90 (1634) ; Mey.,

in Godart's Metamorph. et Hist. Nat. lus. i. Append, pp. 193-200 (1G62) ; Blegny, Temple d'Esculape,

An. 2", p. 188 (1680) ; Targ.-Tozz., Let. sopr. una numcros. sp. dei Farfalle vedut. in Firenze -sulla

metil di Luglio, pp. 32, froutisp. figs. 1-5 (1711) ; Reaum., Mem. pour scrv. h Thist. dcs Ins. vi. 457-522,

pis. xlii.-xliv. (1742) ; Sclijef., 'Das fliegende Uferaas oder der Haft,' &c., p. 34 (1757) ; idem, reprinted

in Abhandl. von Ins. iii. 30, pi. i. (1779) ; idem, Ic. Ins. Ratisb. ii. pi. clxxv. 1-3 (1776).

EpJiemera virgo, 01., Enc. Meth. vi. 419 (1791) ; Lat., II. N. xiii. 98 (1805) ; idem, Nouv. Diet. H. N.

X. pi. xix. 5 (1847).— ?£. marocana, Fab., Ent. Syst. emend, iii. pars i. 69 (1793). — +£. lutea, Seetzen,

in Meyer's Magaz. f. d. Thiergeseh. i. 41-3 (1794) ; Pz. in Exijlic. Scliref. Ic. clxxv. (1804).— J^;. albi-

pennis, Voigt, Lelirbuch d. Zool. v. 309-11 (1840); Blanch., II. N. Ins. iii. 54, pi. iii. 1 (1840) ; Ramb.,

N(5vrop. 296 (1842).

Palingenia Xlioraria, Burm., Handb. Bd. ii. Abth. ii. 802 (1839) ; idem, in D' Alton. Zeit. f. Zool. &c.

i. xiv. pp. 109-12, t. i. 1-12 (1848) ; Hag., Stet. ent. Zeit. xxvi. 229 (1865); Leunis, Synop. d. Natur-

gesch. d. Thierreicbs &c. ed. ii. p. 635 (1860) ; Loew, Verb, zool.-bot. Gesellsch. Wien, xvi. 947 (1866).—

P. Virgo, Pict., Nat. Hist. Nevropt. ii. Epbem. 141, pi. ix.-xi. 3 (1843-5); A. & G. B. Villa, in Eeono-

mista,p. 1-6, illustrat. (1847, November) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 547 (1853) ;

Letzner, in Arbeit, sehles. Gesellsch. p. 101 (1854) ; Brau., Neuropt. Aust. 25 (1857) ; Karsch, Die

Insectenwelt, v. 100-1 (1863) ; Oulian., Neuropt. &c. of Moscow, p. 26 (1867) ; Ausserer, Annuar. d. Soc.

Natur. Modena, An. iv. 132 (1869) ; N. Joly, Me'm. Acad. Sc. Inscript. Belles-Let. Toulouse (7), iii.

379-386 [development] (1871, Sept.); ditto, Ann. Sc. Nat. (5), xv. Art. x. pgs. 5 (1871-2); ditto,

Compt. Rend. Ixxxi. 809 (1875) ; ditto, Robin's Journ. Anat. and Physiol, xii. 486-95, pis. i.-ii. (1876,

Sept.); ditto, Rev. Sc. Nat. Montpellier, v. 305-330 (1876, Dec.); ditto, Bull. Soc. d'Et. Sc. d'Augers,

1874-5, p. 40, note a (1876) ; idem, Compt. Rend. Ixxxiii. 809 (1877) ; ditto (translated), Ann. & Mag.

Nat. Hist. (4), xix. 193-5 (1877); idem, Mem. Acad. Sc. Inscript. & Belles-Let. Toulouse (separate),

10 pgs. pis. i.-ii. [development] (1878) ; idem. Bull. Soc. d'Et. Sc. d'Angers, 1878-9, p. 171 (1880).

46 EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

Polymitarcys [type] virgo, Etn., Ent. Mo. Mag. v. 84. (1868, Aug.) ; Traus. Ent. Soc. Lond. (1871),

60, pi. i. 5 & iii. 15-15 b [details] ; Palmeu, d. Morphol. d. Traclieensyst. sect. i. pp. 1-21, taf. i. 1-7

(1877) ; Mocsary [vide Ephtmerum under citations for Palingenia longicauda (1878)] ; Rostock,

Jahresber. d. Vcr. f. Naturk. Zwickau, 1877, p. 81 (1878); Vayssiere, Ann. Sc. Nat. (6), Zool, xiii. 43,

figs. 9-12, & 80-80 bis [nymph] (1882).

Adult {in life), 6 . — Head whitisli, tinged with grey above, the oculi and bases of the

ocelli black, tlie hinder ocelli met interiorly by a fine curved fuscous line. Pronotum

whitish, clouded more or less with grey, and on its front edge in two places on each

side tinged with sepia-grey. Meso- and metathorax pale brown-ochreous or lutescent,

their peaks and the decurrent membranes of the wing-roots whitish. Abdomen

whitish, the dorsum clouded more or less with grey, especially at the tips of the

segments, the last two ventral segments and the peuis somewhat ochroleucoiis. Seta3

and forceps white, the former pellucid, with opaque joinings. Wings white, the costa,

subcosta, and radius of the fore wings grey. Legs white, the fore legs with a longitu-

dinal streak from the base outside the coxa, the femur (all but the back of the knee)

and the tibia blackish. The body of the 2 is more completely pale brown-ochreous,

before the eggs are discharged; afterwards the emptied abdomen is of a pale warm

sepia-grey. Length of body, <s 10-11, ? 16-17 ; wing, <s 11-12, ? 10 ; setse, <S im.

30-33, subim. 16, ? adult 13 mm.

Bab. In Europe, from Madrid, France, and the Netherlands, eastwards, inhabiting

the chief rivers {e. g. the Seine at Paris, the Rhone at Lyons and Avignon, and the

Garonne at Toulouse) ; perhaps in Morocco as well. During the last and the first

quarters of the moon at the end of August and the early part of September, " la manne"

occasionally swarms late in the evening over the water. Dr. E. Joly narrates the in-

vasion of a milliner's shop by them at Toulouse, — the flies thronging to the gas-burners

and actually quenching the flames. Pictet's figure of the 6 fore leg is incorrect ; he has

given a fifth joint to the tarsus (seemingly by dividing the first jonit) and has exag-

gerated the inequality of the ungues. Doubtless his subjects were dried.

Polymitarcys Savignti, Pict.

Ephemera, Sav., Descript.de I'Egypt. Hist. Nat. i. 191 [cxplic. ic.], ii. Nevropt. 5 (1817).

Palingenia Savignyi, Pict., Hist. Nat. Nevro[it. ii. Eplieni. 157 [uudcscribed] (1843-5) ; Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 550 [undescr.] (1853).

PvUjmitarcys Savignyi, ! Etn., Trans. Ent. Soc. London (1871), Gl, pi. iii. 10, 16 a [details].

Imago {dried), 6 . — Pronotum warm sepia-grey, with a longitudinal median line and

the front and lateral edges black ; meso- and metathorax light brown-ochreous, probably

varied above with warm sepia-grcy (the specimen is eroded). Abdomen beneath and at

the sides of the palest yellow ochre, becoming light brown-ochreous in segments 8-10 ;

above, segments 1-7 are broadly shaded with light Vandyke-grey, with the edges of the

dorsal vessel darker, and the joinings broadly whitisli ; in segments 8-10 the grey gives

place to light Vandyke-brown, which in certain positions changes to violet-grey, and the

sides of the segments are concolorous with the venter. Seta) and forceps white. Pore

femur above, and the tibia, viewed in certain directions, violet-grey ; the tarsus whitish ;

hinder legs with very pale yellow-ochreous femora, and the remaining parts whitish.

REV. A. E. EATON ON EECENT EPHEMEEID.E OE MATELIES. 47

Wings transparent white, with opaque neuration ; the costa, suhcosta, and radius of the

fore wing, up to the commencement of the pterostigmatic space, tinged with light pur-

plish or violet-grey ; a faint tint of the same colour is perceptihle in the contiguous

areas. Length of body 10, wing 11 mm.

Sah. The Nile, Egypt (Pictet & M^Lachlan, Mus.). The only example in this last

collection was given to me by M . Pictet.

POLYMITAECYS INDICTJ.S, Pict.

PaUngenia indlca, Pict., Hist. Nat. Nevropt. ii. Eplicm. 151, pi. xiii. 4 (1813-5) ; Walk., List of Neu-

ropt. Ins. iuBrit. Mus. part iii. 549 (1853).

Pohjmitarcys indicus, Etn., Traus. Ent. Soc. London (1871), Gl.

Subimciffo (dried), ? . — Body in great measure ochreous, with a fuscous spot in the midst

of the pronotum, three longitudinal fuscous lines (coincident with the sutures ?) on the

mesonotum,— one in the middle, the others directed towards the wing-roots,— and a

broad violet dorsal stripe along the abdomen. Setae ochraceous. Eore legs ocliraceous,

the tibia and a streak on the femur blackish ; hinder legs white. Wing-neuralion white;

the fore wing tinted slightly witli violet along the costa. Length of body 12, exp. of

wings 30 mm. (After Pictet.)

Tlah. East Indies (Vienna Mus.).

POLTMITAECYS ALBUS, Say.

^^Aorow Ze«</i:o?«, Will., Trans. Am. Soc. Philad.v. 71-3(1802); Etn., Trans. Ent. Soc. London (1871), 124.

tBaetisalba, Say, West. Quart. Rcpt. ii. 305 (1823) ; Le Conte, Complete Writings of T. Say, i. 204

(1859) ; Hag., Proc. Ent. Soc. Philad. ii. 170 (18G3) ; Walsh, op. cit. ii. 193, note 12 [in Cloe aJ (1863).

— B. albus, Etn., Trans. Ent. Soc. London (1871), 124; Hag., op. cit. (1873), 390.

? P«///;_ye«ia/j?<e//a, Pict., Hist. Nat. Nevropt. ii. Epli(5m. 145, pi. xi. 4, 5 (181.3-5); Walk., List of

Neuropt. Lis. in Brit. Mus. part iii. 548 (1853); Hag., Smitlison. Misccll. Coll. (18G1), Synop. Neuropt.

N. Am. 40.— P. alba, id., op. cit. 40 (18G1) ; id., Trans. Ent. Soc. Loudon (1873), 391.

? Campsurus puella, Etn., op. cit. (1871), 58.

/Miffy/o.— Milk-white ; pronotum yellowish white ; fore legs greyish fuscous ; hinder

legs wliite ; wings whitish, the fore wing greyish along the costa. Length of body 11-

12 ; exj). of wing 22 mm.

Hab. Passaick river, Belville, New Jersey ( Williamson) ; Winnipeg river {Say) ; North

Red River and N. York {Ilagen).

Second Series of Groiip I. of the Genera.

Adult. — Legs all functional, the hinder pairs rather short, the fore legs the longest

pair in the 6 , and in the ? at least as long as the hind legs, but usually a little longer

than these ; femora shorter tlian the tibiae ; ungues efficient, unequal, those of the

hinder tarsi mutually dissimilar. Valves of tlie thoracic spiracles straiglit-edged,

usually closed in dried specimens. Proximal joint of 6 forceps-limbs short, the second

joint the longest. Subimago quiescent during many hours ; the fore legs smooth ; the

last moult complete. Ni/mph. — Palpus of first maxilla long and slender, curved and

3-jointed. The 2-jointed palpus of second maxilla, dilated terminally and geniculated.

48 EEV. A. E. EATON ON EECENT EPHEMEllID^ OR MAYFLIES.

Section 3 of the Genera. — Type of Ephemera. Adult. — Wing-neuration complete and

plentifvil ; in the fore wing the subcosta is displayed, the anal (8) is unequally sinuous, and,

together with the second axillary nervure (9-) and the inner margin, encloses an almost

semi-sagittate space; the first axillary nervure (9^) is strongly arched towards its extremity;

the second is essentially simple and very gently curved. Hind wings well developed, their

membrane devoid of a contracted longitudinal fold. Sette of moderate length in $ , very

long in d ; in dried examples the outer setas of 6 are divergent from the median setae

(wlien there are three) or divaricate (when the median is aborted). Eorceps-limbs inserted

at the sides of the terminal border of a short transverse laminar lobe prolonged from the

segment, which lamina is undeveloped in the $ , their proximal joint shorter than the

second, which is the longest joint. Nymph [Fentagenia (13) unknown] fossorial, with

tracheal branchiae inserted upon the sides of the respective segments in advance of the

unprolonged hinder lateral angles, and arched upwards over the back with the tips

turned posteriorly ; median lobe of tongue emarginate. Legs short and strong ; the fore

tibia and femm* pilose, tlie former compressed and obliquely truncate distally.

HEXAGENIA, WalsL, 1863.

Illustrations. Adult, PI. VII. 11 a-11 c (details) ; (whole figures,) see citations of

Guerin (1829-31), Gray (1832), and Eambur (1812), under II. hilineata ; also of Pict.

(1843-5) under II. variahilis. Nymph PI. XXIX. (whole figure and some details) and

PL LXIII. (other details) ; also Walsh, ' American Entomologist,' i. 6, woodcut (1868).

Adult. — Pronotum in ? longer than broad, enlarged posteriorly, inflated medially,

slightly constricted at its anterior \ at the sides ; its arched and curved hinder border

rather prominent just in the middle, and somewhat rctuse when dried. Eore leg of 6

nearly as long as the body, the tibia about 1^, the tarsus about 1§ as long as the femur ;

? fore femur but little shorter than the tibia, which is about as long as the tarsus.

Thoracic S2)iracles elongate, their lips straight-edged or nearly so, usually closed in dried

specimens ; but sometimes the anterior gapes narrowly in front ; its ujiper valve is much

the larger and is strongly concave within. Median seta extremely rudimentary in both

sexes ; outer setae generally upwards of 2J times as long as (in subimago about the

same length as) the body, in $ about § as long as it ; when magnified their surface is

minutely pubescent throughout, and their joinings are well defined. Terminal joints of

forceps-limbs small. Lobes of penis strongly hooked, and without apjiarent stimuli.

Abdominal segments of ? : — 1 and 2 very short, the first tlioracoid ; 3-6 rather short,

7-9 longer, 10 short ; 8 is the longest, and 9 about as long as 7. Anterior ocellus much

smaller than the others. Eyes of 6 suboval, curved, large, moderately distant from each

other above. Nymph in the construction of its tracheal branchiae, legs, and mouth-

parts very similar to Ephemera ; but the tusks of the mandibles are connivent, and the

frons is armed with a single obtuse median protuberance. Abdominal segments 1-7

brancliiferous ; the gills all double, those of the anterior segments arising each from the

upper surface of the pleural region of the segment in the hinder part of the same, but

the gills of the seventh segment issuing from it near the base ; the gill-roots armed (as

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 49

in several other burrowing nymphs) each with a minute tubercle ; the divisions of the

minute gills of the first segment are linear and fringeless ; those of the gills of the

other segments are larger, and are flat, ovate-lanceolate, acuminate, fringed, membranous

laminae. Wings aduate to the notum along their inner margins only. Pronotum large,

quadrangular, ciliated at the sides, which are nearly straight ; its border in front and

behind slightly thickened, and armed at the fore corners with single triangular points

projecting forwards. Seta? acuminately plumose, a little more than half as long as

the body. Ventral segments 7-10 of the abdomen, taken together, are about If as

long as the rest put together.

Tyi^e. H. hillneata (in % Baetis), Say.

Distribution. Amei'ica, from Canada to Brazil ; also India.

Etymology, eg and jeved, on account of its being the sixth of the Sections of Paliiigenia

cmctor'um defined by Hagen in 1863, and named by Walsh in that year.

The species of this genus and of Ei)hemera might be described concisely from living

specimens.

Hexagenia albivittata, Walk.

XBaetis albivitta , ! Walk., List of Ncuropt. Ins. in Brit. Mus. part iii. 566 (1853).

Pallngmia continua, ! id., Trans. Ent. Soc. London, n. s. v. 199 (1860) . — P. dorsigera, ! Hag. MS. (1861) .

Hexagenia albivitta, ! Etu., op. cit. (1871), 64, pi. iv. 2, 2a [details] ; Hag., ojj. cit. (1873), 392.

Suhimago {dried). — Wings transparent pale smoke-grey with opaque black neuration ;

but the main nervures are pale near the base of the wings and in the hinder portion of

the disk of the hind wings, with the exception of the subcosta of the hind wing, which is

black up to the wing-roots.

Imago {dried). — Body above snow-white varied with black ; the black forms a broad

longitudinal stripe on each side of the pronotum, and encloses a large somewhat mitri-

form blotch on the meso- and metanotum ; white predominates upon the dorsum of the

abdomen, leaving a serrated black stripe above the spiracular line on each side (composed

of a series of triangular spots, each with its hypotenuse descending obliquely from the

hinder margin towards the lower anterior angle of the dorsum of the segment) and en-

closing some small black intermediate markings in the anterior portion of some of the

segments, viz. : — in both sexes a short longitudinal linear streak adjacent to the dorsal

vessel in the last few segments, and in the ? in each of the segments 3-6 a pair of

similarly situated triangular streaks, whose apices coalesce somewhat with the tips of the

serratures of the lateral stripes ; venter pale dull reddish sepia-brown with a longitudinal

median testaceous streak, and with darker tips to the segments, or, in very faded speci-

mens, pale dull lutescent with the overlapping borders of the segments paler. Seta?

either fawn-colour banded with brown, or brownish with irregular dull yeUow-ochreous

bands. Wings in c? perspicuous, faintly tinted with very pale sepia-grey, paler in the $ ;

neiu^ation pitch-black. Legs in ? lutescent, the hinder tarsi with the terminal joint

and ungues, and the extreme apical borders of the paler other joints reddish sepia-brown :

the fore legs in d fuscescent, with all of the tarsal joints but the Jast black. Length of

body 15 ; wing, d 15, ? 17 ; setse, s im. 35, subim. 23 mm.

SECOND SERIES. — ZOOLOGY, VOL. III. 7

50 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

Hab. Buenos Ayres {Rag.); the Amazons Eegion {Walk.); Espirito Santo (M^'Lach.

Mus.).

Hexagenia mexicana, sp. nov.

Imago, 6 {dried). — Wing-membrane transparent pitch-brown throughout, with black

neuration, the hind wings rather the darker pair; most of the longitudinal nervures and

cross veinlets are narrowly bordered with blackish, and this edging is widened along the

cross veinlets in the midst of the wings ; but the costa, subcosta, and radius, with their

interjacent cross veinlets are not bordered in the fore wings. Tliorax opaque pitch-

brown ; the pronotum with a broad longitudinal black stripe on each side. Abdomen

discoloured ; sette brown-black ; forceps pale, blackened towards their extremities. Fore

legs with pitch-brown femur and tibia, the tarsus pitch-black ; hinder legs flavescent,

the femora towards their distal extremities, the borders of the extremities of the tibia

and tarsal joints, the plantar surface, the last tarsal joint and the ungues, tinged more or

less with pitch-brown. Length of wing 13 mm.

Sal). Mexico (Hagen Mus.), captured by Salle; formerly represented in Baron de

Selys-Longchamps's collection.

Hexagenia. bilineata, Say. Plate VII. 11 6, 11 i' & 11 i ? (wings [part] and forceps).

XBaetis bilineata, Say, Godman's West. Quart. Rep. ii. 303 (1834') ; Lc Conte, Complete Writings of

T. Say, i. 203 (1859) .—B. angulata, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 5G4. (1853).

Ephemera limbata, Serville MS., Guer. Iconograph. Reg. Auim. ii. part I, pi. Lk. 7-9, texte, iii. 384

(1829-31) ; Gray, Grif. CI. Ins. ii. pi. xeiv. 7 (1832) ; ! Ramb., Hist. Nat. d. Ins. Nevropt. 295, pi. viii.

2 (1842).

PaUngenia viridescens, ! Walk., o;j. cit. iii. 550 (1853). — P. occulta, ! id., op. cit. iii. 551 (1853) ; Hag.,

Smitlison. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 43. —P. limbata, id., op. cit. 43 (1861) ; Pro-

vancher. Natural. Canad. viii. 265 (1876) ; id., Fn. Ent. d. Canad. ii. fasc. i. 82 (1877). — P. bilineata,

Walsh, Proc. Acad. Nat. Sc. Pliilad. (1862), 373; Hag., Proc. Ent. Soc.Philad. ii. 174-5 (1863) ; Walsh,

op. cit. 189 k 199 (1863).

Hexagenia bilineata, Walsh, op. cit. ii. 199 (1863) ; ! Etn., Trans. Ent. Soc. London (1871), 66, pi. iv. 4

[detail] ; ? Hag. MS., ! Lintar in 10th Ann. Rep. N. Y. State Commission of Fisheries, p. 3, pi. ii. 6

(1878).

Suhimago {dried). — Wings transparent grey, with pitch-black neuration, the longitu-

dinal nervures occasionally tinged with broAvn-ochre or bistre-brown close to the wing-

roots ; hind wings, as a rule, from just before the tip to the commencement of the inner

margin bordered with dark grey in ? , or black in the d , and sometimes with several

of their cross veinlets near the midst of the wing edged with a like colour.

Imago {dried), 6 . — Pronotum bistre-brown, or sometimes pitch-brown, with a broad

longitudinal dark bistre-sepia-brown, or sometimes pitch-black stripe on each side, which

is extended upon the mesonotum to at least the wing-roots ; mesonotum for the most

part rufo-luteous or rufo-piceous, with the peak often pitch-black, and sometimes less

rufescent on its hinder slopes, rarely of a uniform pitch-brown throughout ; metanotum,

as a rule, pitch-brown, but sometimes rufo-lutescent or even light brown-ochreous with

the peak pitch-brown. Abdomen variable in depth of colour and definition of markings,

EEV. A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES. 51

the ground-colour ranging from very light yellow-ochreous, or very light Mars-yellow,

to light yellowish raw-umber ; and the markings from pitch-black and intense burnt-umljer

brown to a slightly yellowish modification of intense Roman sepia-brown, approaching raw

umber. The dominant pattern of the darker markings is, on the dorsum, a median

longitudinal stripe and a diagonal lateral stripe extending from the stigma to the hind

margin of every intermediate segment ; that on the venter, in nearly every segment, is

a pair of stripes extending, one on each side, from the hinder angles of the segment (or

thereabouts) to the base of the segment, convergent towards each other, and in indirect

continuity Avith the oblique dorsal stripes of the following segment. Some examples

simply display this dominant pattern, and in them the light ground-colour in segments 2

to 8 is shown on each side of the median stripe in the form of two right-angled triano-ular

spots occupying the upper anterior and the lower posterior halves of the space diagonally

intersected by the lateral stripe ; in segment 9 the lower posterior compartment is

obscured ; segment 10 has a small dark spot at the base in the middle, and no lateral

stripes; the midribs of the subanal lobes are pitch-black. This dominant pattern

undergoes the folloAving modifications in individual specimens. The median stripe in

segments 2-5 is dilated posteriorly so as to form a triangular sj)ot in every segment ; the

triangular compartments of the quadrangular areas on each side of the median stripe

have the angles adjacent to the diagonal stripes filled up with the dark colouring, so as to

restrict the lighter ground-colour to oval spots above and ovate or linear spots below the

diagonals, or to quadrangular spots in the anterior segments, and semiovate spots in the

hinder segments above the diagonals, and a narrow bordering along the spiracular margin

below the diagonals ; in some examples the pale colouring below the diagonals is re-

stricted almost completely to the hinder lateral angles of the dorsum ; the additional

colouring is apt to convert the latero-dorsal markings on each side into a broad zig-zag or

serrated stripe. On the venter, the spaces included by the two convergent stripes, and

the hinder border of nearly every segment are sometimes sufiiised Avith the darker

colouring, leaving a light-coloured triangular space on each side of the segment external

to the stripes ; when this is not so, the stripes are sometimes dilated behind. There are

often dark spots at the ganglia. Sette variable in colour, their joints either uniformly

or in a large measure bistre-, burnt-umber, or warm sepia-brown, often pale or light-

ochraceous anteriorly, sometimes lighter at the joinings only, rarely dark and opaque at

the joinings ; all of the joints in the same individual specimen are much alike in coloration.

Eore leg from trochanter to ungues usually in opaque view dark burnt-umber, changing

with transmitted light to madder-brown, the first tarsal joint, the ends of the other tarsal

joints and that of the tibia opaque ; sometimes they are pitch-brown, or even bistre-

brown, with the whole of the tarsus lighter and changing Avith transmitted light to warm

sepia-grey ; sometimes the basal portions of the intermediate tarsal joints are in a large

measure whitish ochraceous, or the tarsus is nearly uniformly sepia-grey • one example

has the tibia pitch-brown, black at the tip, the trochanter and femur intense bistre-brown,

lighter above towards the base of the femur, and the tarsus light bistre-brown, with the

first and terminal joints and the extremities of the intermediate joints pitch-black, the

bistre changing in transmitted light to raw umber. Hinder legs in opaque vicAV, flavescent

7*

52 EEV. A. E. EATON ON EECENT EPHEMEEIDiE OE MAYFLIES.

or light yellowish ochraceous; changing in transmitted light to light yellowish amber;

the ungues, the terminal joint and the distal borders of the other joints of the tarsus, warm

sepia, burnt-umber brown, or pitch-black, the dark colouring in the intermediate joints

of the tarsus sometimes predominating almost to the exclusion of the light ground-

colouring, at other times narrowly restricted to their terminal borders. Wing-membrane

usually quite clear in the disk, bistre- or raw-umber brown in the marginal and submar-

ginal areas of the fore wing, and narrowly grey or intense sepia along the terminal margin

of the hind wing ; but sometimes even those areas in the fore wing from the wing-roots to

the pterostigmatic space are colourless, and the bordering of the terminal margin of the

hind wing is either limited to a faint spot at the apex of the wing or is entirely deficient.

The cross veinlets, which are liable to be bordered with black or grey in the subimago,

are apt to exhibit corresponding greyish markings in the imago. Individual specimens

occasionally have the greater portion of the wing-membrane tinted almost imperceptibly

with greyish. Neuration of similar colour to that of the subimago.

The ? has the thorax nearly of the same colours as the d ; the abdomen very light

brownish ochraceous or burnt-umber grey, or vandyke-brown, marked with burnt-umber

brown in the opaque portion, but with bistre in the empty terminal segments ; the median

dorsal stripe corresponds in variety of form with that of the d , the latero-dorsal stripes

are of the broad serrated type, the ventral markings vary as in the d . Fore legs usually

piceous, either entirely, or with the tarsal joints whitish at their bases ; one example has

the fore leg bistre-brown, with the terminal tarsal joint and the extreme edges of the

others black. Hinder legs, in opaque view, light bistre-brown, sometimes with the tibia

and tarsus darker than the femur ; the terminal joint of the tarsus and sometimes the

terminal borders of the other joints intense burnt-umber or piceous. Setae light warm

sepia-brown with opaque joinings, or sepia-grey with dark sepia joinings. Wings with

transparent membrane and pitch-black or pitch-brown neuration, the longitudinal ner-

vures becoming lighter close to the wing-roots ; hind-wings commonly, but not invariably,

bordered narrowly with dark sepia along the terminal margin and at the adjacent angles,

the bordering uneven in its definition along its inner edge ; fore wings often almost

imperceptibly and narrowly tinted with very light sepia-grey along the corresponding

margin, and more distinctly tinted with sepia-grey in the pterostigmatic region ; in many

examples the marginal and submarginal areas of the fore-wing, anterior to the bulla, are

more lightly tinted with the same colour. Cross veinlets in the fore wing between the

costa and the pobrachial (7) nervures, and those in the hind wing from the subcosta to

the first axillary nervure (9), generally (but not in every specimen) bordered with light

or dark sepia-grey ; this bordering is usually lighter in colour and narrower in the fore

wing than in the hind wing, and frequently forms irregular blots upon the stem of the

sector (4), the end of the longest adventitious nervure contained within its fork, and upon

the end of the corresponding nervure included within the fork of the praebrachial (6).

Length of body, d 2 lG-23 ; wing, d 14-21, ? 18-22 ; setse, d 44-65, subim. 21-25,

S 35-40 and 1, subim. 17 mm.

Sab. Generally distributed in North America, in lakes and rivers, from Louisiana

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYELIES. 53

aud Texas northwards, and from the Atlantic to the Pacific. June (or May in the

South) to September.

Hexagenia mtjnda, sp. nov.

Imago {dried), 6 . — Thorax above light raw-umber, with a broad pitch-brown or intense

sepia longitudinal stripe on each side of the pronotum, narrowly and less distinctly

produced backwards nearly to the peak of the mesonotum ; the tegute of the fore winf-s

and the pectus and sides of the pro thorax, together with the fore coxae, yellow ochreous ;

metanotum partly piceous ; intermediate coxse in front and the fore part of the meso-

sternum piceous, or intense warm sepia ; a lighter spot of the same colour occupies the

joining of the meso-, and metasternum. Abdomen very light yellow ochraceous, marked

Avith pitch-black above, and light burnt-umber beneath : the dorsal markings in segments

1-7 are a pair of broad stripes rising obliquely upwards from the base of the dorsum near

the anterior lateral angles, one on each side of the back, rounded oif posteriorly just

before the distal border of the segment, and joined to each other in front and behind by

a streak (in the anterior segments), or narrow band (in the hinder segments), of the same

colour as the stripes, running respectively parallel with and adjacent to the joining and

the apical border of the segment, — in short, a mark like the letter U closed by a line across

the top, with arms of ecpial thickness ; in segment 7 a broad longitudinal stripe occupies

the middle of the space thvis enclosed, whereas in the preceding segments only the dorsal

vessel is there \-isil)le as a greyish line : segments 8 and 9 differ from segment 7 in their

markings failing towards the anterior lateral angles of the segments. Ventrally, in

segments 1-7, a light burnt-umber spot semielliptical in the hinder, but in the form of

a small segment of a circle in other segments, extends almost across the whole of the

apical border of each somite, and thence forwards no farther than the midst of the

segment at the utmost, and that only in the anterior segments : in segments 8-10 the

predominant colour is bright light brown-ochreous ; the ganglionic track is blackened at

the base of every segment. Setae intense bistre-brown, lighter close to their insertion,

their joinings very light, and some of their joints lighter anteriorly than at their distal

extremities. Eore legs from the trochanter to the fi.rst tarsal joint pitch-brown, the

trochanter and base of the femur lighter on their inner side ; the intermediate tarsal

joints pitch-brown distally, but warm sepia-grey in their proximal halves. Hinder legs

light yellow-ochreous in opaque view, changing to very light yellow amber in transmitted

light ; the ungues, terminal joint, and the distal border of the penultimate joint of the

tarsus warm sepia-brown or intense burnt-umber. Wings transparent, almost uniformly

tinted with extremely light bistre-grey ; the marginal and submarginal areas of the fore

wing distinctly bistre-grey ; the terminal margin of the hind wing very narrowly tinged

witli light greyish : longitudinal neuration bronzy raw umber-brown, becoming light

yellowish at the wing-roots, and in part appearing black in certain lights ; cross veinlets

black, bordered narrowly with blackish in the same parts of the wings as in H. hilineata.

Length of body 18 ; wings 14 ; setae 35 mm.

Kah. Morganton N. C. (Mus. Comp. Zool., Cambridge, Mass.).

54 EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYELIES.

Hexagenia venusta, sp. nOT.

SuUmago {dried), ? . — "Wings dull light brown-ochreous, with black, usually immargi-

nate cross veinlets. Setse uniformly light brown-ochreous. Legs brown ochreous, with

tarsi and the extremity of the fore tibia intense burnt-umber brown. — Variation. Tarsi

in a large measure concolorous with the rest of the legs ; but the ungues, terminal

joiiit, and the extreme distal edges of the other joints of the tarsi, and also a broad band

at the extremity of the fore tibia, dark burnt-umber.

Imago {dried), 6 . — Thorax either very light yellowish bistre-brown, or light brown-

ochreous, varied on the meso- and metanotum with light yellow-ochreous, and with a

light purple-madder stripe on each side from the edge of the occiput to the fore wing-

roots. Abdomen translucent whitish chrome-yellow in segments 2-8, and then posteriorly

darker, marked in light purple-madder with the same pattern as the 2 ; but in segments

7-9 the dorsal vessel is edged to a greater or less extent with purple-madder : again,

the ventral median stripe is prolonged to the prosternum, and in every abdominal

segment but the last two contains a pair of pale dots placed transversely in, or a little

behind, the middle of the segment ; also at the bases of the respective ventral segments,

close to the joinings 2-8 and the spiracular borders, in the extreme anterior lateral

angles of the segments, are small triangular light purple-madder spots, one spot in each

angle. Setse marked with nearly the same colours as the abdomen, the purjile-madder

coinciding in certain cases with the joinings, in others with the distal terminations of

the joints, in otliers with the whole of every fourth joint as well so as to form bands of

colour each about a joint and a half in breadth in addition to rings ; in one example the

bands are nearly two and a half joints broad. Pore legs madder-brown, or purple-madder,

with the tibia brighter than the femur, and the tarsus dull, vmiformly dark in joints

1 and 5, but whitish towards the bases of joints 2-4. Hind legs translucent whitish

chrome-yellow, like the abdomen ; the terminal joint and the lower point of the penulti-

mate joint of the tarsus, light purple-madder. Wings transparent, and in a large extent

tinted almost imperceptibly with light yellowish, but coloured distinctly with raw-

umber in the marginal and submarginal areas of the fore wing (this colour receding

slightly from the costa between the cross veinlets in the proximal half of the marginal

area so as to leave the membrane clear thereabouts, and not extending nearer to the

wing-roots than the great cross vein), and sometimes with a more or less narrow blackish-

grey bordering along the terminal margin of the hind wing : neuration of diverse colours,

the costa, subcosta, and radius outside the great cross vein of the fore wing dark pitch-

brown, the remainder of the longitudinal nervures light yellowish (inclusive of the bases

of those three) ; cross veinlets black, sometimes narrowly edged with blackish in the

customary parts of the wings, but not so as to form spots.

? . Body yellow-ochreous marked with violet-grey, viz. :— with a stripe on each side of

the pronotum reaching to the wing-roots ; on the dorsum of the abdomen, in segments

1-8 a series of oblique triangular spots, on each side one in every segment, the triangles

truncate posteriorly, and in segments 1-4 reaching from base to joining, but in the others

not starting from the base of the segment; in segment 9 the corresponding spots are

EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 55

reversed ; also in segments 8 and 9 a broad median longitudinal streak from the base,

vanishing beyond the middle of the segment before the joining; also a large spot oc-

cupying almost the whole of segment 10: beneath, a ventral stripe, dilated in the meta-

sternam, but linear in the abdomen, and somewhat blackened at the joinings, extends

backwards to the ninth abdominal segment ; the midribs of the perinatal lobes are of

the same dark colour. Setxe uniformlv verv light yellow-ochraceous. Eore le^ liirht

brown-ochreous, the tibia and tarsus rather lighter than the femur ; ungues, terminal

and first joints, and narrowly the distal margins of the other joints of the tarsus, also the

distal extremity and the joining at the knee of the tibia, dark Roman-, or warm sepia-

brown. Hinder femora yellow- ochreous or light Mars-yellow, changing in transmitted

light to dull yellowish-amber colour ; tibite and tarsi lighter ; the terminal joint and

lower distal borders of the next two joints of the tarsus very light purple-madder, the

larger of the ungues much darker. Wings more of a dull light-yellowish amber than

those of the subimago ; their longitudinal neuration light-yellowish ochraceous, or some-

times light Mars-yellow, the cross veinlets, and the great cross vein of the fore wing

black, as also are the bullfe of the subcosta and radius. Length of body, d 15-18,

S 22-23 ; wing, d 15, 2 17-23 ; setae, im. 6 44, ? 27-28 mm.

ITab. Texas, Dallas, Waco, and W. Texas [Belfrage), in May; Utah Lake (in

M"Lacli. Mus. and Mus. Comp. Zool. Cambridge, Mass.). In 1871, having no s im., I

failed to distinguish this sjoecies from S. variabilis.

Hexagenia VARIABILIS (renamed). Plate VII. 11 c (wings, legs and 6 forceps)

[H. limbatci].

Palinyenia % Umhata, Pict., Hist. Nat. Nevi'opt. ii. Ephem. 146, pi. sii. (1843-5) ; Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 548 (1853); ! Walsh, Proc. Acad. Nat. Sc. Pliilad. (1862), 373;

Hag., Proc.Ent. Soc. Philad. ii. 176 (1863) ; Walsh, op. cH. p. 199 (1863) ,—P.X Mlineata, ! Hag., Smithson.

Miscell. Coll. (1861), Synop. Neuropt. N. Am. 41.

Hexayenia [type] % limbata, ! Walsh, Proc. Ent. Soc. Philad. ii. 197 (1863) ; ! Etn., Ent. Mo. Mag. v. 85

(1868) ; ! id., Trans. Ent. Soc. London (1871), 65, pi. i. 7 & iv. 8, 3 a [details].

Subimago {dried). — Wings of d somewhat greyish, of 2 dull light yellowish, the

marginal and submarginal areas of the fore wing coloured more or less intensely with

bght bistre-brown or brown-ochreous, and the hind wings in the 6 along the terminal

margin from just round the apex of the wing to the commencement of the inner margin

bordered with warm sepia-grey : longitudinal neuration yellowish or very light bistre-

grey ; cross veinlets black, commonly with dark borders in the usual parts of the wings,

these borders narrow and blackish in the fore wing, and rather wider as well as more

nearly warm-, or Roman-sepia brown in the hind wings. In some specimens the markings

are extensively blurred in the hind wings, imparting a warm sepia-grey cloud to the

whole of the membrane excepting at the base of the wing, where the light yellowish tint

is stronger than in the fore wing.

Variation, 2 . — Wings free from markings ; the membrane uniformly light bistre-grey,

very faintly tinted with yellowish in the hind wings ; cross veinlets in most of the disk

of the fore wings, and those in the hind wings less decidedly blackened than in the d ;

56 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

in certain positions, wliile the subcosta, radius, and prfebracliial nervures of the fore wing

remain yellowish, other finer longitudinal nervures appear greyish (Galena).

Imago, <s (liviiifj). — Eyes bright greenish yellow above, black below {Walsh). — {Dried.)

Pronotum translucent, sometimes tinged with bistre-grey overlying yellow-ochre, tra-

versed lengthwise on each side by a lighl burnt-umber or pitch-brown streak reaching

from the occiput to the fore-wing roots. Meso- and metanotum of a colour inter-

mediate between light brown-ochre and Mars-yellow, varied posteriorly with the former

colour. Abdomen varying from light yellowish-ochre, or light raw-sienna, to light

brown-ochre, marked on the dorsum with dark madder-brown, and on the venter with

intense burnt-umber, the form and extent of the markings presenting much variation.

In strongly marked specimens the dorsal pattern consists of a median stripe the whole

length of the back, with a jagged stripe on each side of it : the median stripe may

maintain a nearly even width in every segment ; sometimes in segments 1 and 2 the

whole of the dorsum (excepting at the joinings) is dark, in segments 3-6 (whose

joinings are also pale) the median stripe is narrowed in every segment from behind

forwards so as to be resolved into a series of triangular blotches, while in segments 7-9

its breadth is more equal, and it terminates in a spot at the base of segment 10 ; but

in ill-marked specimens both median triangles and stripe ai'e either deficient, or

reduced to a linear streak along the dorsal vessel in segments 7-10. The lateral stripes

of the dorsum in strongly-marked specimens are each composed of a series of diagonal

triangles or of diagonal stripes extended forwards from the hinder borders, nearly in the

middle, to the anterior angles of the segments, which stripes in segments 7-9 are some-

times confluent posteriorly with the median stripe ; in some specimens the triangles,

instead of tapering forwards, are reversed ; in ill-marked specimens the stripes are almost

linear. Pectus and ganglionic track intense burnt-umber, the latter sometimes Ul-

defined ; in segments 2-9 at each anterior lateral angle is a small triangular spot of the

same colour. Setae light Boman-sepia brown, many of their joints becoming whitish

yellow-ochreous anteriorly in varying extent; sometimes the lighter colour is pre-

dominant, and, in the midst of the seta, only every fourth joint and more or less narrow

annulations at the distal extremities of the other joints remain of the darker colour.

Pore leg as an opaque object madder-brown from the trochanter to the end of the tibia,

but slightly blackened at the extreme distal border of the femur and at the base of the

tibia ; tarsus ligliter ; the terminal and proximal joints of the tarsus, the tips of its inter-

mediate joints, the ungues, and the distal extremity of the tibia, blackish, or intense

burnt-umber ; viewed with transmitted light the femur and tibia appear fuscescent.

Hinder legs as opaque objects very light brown-ochreous, but as transparencies light

amber-yellow ; the ungues, terminal joint, and the tips of the other joints of the tarsus

intense burnt-umber brown. Wings transparent, the fore wings very slightly tinted,

the hind wings tinted, sometimes as slightly, sometimes more strongly, with light

greenish yellow ; the marginal and submarginal areas of the fore wing exterior to the

great cross vein, and the longitudinal neuration raw-umber brown, the colouring some-

times receding from the costa towards the subcosta ; cross veinlets of the fore wing black,

and those in the basal two thirds of the wing between the costa and pobrachial ncrvure (7)

EEV. A. E. EATON ON EECEXT EPHEMEEIDiE OE MAYFLIES. 57

bordered narrowly with blackish. Hind wing with similarly pale longitudinal and dark

transverse neuration, and with nearly all the cross veinlets bordered with blackish ; the

terminal margin not perceptibly bordered with colour darker than that of the disk.

(Texas.)

Variation. — In the fore wing the dark borders to the cross veinlets are obsolete, and

those in the hind wing are much reduced in width. Both wings are quite free from all

tint of discoloration in the disk ; the marginal and submargiual areas of the fore wing

are greenish grey or light umber-grey ; the terminal margin of the hind wing not

bordered with dark colouring. (AVashington, D. C.)

Variation. — Both wings are tinted alike throughout in the disk ; the marginal and

submargiual areas of the fore wing are tinted with umber-brown ; the hind wings are

bordered with black-grey along the terminal margin : the edgings of the cross veinlets,

mostly linear in the hind wing, are obsolete in the disk of the fore wing, but between

the great cross vein and the pterostigmatic region of this wing exist as a small rounded

spot on every cross veiulet, the roundness of the spots diminishing towards the ptero-

stigma. (Utah Lake.)

Variation. — ^Wing membrane faintly and uniformly tinted in both wings ; no dark

bordering along the terminal margin of the hind wing ; no bordering perceptible along

the cross veinlets of the marginal and sultmarginal areas, next to none along those in

the disk of the fore wing, and hardly any along those of the hind wing. (New England.)

Variation. — Very similar to the foregoing ; but some faint indications (as spots) of

bordering in the marginal and submarginal areas of the fore wing, narrow sharply

defined edging to the other usually bordered cross veinlets, and a grey-black bordering

along the terminal margin of the hind wing. Hind legs in their general colouring duller

than usual. (Detroit, Mich.)

$ imago (dried). — Integument of pronotum translucent very light bistre-grey overlying

yellowisii-ochre ; the rest of the notum, ranging in colour from dark yellow-ochre or duU

Italian-ochre to light brown-ochre, is varied with Boman-sepia at the projecting peaks ;

the light Roman-sepia streak extending backwards on each side of the notum from the

occiput is broadest at the hinder part of the pronotum, is much narrowed in front, and

is not clearly traceable (though sometimes faintly indicated) on the mesonotum. Dorsum

of the abdomen marked longitudinally with a median sepia or warm-sepia stripe, extending

from the first segment to very nearly the hind margin of the tenth : in segments 1-5 this

stripe is dilated posteriorly so as to form an acutely triangular blotch in each of them ;

in segment 6 the corresponding triangle is more slender and truncate ; in segments 7-9

the stripe in each segment maintains more nearly an evenness of width ; but it tapers to

a point behind in segment 10. Erom the median stripe in every segment but the last,

on each side of the dorsum, in the vicinage of the hinder border, a tapering streak of a

like colour extends obliquely forwards and downwards, either diagonally (as in segments

1-6) or (as in the longer segments 7-9) towards the spiracular border, gradually further

and further away from the anterior angle of the dorsum in successive segments. Venter

traversed lengthwise, or at least in segments 8 and 9, by a median linear stripe similar

in colour to the dorsal markings. Setee very light yellowish ochraceous. Pore femur

SECOND SERIES. — ZOOLOGY, VOL. III. 8

58 REV. A, E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

and both extremities of the tibia madder-brown ; the rest of the tibia and most of the

tarsus in opaque view light brown-ochreous, or in transmitted light yellowish amber-

colour, but the ungues, terminal joint, distal borders of the intermediate joints, and the

whole of the proximal joint of the tarsus blackish or intense burnt-uinber. Hinder

legs and wings nearly as in the lighter variations of the c? , the cross veinlets being

immarginate : marginal and submarginal areas of the fore wing uniformly tinted with

very light amber-yellow. Length of body, d 14-16, ? 18-24 ; wings, <s 13-15, $ 17-24 ;

setse, <S im. 36-46, subim. 23, ? im. 26, subim. 23-25 mm.

Sab. Widely distributed in the United States : Utah Lake ; Texas ; Lake Harney,

Fla. ; St. Louis, Miss. ; Galena and Rock Island, 111. ; New Eed River ; Detroit, Mich. ;

New England ; Philadelphia, Penn. ; and Washington, D. C. (Mus. Com. Zool. Cambridge,

Mass.; Hag. Mus.; M^Lach. Mus,).

EPHEMERA, Linn. 1746; restricted, Leacli, 1815.

Illustrations. Adult, PL VIII. 12 a-d (details) ; (whole figures) see citations under

JE. vulgata, danica, lineata, and glaucops, especially those referring to Pictet (1848-5),

Curtis (1838), and Stephens (1835). Nynqih, PI. XXX. ; see also citations under

E. vulgata of Guerin (1829-43), Gray (1832), Blanchard (1868), and Vayssiere (1882) ;

also under E. danica, of Pictet [pis. 1 & 2] (1843-5).

Adult. — Pronotum in ? somewhat transverse, tumescent above, about as wide as the

head behind but narrower in front ; the anteriorly convergent lateral borders slightly

constricted at about their first ^, and suddenly rounded off at the angles in front and

behind; the arched and sinuous hind margin slightly retuse in the middle, and a little

everted at the lateral angles. Pore leg of d about f as long as the body, tibia 2| or

3 times as long as the femur, the tarsus about 4 times as long as the femur ; $ fore femur

about f as long as the tibia, and subequal in length to the tarsus. Thoracic spiracles

straight lipped, relatively smaller than in Hexagenla, usually closed in dried specimens,

but sometimes the anterior gapes narrowly. Median seta about as long as the others in

both sexes ; outer setae in 6 about twice as long as the body, in s subim. and in ? im.

nearly of the same length as the body : under a lens they appear pubescent throughout,

and theu' joinings are well marked. Last two joints of forceps limbs well develoi^ed.

Lobes of the penis usually flattened, and oblique at the ends through prolongation of the

thickened outer lateral border, but deviating from this European type in some exotic

species ; stimuli, when present, interior, subulate and slender. Abdominal segments

of 2: — 1-4 relatively short, the first thoracoid, 5 rather longer, 6-9 long, 10 short;

segment 8 is subequal to 7, and rather longer than 9 ; segment 7 is a little longer than

6 ; segments 6-10 together constitute about f of the abdomen. Anterior ocellus much

smaller than the others. Eyes of d oval, their inner orbits curved, mutually remote

above. Suhhnago quiescent for about 24-36 hours, standing with erect connivent wings

upon its hinder legs, the fore legs prorect off the ground, and the setse placed close

together, the outer either above or below the median seta. Nymph. — Head narrowed

anteriorly, and armed in front with two conical projections ; mandibles tusked, the tusks

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 59

subulate, curved slightly upwards and towards their extremities outwards, their tips

interlocking when the jaws are closed. Antennae setaceous; the first two joints the

stoutest, the former minutely pubescent, the latter more strongly so ; flao-ellum pilose

near the base, with spreading hair disposed in whorls diminishing successively in leno-th,

and becoming very short and minute beyond the middle. Wings and gills as in Hexa-

genia. Pronotum slightly narrowed in front and behind, evenly curved at the sides, and

armed in front with a strong triangular projection behind each of the eyes. Setse in a

great measure plumose, and then shortly tail-pointed with whorls of minute spreading

hair ; their length is nearly | that of the body. Ventral segments 7-10 together are

almost I as long as the abdomen. — Labrum quadrangular, rounded at the fore corners,

emarginate in front, and pubescent. Lobes (or fangs) of the mandibles adjacent to the

molar tuberosity, and set at right angles with the tusk, which is minutely spinulose

above for some distance from the base, and partially pilose. Lacinia of 1st maxilla

small, narrow, and incurved, terminated by a few spines, strongly ciliated internally, and

partially pubescent outside from the middle to the point ; the 3-jointed palpus about three

times as long as the lacinia, slender ; its nude first joint nearly ^ as long as the re-

mainder, the second almost as long as the third, and similarly pilose with sjireading

hair. Labium and 2nd maxillae deplanate, the former small, its lobes narrowly ovate

and close together. Laciniee of 2nd maxilke large and oval ; the palpi robust, their first

joint flattened, tapering from a wide base, and ciliated within ; the second joint incm'ved,

dilated distally, obliquely truncate at the extremity, the truncated surface hispid, the

outer surface pilose. Median lobe of tongue semimitrif orm ; paraglossoe rounded, well

developed and distally ciliated. Legs pilose along the edges of the femur, the front of

the tibia, and the dorsum of the tarsus, and densely hirsute at the back of the tibia ;

the sole of the tarsus pubescent ; the anterior tibia minutely spinulose behind ; the

femora are compressed, the tibiae distally dilated and oblique at the ends, where the hind

tibia is produced into a spine.

Type. E. vulgata, Linn.

Distnbution. Northern temperate and Indian regions ; also (undescribed sp.) New

Zealand.

Etymology . e<piuie§oc (tVi and I'utega), from the supposed shortness of life of the imago.

Ancient authors in southern Europe probably wrote of Polymitarcys under this name, if

not of Oligoneuria.

I have seen nymphs of E. vulgata, danica, and llneata alive, and of E. gUmcops and

japonica in alcohol. In swimming they labour with their legs and progress rather

slowly, propelled chiefly by undulations of the body and setse.

Ephemera vtjlgata, Linn. Plate VIII. 12 1) (wing [part] and penis).

\_Ephemera\ or Ephemera vulgata [Linn., Fn. Suec. ed. i. no. 750 [ll-^Q] ; De G., Mem. Sav. Etr. Acad.

Paris, ii. 461-9, pi. xvii. 1-2 (1755)] ; Linn., S. N. ed. x. i. 546 (1758) ; idem, Fu. Suec. ed. ii. no. 1472

(1761) ; Sulzer, Die Kenntz. d. Ins. 43, pi. xvii. 103 (1761) ; [Geof., Hist. Abr. Ins. Paris, ii. 238,

no. 1 (1764)] ; Mill., Fn. Ins. Fried. 63 (1764) ; Pontop., Naturh. Dan. 223, pi. xvii. (1765) ; Schsef.,

Elem. Ent. tab. Ixii. 1-3 (1766); Linn., S.N. ed. xii. pars ii. 906 (1767) ; Houttyn, Nat. Beschr. d. Ins.

8*

60 EEV. A. E. EATOX ON EECENT EPIIEMERID^ OR MAYFLIES.

(1766-9) ; De G., Mem. d. Ins. ii. pars ii. 621, pis. xvi. and xvii. 1-10 (1771) ; Berkenhout, Outl. Nat.

Hist. Gt. Brit, and Ireland (1769-72); Fab., Syst. Ent. 303 (1775); [Scliiif., le. Ins. Ratisbon. i.

pi. ix. 5-6 (1776)] ; Mull., Zool. Dan. Prodr. 142 (1776) ; Schr., Enumer. Ins. Austr. indig. 602 (1781) ;

fab., Sp. Ins. i. 383 (1782) ; Fourc, Ent. Paris, ii. 351 (1785) ; Fab., Mant. Ins. i. 243 (1787) ; Berken-

hout, Outl. Nat. Hist. Gt. Brit. &e. ed.ii. i. 150 (1789) ; Vill., C. Linn. Ent. iii. 16 (1789) ; [Zsch., Mus.

Lesk. i. 150, no. 13 (1789)] ; Gmel., Linn. Syst. Nat. ed. xiii. i. pars v. 2628 (1790) ; Ros., Fn. Etrusc.

ii. 7 (1790) ; 01., Encyc. Meth. vi. 417(1791); Fisclier,Vcrsucli e. Naturgesch. v. Livland, 337, no. 564

(1791); Fab., Ent. Syst. emend, iii. pars i. 68 (1793) ; Schr., Fn. Boiea, ii. parsii. 196 (1798); Cederhjelm,

Fn., Ingric. Prodr. 134 (1798) ; Walck., Fn. Paris, ii. 8 (1802); Lat., Hist. Nat. Crust. & Ins. xiii. 94 (1805);

Panzer, in Explic. Scliffif. Ic. ix. 5-6 (1804) ; idem, Fn. Ins. Germ, initia. Heft xciv. 16 (1805) ; Shaw,

Gen. Zool. vi. part ii. pi. Ixxxi. (1806) ; Lat., Gen. Crust. & Ins. iii. 184 (1807) ; Leach, Brewster's Edin.

Encyc. ix. 137 (1815); Cuv., Regn. Anim. ed. i. iii. 430 (1817) ; Lamarck, Hist. Nat. d. Anim. s.Verteb. ed.

i. iv. 221 (1817) ; Stewart, Elem. Nat. Hist. ed. ii. ii. 225 (1817) ; Cuv., Regn. Anim. ed. ii. v. 244 (1829) ;

Gu^r.-Men., Iconogr. Regn. Anim. ii. pars i. t. Ix. 8 [aquat.] (1829-13) ; Gray in Griffith's Anim. Kingd.

ii. pi. xciv. 8 [aquat.] (1832) ; ! Steph., III. Brit. Ent. vi. 55 (1835) ; [! Ronald's Fly-fish. Ent. ed. i. pi. xiv.

30-31 (1836)] ; Dahlbom, Kort. Underiittcl. om Skandin. Ins. 228 (1837); Perch., in Gu^r., & Perch.

Gen. d. Ins. &c. livr. vi. pi. iv. 1 m. (1838) ; Barm., Handb. d. Ent., Bd. ii. Abth. ii. 804 (1839); Zet.,

Ins. Lap. 1044 (1840) ; Voigt, Lehrb. d. Zool. v. 311 (1810) ; Blanch., Hist. Nat. d. Ins. iii. 53 (1840) ;

Duf., Mem. par divers Savans, Instit. d. France, viii. 580, note (1841); Lat., Nouv. Diet, d'llist. Nat.

X. 348 (1847) ; ! Walker, List of Neuropt. in Brit. Mus. part iii. 354 (1853) ; Leunis, Synop. d. Natur-

gesch. d. Thierr. cd. ii. 635 (1860) ; Karsch, Die Insectenwelt, v. 400 (1863); Hag., Ent. Ann. (1863),

14; Stein, Berlin, ent. Zeit. vii. 414 (1864); Hag., Stet. ent. Zcit. xxvi. 229 (1865); Blanchard, Meta-

morph&c. dcs Ins. 594 pi. [nee p. 127] (1868); Rostock, Berlin, ent. Zeit. xii. 225 (1868); ! Etn.,

Trans. Ent. Lond. (1871), 68, pi. i. 9 & iv. 5 (details) ; Girard, Traite Elem. d'Ent. part ii. fasc. i. (1876);

Boulytchoff, Bull. Soc. Oural. Sc. Nat. Ekaterinb. iv. 37 (1878); Rostock, Jahresb. d. Ver. f. Naturk.

Zwickau, 1877, p. 83 (1878) ; A^ayssiere, Ann. Sc. Nat. (6), Zool. xiii. 38, figs. 3-7 & 53 [nymph and

details] (1882). — E. maculata, Linn., Syst. Nat. ed. v. p. 02 (1747). — E. communis, Retz, C. de G. Gen.

and Sp. Ins. 56, no. 180 (1783).—! E. J danica, Ronald's Fly-fish. Ent. ed. v. no. 31 (1856).

Subimago (living). — Wings at first yellowish green or greenish grey, changing to

cinereous, broadly tinged with black-grey along the anterior and terminal margins, the

discal spots fuscous orpiceoixs, the cross veinlets edged with ivory-black in the male, the

neuration dark. Notuni ultimately black, but at first varied with luteous, when the

pronotum has a black longitudinal stripe on each side, the mesonotum a large rhom-

boidal luteous spot prolonged at each end into pair of curved streaks, and the luteous

metanotum has a pair of L-shaped black marks. Setse brown-black.

Imago [living). — s . Head black-brown, the antennae paler at the base ; eyes deep sepia-

brown with a pale equator. Pronotum dull greyish olivaceous, with a faint trace of the

lateral stripes of the subimago : the joining of the head and prothorax and the pleura of

this last, as well as the tegulte, greenish yellow. Meso- and metanota jet-black. Abdo-

men very pale olivaceous, with pitch-brown markings, sometimes tinged with luteous or

yellow-ochre at the tips, joinings, and in the middle line of some of the hinder segments ;

the dorsal markings are a pair of curvilinear triangles, broadest at the base of the seg-

ment, and ending abruptly at its thickened hinder margin, and a pair of fine curved

longitudinal lines interposed lietween them, which are often effaced ; ventral markings,

a pair of subparallel fine longitudinal abbreviated black lines, and between them, near

the base of the segment, two shorter lines convergent forwards towards one another ;

EEV. A. E. EATON OX EECENT EPIIEMEEID.E OR MAYELIES. 61

the last segment greenish black above, olivaceous at the sides ; eighth and nintli seg-

ments often lutescent or ochraceous beneath. Wings pale greenish grey-tinted or yel-

lowish green-tinted with black neuratiou ; many of the cross veinlets away from the

terminal margin bordered with pitch-brown, their bordering forming (through con»

fluence) spots in the midst of the fore wing, and a blotch nearer the base of the wing,

and also confluent in the submarginal area near the base ; hind wings broadly grey-

tinted along the terminal m.argin. Legs olivaceous or olive-brown ; fore femur pitch-

black, tarsus brownish ; hinder tibire and tarsi more or less deeply tinged with brown-

ochre or lutescent, with the extremity of the last tarsal joint and the ungues dark.

Forceps and setfo pitch-brown or lutescent, the former with the apices; the latter at the

joinings black-tinted.

5 . Very like the S , but with the upper half of the oculi pale olivaceous, and the under

half dark sepia-brown. Pronotum jet-black. Fore femora olive-brown, the tibia and

tarsus tinged with brown-ochre or lutescent, witli the tips of the tarsal joints and the

ungues darker. Wings paler than in the d ; there is sometimes a spot in the midst of

the hind wing.

In ill-marked examples of either sex curved lines take the places of the triangular

abdominal streaks.

Length of body 14-22 ; wing, s 16-17, ? 18-24 ; setfe, 6 im. 33 & 31-32 & 36,

subim. 16 & 17-19-5 & 21 ; 2 im. 22 & 21-2G & 20, subim. 17 & 16-18 & 19.

Hab. In Europe, from Bavaria, Switzerland, and the middle of France, northwards to

Lappmark ; May, June, and part of July. Dr. Hagcn forwarded an Ephemera obtained

in Eastern Siberia, very similar to, if not identical with, E. vulgata, but having the

hinder legs much lighter in colour than the normal European insect. Some specimens

from Saxony and Posen (in M^Lach. Mus.) have the wings more strongly tinted, and

the bordering of the cross veinlets rather broader than is customary in English

examples.

Ephemera danica, Miill. Plate VIII. 12 a (wings, legs, forceps).

Ephemera clanica, Miill., Fn. Ins. Fried. 63 (1764) ; id., Zool. Dan. Prodr. 112 (1776) ; Vill., C. Linn.

Ent. iii. 18 (1789); [Ephemera, ! Ronald's Fly-fish. Ent. cd. i. pi. xiii. 28-.29 (1836);] Walk., List of

Neuropt. in Brit. Mus. 535 (1853); Hag., Ent. Ann. (1863), 15; ! Etn., Trans. Ent. Soc. Lond. (1871),

72, pi. iv. 8, 8 a [details] ; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, p. 82 (1878); Meyer-

Diir,Bull. Soc. Ent. Suisse, iv.306 (1871).— &$ maculata, Vill., C.Linn. Ent. iii. 22 (1789).— £. XvuUjata,

Scop., Ent. Carn. 263 (1763) ; Don., Nat. Hist. Brit. Ins. iv. 53, pi. cxxviii. (1795); Sara., Ent. Comp.

260, pk vii. 2 ( 1819) ; Wood, 111. Linn. Gen. Ins. ii. 21-23, pi. xlvii. (1821) ; Dumeril, Cons. Gen. s. la CI.

des Ins. 20-1, pi. xxviii. 4-5 (1823) ; Newport, Todd, Cyclop, f. Auat. & Physiol, ii. 864, fig. 345 (1839) ;

Westw., Introd. ii. fig. 61, 1 [the abdominal spots hind before] (1840) ; Blanch., Hist. Nat. des Ins. iii.

53 (1840); ! Ranib., Hist. Nat. des Ins. Nevropt. 293 (1842) ; Pict., Hist. Nat. Nevropt. ii. Ephem. 126,

pis. i.-vi. (1843-5); Blanch., Cuv. Reg. An., ed. Crochard, xiii. 91, xiv. pi. cii. 1-1 c (1818) ; Ronald's

Fly-fish. Ent. ed. v. no. 28, pi. xiii. (1856) ; Brauer, Neuropt. Austr. 25 (1857); Gerstackcr, Handb. d. Zool.

ii. 59 (1863); E. Pict., Nevropt. d'Esp. 22 (1865) ; Oulianine, Neuropt. & Orthopt. of Prov. of Moscow,

25 (1867) ; Ausser., Ann. d. Soc. Natur. Modena, An. iv. 131 (1869) ; Meyer-Diir, Bull. Soc. Ent. Suisse,

iv. 306 (1874) ; Joly, Rev. d. Sc. Nat. Montpcllier, v. pi. vi. 1 [after Pict.] (1876).— £. corjnalu, ! Steph.,

62 EEV. A. E. EATON ON EECENT EPHETHEEID.^ OE MAYFLIES.

111. Brit. Ent. vi. 56 (1835) ; Curt., Brit. Ent. xv. no. & pi. 708 (1838). E. hispanica, ! Ramb., Hist. Nat.

d. Ins. Nerropt. 294 (1842) ; Walk., List of Neuropt. Ins. in Brit. Mus. 535 (1853) ; E. Pict., Nevropt.

d'Esp. 23 (1865).

Subimago {living). — Wings at first yellowish green or greenisli grey, becoming greyer,

very narrowly edged Tvith grey-black along the extreme terminal margin, the discal

spots and, in the fore wings, most of the cross veinlets black, the rest of the neuration

concolorous with the wing-membrane, or yellowish green. Head in ? dull pale

ochreous tinged with green, the vertex somewhat lutescent, and between the ocelli

blackened or pitch-brown ; oculi deep sepia-brown. Notum at first blackened, with

lutescent markings ; the pronotum grey-black, tinged with greenish along the middle,

and with a large similarly coloured pale blotch on each side ; mesonotum lutescent, with a

mitriform blotch in front bisected longitudinally by a fine line, from whose base on each

side a curved black streak recedes inside the wing to the hind border of the segment,

gradually expanding towards its termination, where it is flanked inside by an acutely

triangular spot ; tegulae pale yellowish green ; metanotum grey -black with pale sutures.

Setae black.

Imago (Iwing). — d . Head and thorax above deep blue-black, polished ; the pro-

notum at the edges, and the joining of the head and thorax, also a fine line on each side

of the mesonotum in advance of the teguloe very pale ochraceous ; oculi deep sepia-

brown above, brown- black beneath; third joint and awn of antennae black-brown; face

and prosternum pale greenish yellow. Abdomen with the foremost four or five dorsal

segments ivory-white, with a pale cinereous broad triangular blotch at their base on

each side, pointing backwards ; the hinder segments varied with pitch-brown or very

deep brown-ochre instead of with cinereous, their markings sometimes confluent (leaving

in the middle an ivory-white triangle upon the hind margin of the segment pointing

forwards), sometimes differentiated into an abbreviated thin streak on each side of the

dorsal vessel at the base of the segment, flanked by a longer and broader tapering streak

which falls short of the hind margin of the segment and does not extend to the side.

The larger of these streaks are represented sometimes by triangular spots in some of the

more forward segments ; last segment altogether dark above. The spiracular region is

edged with an irregular dark line above, and an abbreviated line from the base below, in

every segment. Venter somewhat tinged with brown-ochre, especially in the hinder

segments, and marked in segments 2-8 or 9 with a pau' of subparallel linear brown-black

streaks, some of which are slightly connivent in front and abruptly pointed behind.

Wings faintly grey-tinted, most distinctly so towards the anterior and terminal margins

and in contiguity with their black neuration ; the spots pitch-brown, placed somewhat

as in E. vulgata, but less strongly marked. Legs pitch-black, the hinder pairs tinged

with olivaceous, and with their joinings darkened. Forceps intense sepia-brown. Setae

black.

$ very like the S , but with the dorsal markings of the pale ochraceous abdomen

better defined. Eore legs with piceous femora, and olive-grey tibiae and tarsi ; the tibiae

at both extremities, and the apices of the tarsal joints darkened ; hind legs olive-grey,

the coxa, trochanter, ungues, and tarsal joinings, the base and extreme tip of the tibia,

EEV. A. E. EATON ON EECENT EPHEJMEEID^ OE 3IATFLIES. 63

and a spot at the tijo of the femur black. Setae brownish black, darkened at the tips of

the joints. Wing-membrane colourless ; hence the narrow grey bordering of the cross

veinlets is better shown than in the d ; spots grey. Length of body, 6 16-17, ? 16-23 ;

wing, c? 16-17, S 14-22 ; setce, 6 35 & 30-41 & 36, 2 im. 14-25, subiui. 17 mm.

Sab. From Madrid {Bbr.), France, Switzerland, and Bavaria, northwards to Lapland

(Pict.). This species usually inhabits colder and swifter waters than E. vulgata, and is

the Mayfly of anglers. The $ subim. and 6 subim. are respectively designated by them

" Green Drake " and " Bastard Drake."

Ephemera lineata, Etu.

Ephemera % danica, Pict., Hist. Nat. Nevropt. ii. Eph(jm. 130, pi. vii. (1843 5) ; Ouliauine, Neuropt.

& Orthopt. of the Prov. of Moscow, 26 (1867). — ? E. % vulgata, part, Blanch., Metamorph. &c. des Ins.

127(1868) [nee p. 594, pi.]. — E. lineata, !Etn., Trans. Eut. Soc. London (1870), 1 ; id., op. eit. (1871),

71, pi. iv. 7-7 b [details] ; Hag., op. cit. (1873), 393 ; Meyer-Diii-, Bull. Soc. Ent. Suisse, iv. 306

(1874).

Stibimago (living). — Wings greenish grey, broadly tinged with light grey along the

terminal margins ; cross veinlets black, some of them in the midst of the fore wing

bordered with black-brown so as to give rise to a series of spots.

Imago (living). — d . Eyes dark sepia-brown above. Thorax pitch-brown above.

Abdomen above in the anterior segments greenish grey modified with bistre-brown, but

in the hinder segments becoming lutescent ; the segments marked with longitudinal

cm'ved or slightly sinuous black streaks tapering at the ends, the anterior segments

having each two long streaks on each side of the middle of the back, and the posterior

segments two short lines from the base between the two pairs of streaks ; venter

bilineated lengthwise with black. Forceps lutescent. Setae fuscous with black

joinings. Fore legs with the femiu- piceous, the tibia and tarsus black : hinder legs

greenish grey ; the coxa, a spot on each side of the end of the femur, the tip and the

joinings of the tarsus black. Wings vitreous, the fore wing in the marginal and sub-

marginal areas, and broadly along the terminal margin tinted with blackish grey.

? . Head yellowish ochreous, about the ocelli brown-ochreous, the eyes intermediate in

colour between bistre and sepia-brown. Pronotum greenish grey, with a black lon-

gitudinal stripe on each side ; meso- and metanotum brown-ochreous, with two dark

longitudinal streaks between the wings. Fore legs warm sepia-brown, the end of the

femm", both extremities of the tibia, and the terminations of the tarsal joints black.

Wings vitreous, the anterior tinged in the marginal and submarginal areas with

greenish grey ; longitudinal nervures greenish grey, cross veinlets black. Length of

body, d 15-20, ? 21-25 ; wing, s 16, ? 20-21 ; setae, 6 im. 30 & 35-36 ; 2 im. 24 & 26

to 25 & 24, subim. 15 mm.

Sab. England, near B;eadiug, on the Thames and Holybrook ; France, near Paris ;

Switzerland, at Genthod, near Geneva. June and July. Dr. Hagen has sent me the

two 2 specimens cited as English examples of E. glaucops in his ' British Synopsis

(1863). My conjecture in 1871 that they were in reality E. lineata was correct.

64 EEV. A. E. EATON OX EECEXT EPHEMEEID.E OE MAYFLIES.

Ephemera glaucops, Pict. Plate VIII. {cl lieadcJ).

Ephemera Xlutea, Sulz., Abgek. Gesch. d. Ins. 171, pi. xxiv. 6 (1776) ; Rom., Gen. Ins. Lin. & Fab.

Icon. Illust. pi. xxiv. 6 [after Sulz.], Explic. 23 (1789) ; Burm., Handb. d. Ent. Bd. ii. Abtli. ii. 804 (1839) ;

! Ramb., Hist. "Nat. des Ins. Xevropt. 29-i {1842).— E.c/laucops, ! Pict., Hist. Nat. Nevropt. ii. Ephem. 132,

pi. viii. 1-3 (1843-5) ; Walk., List of Nem-opt. Ins. in Brit. :Mus. 536 (1853) ; Brau., Neur. Austr. 25

(1857); Hag., Ent. Ann. (1863), 16; Karscli, Die Insectenwelt, v. 400 (1863); Meyer-Dur, Mitth.

schw. ent. Gesch. i. 221 (1864) ; Oulianine, Neuropt. & Orthopt. of the Prov. of Moscow, 26 (1867) ;

Ausser., Ann. d. Soc. Natur. Modcna, Ann. iv. 132 (1869) ; ! Etn., Trans. Ent. Soc. London (1871), 73,

pi. iv. 9 (details) ; Hag. & Etn., op. cit. (1873), 393; Meyer-Diir, BuU. Soc. Ent. Suisse^iv. 306 (1874) ;

Rostock, Jahresb. d. Yer. f. Naturk. Zwickau, 1877, 82 (1878).

Suhimago {living). — Wings very light warm sepia-grey, the cross veinlets black, edged

with darker warm sepia-grey, their edging forming spots in the usual places about the

middle and near the base of the wing, tbe terminal borders of the wings broadly margined

with light grey or warm-sepia. Eyes csesious, or extremely light verdigris or blue

verditer.

Imago {living). — 6 . Eyes above either light brownish-olivaceous or rusty yellowish,

beneath either dark brownish-olivaceous or rusty purple-madder ; face light yellowish. —

{Dried.) Thorax above polished light reddish brown, the pronotum on each side slightly

fuscescent (with a black streak tliere during life). Abdomen very light brownish ochre

above, lighter beneath and marked with black ; the dorsal markings are in segments 2-6 a

single grey or black spot or longitudinal streak on each side of the segment about mid-

way betAveen the dorsal vessel and the lateral margin, gradually lengthening in the more

hindward segments, and originating near the base of each segment, but terminating at

some distance from the hinder border ; in segments 7-9 two such curved linear streaks

placed close together on each side in a corresponding position ; in segment 10 a similarly

placed black spot on each side ; also in every segment but the last a black spot on each

side at the base upon the prominent lateral joining, followed in segments 4-5 by a

curved Line, but in segments 6-7 by a fine slightly sinuous longitudinal black line, and

in segments 8-9 a fine straight line situated a little higher up the side towards the

hinder margin ; ventral markings variable, con.sisting in Avell-marked specimens of a

single discontinuous longitudinal series of linear stripes on each side of the middle tract,

dilated a little at both ends in segments 4-7 ; but sometimes the stripes are interrupted

in every segment between these dilatations, so as to leave a streak pointing backwards

near the base, and another pointing forwards near the distal border, or (in some of the

anterior segments) only small spots instead of streaks ; and sometimes the hinder of these

streaks or spots is obsolete in every segment. Setae light rusty brown with dark-brown

joinings. Forceps partly concolorous with the abdomen, and either black or piceous at the

joinings only, or else with the basal and last two joints dark brown. Wings transparent,

with rufescent or light Mars-yeUow longitudinal nervures, and black cross veinlets, the

former in transmitted light becoming rufous-amber colour ; in the fore wing the submar-

ginal area, the pterostigmatic portion of the marginal area, the narrow edging of most of the

cross veinlets in front of the anal uervure (8), and the usual spots are very light raw-umber,

and an almost imperceptilile cloud of the same colour lies along the terminal margin ;

in the hind wing the corresponding borderiug of the terminal margin is slightly darker

EEV. A. E. EATON ON EECENT EPHEIMEEID.^ OE MAYFLIES. 65

(during life it is light sepia-grej); the base of the subcosta and the anterior extremities of

the cross veinlets anastomosing with it from behind are dark brown ; the other cross

veinlets jDOsterior to the radius (3) are bordered with light raw-umber, but their l)ordering

hardly gives rise to spots ; in certain lights the colour described as raw-umber changes in

both wmgs to light pitch-brown. Fore legs in opaque view dull obscure brownish ochreous,

or sometimes rather redder, the tarsus darker and duller, the tip of the femur, both ends

of the tibia, and the tips of the tarsal joints dull blackish ; hinder legs testaceous, or dull

light yellowish, the tarsi tinged somewhat with warm-sepia.

$ similar, but the wings more faintly marked, the pronotum light bistre-grey, the

abdomen of a very pale yellowish green-grey ground-colour, and the fore tarsus conco-

lorous with the tibia. Length of body 11-17 ; wing, s 10-15, $ 10-16 ; setee, S 15-23,

subim. 17, ? im. 11-14 mm.

Hab. Extensively distributed on the continent ; southern Sweden, Moscow, Germany,

Switzerland, N. Italy ; France, Paris district (M'Lach.), Toulouse ; Algarve, Sao Marcos

da Serra (Etn.) ; and Algeria (M^Lach.). It inhabits lakes and gentle rivers. At Geneva

and Lucerne the subimago abounds at street-lamps in favourable situations ; and spiders

lie in wait for them on the neighbouring walls in considerable numbers. Some nymphs

of this species in Dr. Joly's collection were labelled E. vulgata, and therefore it is very

possible that B. glaucops was the subject of both his and M. Vayssiere's anatomical

studies, and not the one quoted.

Ephemera compar. Hag. Plate LXIII. 12 e (forceps).

Ephemera compar, ! Hag., Ann. Rep. U. S. Geol. & Geograph. Sui'vey of the Territ. 1873, part iii.

Zool. 578 (1875).

Imago {dried), 6 . — Brown-ochreous, marked with black and rufo-piceous. Head pitch-

black, anteunse somewhat ochraceous. Pronotiun striped on each side lengthwise with

pitch-black ; the stripes lanceolate, broadest behind ; mesonotum light rufo-piceous with

a light translucent broAvn-ochreous stripe down the middle ; tegulse of a light ground-

colour, the notum marked in front of them with an abbreviated wedge-shaped pitch-black

streak on each side. Dorsal abdominal markings : — in segments 3-8, on both sides of

the disk, a pair of longitudinal subparallel black linear stripes, gently curved outwards,

and every stripe at its proximal extremity slightly enlarged on the inner side ; between

these stripes, in segs. 6-8, is interposed a single i)air of divergent black streaks from the

base, longest in the hindermost ; in seg. 9 the corresponding markings are confluent

across the back ; in seg. 2 the stripes on each side coalesce with one another and so

form two quadrangular blotches; in seg. 1 the corresponding spots are small and

indistinct ; seg. 10 is pale (of the ground-colour) with a triangular greyish cloud on each

side behind in place of the stripes ; every segment has an abbreviated black streak from

the base at the side close to the spiracular line, and segs. 5-7 have another from the tip ;

the joinings of the segments in some lights are opaque. Ventral abdominal markings :—

in segs. 2-8 a longitudinal black line on each side of the middle, slightly curved in-

wards ; in seg. 9, a quadrangular black blotch in the midst of the disk, narrowed some-

what anteriorly ; in seg. 10 a large rounded black spot on each side at the base. Setaj

SECOND SERIES, ZOOLOGY. — VOL. III. 9

66 EEV. A. E. EATON ON EECENT EPHE]\£EEID.E OE MAYFLIES.

liglit fuscescent, tlie joinings subopaque. Porceps browu-ochreous. Trochanters eacli

with a small black dot oiitside ; fore femur rufo-piceous, greyish towards the base above ;

fore tibia and tarsus piceous ; hinder femora somewhat brown-ochreous, the tibise and

tarsi lighter, the ungues fuscescent. Wings transparent, tinted with very light dull

yellowish ; fore wing with the costa, subcosta, and radius rufo-piceous, the other longi-

tudinal nervures light yellowish, the cross veinlets black ; the pterostigmatic portion of

the submarginal area, and the adjacent (outer) half of the corresponding part of the

marginal area, together with the extreme apex of the third area from the costa, burnt-

uml)er brown ; the same colour occupies the basal portion of the submarginal area to a

little beyond the great cross vein, and extends onwards from thence for some distance

along the subcosta and radius, and more or less distinctly borders the cross veinlets,

besides giving rise to the usual spotting of the wing ; the spots are small and distinct.

Hind wings with the longitudinal nervures pale yellowish excepting the subcosta towards

the base, which is fuscescent ; cross veinlets mostly black, several of tliem faintly bor-

dered with burnt-umber grey, and a few marked with minute burnt-umber brown spots ;

the outer margin broadly edged with brownish grey. Length of wing 15 mm.

Hab. l^oot Hills, Colorado (Lieut. W. L. Carpenter), in Mus. Comp. Zool. Cambridge,

Mass.

Ephemera guttulata, Pict. Plate LXIII. 12/ (forceps).

Epheme7-a ffuttulata, Pict., Hist. Nat. Nevropt. ii. Epliem. 135, pi. viii. 4 (1843-5) ; Walk., List of

Neuropt. lus. iu Brit. Mus. 536 (1853) ; ! Hag., Ann. Rep. U. S. Geol. & Geograph. Survey of the Terr.

1873, part iii. Zool. 579 (1875). — Ephemera, sp. nov., ? , ! Hag., rroc. Ent. Soc. Philad. ii. 177 (18G3). —

E. I myops, var. ? Etn., Trans. Ent. Soc. London (1871), 71 ; Hag., op. cit. (1873), 393. — E. % simulans,

! Provaneher, Nat. Canad. viii. no. ix. 265 (1876) ; id., Fn. Ent. d. Canad. ii. fasc. i. 81 (1877).

Imago (dried), 6 . — Thorax above rufo-piceous, varied with piceous, inclining towards

intense bistre-brown on the pronotum. Abdomen above, in segments 1-8, spotless

whitish Naples-yellow ; segment 9 of the same colour, excepting along tlie spiracular

border, where it is narrowly margined with raw-umber brown ; segment 10 raw-umber

brown, with a longitudinal whitish yellow stripe in the midst of each side. Venter from

the tip of segments 1-8 of the same colour as the dorsum, segment 9 ditto, with a trian-

gular spot on each side as long as the segment tinged with raw-umber brown ; segment

10 raw-umber, but the thinner portions of the perinseal lobes whitish yellow. Forceps

raw-umber, the second joint lighter. Set^e, in opaque view light Vandyke-brown, with

blackish joinings. Pore legs lost, excepting the coxae and trochanters, which resemble

the hinder. Hinder legs, in opaque view, light yellowish, with a blackish spot at the end

of the tibia, the ungues (if not the whole tarsus) light reddish brown, the trochanter light

bistre-brown, and the coxa outside in front rufo-piceous. Wings imperfectly transpa-

rent, marked in opaque view with dark bistre- or pitch-brown, changing in transmitted

light to light sepia-brown, the markings consisting of a broad, slightly mottled cloud

extending from the anal angle to the apex of the fore wing along the terminal margin,

the pterostigmatic region, broad bordering to all the cross veinlets in the rest of the fore

wing anterior to the anal nervure (8), and narrower bordering to those posterior to it, as

EEV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES. G7

well as to the proximal ends of the nervures from the terminal margin that join it as

branches, the bordering confluent irregularly in transverse bands (in lieu of the customary

spots) in addition to the median band ; in the hind wing, a broad cloud tapering behind

runs backwards along the terminal margin from the distal portion of the costal margin,

the edging of the cross veinlets in the submarginal area is confluent near the subcosta

towards the base of the wing, but tapers rapidly towards the radius (3) beyond the limits

of the confluence, a narrow irregular blotch extends from about the proximal extremity

of the cubitus (4) to about the second series of the cross veinlets included within its

fork (doubtless an instable character), and the edging of the cross veinlets in the

remaining parts of the disk constitutes numerous small sjjots. Neuration piceous, but

lighter in a large portion of the hind wings and in part of the axillary region of the fore

wings.

? very similar to the d , the thorax rather lighter ; the 9th abdominal segment as

well as the foregoing segments Naples-yellow, the 10th light brownish. Setae light raw-

umber grey with black joinings. Tore femur intense Vandyke-brown or piceous, blackish

lengthwise through the middle ; tibia and tarsus light olive-brown, the extremities of the

former, and the first joint together with the distal extremities of the intermediate joints

of the latter, blackish brown, the terminal joints and ungues reddish brown ; hinder legs

nearly as in the d . Wings more transparent than in the d , the clouds along the ter-

minal margins obsolescent and greatly restricted ; the usual median fascia of the fore

wing is broad and very distinct, but the edging of the cross veinlets elsewhere does not

coalesce into blotches, excepting to a very limited extent in the places of the usual spots ;

the branches of the anal nervure (8) arc marked each with a round spot close to their

anterior extremities. In the hind wing the spot at the end of the cubitus (4) is separate

from that at the fork ; but otherwise the wing is very like the d hind wing. Length of

body, cj 13, ? 18-5 ; wing, d 13'5, ? 19 ; setae, d about 30 mm.

Mab. New York (Osten Sacken), 9th June ; Quebec (Provancher), in Mus. Comp. Zool.

Cambridge, Mass.

Ephemera simtjlans, Walk. Plate LXIII. 12 (/ (forceps).

Ephemera shnulans, ! Walk., List of Neuropt. lus. in Brit. Mus. part iii. 536 (1853); Hag., Smithson.

Miscell. Coll. (1861), Synop. Neuropt. N. Am. 38.— £. decora, ! Walk., List supra cit. part iii. 537 (1853) ;

Walsh, Proc. Acad. Nat. Sc. Philad. (1862), 376; id., Proe. Eut. Soc. Philad. ii. 177 {\^Q,^).—E.natata,

! Hag., Smithson. Miscell. Coll. supra cit. 39 [after Walker] ; id., Proc. Ent. Soc. Philad. ii. 177 (1863) ; id..

Trans. Ent. Soc. London (1873) , 393 ; ! id., Ann. Rep. U.S. Geol. and Geograph. Survey of the Terr. 1873,

part iii. Zool. 580 (1875) .—E. % ijuttulatu, ! Etu., Trans. Ent. Soc. London (1871), 69, pi. iv. %-(^h [details] .

X Palingenia natuta, ! Walk., List sujjra cit. part iii. 551 (1853).

Snhimago {dried).— Wm^s translucent, dull light sepia-grey, the wing-roots and lon-

gitudinal nervures in opaque light bistre-brown, the disk and black cross veinlets marked

as in the imago. Setae pitch- or intense raw-vimber brown, with opaque joinings. Tibiae

lighter than the femora and tarsi ; fore femur pitch-brown, hinder femora dark bistre-

brown : tarsi sometimes blackish, sometimes Vandyke-brown.

Imago {dried), d .—Thorax above deep rufo-piceous, the pronotum in some positions

9*

68 EEV. A. E. EATON ON EECENT EPHEIMEEID^ OE MATELIES.

marked on eaeli side with a rather darker longitudinal stripe : in the living insect the

pronotum doubtless is translucent light sepia-brown with a pitch-black stripe on each

side. Abdomen discoloured when dry, dark pitch-brown with blackish markings : in

specimens preserved in spirits it is light translucent bistre with opaque intense bistre-

brown (? pitch-black in life) markings, viz. — a blotch of irregular form on each side of

segments 1-9 reaching from the base of the segment nearly to the edge of the terminal

border (resembling a quadrangular figure emarginate at the sides and summit, composed

of a pair of subtriangular longitudinal streaks, curved slightly in opposite directions,

standing apart back to back and united to each other by a broad band in the greater

part of their length anteriorly), constituting a single series of blotches on each side of the

back ; also in segments 7-9, between the blotches and adjacent to the dorsal vessel, a

narrow longitudinal streak on each side from the base of the segment ; also in segments

1-8, on each side of the venter, a single series of discontinuous longitudinal subliuear

stripes, some of them dilated a little at the tips. Setae medium raw-umber brown with

piceous joinings. Fore legs dark raw-umber or dark bistre-brown, the tarsus more

translucent, the knees, end of tibia, first tarsal joint and ungues more opaque. Hinder

legs, with the femur light bistre-brown, coxa and trochanter varied with pitch-brown, the

tibia and tarsus lighter than the femur and perhaps rather yellower, the ungues rufo-

piceous or dark burnt-umber-brown, and sometimes the terminal borders of the tarsal

joints of this colour, the whole leg from the femur onwards changing in transmitted light

to brownish or greyish aml^er : sometimes a depression outside the femur close to the

extremity, and also the tip of the tibia is dark. Wings transparent, tinged at the wing-

roots with intense bistre-brown, and marked elsewhere with ivory-black in opaque view,

or with intense sepia in transmitted light ; the hind wings usually bordered rather l)roadly

along the terminal margin with a faint tint of light greyish : neuration uniformly piceous.

The markings of the wings present considerable diversity in the size of the spots and the

edging of the cross veinlets. In strongly marked examples nearly every cross yeinlet in

the disk of the fore wing (excepting those near the terminal margin) situated between

the costa and the anal nervure (8) is dark-bordered, the bordering of many being

dilated and generally somewhat guttulate in certain areas, especially in the marginal

and submarginal areas, in the distal part of the next area, and occasionally in the two

areas adjacent to the first accessory nervure after the pobrachial (7). In addition to the

customary fascia extending from the costa to the fork of the pra?brachial (6), spots of

irregular shape are apt to be formed at the proximal terminations of many of the inter-

polated nervures, or near them, viz. — Three spots within the space bounded by the

sector (3) and the cubitus (5), two of them beyond the fascia, and one in the axil of the

main nervures ; also three spots in the interspace between the pobrachial (7) and the

anal (8) nervures, one of them at the termination of the foremost of the long interpolated

nervures, another at the head of the much shorter nervure in front of that, confluent

sometimes with the fascia, but often only extended forwards to the hinder branch of the

praibrachial (6^), and a third sj)ot at the head of the other short nervures interposed

between the two long interpolated nervures. In the hind wing the dark bordering of

EEV. A. E. EATON ON RECENT EPHEJIERID^ OE MAYFLIES. 69

the cross veinlets is generally narroAV, but in the midst of the wing the edging of about

half a dozen veinlets or more is enlarged into small spots.

Variation. — In the fore wing the fascia is virtually resolved into its comj)onent spots,

the other spots are reduced in size, the bordering of the cross veinlets is much restricted

and scarcely any^vhere guttulate ; in the hind wing the terminal margin is not bordered

with the faint greyish cloud, the spots are rudimentary or reduced to two or three in the

midst of the disk, and many of the cross veinlets are not dark bordered.

? {dried and in spirits). — Very similar to the 6 , but with the latero-dorsal blotches

more nearly resolved into a pair of separate triangular streaks on each side of segments

3-6, the blending of those in the other segments corresponding with what is usual in

the other sex. The wings are rather clearer than is customary in the s , especially in

the pterostigmatic region, and the edging of the cross veinlets is rather less distinct.

Fore legs light rufo-piceous with the femur and tip of the tibia darker ; the tarsal joints

lighter towards their bases. Hinder legs as in the c? , but the tibia and tarsus slightly

redder than the femur than yellower. Setse light burnt-timber brown, with pitch-brown

joinings.

Variation (probably killed before attaining maturity of colouring). — Thorax brown-

ochreous : fore femur light bistre-brown, the tibia and tarsus rather lighter, but with the

ungues, the tips of the intermediate and first tarsal joints and also of the tibia dark

burnt-umber brown. Hinder legs in opaque view with the femur light greenish bistre-

grey, and the rest lighter, changing in transmitted light to greenish amber and light

yellow amber. Abdominal markings as in the c? .

Variation. — Colour of legs, thorax, and wings, normal ; but differing in the dorsal

markings of the abdomen. In segments 3-6 only the upper triangular streak of every

latero-dorsal blotch is present on each side, the lower is absent (perhaps owing to the

ravages of Anthremts): a short linear black streak is produced forwards along the

spiracular margin from the posterior lateral angle of the dorsum of each of these

segments. This is the variation simulating E. vulgata mentioned by Hagen. Length

of body, 6 11-13, ? 13-15 ; wing, 6 12-11, ? 15-19 ; sette, 6 im. 25-32, submi. 14,

? im. 16, subim. 15 mm.

Rab. North America, from Akhurst, Virginia, to St. Martin's Falls, river Albany,

Hudson's Bay, and from West Beach, Maine, to Saskatchewan. This species swarms

yearly at Chicago, 111., at street lamps, about the third week in July. A tube fuU of

specimens collected at an island in Lake Erie, near the mouth of Detroit river, by Mr.

Scudder, is dated 21th July.

Ephemeha varia (renamed). Plate LXIII. 12 h (forceps).

Ephemera % decora, ! Hag., Smithson. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 38 ; idem, ! Ann.

Rep. U. S. Geol. and Geograph. Survey of the Territ. 1873, part iii. Zool. 578 (1875).

Suhimago {dried), <5 .—Wings translucent, very light grey or whitish grey, the sub-

marginal area of the fore wing before the pterostigmatic space shghtly yellowish : neura-

tion partly Light and partly dark, the longitudinal nervures of the fore wing to a great

70 EEV. A. E. EATON ON EECENT EPHEMEEiD^ OE MATELIES.

extent in the disk, and the whole of the ueuration in the vicinage of the terminal and

inner margins, light yellowish, hut the suhcosta and parts of the other nervures adjacent

to spots, as well as the cross veinlets in the disk are black ; these cross veinlets also are

bordered with black-grey, and the bordering is enlarged here and there into spots as in

the imago. Neuration of the hind wing mainly light yellowish, but a few cross veinlets

in the basal f of the disk are blackish, though not bordered.

Imago {dried), s . — Thorax above light reddish brown, approaching brown-ochreous,

with a longitudinal pitch-brown stripe on each side of the pronotum. Aljdomen above

largely suffused with violet-grey, leaving at the sides of the segments a narrowly

limited space of a light yellowish colour ; the usual dorsal streaks are situated within

the violet-grey spaces ; their pattern, best seen in segments 6-9, comprises, — a pair of

longitudinal linear streaks, one on each side of the dorsal vessel, approximated to each

other at the base and blended together posteriorly ; also a large triangular spot as long

as the segment on each side, close to the streak and tapering distally, from whose

hypotenuse in segments 5-7 a curved streak is prolonged obliquely backwards and

downwards ; in addition, the spiracular border of the dorsum in segments 8-9 is

narrowly blackish throughout, but in the preceding segments it is blackish only for a

short distance from the anterior angle apart from the terminations of the curved streaks

described above. Venter very light translucent yellowish, shading into light yeUow-

ochraceous in the hinder segments and brown-ochre at the base of the forceps, marked

lengthwise with three interrupted narrow pitch-black streaks, — one along the ganglionic

track, and another on each side of it almost exactly intermediate between that and the

spiracular border, posteriorly dilated in segment 9. Setse light bistre-, or raw-umber

grey with pitch-black joinings. In opaque view, the fore coxa and trochanter are light

yellowish, the femur light bistre-brown, the tibia and tarsus much lighter, but with both

extremities of the tibia, the first tarsal joint, the base of the second and the extremities

of the other joints as well as the ungues pitch-black ; the hinder femora are very light-

yellowish, the tibiae and tarsi yellowish white, and the ungues light brownish ; in trans-

mitted light the fore legs are rich brownish-yellow amber, marked with pitch-brown

in the places enumerated above, and the hind legs have the femur very liglit yellow

amber, the tibia and tarsus whitish. Wings transparent ; the hiud wings, and the fore

wings in the immediate vicinage of the inner margin colourless, these anteriorly becoming

gradually tinted more and more with light raw-umber, this tint attaining its greatest

depth in the pterostigmatic portion of the marginal area and the whole of the sub-

marginal area. Longitudinal nervures and the great cross vein from the costa to the

subcosta, in opaque view, light raw-umber or light bistre-brown, changing with light trans-

mitted to brownish-yellow amber, or golden brown ; cross veinlets, great cross vein from

the subcosta to the radius, and the anterior curves of the branches of the anal (8) nervure

of the fore wing black, the veinlets in general edged more or less faintly and narrowly

with greyish or with dark bistre-brown, many of those in the disk anterior to the anal

nervure having the edging dilated roundly, and others (more broadly margined) esta-

blishing through the confluence of their bordering a dark bistre-brown band and spots in

the usual situations, viz. : — a transverse curved or angulated stripe from the costa to the

EEV. A. E. EATON ON EECENT EPHEMERID.i; OR MAYFLIES. 71

fork of the prfebrachial (6) nervure ; a spot more distant from tlie wing-roots, beyond the

termination of the stripe, ontside that fork ; and a spot nearer the wing-roots, placed at

the proximal extremities of the accessory nervures interjacent between the pobrachial(7)

and anal (8) nervnres.

S {dried). — Meso- and metanotum light brown-ochreous ; pronotum lighter, marked

on each side with a broad longitudinal pitch-black stripe, which is preceded by a quadran-

gular spot on the cervical membrane, and is narrowly incurreut along the hinder edge of

the segment ; below the peak of the metanotum the prominent border is dark. Abdominal

markings seemingly similar to those of the <s , bu.t largely effaced by Psocidse in the

specimens examined. Seta? greenish grey, with pitch-black joinings. Fore coxa and

trochanter light yellow-ochreous ; femur and tibia very light l)istre- or raw-umber grey,

blackened distally ; tarsus nearly coucolorous with the tibia, but duller ; a small triangular

spot at the outer extremity of the coxa, both ends of the tibia, the first tarsal joint and

the extreme base of the second, pitch-black ; the apical borders of the other intermediate

joints, the terminal joint and the ungues, light burnt-umber brown. Hinder legs

coloured as in the d . Wings transparent, colourless generally, but in the submarginal

area of the fore wing tinged very faintly with greenish yellow ; the spots, less blended

than in the 6 , are greyish black, and the lighter edging of tlie cross veinlets is more

restricted; wing-roots and near ends of longitudinal nervvu-es light yellowish ; the costa,

subcosta, and radius external to the great cross vein of the fore Aving light brownish- or

greenish grey, changing in transmitted light to amber-brown ; cross veinlets, and the

great cross vein from the subcosta to the radius of the fore wing, black ; neuration of

hind wings uniformly light yellowish, membrane colourless. Length of body, d 11,

? 15 ; wing, 6 12, 2 li ; sette, d 25-27 mm.

Hob. New England; Norway, Maine; New Haven, Conn. (Mvis. Comp. ZooL, Cam-

bridge, Mass.).

Ephemera flaveola, Walsh.

Epheme7-a flaveola,Walsh, Proc. Acad. Nat. Sc. Pbilad. (18G2), 377; Hag., Proc. Eut. Soc. Philad, ii.

178 (1863) ; Etn., Trans. Ent. Soc. London (1871), 70.

Snhlmago. — Wings subopaque, the membrane slightly dusky, and, in a single 6 , with

slightly dusky neuration. Seta3 dull pale greenish.

Imayo, d . — Head ferruginous above, the orbits of the ocelli and basal joints of the

antennte a little dusky. Thorax pale ferruginous. Abdomen yellowish, joints 3-7

with a lateral pale fuscous vitta interrupted at the sutures ; setae whitish with fuscous

joinings. Legs yellowish ; the terminal half of the fore femur ferruginous, the fore

tibia and first tarsal joint, the other joints at the joinings and the last joint at the tip,

fuscous ; the tips of the hinder tarsi fuscous. Wings hyaline, the fore wing slightly

yellowish along the costa, the neuration colourless, excepting the costa, subcosta, radius,

and great cross vein, which are yellowish.

$ similar to the d , but having the abdomen egg-yellow in the parts full of eggs,

and having fuscous cross veinlets in the wings, excepting in the tips and along the

terminal borders. Length of body, <^ 7-5-9-5, 2 9-10-5; exp. of wing, d 17-19, ? 19-

72 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYELIES.

20; sete, d im. 20 & 14, subim. 9-12, ? im. 12 & 10, subim. 12 mm. (after

Walsh).

Sab. Rock Island, 111. (Walsh). A fragment of a ? subim. apparently of this species

is in Mr. M°Lachlan's collection.

Ephemera myops, Walsh.

Ephema-a myops, Wahh, Proc. Eat. Soc. Philad. ii. 207, note 20 (1863); Etn., Trans. Ent. Soc.

Loudon (1871), 71.

This species was described by Mr. Walsh from two d examples, one of them reared

from the subimago, which differed in colour from one another. The description is

diagnostic only. Eyes smaller and wider apart than in U. flaveola ; abdomen either

yellowish throughout, or in segments 1-5 ferruginous, in segment 6 and segment 9 paler,

and in segments 7 and 8 yellowish. Length of body 12-13 ; exp. of wings 26-27 ;

setffi 27 & 19-29 & 21 mm.

Hal). Eock Island, 111. (Walsh).

Ephemera immaculata, Etn.

Ephemera immaculata, ! Etn., Trans. Ent. Soc. London (1871), 74. pi. iv. 10 [detail].

Imago {dried), 6 . — Thorax brunneo-luteous above. Abdomen fuscous, the tips of the

segments and the spiracular lines darker. Setie light bistre-brown. Wings spotless,

vitreous; the fore wing in the submarginal area, and the hind wing at the terminal

margin tinged with sepia-grey ; neuration dark. Fore legs piceous, the bases of the

femora lighter ; hinder legs brunneo-testaceous. Length of body, 6 , 10*5, wing 11 mm.

Hab. Cuna, Hindostan (Hope Mus., Oxford).

Ephemera expectans. Walk.

XPotamanthus expectans, ! Walk., Trans. Ent. Soc. London, N. S. v. 198 (1860).

Ephemera expectans, ! Etn., Trans. Ent. Soc. Loudon (1871), 74.

Subimago {dried). — Fore wings very pale raw-sienna, with dull light brown-ochreous

longitudinal neuration, and intense violet-carmine (approaching black-purple) cross

veinlets ; hind wings rather greyer, with black-purple cross veinlets. Setse raw-umber

grey, with pitch-black joinings. Thorax brown-ochreous above, with a broad pitch-

brown stripe on each side of the pronotum, followed by a line on each side of the

mesonotum, extending to the area above the wing-roots. Abdomen (discoloured) dark

orange-brown, with four slender longitudinal black lines in segments 2-8, and two lines

alono- the venter. Fore legs dark brown-ochreous, the termination of the tibia pitch-

black, the distal edges of the nearer tarsal joints and the whole of the terminal joint

and ungues pitch-brown ; hinder legs lighter, with the broader ungues pitch-brown.

Length of body, ? 11, wing 14 mm.

Hab. Hindostan (Walker, in Brit. Mus.).

Ephemera supposita (renamed). Plate VIII. 12 c (forceps).

X Potamanthiisfusciatus, ! Hag., VerL. zool.-bot. Gesells. Wien, viii. 476 (1858) [part].

Eijhemera fasciata, ! Etn., Trans. Ent. Soc. London (1871), 74, i^l. iv. 11, 11 a [details] ; idem, op. cii.

(1873), 393.

EEV. A. E. EATOX OX EECENT EPHEMERID.E OE MAYFLIES. 73

Siiblmago [dried), $ . — Wings fawn-colour, the stronger of tlie longitudinal nervures

yellowish, the cross veiulcts of the fore wings black; the submarginal area of the fore

wings is tinged with yellowish, and some of the cross veinlets in the marginal area are

edged Avith darker towards the sul)costa.

Imago {dried). — Thorax testaceous above. Abdomen eroded by Psocidaj, but it

appears to have been light bistre-brown on the dorsum, with two darker streaks

projecting forwards on each side from the darker hinder borders of segments 1-9,

subparallel with each other in segments 9-7, but curved sliglitly away from each other

towards their anterior exCi'emities in the other segments ; also in at least segments 9-7

the dorsal vessel appears as a black line ; on the venter are visible traces of the usual

two longitudinal series of discontinuous linear black stripes. Setee medium Mars-yellow,

with many of the joinings reddisli brown. Forceps dull yellowish, with the terminal

two joints black. Wings transparent, slightly tinted with greyish, with reddish brown

longitudinal nervures and piceous cross veinlets ; tlie fore wing in the submarginal

area, and the ptcrostigmatic portion of the marginal area, tinged witli madder-brown,

and having small spots of a similar colour in the usual places in the midst of the wing —

one at the fork of the prasbrachial nervure (6), one close to it on the cubitus (.5), another

on the first sector (1), and a dot more distant from the wing-roots than these on the

pobrachial nervure (7) ; hind wings similar in the colours of their neuration, but spot-

less, and rather faintly clouded very narrowly with reddish grey along the terminal

margin. Fore tibia madder-brown, the tarsus rather obscurer, the femur somewhat

rufescent; hinder legs light yellow-amber, the tarsus more opaque with red-brown

ungues. Length of body, d , 13, wing 11, sette about 21 & 23 mm.

Sab. Ceylon (Hag. & M'Lacb. Mus.). The ? im. from Masuri, northern India,

mentioned by mo in 1S71, is very similar in the pattern of its markings, but perhaps is

another species.

Ephemera seuica, Etn.

Ephemera serica, !Etii., Traus. Ent. Soc. London (1871), 7.j, pi. iv. 13, 12a [details].

Subimago [dried), $ .—Wings very light yellowish grey, with dull light yellowish

neuration ; in the fore wing most of the cross veinlets between the costa and the sector,

and many of those posterior to this last nervure in the proximal third of the disk of the

wino" are black, a few are also bordered with black, and in the area posterior to the

submarginal area 3-5 cross veinlets beyond the bulla are marked each in the middle wjth

a round black spot.

Imago [dried), s . — Head light brown-ochreous, reddish brown in the vicinage of the

ocelli. Thorax brown-ochreous, with an elongated black spot on each side of the

pronotum. Abdomen pale yellow-ochreous, marked with black lines, shown best in the

$ examples. Seta) ochraceous, the two outer annulated irregularly with black. AA'iugs

vitreous, the fore wing with the neuration in a larger measm-e golden brown, but with

the cross veinlets in advance of the sector, and those behind it in the basal ^ of the disk

pitch-black, some of them spotted with warm-sepia-brown in correspondence with the

markings of the subimago ; hind wings spotless. Fore femur deep raw-umber brown,

SECOND SERIES. — ZOOLOGY, VOL. III. 10

74 EEV. A. E. EATON ON EECENT EPHEMEEIDvE OE MAYFLIES.

pitch-black at the kuec ; fore tibia and tarsus light brown-ochre, the femur pitch-black

at both extremities ; fore coxa and hinder legs very light yellow-ochraceous, all with a

black spot on the coxa.

$ (dried). — Very like the male; the pronotal spots smaller, the wing-spots very

indistinct, almost effaced. Abdomen above in segments 3-9 marked with a pair of sub-

parallel line black lines along the middle of the back, interrupted only at the overlapping

apical borders of the segments, also with an abbreviated black line on each side along

the spiracular border from the posterior angle of the dorsum extending to half the length

of the segment, and perhaps with the hinder border of the dorsum black in the middle ;

venter in segments 3-7 marked along the middle with tAvo slightly sinuous black lines,

and with a greatly abbreviated longitudinal black line from the base on each side at the

spiracular border. Legs very light yellow-ochraceous ; the fore femur slightly darker ;

its tip, both extremities of the fore tibia, and the proximal joint of the fore tarsus pitch-

black ; the flat claw blackish in every tarsus. Length of body, d 11, ? 14 ; wing, d 13,

? 18 ; seta?, $ subim. 17 mm.

Ilab. China, Hongkong (Brit. Mus.). The subimago in the Museum has no spots

on the pronotum.

Ephemeka oeientalis, M°Lach.

Ephemera orientalis, ! M'^Lach., Trans. Eut. Soc. Loudon (1875), 168.

Imago [dried; after M'Laclilan), <s . — Body pale greyish yellow, with a black longi-

tudinal streak on each side of the mesonotum, and some blackish markings on the

abdomen, viz. — with the posterior borders of the dorsal segments narrowly blackish, also,

in segments 4-8, with a black line from the base of each segment extending some

distance along the covu'sc of the dorsal vessel and flanked on each side of the dorsum

with a pair of slightly curved black linear streaks ; venter marked in the intermediate

segments with a longitudinal straight black lino on each side. Setae at the base

universally yellowish, afterwards narrowly blackish at the joinings. Eorceps rather

short, their last two joints short. Legs pale yellow ; the tibiae and tarsi of the fore legs

fuscous. Wings vitreous, with a faint yellowish tint, the hinder spotless, and along the

terminal margin rather broadly bordered with pale greyish ; neuration blackish, the

cross veinlets of the marginal area incrassate and deep black, the bullae black, and the

cross veinlets adjacent to that of the subcosta distinctly bordered with black. Length

of wing 15 mm.

Ilab. Japan ; Von Siebold (Leyden Mus.).

Ephemera japonica, M'Lach.

Ephemera japonica, ! M^'Lacli., Trans. Eut. Soc. Londou (1875), 1G9.

Suhimago {dried), S .—Wings transparent light greenish grey, spotless in one example,

the submarginal area of the fore wing clear yellowish green, the terminal margin of the

hind wing narrowly edged with greyish, that of the fore wing hardly perceptibly so ;

nei;ration mostly pitch-black, but just at the wing-roots brown-ochreous. Setae deep

sepia-brown at the base, becoming lighter distally, the joinings not conspicuously darker.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 75

Imago (dried), 6 . — Head above very light Mars-yellow oclireous, in 2 pitcli-brown.

Pronotum light raw-umber brown, with a linear pitch-brown longitudinal stripe on each

side ; the remainder of the notum in d slightly yellower, in ? brown-ochreous, varied in

the metanotum with light yellow-ochre. Abdomen above in d , and after oviposition in

$ , very pale translucent raw -umber, the hinder segments (7- or 8-9 or 8-10) light ycUow-

ochraceous, the tenth sometimes very light broAvn-ochre ; segments 2-9, each with a pair

of warm sepia-brown dorsal stripes, divergent and gradually tapering froin behind

forwards, descending obliquely one on each side from the hinder border to the spiracular

border close to the l)ase of the segment, and approximated to one another at the

hinder border more closely in the more forward than in the hinder segments ; these

stripes in segments 'i-8 are connected each with the other by an extension of the

saiue colouring along the intervening portion of the hind margin ; and the bands thus

connecting them together are intersected in the d , l)ut not in the S , by a tine longitudinal

black line along the dorsal vessel in segments G- or 7-0 ; this line in the ? does not

attain the hinder borders of the segments. Venter rather lighter than the dorsum in

segments 1-7, and thence posteriorly becoming bright l)rown-ochreous ; a fine pitch-

black streak on each side of segments 7-2, subcontinuous with the dorsal stripe of

the following segment, runs from the hinder angle of the segment obliquely inwards to

the anterior margin, subparallel with the immediately superjacent dorsal stripe ; viewed

laterally, the ventral streak of one segment in combination with the dorsal stripe of the

following segment appears slightly sinuous ; in segment 8 of the d the corresponding

ventral streaks taper at both ends, and do not reach the hinder lateral angles ; those in

the same segment of the ? meet one another close to the opening of the oviducts ; in

segment 9 they are subparallel with one another, almost perpendicular to the hinder

border of the segment, linear in the 2 , l)ut in the d broader, deep burnt-umber brown,

and sometimes ill-defined posteriorly. Setse deep warm sepia-brown, the joinings pitch-

black. Forceps light brown-ochreous, darker distallj^. Eore femur (as an opaque

object) light reddish brown, or (in transmitted light) bistre-amber colour, the tibiai

pitch-brown, the tarsus rather lighter ; hinder legs extremely liglit yellowisli ochre with

brownish ungnes ; the femora in transmitted light very pale yellow amber-colour. Things

vitreous, faintly tinted with light greenish yellow ; submarginal area of the fore wing

more strongly so tinted ; terminal margin of the fore wing very narrowly and faintly,

that of the hind wing more distinctly and to a moderate deptli, bordered with warm sepia-

grey ; neuration pitch-brown, the subcosta, or subcosta and radius, of the fore wing pitch-

black, the nervures becoming lighter towards the wing-roots, the bulla of the suljcosta

and that of the first sector, together with a minute spot, nearly in a line with them, on the

cubitus of the fore wing slightly greyish. Length of body, 2 , Il-IG, wing 18-19,

setse, ? im. 25-5, subim. 16 mm.

Eab. Yokohama (Pryer, M^Lach. Mus.).

PENTAGENIA, Walsh, 1863.

Illustrations. Adult. PL VIII. 13 (details).

Adult.— Yionoium in 2 transverse, enlarged posteriorly, subtumescent above, broader

76 EEV. A. E. EATON ON EECENT EPHEMEEID.i: OE MAYFLIES.

and higher than the head behind, but narrowed and sloping downwards anteriorly ; its

lateral borders, posteriorly, suddenly everted to a slight extent so as to originate a

strongly defined sinus or rounded depression on each side of the back ; its hind margin

curved ; in d the pronotum appears to be more appressed to the mesouotum, so that in

front view the hind margin seems almost retuse in the middle. Fore lep- of <3 about

half as long as the body, the tibia about 1| as long as the femur, the tarsus scarcely as

long as the femur ; 2 fore femur little shorter than the tibia, the tarsus scarcely f as

long as the tibia. Median setae in d extremely rudimentary, in $ not much shorter

than the others ; outer setse in d about 2^ as long as the body, in ? im. and d subim.

subequal in length with it; under a lens their surface appears minutely pubescent

throughout, and their joinings are inconspicuous. Last two joints of forceps-limbs

rather small. Lobes of penis nearly straight, subtubular, and somewhat tapering

distally ; the orifice of the seminal duct terminal ; no apparent stimuli. Abdominal

segments of $ : — 1 short and thoracoid, 2-6 gradually and successively longer, 7-9 nearly

equal to one another, but 8 perhaps a little the longest, and 9 a little longer than 7,

which is only a little longer than 6 ; segments 6-10 together constitute ^ of the abdo-

men. Anterior ocellus rather smaller than the others. Eyes of d nearly approximated

if not mutually contiguous above.

Nymph unknown.

Type. P. vittigera, Walsh.

Distribution. Illinois and Texas.

Etymology, vhre and 7ei'ea', from its being the fifth of the sections of Falingenia

anctomm, defined by Hagen in 1863, and named by Walsh in that year.

Pentagenia vittigera, Walsh. Plate VIII. 13 (wings, legs, d & ? , forceps).

Palmgenia vittigera, ! Walsh, Proc. Acad. Nat. Sc. Philad. (18G2), 373 ; Hag., Proc. Eut. Soc. Pbilad.

ii. 174 (1863).

Pentagenia [type] vittigera, ! Walsh, op. cit. ii. 197 (18G3) ; ! Etn., Eut. Mo. Mag. v. 85 (1868) ; ! id..

Trans. Eut. Soc. London (1871), 63, pis. i. 6 and iv. 1 [details].

Subimago. — " Wings dull opaque yellowish" (Walsh).

Imago. — Eyes of the living d {teste Walsh) yellowish above, their lower \ fer-

ruginous. (Dried) d . — Body traversed from head to tail along the middle of the back by

a deep warm sepia stripe, containing in segments 1-9 of the abdomen the usual pair of

short divergent yellowish lines at the base of every segment ; sides and under parts of

the body chiefly light yellowish ochreous or Xaples-yellow, but segments 8-10 of the

abdomen are of a brighter yellow beneath, and on each side of the mesothorax a warm

sepia stripe descends from the roots of the fore wing obliquely. Legs, viewed opaquely,

very light yelloAvish ochraceovis, but in transmitted light of a yellowish amber-colour ;

fore tibia light brown-ochreous, the tarsus rather darker, the end of the tibia and the

extremity of the broader of the tarsal ungues warm sepia or burnt-umber brown ; hinder

tarsi with the ungues and the tips of the terminal joints tinged with bistre-brown. Wing-

neuration translucent, mostly colourless ; in the fore wing the great cross vein between

the subcosta and the radius, and a short linear spot at the bulla; of the subcosta and the

KEV. A. E. EATOIS ON KECENT EPHEMEEID.E OK MAYFLIES. 77

sector are pitch-black; but the costa, subcosta, and radius, tog'ether with the cross

veiulets of the marginal and submarginal areas, are in opaque view bistre-grey, and

in transmitted light pale golden brown, or brownish amber-colour. Set* dull light

yellowish white.

? (dried) very similar. The wings towards the base, especially in the marginal area

of the fore wing, tinted with lurid.

Length of body, d 17-19, 2 17-20; wing 18-19; sette, d 40-50 & 5, subim. 18 &

4-5, ? 13 & 10-5-20 & 15 mm.

Sab. Near Hock Island, Illinois, and in Texas (Walsh & M'Lach. Mus.). The part of

the dorsal stripe in each segment of the abdomen is quadrangular, nearly straight at the

sides, and only a little broader in front than behind.

Pentagenia quadri-punctata, Walsh.

Pentagenia quadripunctata, Walsh, Proc. Ent. Soc. Philad. ii. 198 (1863); Etn., Traus. Ent. Soc.

Loudou (1871), 64.

This species is diagnosed by Walsh as differing from F. mttigera in the following

details. The part of the dorsal stripe in each segment of the abdomen is angulated at

the sides and hexagonal in form. In the fore wing a series of four distinct fuscous dots,

surrounded each by a slight cloud, is extended transversely in a slight curve from the

middle of the costa to the midst of the wing (the dots presumably corresponding with

buUte), marking the subcosta and the 4th, 6th, and 9tli longitudinal nervures from the

costa. Wings of subimago opaque whitish. Length of body, j 19, $ 19-5-22; wing,

cf 15 ; $ 18-19-5 ; seta?, 2 im. 22-5 & 19*5, subim. 17 & 14, 6 subim. 15 & 3 mm.

Rab. Hock Island, Illinois.

Part II. Read February 7th, 1884.

Group II. of tue Genera.

Adult. — At the fore-wing roots the anal nervurc (8) communicates with the pobrachial

(7) only by means of an obsolete channel of circulation permeating the membrane in

proximity to the prominent curved or angulated fold that meets the basis of the radius

(3) [excepting perhaps in Tricorythus and Cceiiis (PL XV. 25 and 26). N.B. In PL IX.

the figure of part of the wing of RhoenantJms, 15, is defective thereabouts]. Legs all

functional ; hinder tarsi with 4 distinct joints, and sometimes with colour-indications of

a fifth joint intimately concrete with the tibia {i.e. not definitely limited by suture) ;

ungues rather small. Contour of 6 oculi various in different sections. Nijmjoh. — Palpi

of both pairs of maxillte 3-jointed. [Exceptions : palpus of maxilla I. 4-jointed in Fros-

opistoma, 2-jointedin Callibaiis ; palpus of maxUla II. with joint 3 ill defined in Baeiis.']

First Series of Group II.

Adult. — The anal (8) and bifid 2nd axillary nervures, together with the inner margin

of the fore wing, enclose a semisagittate space ; the 1st axillary nervure (9') conniveut

second series. — ZOOLOGY, VOL. III. 11

78 EEV. A. E. EATON ON EECENT EPHEMEEIDiE OE MAYFLIES.

with the anal at the roots, and running nearly alongside of it for some distance, presently

recedes from it in a bold curve to the middle of the inner margin. Hind wings well

developed, broad ; the costal shoulder sharply defined, almost right-angled, and situated

at about the first ^ of the front margin ; the subcosta (2) elbowed correspondingly, and

approximated to the costa soon after the flexure. Thoracic spiracles str.iight-lipped,

usually closed in dried specimens. Forceps-limbs inserted at the sides of the terminal

border of a transverse laminar lobe prolonged from the segment, which lobe is repre-

sented in the ? . Eyes of d evenly contoured ; anterior ocellus rather smaller than the

others. Subimago quiescent many hours.

Section 4 of the Genera. — Type of Fotamanthus. Adult. — Proximal joints of 6

forceps-limbs many times longer than the remainder combined. Nymph. — Wings free

along their terminal margins. Palpus of maxilla I. longer than the lacinia. Lobes of

the labium smaller than the lacinise of maxilla3 II. Abdominal segments 2-7 branchiate ;

the gills inserted into postero-lateral prominences of the segments, and divergent back-

wards from the sides of the body ; hinder lateral angles of tlie segments not prolonged.

Natation laboured, aided by movements of the legs ; fore legs of moderate proportions

and simple construction, the femur rather shorter than the tibia.

The insects ranked in this section have strong affinity with the Ephemerce. The chief

differences between the flies consist in the structure of the forceps, the laminar lobe

of the ? 9th ventral segment, and the bifurcation of the second axillary nervm'e of the

fore wing. This last characteristic is met with in some uudescribed allies of Fotunumthus,

as well as in all that have been published. The nymph has more congruity with the

Leptophlebiae ; and the structure of the flies justifies their being grouped with these

rather than with Ephemera.

POTAMANTHUS, Pict. 1813-5; restricted, Etn. 1871.

Illustrations. Adult, PL IX. 14 (details) ; (whole figures) Pict., Hist. Nat. Nevropt.

ii. Ephdm. pi. xxv. 1-3 (1843-5). Nymph, PI. XXXI. (whole figure and details) ; refer

also to Eucharidis, Joly (1876), under P. luteus.

Adult. — Seta) 3, subequal to each other ; in s im. about \\, 2 Ij, and in s subim. just

as long as the body. Pore leg of s as long as the body, the tibia If as long as the femur,

and nearly as long as the tarsus ; ? fore femur almost as long as the tibia, tarsus nearly

\ as long as the tibia ; hind tarsus about \ ^s lo^a ^s the hind tibia ; ungues unequal,

and (excepting in s fore tarsus) dissimilar. Anterior ocellus a little smaller than the

others. Pronotum of 2 transverse, produced into a flattened lobe closely appressed to

the mesonotum and rounded posteriorly. Lobes of the penis flattened, without apparent

stimuli. Body slender : abdominal segments of ? 1 and 10 short ; 2-4 equal, and about

twice as long as 10 ; 5, 6, and 9 mutually subequal, and little longer than 4; 7 and 8

mutually equal, and longer by as little than 6. Flight chiefly late in the evening and

nocturnal. Subimago usually quiescent about twenty-four hours, standing upon its

hinder legs with the fore legs mutually subparallel and horizontally prorect, the seta^

close together, and the wings erect. Nymph latent ; tracheal branchiae all double and

KEY. A. E. EA.TON ON EECENT EPHEMERID.^ OR MAYFLIES. 79

uniform ; their divisions subequal, plumose or pinnatisect with linear acuminate seg-

ments, and not conduplieate lengthwise. SetaB plumose, about i as long as the body.

Outer surface of each mandible armed with a single acute spine or tubercle, not prolonged

into a tusk ; their innermost fang furnished with a moveable appendage [endopodite].

Lacinia of the 1st maxilla crowned with a patch of dense hair. Median lobe of the

tongue obcordate. Antennae setaceous, almost glabrous. Labrum externally strigose.

Lobes of the labium very small. Pronotum oblong, nearly straight at the sides, and

slightly concave at the margin in front and behind. Intermediate leg the longest.

Type. P. lutens (in Ephemera), Linn.

Distribution. Temperate and southern Europe ; also (undescribcd sp.) in the State of

Virginia.

Etymology, ttoto^iuc and avOog, river-flower.

PoTAMANTHUS LUTEUS, Linn. Plate IX. 14 (wings, legs s 2 , head, penis, and forceps

d adult).

[Epliemera] or Ephemera hitea [Geof., Hist. Ab. Ins. Paris, ii. 238, no. 2] (1764); Linn., S. N. ed.

xii. 906 (1767); Fab., Syst. Ent. 303 (1775) ; [? Schaef., Ic. i. pi. xlii. 7 (1776)] ; Schr., En. Ins. Aust.

603 (1781) ; Fab., Sp. Ins. i. 383 (1782), and Mant. Ins. i. 243 (1787) ; Vill., C. Linn. Ent. iii, 17 (1789) ;

Roem., Gen. Ins. 23 (reproduced from Scliaef. 1776) ; [Zsch., Mus. Lesk. i. 50, no. 14] (1789) ; Gmel.,

Linn. S. N. ed. xiii. p. 2628 ( 1790) ; Ros., Fn. Etr. ii. 8 (1790) ; 01., Encyel. Method, vi. 417 (1791) ; Fisch.,

Vers. ein. Naturgesch. v. Livland, 565 (1791); Fab., Ent. Syst. emend, iii. pars i. 68 (1793) ; Seetzen,

Meyer Mag. f. d. Thiergesch. i. 41-63 [Hag.] (1794); Schr., Fn. Boica, Heft ii. Bd. ii. 197 (1798);

Walck., Fn. Paris, ii. 8 (1802) ; Lat., Hist. Nat. xiii. 95 (1805) ; Blanch., Hist. Nat. Ins. iii. 54 (1840) ;

Duf., Mem. par div. sav. Instit. de France, viii. 580, note ( 1841) ; [Joly, Feuil. d. jeun. Nat. 1876, Mars,

pi. ii. 6 (legs misdrawn)]. — ? E. J marginata, Miil., Zool. Dan. Prod. 142 (1776).^ — E. reticulata,

Fourc, Ent. Paris, ii. 350 (1785). — E. hyalhia, Pz., Explic. Schaef. Ic. xliii. (1804).^^. flavicans,

! Ramb., Nevropt. 296 (1842) ; Walk., List of Nenropt. Ins. in Brit. Miis., part iii. 536, ? var. (1853).—

E. chlorotica, ! Ramb., Nevropt. 296 (1842) ; Walk., op. cit. 540 (1853).

%Baetis mellea, Curt., Phil. Mag. ser. 3 (1834), p. 121. — jB. marginalis, Burm., Handb. Ent. Bd. ii.

Abth. ii. 801 (1839).

Potamanthus luteiis, Pict., Hist. Nat. ii. Ephe'm. Nevropt. 208, pi. xxv. 2, 3 (1843-5); Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 539 (1853) ; Hag., Stet. ent. Zeit. xxvi. 229 (1865) ; Etu., Trans. Ent.

Soc. London, 1871, p. 76, pi. ii. 1 (wing), and iv. 13-13 « [details] (1871) ; Meyer-Diir, Bull. Sec. Ent.

Suisse, iv. 317 (1874) ; Rostock, Jahresber. d. Ver. f. Naturk. Zwickau, 1877, p. 83 (1878); M'Lacn.,

Ent. Mo. Mag. xv. 92 (1878).

Eucharidis Reaumuri, ! N. & E. Joly, Rev. d. Sc. Nat. Montpellier, v. 314, pis. vi. 13-15, vii. 16, and

viii. 30, 31 [nymph] (1876).

Suhimago {living). — Wings yellow, or in the ? tinged with greenish grey ; the fore

wings rather darker towards the costa, with black cross veinlets. Eyes of 6 light olive-

green (flavo-virens, Miiller), or sometimes light grass-green (gramineus. Mill.). From

head to tail a broad median brownish yellow-ochreous stripe occupies most of the

dorsum; this is narrowed towards the base of every abdominal segment, and contains

the usual pale pair of short divergent lines and dots in each of them : the remainder of

the body is sulphur- or straw-yellow, but in the abdomen near the bases of segments 2-9,

close to the spiracular line, is a black dot on each side of the dorsum, and higher up in

11*

80 EEV. A. E. EATON ON RECENT EPHEMEEID^K OR MATELTES.

the hinder portion of the segment in segments 1-7 is a piceous dot on each side: the

penultimate ventral segment more or less hrown-ochreous. Setae chieily brownish

yellow-ochreous, becoming whitish distally ; their joinings and a tinge at their roots

reddish or piceous.

Immjo [living). — Eyes of 6 glaucous or olive-brown above. jBody marked in a

manner similar to that of the subimago. Eorceps stramineous, their joinings narrowly

testaceous. Coxa, trochanter, and base of the femur of the fore leg straw-yellow, the rest

of the femur brownish yellow-ochreous ; tibia rufo-piceous at the knee, then testaceous,

but at the extremity, including the pedicel of the tarsus, piceous ; tarsus fumatose with

piceous joinings and subrubiginose ungues. Hinder legs straw-yellow, their tarsi

testaceous, with the joinings and ungues subrubiginose. Setae suhlutosceut with piceous

or black joinings. Wings flavescent, with fuscescent cross veinlets ; these, in the ptero-

stigmatic space of the fore wing, are numerous, sinuous, and anastomose with one

another.

2 brighter than the S , but otherwise very similar ; the fore legs more nearly of the

same colours as the hinder pairs, with their tarsal joinings dark fuscous. Length of body,

d 10-13, 2 9-13 ; wing, c? 12-13, 2 15 ; setge, d im. 18 & 15-19 & IG, subim. 13; 2 im.

12 mm.

Sab. England, at Weyhridgc, Surrey {MfLacli.) ; first recorded by Curtis without

locality. Erance, near Paris {Oeoffroy) ; common near Brive (Haute Loire) at 2000 ft. ;

in the defile of Pierre-Lis, near Quillan (Aude) at 1100 ft.; Toulouse, at 426 ft. altitude.

Switzerland, at Zurich [M'Lach.). Germany {Sulz.), Heidelberg [Pict.) ; Courland

[Brauer), July and August. My captvires at Brive and Quillan were made by beating

alder trees near swift parts of the rivers in the daytime ; hut those at Toulouse were

effected after nightfall at gas lamps in the vicinage of Pont St. Michel. The scarcity of

this species in collections is probably due more to its time of flight than to its actual

rarity. The nymph harbours under stones in gently flowing water at the borders of

rapids.

POTAMANTHUS EeRRERI. Pict.

Potamanthus Ferreri, Pict., Hist. Nat. Nevropt. ii. Ephem. 203. pi. xxv. 1 (1843-5) ; Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 539 (1853) ; Etn., Trans. Ent. Soc. London (1871), 77.

Imago {dried), <s . — According toM. Pictet this species differs from P. hiteus in having

uniformly pale yellow setae, colourless wings with very light yellow longitudinal nervui*es

and translucent cross veinlets, and a strongly defined brown spot on the hinder part of

the mesonotum, where P. hiteus is often bright yellow. When he describes the dorsal

stripe as composed of a series of trianglar spots, one in every segment but the last, there

is reason for suspecting that these triangles are truncated anteriorly. Length of body 13,

exp. of wings 30, setae 18 mm.

Rub. Captured near Turin by le Chanoine Eerrero. The unique specimen formerly in

the Geneva Museum, was not there in 1867.

KEV. A. E. EATON ON RECENT EPHEMERIDtE OR MATELIES. 81

RHOifNANTHUS, Etn. 1881.

Illusti'ations. Adult (details), PI. IX. 15.

Adtdt. — Setae 2 (the median being aborted), in s twice as long as the body. Legs

apparently more slender than in Potamanthus ; fore tibia of 6 upwards of If as long as

the femur, the tarsus f as long as the tibia ; hind tarsus scarcely \ as long as the tibia-

Ungues unequal and dissimilar. Very like Totamantlms in other respects.

Type. nil. speciosus, Etn.

Distribution. Dntch East Indies.

Etymology . port and av6og, in imitation of Potamanthus.

Rhoenanthl's speciostjs, Etn. PI. IX. 15 ( d , wings, legs, penis, and forceps).

Rhoenanthus speciosus, ! Etn., Eut. Mo. Mag. xvii. 192 (1881).

Suhimago (dried). — TTings whitish, tinted more or less with very light yellowish

ochraceous along the inner and terminal margins ; most of the cross veinlcts between the

costa and anal nervure (8) of the fore wing edged with blood-red.

Imago (dried), d . — Mesonotum brownish ochreous. Abdomen discoloured above, but

varied with sanguineous ; venter light yellow-oehreous. Setae whitish ochreous, their

joinings more or less sanguineous or atro-sanguineous ; the forceps tinged with the same

colour. Wings transparent ; many cross veinlets of the fore wing are conspicuously

bordered with sanguineous, and their bordering is irregularly confluent so as to form

blotches of variable extent. Legs pale ochraceous ; the fore leg at the tip of the femur,

at both ends of the tibia, and at the tarsal joinings, tinged with red-purple or sanguineous ;

hinder legs with the distal edges of the tarsal joints very narrowly sanguineous.

2 marked similarly, but less distinctly. Length of body, d 13, 2 16; wing, d 11-12,

? 16 ; setre, ? 25 & 1-26 & 1 mm.

Hab. Lahat, Palembang, Sumatra (Mus. Soc, Zool. " Natura artis magistra " Leyden,

and Mus. Comp. Zool. Cambridge, Mass.). Also Java (Leyden Mus.).

Second Series of Group) II. of the Genera.

Adult. — The anal (8) and normally simple second axillar (9°) nervures, with the inner

margin of the fore wing, enclose a trilateral space somewhat leg-of-mutton-shaped [a

curved trilateral, truncate at the narrow proximal end, in Ephemerella and Sageniilus'\ ;

anal nervure distinctly sejiarate from the pobrachial (7) at the roots ; first axillar (9')

usually projected in a simple curve from the prominent basal fold, and strongly arched

towards the inner margin ; but sometimes at the base of the wing it is curved forwards

abruptly, tending to annex itself to the extremity of the anal nervure, thus becoming in

a small degree unevenly sinuous. The area intervenient between the anal (8) and tirst

axillar (9') nervures is termed the " anal-axillar interspace" ; it contains from 2-5 inter-

polated longitudinal nervures, incurrent from the margin, termed " intercalar " or

" intercalary " nervures, and designated numerically in the text (but unnumbered in the

Plates) in the order of their nearness to the anal nervure. Hind wings of moderate or

small proportions, either gently, and on the whole continuously, curved in front, or else

suddenly refracted in the middle of the fore margin ; in the former case the subcosta (2)

82 REV. A. E. EATON ON RECENT EPHEMERID,^ OR MAYFLIES.

is curved in correspondence, but in the latter it is usually almost straight, and often

subparallel with the abruptly abbreviated costa. Metathoracic spiracle straight-lipped ;

the valves usually closed, or connivent, in dried specimens : mesotnoracic spiracle larger,

the aperture narrow, and sometimes furnished with a very minute guard at its anterior

corner, the lips unequal, usually gaping a little in front, the uppermost strongly vaulted

and (when the guard is absent) often bent round the front of the aperture. Pronotum

of ? closely appressed to the mesonotum, longitudinally cariuate, and posteriorly excised

or retuse in the middle. Forceps-limbs inserted at the sides of the terminal border of a

transverse, and commonly deflexible, lobe extended from the segment, termed the

"forceps-basis," and represented by a projecting lamina in the ? , termed the "ventral

lobe of segment 9." Eyes of 6 ascalaphoid ; anterior ocellus rather smaller than the

others. Subimago quiescent during many hours, standing (so far as observed in

European genera) upon all of its feet, with wings erect, and with the lateral caudal setae

spreading, or divergent from the middle seta.

Section 5 of the Genera. — Type of Leptophlehia. Adult. — Pronotum of $ traversed

lengthwise by a raised median line or fine ridge, and excised (or at least strongly

emarginate) in the middle of its posterior border. Hind tibia usually longer than the

femur, rarely subequal to it ; the tarsus shorter than the tibia. Eirst axillary nervure

(9') in some degree convergent towards the second axUlary (9-) near the base of the fore

wing [not obviously so in PI. XII. 19, Choroterpes]. Nymph [out of nine genera in this

Section four are imknown]. — Wings free along their terminal margins. Palpus of 1st

maxilla longer than the lacinia, which is crowned with a dense tuft of hair, and ciHate

on the inner edge below the point. Lobes of the labium smaller than the laciniae of

the 2nd maxillae. Abdominal segments 1-7 furnished with tracheal branchiae, those of

the first segment erect. Hinder lateral angles of the posterior segments slightly pro-

duced. Natation laboured, aided by movements of the legs.

To exclude the possibility of the figures of wings being supposed to afford precise

characteristics of genera, suitable for employment in analytical tabulation, variations of

the most obvious features of the neuration are tediously noted in the generical descriptions.

The variations in every genus proceed metliodically, not at random. In view of the

consequent prolixity of the descriptive text, the following aid to the determination of

genera may be referred to with advantage when adult specimens require assorting.

Analysis of Geneba of the Leptoplilebia Type : —

Hind wing in front somewhat

arcuate; tarsal claws all narrow and hooked Atalophlebia.

depressed in the middle ; each tarsal claw unlike the other ; median caudal seta

subequal to the others Leptophlebia.

far shorter than the others Blasturus.

strongly angulated ; tarsal claws

all narrow and hooked ; basal joint of forceps-limb longer than the remainder Adenophlebia.

EEV. A. E. EATON ON RECENT EPHEMERID.^ OR MATELIES. 83

each unlike the other ; basal joint of forceps-limb

longer than the remainder; egg-valve

strongly developed; ? ventral lobe of segment 9 bifid and excised . Hagenulus.

absent ; $ ventral lobe of segment 9

obtuse or slightly emarginate ; of the interealaries in the anal-

axillar interspace of the fore iving, the nearest to the anal

out of 4 or 5 is long Thraulus.

bifid and acutely excised ; of the interealaries quoted, the

nearest out of 4 to the anal nervure is short Calliarcys.

about as long as the remainder; egg-valve absent; ? ventral lobe of

segment 9 bifid and excised ; of the interealaries quoted, the nearest

to the anal out of 3, 4, or 5 is short Habrophlebia.

very short; joint 2 longer than the remainder; 2 ventral lobe of seg-

ment 9 obtuse Choroterpes.

ATALOPHLEBIA, Etn. 1881.

Ilh(strations. Adult (details), PI. X. 16«-16 h ; (whole figures) see citation of Pictet

under A. anstralasica. \_N.B. A median seta is commonly present.]

Adult. — Hind Aving in front somewhat arched, the summit of the arch ohtusely sub-

angular, situated usually before the middle of the curve; subcosta (2) strongly arched,

meeting the margin very obliquely ; radius (3) usually nearly straight, constituting as it

were the chord of the arch described jointly by the subcosta and the portion of the

margin included between its extremity and the radius ; hence, while the narrow marginal

area is broadest at the base and acuminate at its termination, the submarginal area is

broadest either in the middle, or a little before the middle, and tapers gradually to its

oblique apex. Cross veinlets abundant in the fore wing, those in the marginal area

before the bulla well defined. At the terminal margin the longitudinal nervures are

provided with curved simple branchlets, and there are no isolated veinlets. The two

intercalar nervures of the anal-axillar interspace of the fore wing have simple branchlets,

and usually the hinder one, close to its proximal extremity, curves forwards to unite with

the other, whicli similarly curves forwards to join the anal nervure (PL X. IG c) ; occa-

sionally, especially in female specimens, a cross veinlet is trausfei-red from near the

wing-roots to establish communication between the first axillary and the anterior inter-

calated nervure (/. c. 16 d) ; less frequently, this last nervure annexes itself to the first

axillary [l. c. IC e). The figure 16 i exhibits a further departure from the normal neura-

tion (supposing the insect to belong to this genus). In A. cmnnlata from Ceylon, the

two intercalated nervures referred to are abrupt and free at their proximal extremities as

a rule (/. c. 16 a), but individual " sports " occur in which the anterior nervure imper-

ferfectly establishes direct communication wdth the anal nervure. Guard at the orifice

of the mesothoracic spiracle small and triangular. Porceps-limbs of 6 3-jointed ; the

proximal joint much longer than the remainder, somewhat compressed, and in its basal

half broadly dilated beneath ; the deflexible basis, usually prominent in the middle of its

distal border, is otherwise merely emarginate; the corresponding lobe in 2 , usually bifid

and sharply excised witli acute triangular points, is seldom emarginate only. Segments

84 EEV. A. E. EATON ON EECENT EPHEMElilD.E OR MAYFLIES.

6-10 constitute about J of the abdomen ; segment 8, the longest, is nearly equalled by

segment 7 ; the others are successively shorter. Median caudal seta about as long as the

others, seldom thrown off by specimens ; outer setae, in both sexes, usually double (in some

species treble) the length of the body. Tarsal ungues all nearly alike, small, narrow,

and hooked at the tip. In normal species the d fore tarsus is nearly as long as the

tibia, or a little longer than it, and the latter is about 1^ as long as the femur ; the ?

fore tarsus is nearly ^ the length of the tibia, and this about IJ as long as the femur ;

in both sexes the tarsal joints, arranged in diminishing succession, rank thus: — 3, 2, 4, 5, 1.

Hind tarsus visually about ^ the length of the tibia. Some Cingalese species have the

d fore tarsus rather shorter than the tibia, and the joints in diminisliing order rank 2, 3,

4, 5, and 1, while tlie hind tarsus is scarcely ^ as long as the tibia.

Nymph unknown.

Type. A. australls (in Ephemera), Walker.

Distribution. S. Africa, Ceylon, Australasia, Japan (undescribed sp.), and S. America.

Etymology. uTa\6g and <fiAtj3ioi', in allusion to the delicacy of the cross veinlets of the

wings of some species.

In the absence of female examples of most of the species, I am unable to separate

satisfactorily those referred to above, as deviating from the typical form, from the others

which exhibit the normal characteristics of the genus. Judging from analogy, there is

much probability that the differences in the proportions of the setpe to the body, and in

the proportional lengths of the joints of the limbs, distinguishable in the adult flies, are

attended with manifest differences in the nymphs. The nymphs should be searched for

under stones in shallow water at the borders of streams, or in proximity to the outflow

of pools in river-beds, where the current is gentle, favourable sites would be indicated

by females alighting upon the water to oviposit, and by the departure from it of sub-

imagines.

Atalophlebia pasciata, Hag. Plate LXIV. 1 (penis).

Potamanthus fasciatus,\ Hag., Verb, zool.-bot. Gesells. "Wien, viii. 476 (1858) [part].

Imago [dried), d . — Thorax testaceous, with a brown-ochreous longitudinal stripe in

the midst of the mesonotum followed by some dark blackish clouds near the peak.

Abdomen very pale ochreous, approaching dull straw-colour; segments 2-8 and 10,

narrowly edged at the tips with pitch-black, segments 7 and 8 ochreous-brown above,

the two foUowiug yellow ochreous ; venter subochraceous, slightly darkened at the

joinings of the segments. Setae clove-brown, their joinings near their insertions dark ;

forceps lutescent. Wings vitreous ; fore wings faintly tinted with yellowish in the

marginal and submarginal areas, and provided with about 20 simple slightly curved

cross veinlets in the pterostigmatic space ; longitudinal neuration yellowish, cross veinlets

black, many of those in the anterior portion of the fore wing and some near the wing-

roots edged narrowly with black. Legs fusco-lutescent, the femora banded in the middle,

broadly but not strongly, with darker. Length of body 11, Aviug 15, setaB 35 mm.

Hub. Rainbodde, Ceylon, at an altitude of over 4000 ft. The subimago formerly

attributed to this species is a female Ephemera mpposita. The coloration of the body

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 85

of the type specimen, the subject of the above description, may have been modified by

ravages of Anthrenus (Hag. Mus.).

Atalophlebia annulata, Hag. Plate X. 16 « ( d , wings, legs, and genitalia).

Potamanthus amiulatus, ! Hag., Verb, zool.-bot. Gesells. Wien, viii. 176 (1858).

Leptophlebia annulata, ! Etii., Trans. Ent. Soc. Londou (1871), 82, pi. iv. 23-23 h ; Hag. & Etn., op. cit.

(1873), 393-4.

Subimago {dried). — Wings brownish grey, translucent ; neuration dull black, excepting

that some of the longitudinal nervures are lighter in colour towards the wing-roots.

Imago [dried), 6 . — Thorax and legs pitch-brown, the ungues and at least the last

tarsal joint subtestaceous. Dorsum of abdomen from its extremity to almost the base of

the 7th segment pitch-brown ; segments 2-G each banded with piccous and very pale

translucent dull brownish yellow, the dark terminal band dilated triangularly in the

middle, and the pale band at the sides ; there is also a very narrow pale band at the base

of the seventh segment ; venter pitch-brown at the joinings and throughout the last

three segments, otherwise concolorous with the pale dorsal bands. Forceps pitch-brown ;

setae warm sepia-brown or fuliginose. Wings vitreous, with pitch-black neuration ; the

fore wings tinged slightly with piceous near the wing-roots and the great cross vein, and

for a short distance in the submarginal area ; the remainder of this last, and the ptero-

stigmatic space, is faintly tinted with fuscous, and there are about IG simple gently

curved cross veinlets in this space. Length of body, S 9-11 ; wing 12'5 ; setae 35 &

37 mm.

Sab. E-ainbodde, Ceylon, at upwards of 4000 feet altitude (Hagen Mus., & Thwaites

in M'Lach. Mus. ; also Brit. Mus.).

Atalophlebia Taprobanes, Walk. Plate X. 16 b (penis).

' \Baetis Taprobanes, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 567 (1853) ; Hag., Verb, zool.-

bot. Gesells. Wieu, viii. -176 (1858).

Leplophkbla Taprobams, ! Etn., Trans. Ent. Soc. Londou (1871), 82, pi. iv. 22, 22 a [details] ; Hag. &

Etn., op. cit. (1873), 393.

Imago {dried), 6 . — Thorax pitch-black ; abdomen scarcely lighter, excepting in the

translucent whitish bases of segments 2-6. Setae burnt-umber brown. Fore legs

black ; hinder legs dark piceous. Wings vitreous, very faintly tinted with very light

bistre-grey, with a streak at the great cross vein, a spot at the wing-roots, and with the

marginal and submarginal areas of the fore wing beyond the middle burnt-umber brown ;

neuration pitch-black. The marginal area of the fore wing contains about 8 cross

veinlets before the bulla, and 18 straight and simple beyond it. Length of body, d 12 ;

setae 30 (or more) mm.

Hub. Ceylon (Brit. Mus.).

Atalophlebia femoralis, Hag.

Potamanthus femoraUs,\ Hag., Verb, zool.-bot. Gesells. Wien, viii. 476 (1858).

Leptophlebia femoralis, Etn., Trans. Ent. Soc. London (1871), 83; Hag. & Etn., op. cit. (1873), 394.

Subimago {dried). — Wings transparent, pale sepia-grey, with fuscous neuration. Setae

brown.

SECOND SERIES. — ZOOLOGY, VOL. lU. 12

86 REV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

Imago {dried). — Thorax glossy, dark chestnut-brown. Abdomen in 6 above, as far

as the base of the 6th segment, translucent whitish tinged with fuscous, the remainder

fuscous, all the segments narrowly margined with pitch-black at the joinings ; venter

similarly pale to the seventh segment, and then fuscous or ochraceous, and likewise

piceous at the joinings ; in the ? type all is discoloured. Setaj light sepia-broAvn ; forceps

defective in the type. Legs in $ with pale flavescent femora banded broadly in the

middle and narrowly at the tip with black, the tibiae and tarsi pale dull burnt-umber

brown ; the hinder legs of 6 are paler, with sepia-brown tibia and tarsus ; its fore legs

are lost. Wings vitreous, with piceous neuration and a rounded brown-tinted cloud at

the wing-roots ; cross veinlets in the pterostigmatic space about 10 in number in d , 13

in 5 . Length of body, s 8 ; wing, d 9'5, ? 8 ; setae, 6 about 23, $ 16 mm.

Hab. Eainbodde, Ceylon, at an altitude of over 4000 feet (Hag. Mus.).

Atalophlebia austkalis, Walk.

X Ephemera avstralis, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 538.

Leptophlebia australis, ! Etn., Trans. Eut. Soc. London (1871), 78, pi. iv. 14—14 i [details].

Atalophlebia [type] australis, ! Etn., Ent. Mo. Mag. xvii. 193 (1881).

Subimago {dried). — Wing neuration pitch-brown, the cross veinlets 1)ordered with light

bistre-brown, their bordering in the fore wing confluent along the sides, of a lambda-

shaped space free from cross veinlets and colouring, the long stroke of the letter being

represented by a narrow clearing describing a gentle curve from the apex to the anal

angle of the wing, and the sliort stroke by another narrow clearing running out from

the midst of the wing-roots to the former. In some specimens the short clearing at the

base of the wing is isolated by colouring from the longer clearing.

Imago {dried), d . — Thorax pitch-black above. Abdomen rufo-piceous above ; venter

dull light burnt-umber, appi^oaching rusty brown. Setre light rufo-piceous. Wings

vitreous, their neuration light pilch-brown ; tlic pterostigmatic space of the fore wing,

tinged with greenish grey, contains many oblique nearly straight cross veinlets sparingly

conjoined ; the marginal area contains, approximately, 7-9 cross veinlets before the bulla,

and 21 between it and the apex of the wing. Fore legs with the femur pitch-brown, the

tibia pitch-black, and the tarsus light burnt-umber ; hinder legs rufo-piceous, with rather

lighter tarsus, and with a faint black band in the middle and another at the tip of the

femur. Length of body, 6 7-10 ; wing 9-11 ; setae 23 & 22 mm.

Hub. Tasmania (Brit. Mus.).

Atalophlebia atjstralasica, Pict. PL X. 16 c (wings and penis).

XBaetis australasica, Pict., Hist. Nat. Nevropt. ii. Ejihem. 189, pi. .^xiv. 1, 2 (1843-5); Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 559.

Leptophlebia australasica, ! Etn., Trans. Ent. Soc. London (1871), 78, pis. ii. 2 [wing], and iv. 15-15 6

[details] .

Subimago (after Pictet's figure). — Wings light black-grey, with dark neuration.

Imago {dried). — Thorax pitch-black above. Abdomen in segments 2-8 rufo-luteous

marked with pitch-black, viz. each segment with an al)breviated black line from the base

in the middle, a round black spot on each side of the middle at the tip, and a stripe on

KEY. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 87

each side descending obliquely from the hinder border of the segment almost to its base,

dilated very broadly in front on its lower side so as to resemble somewhat a quadrangular

blotch squarely excised at its lower distal angle ; segment 9 pitch-black excepting at its

rufo-luteous distal margin. Forceps rufo-lutcscent at the base, becoming rufo-piceous

distally. Setse intense warm sepia-brown. Wings vitreous, sometimes faintly tinted

with lurid in the disk ; their neuration pitch-black ; the marginal and sul)mar"-inal

areas of the fore wing tinged with burnt-umber brown, and more deeply so in the ptero-

stigmatic space, where the cross veinlets (mostly simple) are crowded and oblique ; of

these there are about 8 before and 23 beyond the liulla in the marginal area. Fore le"-s

pitch-brown ; hinder legs rufo-luteous ; all with two black bands on the femur. Ventral

lobe of the penultimate segment of the ? excised. Length of body, 6 9-10 ; win"-,

d 2 11 ; setoe, d 32 mm.

Sab. Sydney, and perhaps Melbourne (Brit. Mus.).

Atalophlebia furcifera, Etn.

Leptop/ilebia furcifera, !Etu., Trans. Ent. Soc. London (1871), 79, pi. iv. lG-16 6 [details].

Imago [dried), 6 . — Mesothorax brownish luteous above ; metatergum deep sangui-

neous-black. Abdomen sanguineous Ijlack, with a median longitudinal line, the spiracular

lines, and triangular spots, one on each side of the dorsum, adjacent to the hinder border

in segments 2-6, of a lighter colour. Setse cretaceous, with the alternate joinings black.

Wings vitreous, iridescent, with piceous nervures ; the pterostigmatic region of the fore

wingrufo-fuscescent, with numerous simple and nearly straight cross veinlets ; the other

cross veinlets in the front of the fore wing, as far back as the radius and first of the

sectors, bordered Avith rufo-fuscous ; the bullae of the subcosta and radius, and the point

of furcation of the prtebrachial (G), are surrounded each by a small warm-sepia nebula.

Fore legs deficient ; hinder legs testaceous, with two femoral bands, and the base of the

trochanter fuscous. Length of body and wing, d 11 ; setne 13 and 16 mm.

Sab. Melbourne (M^Coy). The species was forwarded to Mr. F. Walker, who referred

it to me ; the type may therefore be in the Melbourne Museum. The name has referen j

to the form of the penis.

Atalophlebia inconspictja, Etn.

Leptophlebia inconspicua, ! Etu., Trans. Ent. Soc. London (1871), 79, pi. iv. 17-17 b [details].

Imago (dried), <J . — Abdomen piceous posteriorly, paler in the intermediate segments,

with small, oval, yellowish dorsal spots at the sides. Sette fuscous, with darker joinings.

Wings faintly lutescent, with piceous neuration : the pterostigmatic portion of the fore

wing contains a few simple, straight, oblique cross veinlets. Legs piceous ; sometimes

the fore tarsi and the hinder legs are lighter. Lobes of the penis broadly flattened out

and obtuse. Length of d , body 5-6 ; wing 6-7 mm.

Hab. Adelaide (Ilope Mus., Oxford).

12*

88 REV. A. E. EATON ON RECENT EPHEMERID^ OE MAYFLIES.

Atalophlebia dentata, Etn.

Leptophlebia dentata, ! Etn., Trans. Ent. Soc. London (1871), 80, pi. iv. 18-18 ef [details].

Stiblmago [dried). — Wings very light sepia-grey, the cross veinlets very faintly and

very narrowly bordered with darker grey ; neuration pitch-black, but brownish at the

wing-roots. Setae deep warm sepia-brown.

Imago {dried). — Thorax bright brown-ochre above. Abdomen light bistre-brown,

modified in segments 8-10 with burnt-umber, the segments narrowly bordered with black

at their tips. Forceps lutescent. Setae pilose, either lutescent or very light bistre-grey,

with black joinings. Wings vitreous, the disk very faintly tinted with yellowish ; mar-

ginal and submarginal areas of the fore wings coloured with dark amber-yellow (raw

sienna), the submarginal wholly, the marginal area only in part, viz. from the base to the

middle and in the distal portion of the pterostigmatic space completely, but only in about

half its breadth along the subcosta in the intervening space ; the cross veinlets in the

marginal area before the pterostigmatic space and those in the submarginal area are

bordered with dark bistre-brown, and give rise to a blotch or cloud at the bulla. Neura-

tion mostly pitch-black, but the nervures near the wing-roots, and the stouter portions

of the costa, subcosta, and radius are pitch-brown. Cross veinlets in the marginal area

about 5 before and 15 beyond the bulla, all straight. Legs luteous, the fore tarsus

lighter and dull, the femora more or less dark at the knee, the fore tibia black at its

distal extremity, the tarsal joinings piceous. ? . Ventral lobe of segment 9 emarginate.

Length of body, d 8, $ 7-9 ; wing, 6 11, 2 7-13 ; setae, 6 18, 2 15-16 mm.

Eab. New Zealand (Brit. Mus.).

Atalophlebia strigata, Etn. Plate X. 16 d (fore leg, $ , and hind wing).

Leptophlebia strigata, ! Etn., Trans. Ent. Soc. London (1871), 80, pi. iv. 19 [detail, ?].

Imago [dried), 2 . — Thorax brown-ochreous above, with two subparallel longitudinal

black stripes on each side of the pronotum (one at the lateral border, and the other

midway between it and the median line of the notum), and also with the longitudinal

furrows in advance of the wing-roots of the mesonotum black. Abdomen light Indian

red, with four longitudinal black dorsal stripes and a median black ventral line extending

its whole length ; each stripe is mainly composed of truncate triangular spots in mutual

contiguity, one spot in every segment ; but in some of the posterior segments the spots

become oblong or linear, and are somewhat suffused with the ground-colour; the com-

ponent spots of the two inner stripes taper behind, those of the outer stripes point for-

wards and downwards : the two inner stripes are rather near together, and enclose a

narrow streak of the ground-colour, whose edges are even, along the track of the dorsal

vessel ; the outer and the inner stripes of each side are farther apart, and give a serrated

outline to the interspace between them, so that the ground-colour thereabouts in every

segment takes the form of an oblong spot, placed obliquely in the anterior segments, but

longitudinally in the hinder segments ; the outer dorsal stripe on each side is separated

by a narrow interval from the spiracular borders of the segments, excepting at the

extreme base of each. Setse light brown-ochreous, with reddish brown joinings. LegSi

EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. 89

in opaque view, of a dull colour approaching brown-ochreous, the femora banded in the

middle and distally with light burnt-umber brown, the tarsi and hinder tibiae much

lighter in colour than the femora, with a dark spot at the extremity of the fore tibia, and

with the ungues, the extremities of the terminal joints, and the extreme distal edges of

the remaining tarsal joints light burnt-umber, or almost madder-brown. Fore wings

vitreous, with the marginal and submarginal areas, the costa, subcosta and radius, and

the bases of the other longitudinal nervures light raw-umber brown, changing in trans-

mitted light to light brownish-amber ; the remainder of the longitudinal neuration and

many of the cross veinlets in the outer and hinder portions of the disk of the wing are

pitch-black in opaque view, changing in other lights to pitch-brown ; but the stronger

cross veinlets near the base and those between the great cross vein and the bulla in the

marginal and submarginal areas, being slightly thickened, are more constantly black ; at

the wing-roots all of the strong nervures are light raw-umber or brownish amber ; the

marginal area contains 8 cross veinlets before and 15 beyond the bulla, all of them

simple. Length of body, 2 im. 11, wing 16, setse 23 and 22 mm.

Hab. North Austi-alia. This description is prepared from the original type specimen

in M^Lach. Mus. The dimensions formerly attributed to it were very inaccurate.

Atalophlebia costalis, Burm.

IBaetisW costalis, Burm., Handb. d. Ent. Bd. ii. Abth. ii. 800 (1839).

Potamanthus costalis, Pict., Hist. Nat. Nevropt. ii. Ephem. 237 (1843-5) ; Walk., List of Ncuropt.

Ins. in Brit. Mus. part iii. 546 (1853).

Leptophlebia costalis, Etn., Trans. Ent. Soc. London (1871), 81.

Subimago {dried). — Black ; thorax with a whitish line in front of the wings ; abdomen

and legs banded with red. Wings suffumatose, with all the cross veinlets in the mar-

ginal and submarginal areas of the fore wing brownish. Length of body, 6 6 Paris

lines. (After Burm.)

Rab. Australia.

Atalophlebia nodularis, Etn. Plate X. 16 e (hind wing and two views of penis).

Leptophlebia nodularis, ! Etn., Trans. Ent. Soc. London (1871), 81, pi. iv. 20-20 c [details].

Subimago (dried). — Wings light sepia-grey, with dark neuration ; cross veinlets, of the

fore wing only, bordered with medium sepia, their bordering in some measure confluent

in the disk near the subcostal bulla (which itself is surrounded by a darker spot), and

again beyond this about midway towards the tip, so as to form an ill-defined irregular

cloud enclf)sing a lighter space of the ground-colour.

Imago {dried), 6 .—Thorax piceous or pitch-black. Abdomen discoloured, pitch-black,

with translucent subtriangular spaces in segments 2-5, one on each side of a dark median

longitudinal line, extending from the base nearly to the hinder border of the dorsum.

Seta; yellowish white, annulated broadly with pitch-brown in the alternate joints. Wings

vitreous, with pitch-black neuration ; fore wing, in opaque view, with the marginal and

submarginal areas, from the great cross vein to the roots, raw-umber brown, and with

narrow dark borders to the cross veinlets, nearly effaced in the disk, but subopaque in the

90 EEV. A. E. EATON ON EECENT EPHEMERID.^ OR MAYFLIES.

marginal and submarginal areas ; in the submarginal area and the next behind it, in both

of the places that are clouded in the subimago, three cross veinlets are nearly approxi-

mated to one in a conspicuous manner, and are very faintly clouded. Eore tibia and

tarsus, in opaque view, dull luteo-rufescent, the femur obscure rufo-piceous, with a black

band in the middle and another at the knee, a black spot at the extremity of the tibia, and

the joinings of the tarsus narrowly black ; hinder legs, in opaque view, redder, with only

the band in the middle of the femur : in transmitted light the prevailing colour of the

legs is brownish amber. Length of body, d 9, wing 10-12, setse 16 mm.

Hah. Christchurch, New Zealand (Pereday in M^'Lach. Mus.). The present photo-

lithograph lacks definition, and is inferior to the figure published in 1871, copied from

the same original di*awing.

Atalophlebia scita, Walk. Plate X. 16/ (penis).

XBaetis scita, ! Walk., List of Neuropt. lus. in Brit. Mus. part iii. 570.

Leptophlebia scita, ! Etn., Traus. Eut. Soc. London (1871), 81, pi. iv. 21, 21 a [details].

Suhimago {dried). — Wings dark warm sepia-grey, with black neuration ; the cross

veinlets of the fore wing are edged with darker grey ; their scarcity behind the subeosta

in the middle of the front of the disk gives rise to the appearance of a pale spot, whilst

the mutual approximation of three or four about the bulla and again in the midst of the

pterostigmatic space produces frequently two dark spots. Setai warm sepia-grey with

black joinings.

Imago {dried), 6 . — Thorax light reddish or pitch-brown. Abdomen dark bistre-brown,

the segments above broadly edged distally with black, and segments 3-0 above marked,

close to the base, each with a pair of translucent yellowish triangular spots in the midst.

Forceps luteous. Setaj dirty white, or light sepia-grey, annulated at the base of every

alternate joint with black, the anuulations gradually increasing in breadth, until, in the

distal parts of the seta, each annulation occupies almost the whole of a joint. Fore

femur, in opaque view, translucent raw umber-brown, with a distinct black band in the

middle, and a fainter one at the tip ; tibia and tarsus light rufo-luteous, with the tip of

the former and joint i of the latter black : in transmitted light the femur becomes chiefly

brownish amber, and the rest of the leg light yellowish-amber. Hinder legs amber-

yellow with a black band in the middle of the femur, and with the terminal borders

of the tibia and tarsal joints very narrowly edged with black. Wings vitreous, with

pitch-black neuration ; the fore wing with a spot at the base of the costa, and with the

narrow bordering of the cross veinlets in the marginal and submarginal areas piceous;

also with a less distinct spot in the marginal area at the bulla, and another in the ptero-

stigmatic space, light raw-umber or light bistre-brown. In the marginal area are 7-8

cross veinlets ])efore the bulla and 11-13 beyond it, mostly simple and free.

2 very similar. The cross veinlets in the marginal area of the fore wing rather more

numerous than in the male (but of similar character), \iz. 9 before, 18 beyond the bulla.

Length of body, d 6, ? 9 ; wing, 6 7-8, ? 11 mm.

Hub. Kew Zealand (Brit. Mus. & M^Lach. Mus.). The figure of the penis in the

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 91;

present wovk was di'a\ya from a specimeu iu tlie latter collection ; but the earlier fi^ur

was prepared from a type specimen.

Atalophlebia chilensis, u. sp. Plate X. 10 g ( 6 , legs and genitalia).

Subimago {dried). — Wings extremely light smoky-grey, with pitch-black cross veinlets

bordered narrowly with light Cologne-earth grey, so arranged in the fore wino- as to

leave a blotch of the ground-colour extending from the costa to about the pobrachial (7)

nervure ; the longitudinal nervures pale for some distance from the wing-roots. Set*

light warm sepia-grey with pitch-black joinings.

Imago {dried), d . — Thorax brown-ochveous above. Abdomen discoloured, collapsed,

and translucent ; segtnents 1-G narrowly pitch-black at the tips, with an oblique

dorsal stripe on each side from the terminal border, and a spot on each side at the base

fuscous. Setrt^ deficient. Wings vitreous, with light amber-yellow longitudinal nervures

and l^lack cross veinlets ; these are thickened somewhat in the marginal and submaririnal

areas of the fore wing ; the former area contains about 9 cross veinlets l^efore, and

16, straight and simple, beyond the bulla. Legs, in opaque view, rufo-luteous, with the

fore tibia luteous, the hinder til)ise towards their extremities and the tarsi paler or sub-

testaceous ; a black band in the middle and another (or a spot) at the tip of the femur,

also a spot at the tip of the tibia, pitch-black. Length of body, d 10, wiiig 12; seta;, d

subim. 12 mm.

Snb. Chili (Reed, in jVPLach. Mus.).

Atalophlebia tabularis, n. sp. Plate X. 16 h { 6 liead, parts of tarsi, forceps, and penis).

Imago {in sjj/rifs), cf . — This species, well characterized by ihe lobes of the penis being,

as is represented in the figure, flat and obliquely pointed, so as to resemble in com-

bination the nil) of a ^len flattened, has a slight projection in the middle of the terminal

border of the forceps basis. Eyes clove-brown. Thorax piceous above, darker than the

abdomen. Sette whitish, with their alternate joinings dark. Femora banded with

black in the middle and at the knee. Wings vitreous ; the marginal area of the fore

wing contains about 10 cross veinlets before the bulla, and after that 6 rather weak,

followed in the pterostigmatic region by 13 well-defined mostly simple and slightly

curved, rarely (and then only very sparsely) connected together. Length of wing 9 mm.

Salj. Cape of Good Hope, on Table Mountain. The only specimen obtained was found

in 1874, floating on the streamlet at the Platteklip. The nymph was vainly sought for

in the haunts of Telphusa ; the disuse of the net may have caused tlie failure.

LEPTOPHLEBIA, Westw. 1840 (part); restricted, Etn. 1881.

Illustrations. Adult (details) PI. XL 17 a-d (whole figures) ; consult Pictet, op. cit.

pi. 26 {Fot. Geerii & castanea). Nijmph PL XXXII. ; also Pictet, loc. cit. (1S13-5)

[who omits the tracheal branchia) of segment 1 of the abdomen].

Adult. — Hind wing in front unequally and very flatly arcuate, the curvature of the

arch being strong at both ends, and interrupted by a very shallow depression nearly in its

middle, immediately beyond its obtusely rounded summit ; the radius (8) constitutes, as

92 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

it were, the chord of this arch ; the subcosta (2), receding iu a bold curve from the radius,

approaches the summit of the same arch, and then takes a nearly straight course, sub-

parallel with the larger segment of the costal border, to terminate obliquely in the

margin rather near the extremity of the radius. Hence the marginal area of that wing

is sublinear, dilated in front at the base, and acuminate at the point ; while the sub-

marginal area is broadest in its first j, and thonce is gradually narrowed in a slight

degree to its oblique, roundly truncate extremity. Cross veinlets abundant, present,

but often weak, in the marginal area of the fore wing before the bulla. The longitudinal

nervures are furnished with branchlets along the terminal margin, which are partly

simple and curved, and partly common to both of the adjacent nervures ; there are no

isolated veinlets. In the anal-axillar interspace of the fore wing, the two long intercalar

nervures communicate mutually by means of cross veinlets, and exhibit the greatest

possible diversity in their ultimate destination inwards. Either of them may be the longer

of the two, and may annex itself to either the anal or the first axUIar, while the shorter

remains abrupt ; or both of them may annex themselves to the one or the other of these

nervures ; or each of them may annex itself to that nervure to which it is nearest ; or

both may terminate abruptly, communicating with those nervures by means of cross

veinlets only. This last arrangement prevails in our native species ; but the variations

from it, noted above, are quite independent of species and sex, and are apt to mar indi-

vidual symmetry. Guard at the orifice of the mesothoracic spiracle small and triangular.

Forceps-limbs of d essentially 3-jointed (a minute terminal 4th joint is of occasional

individual occurrence) ; the proximal joint normally much longer than the remainder,

compressed and dilated towai'ds the base ; the dilatation, usually gradual and at the

lower edge, is in L. mollis sudden and superior. The species L. i^rcepedlta, provisionally

i-eferred to this genus, has 4-jointed forceps-limbs with a short joint at the base, like

CJioroterpes. Abdomen proportioned nearly as iu AlalopJdebia ; the deflexible basis of

the 6 forceps, and the homologous lobe in the 2 , are deeply and sharply excised or

bifid, with acute triangular points. Median caudal seta subequal to the others ; outer

setae in d about 1\ as long as the body, in $ nearly of equal length with the body.

Tarsal ungues all dissimilar each to the other. Fore tarsus of <s little longer than the

tibia, which is nearly of the same length as the femur ; tlie joints in diminishing sequence

rank 2, 3, 4, 5, and 1. Fore tarsus of $ about \ as long as the tibia, which is little

longer than the femur ; its joints rank 2, 3, 5, 4 ; hind tarsus (exclusive of joint 1)

almost \ as long as the tibia and joint 1 combined; its joints rank 5, 2, 3, 4; the first

joint is obsolescent in these tarsi. Nymph latent ; abdominal tracheal branchite uniform,

bipartite, inserted at the latero-dorsal angles of the segments ; their divisions simple,

subulate or linear-acuminate, beset with minute distant hairs ; the hinder pairs in repose

widely divergent backwards from the sides of the body. Caudal setae nearly 1^ as long

as the body, and, like the setaceous antennae, provided with verticils of minute spreading

hairs at the joinings. Fangs of the mandibles strong and acute; appendage (eudopoditej

well developed, terminating in a compact oblique brush. Palpus of maxilla i slender;

its last 2 joints together constitute about | of the whole, Lacinia of maxilla ii acutely

eemi-ovate and narrow, the inner edge rather concave. Tongue broadly obovate, retuse

EEV. A. E. EATON ON EECENT EPHEMERID^ OR MATELIES. 93

distally ; paraglossae obtuse, broadly dilated. Body slender, tapering evenly backwards

in a small degree. Hind leg the longest ; tbe tarsus almost as long as the tibia (exclu-

ding the claw).

Type. L. marginata (in Ephemera), Linn.

Distribution. Northern temperate regions ; also (undescribed sp.) Chili.

Etymology. AeTrroV and <pAe/3ioi', from the tenuity of the cross veinlets.

I have seen nymphs of L. suhnarginata, cincta, and an undetermined Portuo-uese

species alive, and some of an American (Portland, Or.) species forwarded by Dr. Hagen

in spirits.

Lbptophlebia margin ATA, Linn. PI. XI. 17 a (wings, legs, and forceps).

Ephemera marginata, Linu., Syst. Nat. ed. xii. pars ii. 906 (1767) ; Fab., Syst. Ent. 303 (1775) ; id.,

Sp. Ins. i. 384 (1782) ; id., Maut. Ins. i. 243 (1787) ; Vill., C. Linn. Ent. iii. 17 (1789) ; Gmel., Linn.

Syst. Nat. ed. xiii. i. pars v. 2628 (1790) ; 01., Encycl. Method, vi. 417 (1791) ; Fab., Ent. Syst. emend.

iii. pars i. 69 (1793); Schr., Fn. Boiea, ii. pars ii. 198 (1798); Ced., Fn. Ingricte Prodr. 134 (1798) ;

Walck., Fn. Par. ii. 8 (1802) ; Lat., Hist. Nat. d. Crust. & Ins. xiii. 95 (1805) ; Shaw, Gen. Zool. vi.

part ii. pi. Ixxxi. (1806) ; Stewart, Elem. Nat. Hist. Anim. K. ed. ii. ii. 225, pi. xvii. 14, 15 (1817) ;

! Steph., 111. Brit. Ent. vi. 57 (1835) ; Zet., Ins. Lap. col. 1044 (1840) ; Blanch., Hist. Nat. d. Ins. iii.

54(1840). — E.viridescens, Fourcroy, Ent. Par. ii. 351 {l785).—E.procellaria, Schwarz, Nomencl.

Roes. Ins. Belust. pi. xii. 1-3 (1793-1830).— £. \\stigma, ! Steph., 111. Brit. Ent. vi. 56 (18.35).—

E. talcosa, ! Steph., op. cit. vi. 57 (1835).

Potamanttius stigma, Pict., Hist. Nat. Nevropt. ii. Ephem. 235 (1843-5) ; Walk., List Neuropt.

Brit. Mus. part iii. 541 (1853).— P. talcosus, Pict., op. cit. 234 (1843-5) ; Walk., op. cit. 541 (1853).—

P. marginatus, Hag., Ent. Ann. (1863), 17; id., Stet. ent. Zeit. xxvi. 229 (1864) ; Packard, Guide to

Study of Ins. ed. i. 595, fig. 577 (1870).

Leptoplilebia marginata, Etn., Trans. Ent. Soc. Lond. (1871), 84, pis. ii. 2 a (wing) & iv. 25, 25 a-b

[details]; Hag., op. di. (1873), 395 ; Meyer-Dur, Bull. Soc. Ent. Suisse, iv. 317(1874); Rostock,

Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 84 (1878).

Subimago {living). — Wings either sepia-brown- or grey-black-tinted, the hinder pair

either in part (towards the base) or altogether paler ; cross veinlets in the fore wing

and towards the terminal border of the hind wing narrowly edged with black-grey ;

neuration translucent yellowish.

Imago {living), 6 . — Eyes intense sepia-brown, or brown-black. Notum of thorax at

first pitch-brown, changing to jet-black. Abdomen pitch-brown, with the first 4-5 dorsal

joinings usually pale and translucent, the others flavescent or lutescent, and with the

last two or three ventral segments as well as the ventral ganglia pitch-brown, the former

with paler joinings ; but sometimes the pale dorsal segments are cinereous, with dark

spiracular lines and with luteous ventral ganglia. Pore legs pitch-black with cinereous

or greyish tarsi ; hinder legs dark pitch-brown, the tibiae and tarsi paler and often of a

pale reddish sepia-brown. Wings pellucid, with pale pitch-brown neuration, the fore

wings sometimes brown-tinted in the vicinage of the pterostigmatic space. Setae black

or greyish, with the joinings very narrowly opaque. Porceps paler than the 9th segment.

The reclinate appendages beneath the lobes of the penis are closely appressed to the

lobes, and are obliquely truncate at the points.

SECOND SERIES. — ZOOLOGY, VOL. III. 13

94 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES.

$ mucli like the c? , with the fore tihise pale reddish luteous ; abdomen opaque, pitch-

brown above, and intense sepia-brown beneath. Length of body 6-12 ; wing 6-11 ;

setae, <? im. 12-20, subim. 9, ? im. 8-16 mm.

Hab. Temperate and Arctic Europe and America ; also Turkestan (Fedtschenko Exp.).

In cold regions the flies appear in tlie height of summer, elsewhere in spring, early

summer, and the autumn. Mr. Albarda sent me specimens of a species found in Holland,

apparently distinct from, but very nearly related to, L. marginata. An accidental loss

of the detailed drawings precludes its description.

Leptophlebia submarginata, Steph.

Ephemera submarginata, ! Steph., 111. Brit. Eiit. vi. 58, no. 7 (1835). — E. dispar, ! id., op. cit. vi. 58,

no. 8 (1835).— £. helvipes, ! id., op. cit. vi. 59, no. 14 (1835).

Potamanthus Geerii, Pict., Hist. Nat. N^vropt. ii. Ephein. 211, pi. sxvi. 1-3 (1843-5) ; Walk., List

of Neuropt. Ins. in Brit. Mus. part iii. 541 (1853) ; Brauer, Neuropt. Austr. 27 (1857); Hag., Ent.

Ann. (1863), 18; Ausser., Ann. d. Soc. Natur. Modcna, An. iv. 136 (18G9).— P. dispar, Pict., Hist. Nat.

NevTopt. ii. Ephem. 234 (1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 542 (1853).—

P. helvipes, Pict., Hist. Nat. Nevropt. ii. IZphem. 235; Walk., List &c. part iii. 543 (1853). — P. submar-

ginatus, Pict., Hist. &c. 236 (1843-5) ; Walk., List &c. part iii. 545 (1853).

"^XBaetis reticulata, Burm., Handb. d. Ent. Bd. ii. Abth. ii. 801 (1839) ; Pict., Nat. Hist. Nevropt.

ii. Eph(5m. 192 (1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 561 (1853).

XCloeon J culiciformis, ! Walk., op. cit. part iii. 576 (1853).

Leptophlebia helvipes, ! Etn., Trans. Ent. Soc. London (1871), 85, pi. iv. 26-26 d [details] ; Meyer-

Diir, Bull. Soc. Ent. Suisse, iv. 317 (1874) ; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, p. 84

(1878).

Subhnago [living). — Wing-membrane fawn-colour or smoke-grey, with black cross

veinlets broadly edged with grey-black ; these are so arranged as to leave a clear space

of the ground-colour in the midst of the fore wing, extending transversely to a variable

distance from the costa, and sometimes enclosing a small group of crowded cross

veinlets adjacent to the bullae ; there is often another similarly pale space at the base of

the wing, reaching from the anal (8) nervure to the inner margin, and from the wing-

roots to the confines of the intercalar nervures of the anal-axillar interspace. Legs of 2

piceous, with black tarsi.

imago {living), 6. — Eyes dull rufo-piceous or dark purple-brown above, fuscous

beneath. Thorax jet-black above. Abdomen pitch-brown on the dorsum, with the

joinings of the intermediate segments whitish grey ; segments 7-10 darker than the

preceding, and with flavescent joinings. Venter light warm sepia-brown, with joinings

as above ; segments 8 and 9 pitch-brown, lutescent posteriorly ; dark rusty spots indicate

the ventral ganglia. Eorceps furfurosus. Setaa warm sepia-grey, with darker joinino-s.

Wings vitreous, with the stronger nervures furfurosus or amber-brown. Eore legs black,

with grey-black tarsi, or with the femur pitch-black, and the remainder black. Hinder

femora pitch-brown, the tibise and tarsi either dark warm sepia-grey, or sometimes

yellowish brown or fulvescent.

$ very like the 6 . Eyes pitch-brown. Setse reddish brown, with dark joinings.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 95

Length of body 9-11 ; wiug 10-13 ; setae, d iru. 12 & 13-14 & 16, subim. 7 ; $ im. 9-

13, subim. 9 & 10-10 & 12 mm.

JIab. Great Britain ; tlie Vosges (M''Lach.) ; Germany and Switzerland ; in streams,

lakes, and rivers. May to August. This species is easily distinguished from L. margi-

nata by the form of the penis. Each of the lobes is widely dilated at its extremity ; in

dorsal view tlie dilated part is seen to be prolonged laterally into a short deflexed lanceo-

late projection ; beneath the inner extremity of the lobe is a long slender subulate

reclinate spur-like appendage.

Leptophlebia castanea, Pict.

Potamanthus castaneus, Pict., Hist. Nat. Nevropt. ii. Ephem. 215, pi. xxvi. 4, 5 (1843-5) ; Walk.,

List of Neuropt. Jus. in Brit. Mus. part iii. 542 (1853).

Leptophlebia castanea, Etu., Trans. Ent. Soc. London (18ri), 86; Meyer-DUr, Bull. Soc. Ent. Suisse

iv. 310 (1874).

This species is distinguishable from L. submarginata by its smaller size, its thorax

being no darker than the abdomen (which is of a uniform chestnut-brown), traversed in

the mesonotum by a fine longitudinal light-coloured line. Legs and setae unicolorous

light brown. Wing-nervures whitisJi. Eyes of 6 brick-red above. Length of body, S ,

and setai 8 ; exj^anse of wings 17 mm.

Sab. At a swift stream at the extremity of Lake Leman, near the marals deVilleneuoe,

at the beginning of July. (After Pictet.) In 1879 I saw a 6 subimago, seemingly of

this species, in the Museum at Lyons.

Leptophlebia Meyeki, sp. nov, PL XL 17 d (penis).

Imago {dried), 6 . — Thorax polished, deep black above. Abdomen piceous, with

segments 3-6 or -7 translucent greenish-grey or brown. Wings vitreous ; fore wing with

the base and extremity of the costa, the subcosta and radius throughout, tinged with

piceous or amber-brown ; pterostigmatic space colourless, its veiulets somewhat crowded

and curved, many of them also branched, with their branchlets anastomosing towards

the costa. Legs dark piceous, the fore tarsus and the hinder tibiie and tarsi blackish

grey or fumatose, the last with the tips of the joints very narrowly darker. Ventral

ganglia rufescent ; forceps whitish ; setaj fumatose or white, with rufescent jomings.

Length of body 6-9 ; wing 7-10 mm.

Sab. Captured by Herr Meyer-Diir at Zurich and the Melch Alp, in July.— Easily

recognized by the uncinate penis-lobes.

Leptophlebia cixcta, Retz. PL XXXIL (nymph).

[Ephemera] or E. cincta [De G., Mem. pour serv. a Thist. d. Ins. ii. pars ii. 650, pi. xvii. 17-18

(1771)] ; Retz, C. De G. Gen. & Sp. Ins. 57 (1783).— £. J nigra, Fourcroy, Ent. Par. ii. 352 (1785).—

E. inanis, or lEphemera'] , [Zsch., Mus. Lcsk. i. 50, no. 15 (1789)] ; Gm^l., Linn. Syst. Nat. ed. xiii.

i. pars V. 2629 (1790) ; OL, Encycl. Meth. vi. 421 (1791).— £. ll albipennis, Eab., Ent. Syst. emend, iii.

pars i. 70 (1793).— £. % halterata, Shaw, Gen. Zool. vi. part ii. pi. Ixxxi. (1806).— -E. hijaliaata, Zet.,

Ins. Lap. col. 1044 (1840).

13*

96 EBV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

Potamanthus cinctus, Brauer, Neuropt. Austr. 27 (1857) ; Hag., Ent. Ann. (1863), 20; Ausser., Ann.

d. Soc. Natur. Modena, Ann. iv. 137 (1869).— P. inanis, Pict., Hist. Nat. Nevropt. ii. Ephem. 235

(1843-5); Walk., List of Neuropt. Ins. in Brit. Mas. part iii. 544 (1853).— P. Xhalteratus, Pict., Hist.

&c. 236 (1843-5) ; Walk., List &c. iii. 546 (1853).— P. hyalinus, Pict, Hist. &c. 237 (1843-5).

Cloefuscata, Pict, op. cit. 251, pi. xl. i. (1843-5) ; Oulianine, Neuropt. & Orthopt. of the Prov. of

Moscow, p. 28 (1867).

Cloeon fuscata, Walk., List of Neuropt. in Brit. Mus. part iii. 573 (1853).

Leptophlebia cincta, ! Etn., Trans. Ent. Soc. London (1871), 87, pi. iv. 27 [detail] ; Hag. & Etn., op.

cit. (1873), 396 ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 318 (1874) ; Rostock, Jahresb. d. Ver. f. Naturk.

Zwickau, 1877, p. 84 (1878).

Subhnago {living). — Wings black-grey [browner when dry], with the longitudinal

nervures indistinctly yellowish. Thorax pitch-brown or pitch-black. Abdomen in

segments 2-7 cinereous, the posterior segments fuscous, the joinings narrowly greyish-

white.

Imago {living), 6 . — Upper eyes warm sepia-brown ; lov/er eyes black. Thorax jet-

black above. Abdomen seldom, or in large examples, uniformly raw umber- or pitch-

brown above, usually so in segments 8-10 only, and in segments 2-7 vitreous ; these are

often faintly lutesccnt towards their hinder borders, their tracheae are partly black near

the spiracles, and the ventral nervous ganglia somewhat rusty ; joinings of the opaque

segments either light yellowish or reddish. Setaj and forceps whitish, the latter blackish

grey towards the base, and sometimes 4-jointed instead of 3-jointed. Penis-lobes slightly

divergent distally, each with a short acute projection on the outer side near the tip, and

a long slender acuminate reclinate spur beneath (figured by me in 1871). Legs white

or cretaceous, the fore femora darker than the hinder, the tibia? and tarsi in some lights

slightly tinged with testaceous. Wings vitreous ; the stronger longitudinal nervures in

opaque view faintly amber-colour (becoming pitch-brown in the dried insect) ; the

marginal area of the fore wing in specimens of average or large size contains 10-14 very

faint cross veinlets before the bulla, and beyond it 18-26, mostly stronger than the others,

sliffhtly sinuous, and in the pterostigmatic region commonly branched irregularly and

anastomosing near the costa ; in small examples there are about 8 before and 16 beyond

the bulla, and the latter are sinuous, but less irregular than those of large specimens.

2 {living). — Subsimilar to the d , with the stronger nervures of the wings piceous ;

the marginal area of the fore wing contains in large examples about 16 cross veinlets

before, and 25-27 beyond the bulla ; in small specimens, about 9 cross veinlets before,

and 18-20 beyond the bulla ; these in the pterostigmatic region are chiefly sinuous and

generally simple. Abdomen fusco-piceous, with yellowish joinings ; the setse and legs

testaceous, the hinder tarsi whitish. Length of body 7-8 ; wing 8-9 ; setae, d im. 8 & 9-

8 & 11, subim. 9 & 7 ; 2 im. 7 & 10-8 & 11 mm.

Hab. Northern and temperate Europe ; in streams and rivers during the summer and

autumn. Pictet probably confused this species with Habrophlebia lauta (to which his

description of Potamanthus % cinctus applies) because it was mingled with a Hahro-

phlebia in his collection, and is found in the neighbourhood of Geneva. In September

1879 I found both of these species beside a stream at Troinex, near Mt. Sal^ve.

EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 97

Leptophlebia vaciva, sp. nov.

Subimago (dried). — Wings dark sepia-grey, with light reddish brown longitudinal

nervures. Setae sepia-grey. Legs of ? in opaque view yellowish testaceous ; in trans-

mitted light yellowish amber-colour.

Imaffo [dried), <j . — Thorax jet-black above, at the sides pitch-black. Abdominal

segments 2-6 and the base of segment 7 transparent white, with opaque Avhite joinings

and burnt-umber brown ventral ganglia, the other segments pitch-brown above ; seg-

ment 8 beneath is moi*e of a warm sepia-brown, and segment 9 somewhat rusty or

reddened, the colouring extending a little into the forceps-basis. Seta? transparent,

white ; forceps-limbs cretaceous, tapering gradually from the base. Lobes of the

penis slender, each with a single short and slender acuminate barb-like lateral appendage

or process, projecting outwards obliquely at some distance before the tip. Fore legs in

opaque view bistre-brown or pitch-brown, changing in transmitted light to brownish

amber ; hinder legs in a large measure transparent whitish, but tinged with a similar

brownish tint towards the distal extremities of the femora and the extreme bases of the

tibiae, as well as in a still fainter degree towards the extremities of the tarsi. "Wings

vitreous, with the stronger longitudinal nervures light pitch-brown, changing with light

transmitted to brownish amber ; in the pterostigmatic space of the fore wing are about

8-12 slightly curved cross veinlets of a like colour, mostly simple and thickened towards

the subcosta ; in the remainder of the marginal area the cross veinlets are very indistinct.

Length of body, d 7o, wing 8 mm.

Rab. Mt. Hood, Oregon (M^Lach. Mus.).

Leptophlebia mollis. Hag. MS. Plate XI. 17 b (forceps, from side and wings).

Cloe mollis, ! Hag., MS. (1861).

Leptophlebia mollis, ! Etn., Trans. Ent. Soc. London (1871), 88, pi. iv. 28 [details].

Subimago {dried).— Wm^^ very light brownish white. Thorax dark brownish.

hiago {dried).— 6 . Thorax above either pitch-black, luteo-piceous, or rufo-piceous.

Abdomen in segments 2-7 translucent whitisli, the tips of the dorsal and sometimes also

of the ventral segments greyish, and the ventral ganglia rufescent ; segments 10-8 and

the extremity of segment 7 rufo-piceous or luteo-piceous. Forceps-limbs dilated some-

what suddenly towards the base. Coxse and fore femora towards the tips in opaque view

somewhat light testaceous or rufo-piceous, changing in transmitted light to pale amber ;

hinder femora lighter ; the rest of the legs dirty whitish, the fore tibia at its extremities

slightly testaceous, and in some lights changing throughout to dull yellowish amber.

Wings vitreous, the neuration mostly colourless, but the subcosta, great cross vein, and

base of the costa in some lights slightly discoloured. Setae whitish or greyish, dark or

reddish at the joinings.

2 . Body polished, dark pitch-brown, the dorsal abdominal segments darker at the

joinings. Setfe white. Legs all whitish, only faintly discoloured towards the ends of

the femora. Wing-nervures more nearly colourless than in the c? . Length of body 6-7,

wing 8 ; set. c^ im. about 11 ; 2 im. about 6 mm.

98 EEV. A. E. EATON ON EECENT EPIIEMEKID.E OE MAT^LIES.

Hab. New Hampshire, on Mount Wasliington (M''Lach. Mus.), and in May at Amherst

(Mus. Comp. Zool. Cambridge, Mass.). Also West Parms, N. Y. ; AVorcester, Mass. ; and

North Carolina (in the same collections). Two examples are ticketed Washington Ter-

ritory in M''Lach. Mus.

Leptophlebia memorialis (renamed).

Leptophlebia\\ pallipes,\ Hag., Ann. Rep. U.S. Geolog. and Geograph. Survey of the TeiT. 1873,

part iii. Zool. 582 (1875).

Imago {dried), S . — Body pitch-brown ; the head rather brighter and redder or chestnut-

brown, but pitch-black at the orbits of the ocelli, in two depressions behind them on the

vertex, and in the middle of the occipital crest ; thorax rather darker at the sides ;

abdomen growing darker above in segs. 7-10, the first segment broadly and the others

narrowly bordered with pitch-black at the tips above ; the spiracular line dark, the

ventral lobe of the 9th segment pale, bifid, with elliptical segments. Wings vitreous,

with almost colourless neuration ; the longitudinal uervures, distally, tinged faintly with

very pale brownish ; marginal area of the foi'e wing Avitli about 8 evanescent cross

veinlets before the nodal point, and about 17 (only well defined in the ptcrostigmatic

space) be;iond it, mostly simple and almost straight. Legs pale yellovvish Avhite, the

femora faintly tinged with brownish distally, the fore coxa pale, the hinder coxae pitch,

brown, the first three tarsal joints faintly brown-tinted. Length of body G, wing

7 mm.

Hab. Truckee, Nevada, in the Sierra Nevada (G. R. Crotch, in Mus. Comp. Zool.

Cambridge, Mass.). AVith a low power, the legs in some lights seem uniformly pale

brownish white. The name pall'ipes having been preoccupied by Walker in the unre-

stricted genvis Leptophlebia, I have assigned another to this species, which has reference

to its original captor, whose untimely death was primarily due to exposure in the course

of the expedition when the insect was obtained.

Leptophlebia debilis, Walk.

XBaetis ,dtbilis,\ Walk., List of Neui'opt. Ins. in Brit. Mus. part iii. 5G9 (1853); Hag., Smithson.

Miscell. Coll. (1861), Synop. Neuropt. N. Am. 46.

The description of this " museum species " was based upon a single ? imago, whose

generical afldnities were misunderstood by Mr. Walker. In 1871 I cited it as synony-

mous with XPalingenia concinna, XP.palUpes, and probably with %Ephemera hebes of the

same author {i.e. Blasturus cupidus. Say) ; but having re-examined the type specimen, I

now believe it to be a Leptophlebia, not yet definitely described.

Leptophlebia gregalis, sp. nov.

Subimago {dried). — Eore wings very light brownish grey, with the stronger nervures

in opaque view dull light rufo-piceous ; in some other positions their colour is that of the

membrane. Hind wings whitish grey, with yellowish white neuration. Seta> light

brownish grey. Legs rather paler than in the imago.

Imago {dried). — j . Body reddish pitch-brown ; thorax sometimes nearly pitch-black

KEV. A. E. EATON ON EECENT EPHEMERID/E OR MAYFLIES. 99

above; abdominal joinings opaque. Setse rusty whitish or drab, with their bases rusty

Forceps-limbs light rusty-brown. Inferior spurs of the penis-lobes obliquely deflected,

broadly compressed and acuminate. Legs rufescent brown, changing to rufescent amber

in transmitted liglit ; the fore tarsus, and the tibiae and tarsi of the hinder legs, rather

lighter than tlie remainder. Wings vitreous, with the longitudinal neuration and the

opaque cross-veinlets of the pterostigmatic space of the fore wing light rufo-piceous;

these are somewhat irregular and variable, sometimes sparsely branched and anasto-

mosing, and are about 12-lG in number.

? very similar to the d . Setaj whitish. Hind tibite and tarsi whitish, with the

extreme base of the tibia, the ungues, terminal joint, and the distal borders of the other

joints of tlie tarsus, rufescent brownisli. Wings nearly as in c? , but the nervures

posterior to the cubitus of the fore wing arc practically colourless ; the marginal area

contains about 10 weak cross veinlets between the great cross vein and the bulla, and

17-21 (mostly stronger) beyond that ; these are usually simple, and many of tliem

tapering towards the costa arc slightly curved. Length of body 8, wing, 6 8-9, 2 7-9,

setae, d 14 mm.

Bab. Mount Ilood, Oregon (M'^Lach. Mus.).

Leptophlebia rufivenosa, sp. nov.

Siibhnago (dried), 2 ■ — Wings transparent, light yellowish brown-gi'ey ; their neuration

in opaque view light ferruginous brown, changing in transmitted light to rufo-piceous.

Setae (Vandyke) brownish grey.

Imago (dried), ? .—Body brownish piceous, or dark rufo-piceous, with the joinings of

the abdominal segments of empty specimens opaque. Setse somewhat lighter than in the

subimago, with the joinings towards the roots, in large examples, opaqiie and narrowly

rufo-piceous. Fore femur in opaque view intense (ferruginous) brown-ochre, the tibia

and tarsus much lighter or somewhat testaceous ; the leg reflects a warm ferruginous

tint ; in transmitted light the femur and tibia are of a ferruginous amber-colour, the

trochanter and tarsus paler. Hinder legs rather lighter than the fore legs. Wings

transparent, the membrane lightly and uniformly tinted, and the neuration strongly

coloured with ferruginous ochre, the latter reflecting a reddish or golden brown and

transmitting a rich amber-colour. The marginal area of the fore Aving contains 7-8

cross veinlets before the bulla, and 17-20 beyond it ; those in the pterostigmatic region

are simple and slightly sinuous in small specimens, but in large examples are apt to be

irregular in some degree, and to anastomose in parts with one another. Length of body,

? 6-8, wing 7-10, setse ira. 8-10 mm.

Sab. Mount Hood ; Washington Territory (M'^Lach. Mus.) ; S. Raphael, Cal. (Osten-

Sacken, in Mus. Comp. Zool. Cambridge, Mass.), March 7th.

(?) Leptophlebia prj^pedita, sp. nov. Plate XI. 17 c (forceps and penis, in two

positions).

Subimago (dried). — Wings sepia-grey, with pitch-brown neuration. Setse sepia-brown.

Imago (dried), d .—Thorax jet-black above ; alidomen pitch-brown, sometimes light

100 EEV. A. E. EATON ON RECENT EPHEMERID^ OE MAYFLIES,

pitch-brown, with joinings 2-7 opaque ; venter probably lighter than the dorsum, and

more of a warm sepia-brown. Setas warm sepia-brown. Legs pitch-brown, the fore tarsus

and the hinder legs rather lighter than the fore femur. Wings vitreous, with a faint

brownish grey tint; their neuration, in opaque view pitch-brown, transmits a brown

amber-colour ; the marginal area of the fore wing contains 3-7 indistinct cross veinlets

before the bulla, and 11-14, mostly well defined, beyond it, those in the pterostigmatic

region are simple and usually slightly curved. The form of the genitalia is noteworthy.

Length of body 5, wing 5-6 mm.

Hab. Dedham, Mass. (M'^Lach. Mus.). The apparent presence of a short joint next to

the basis in the forceps-limbs is the sole cause of my hesitation in ranking this species in

Leptophlebia.

I have seen specimens of several other North- American species of Leptophlehia, but not

sufficient for their description.

BLASTURUS, Etn. 1881.

Illustrations. Adult (details) PL XL 18. Ni/mph PI. XXXIIL, see also {?)B. ves-

pertinus, L., below.

Adult. — Similar to Lep)topldebia in the form and neuration of the wings, the structure

of the mesothoracic spiracle, the 3 genitalia (in the known species conformable to those

of L. niarginata), the ventral lobe of the 9th $ abdominal segment, the legs, and the

ungues of the tarsi ; differing from that genus in the proportional lengths of the caudal

setie, which vary with the species. Median seta considerably shorter than the others ;

outer seta; in d 2-3 times as long as the body, median from f-1 the length of the body ;

outer setse in $ l^-lf, median \—^ as long as the body.

Nymj)h (judging from its structure) latent ; abdominal tracheal branchiae diversiform,

foliaceous and fringeless ; those of segment 1 bifid, with minutely hairy linear-lanceo-

late divisions ; those of the other 6 pairs reclinate upon the sides of the dorsum,

and formed of jugate, obliquely subovate, tail-pointed lamellae, whose cusps are minutely

hairy at the edges, and are traversed longitudinally by the main tracheai of the lamellae.

The following slight diff'erences are noticeable in the outlines of these lamellae : — in those

of segments 2-6 the outer division of the twin lamella, at the base of the cusp, is incised

on one side and has a sinus on the other side, while the inner division is incised on both

sides of the cusp ; but in those of segment 7 are no incisions. Caudal setae defective in

the specimens examined. Fangs of the mandibles in a large measure similar to those of

Leptophlehia', the endopodite slender, somewhat abrupt, and furnished with a slender

brush of hair. Palpus of maxilla i. slender ; tlie last 2 joints together constitute little

more than half of the whole. Lacinia of maxilla ii. broad, nearly in the form of the

quadrant of a circle. Tongue rotundly subquadrate ; paraglossse broadly rounded.

Abdomen slightly dilated in the middle ; hinder lateral angles of segments 8 and 9

shortly and acutely produced. Hind leg a little the longest ; the tarsus (excluding the

claw) ^ as long as the tibia.

Type. B. cupidus (in Ephemera), Say.

Distribution. Temperate N. America, and perhaps Scandinavia.

REV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 101

Etymology. jSAatrTovw and ov^a, from the median caudal seta resembling one that is

sprouting forth and not fally developed.

The wings of Blasturus figured in PI. XI. belonged to a large specimen ; in those of

smaller examples the branchlets of the nervures along the terminal margin are less

intricate, as a rule, and similar to those shown in the illustration of Leptophlehia. The

nymphs were communicated to me by Dr. Ilagen, and were identified generically mainly

by the wing-neuration and stature of specimens of mature growth, taken into consideration

with their native localities. No aid towards the discrimination of the species described is

afforded by the shape of the penis in the dried insects.

Blasttjrus ctjpidus. Say. Plate XI. 18 (adult wings and legs), XXXIII. (nymph?).

Ephemera cupida. Say, West. Quart. Rep. ii. 163 (1823) ; Lc Contc, Complete Writings of T. Say, i.

173 (1859).— i;. Hebes, Walk., List of Neuropt. Ins. in Brit. Mus. part iii. .538 (1853)?.

PaUngenia pallipes ! & concinna, ! Walk., op. cH. 553 (1853).

Potamanthus cupidus & concinnus, Hag., Smithson. Miscell. Coll. (18G1), Synop. Neuropt. N. Am. 51;

(cupidus), Walsh, Proc. Acad. Nat. Sc. Philad. (1862), 372; Hag., Proc.Ent. See. Philad. ii. 172 (1863).

XBa'etis ignava ! Hag., Smithson, &c. 47 (1861).

Leptophlebia cupida (part), ! Etn., Ti-ans. Ent. Soc. London (1871), 89, pis. ii. 26 & iv. 29-29 <!-

[details] .

Blasturus cupidus !, Etn., Ent. Mo. Mag. xvii. 193 (1881) .—B. concinnus, ! id., in the writing of PL XL

Subimago {dried). — Wings light sepia-grey, with dark nem-ation, but with the mem

brane and neuration at the wing-roots and in the axillary area of the fore wing, and to a

larger extent at the base of the hind wing, paler or even dull yellowish whitish, especially

in the ? . Median seta in 6 rather more than I as long as the outer seta?, and so in the

? , but in a less degree.

Imago {dried). — Median seta about J as long as the outer setae in the 6 , and about ^

in the $ . Pterostigmatic portion of the fore wing tinged slightly with brownish in the

6 ; marginal area in the 6 with 9-15 (commonly 10) cross veinlets before the bulla and

27-33 beyond it, but in the ? 9-13 before and 19-23 beyond (counting along the sub-

costa) ; those in the pterostigmatic region rather irregular, somewhat curved, and some-

times forked and anastomosing near the costa.

d . Thorax pitch-black, varied at the sides and beneath with rufo-piceous. Abdomen

discoloured ; dorsum pitch-brown, with narrow yellowish joinings, sometimes varied with

rufo-piceous in aged cabinet specimens, often in some degree translucent in the midst ;

venter in segments 2-8 pale dull rufo-piceous or subtestaceous, segment 9 rufo-piceous ;

forceps dull yellowish brown or rufo-testaceous, sometimes darkened distally. Fore legs

dark pitch-brown, the tarsi sometimes lighter ; hinder legs in opaque view either light

pitch-brown or (in a specimen from Milford, N.H.) dull bronze-brown, changing in

transmitted light to deep amber and light yellow-amber respectively. Wing-neuration

light pitch-brown, changing in transmitted light to rufous or light amber; the cross

veinlets before the bulla in the marginal area of the fore wing very indistinct.

$ . Head rufescent, the vertex with a large pitch-black blotch in the midst on the

occipital border, and another about the ocelU. Thorax piceous above, the pronotum

SECOND SERIES. — ZOOLOGY, VOL. III. ^"^

102 EEV. A E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

varied with slightly prominent rufescent markings. Abdomen discoloured, the venter

rather redder than the dorsum. Setee sepia-grey, annulated at the joinings with piceous,

the median seta lighter than the others ; the annulations of the outer setae towards the

roots, and again towards the tips, are subequal to one another in breadth, but many in

the intervening portion of the seta are alternately narrow and broad. Wings vitreous,

tinted very slightly throughout, and in the distal portions of the marginal and submar-

ginal areas of the fore wing rather more perceptibly, with light yellowish-brownish ;

neuration pitch-brown, changing to golden brown in transmitted light, but lighter in

colour in the parts corresponding with the paler regions of the subimago's wings. Fore

legs pitch-brown ; the hinder legs rather lighter and more nearly rufescent- or lutescent-

piceous in opaque view, changing in transmitted light to rufous; in some lights the

tarsi aj)pear browner than the tibite, and these, in their turn, lighter than the femora.

Variety (from North Carolina). — "Wings of subimago more nearly uniformly sepia-

grey, and somewhat darker in tint than in normal specimens. Wings of imago clearer,

and in the s not tinged with brownish in the pterostigmatic region ; their neuration

lighter in colour.

Length of body 9-11 ; wing 10-5-12 ; seta3, 6 im. about 30 & 7, subim. about 11 &

7 ; 2 im. 17 & 6, subim. about 13 & 7 mm.

Sal). Cincinnati, Ohio (Say) ; Nova Scotia and (?) Newfoundland (Walker) ; Canada,

West Earms, N. Y., and Mt. Washington, N. H. (M''Lach. Mus.) ; Milford, N. H., Andover,

Me., and Morganton, N. C. (Hagen Mus.). The variation in colour of the N. C. examples

noted above may prove to be merely due to the advanced age of individual subimagines,

and premature death of imagines, respectively.

Blastukus gravastelltjs, sp. nov.

Subimago (dried). — Wings light grey, with dark neuration; the base of the hind wing

and the axillaiy region of the fore wing very little paler than the remainder of the

membrane, althovigh the main nervures are rather pale towards the roots.

Imago [dried). — Median seta of d about ^ as long as the outer seta?; that of $ about

§ or f as long as the outer. Pterostigmatic portion of the fore wing very faintly obscured

in 6 ; the marginal area in 6 contains 7-9 cross veinlets before the bulla and 19-22

beyond it, in $ 9-11 before and 19-24 beyond the l}ulla ; those in the pterostigmatic

space are slightly curved, and often branch irregularly in parts so as to anastomose with

one another near the costa.

6 . Very similar to B. cupidiis ; pleurae and sternum varied in a lesser degree witli

rufo-piceous ; dorsum of abdomen more uniformly pitch-brown ; venter less brightly

coloured, segments 7 and 8 unicolorous, segment 9 not at all strongly contrasted in

colour with those preceding it ; forceps unicolorous, light testaceous ; setae sepia-grey,

annulated with piceous at the joinings, the annulations narrower and less unequal in

breadth than those of B. ctipidus 2 . Fore legs in opaque view uniformly pitch-brown ;

hinder legs luteo-piceous, changing in transmitted light to golden brown or rich amber,

with the extreme edges of their tarsal joinings faintly darker. Fore wings vitreous;

EEV. A. E. EATON ON RECENT EPHEMERIDyE OR MAYFLIES. 103

neuration in opaque view for the most part colourless, but the subcosta and radius as

well as the distal portion of the costa light umber-brown, changing in transmitted light

to pale brownish amber.

S . Head as in B. cupidiis. Thorax pitch-brown above ; pronotum pitch-black in the

middle, but towards the sides lighter than that of B. cupichis. Setaj subsimilar to those

of the same species, but of a warmer tint. Wings vitreous, not tinted in the ptero-

stigmatic space ; neuration not so dark as in B. mipidus. Fore legs in opaque view light

pitch-brown, with the trochanter and base of the tibia dull pale yellowish brown, and

the tarsus more opaque than the tibia ; the femur and tibia reflect a rufo-piceous tint,

the tarsus a dark reddish brown : in transmitted light their prevailing colour is dark

amber-brown. Hinder legs in opaque view either apparently of lighter shades of the

same colours as the fore legs, or more of a light bistre-brown ; their reflection is raw

umber-brown ; in transmitted light their colour is yellow-amber, and the tarsal joinings

arc narrowly opaque. Length of body 8-10 ; wing 8-12 ; sette, im. d 17 & 8-18 & 9,

$ 12 &, 9-5-17-3 & 13 mm.

Hah. Montana (M'^Lach. Mus.). A species smaller and lighter in colour than B.

cupidns.

Blasturtjs nebulosus, Walk.

Palingenia nebulosa, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 554 (1853) .

Potamanthus nebidosus, Hag., Smitlison. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 52; Walsh,

Proc. Eut. Soc. Pbilad. ii. 193, note 13, 194, note 15 (18G3).— P. odonatus, Walsh, Proc. Acad. Nat. Sc.

Philad. (18G2), 372; Hag., Proc. Ent. Soc. Philad. ii. 171 (1863).

Leptophlebia nebulosa, ! Etn., Trans. Ent. Soc. London (1871), 89, pi. v. 1-1 a [details].

Imago {dried) 6 . — Thorax jet-black above. Abdomen pitch-brown above, dull light

bm-nt-umber brown beneath. Forceps either uniformly light umber-brownish, or very

light dull yellowish ochre at the base, passing distally into light brownish. Seta? light

Vandyke-brown, with pitch-brown joinings. Fore legs rufo-piceous, the tarsi lighter ;

hinder legs either testaceous or dull translucent, almost raw-umber brown. Wings

vitreous, with rufo-piceous neuration ; the fore wing with a large round light raw-umber

cloud in its apical third ; its marginal area with 7 faint cross veinlets before the bulla

and about 22 beyond it, many of which in the pterostigmatic space fork near the costa

and anastomose with one another. Length of body 10, wing 10-11, setae 30 »& 6 mm.

Hah. St. Martin's Falls, Albany river, Hudson's Bay (Brit. Mus.) ; Rock Island, 111.

{Walsh).

(?) Blasttjetjs vespektinus, Lin.

Ephemera vespertina or [Ephemera], Lin., [GElandska Ecsa, p. 21 (1745); Fu. Suec. ed. i. 755 (1746) ;

Syst. ed. x. i. 547 (1758) ; Fu. Suec. cd. ii. 378 (1761)J ; id., Syst. Nat, ed. xii, pars ii. 906 (1767);

[De G., Mem. pour scrvir h Phist. d. lus. ii. pars ii. 646, pi. xvii. 11-16 (1771) ;] Zet., Ins. Lap.

col. 1015 (1840); Westw., Introd. mod. classif. lus. ii. fig. 61, no. 19, after De Geer (1840).

Subimago {dried).— EoAj and fore wings black ; hind wings white. One of the smaller

species of the family.

Hah. Plentiful at the river Sathaella, in Smoland. [Abstract from Linne.] De Geer's

14*

104 EEV, A. E. EATON ON EECENT EPHEMEEIDvE OR MAYFLIES.

whole-figure of the nymph is fairly characteristic of a Blasturus; but tliat of the

detached gill (fig. 13) differs from the typical tracheal branchiae of this genus in having

the slender tail-points of the laminae in complete continuity with rest of the membrane.

It is needless to detail references to Geoffroy, Fabricius, Berkenhout, Gm^lin, Eossi,

Schranck, Cederhjelm, Walckenaer, Latreille, and Stewart, who quote Linne's diagnosis.

In 1871 I ranked E. vespertina with the typical species of Leptophlehia, citing as

synonyms Ephemera albqyennis, Eetz. no. 181 (1783), and Baetis fusca, Burm., Handb.

der Ent. Bd. ii. Abth. ii. 800 (1839). It was cited as a Cloe by Oulianine in 1867.

CHOROTERPES, Etn. 1881.

niusirations. Adult (details), PI. XII. 19; (whole figures) see Pictet, Potamanthus

X marginatus, op. c'd. pi. 25 (1843-5). Nymph, PL XXXIV.

Adult. — Hind wing in front strongly and somewhat obtusely angulated nearly midway

between the tip and the wing-roots, the angle, roughly speaking, forming the vertex of

an obtuse triangle whose base is the radius (3) ; the exterior side of the triangle is not

straight, presenting a shallow sinus about the extremity of the subcosta (2), followed by

a very slight salient curve ; its other side is somewhat rounded off at the wing-roots ;

the very gently curved subcosta lies rather nearer to the costa than to the radius, and

terminates obliquely in the margin a little beyond the salient angle, in the vicinage of

which the narrow marginal area is slightly dilated ; the submarginal area is subtriangular,

with the vertex obtuse ; several cross veinlets occupy the distal ^ of the former area, and a

larger number the adjoining f of the latter area. Cross veinlets plentiful towards the

apex of the fore wing, but sparse elsewhere ; next to none present in the marginal area

before the bulla; in the hind wing they are faudy numerous. The nervures of both

wings are devoid of branchlets at the terminal region, and there are no isolated veinlets

there. The axillar nervures (9' and 9-) of the fore wing, strongly arched and mutually

subparallel in the specimen figured, are often disposed in a manner similar to those of

the wing represented in PI. XIII. 20 * -. The anal-axillar interspace of the fore wing

contains four intercalary nervures, of which 1 and 3 are long, 2 and 4 short ; they are

commonly abrupt and linked together by few cross veinlets ; very frequently intercalar 1

is connected with the anal by several cross veinlets, and occasionally intercalar 3 esta-

blishes direct communication with the first axillar ; intercalars 2 and 4 sometimes remain

isolated from the others. The guard is lacking at the orifice of the mesothoracic spiracle.

Porceps-limbs of 6 4-jointed ; joints 1, 3, and 4 short, the 2nd joint long, somewhat

incurved, moderately compressed, and rather broadly dilated beneath at the base ; forceps-

basis short and stout, slightly emarginate in the middle ; the corresponding ventral lobe

of ? obtusely rounded and entire at its extremity. Median caudal seta subequal to the

others ; outer setse of 6 about 11^ as long as the body. Tarsal ungues dissimilar each

to the other. Pore tarsus of 6 nearly as long as the tibia, which is about If as long

as the femur ; the joints in diminishing sequence rank 2, 3, 4, 5, and 1 ; hind tarsus

(exclusive of joint 1) nearly \ as long as the tibia and joint 1 combined; its joints rank

5, 1-3 (subequal), and 4 ; joint 1 is fairly defined.

EEV. A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES. 105

Nymph latent ; abdominal tracheal branchiae diversiform ; those of segment 1 single,

linear-lanceolate and minutely hairy ; those of the other segments imbricate lengthwise

at the sides of the dorsum, and formed of jugate, foliaceous lamellse, oblique at the base

and (speaking roughly) cuspidate at the extremity ; in each twin the laminae are unequal

in size and rather dissimilar in form, the soialler being obliquely ovate, the larger

obliquely subcordate-ovate, with one of the auricles large ; the terminal cusp of both is

effectively discontinuous with the major portion of the lamina (through the membrane

on each side of its base being deeply incised) and is commonly turned upon its longer

axis so as to lie in a plane at right angles with that of the other portion ; the cusps are

wider than those of Blasturus, for the most part, and less prolonged. Fangs of the

mandibles abrupt ; the brush of the endopodite tapers obliquely to a slender point.

Palpus of maxilla i slender; joints 2 and 3, together, slightly longer than joint 1.

Lacinise of the 2nd maxillae rather broader, and the lobes of the labium smaller, than

those of Blasturns. Tongue produced in the middle into an obtuse emarginate lobe,

and prolonged on each side into a slender curved claw-like projection ; paragiossiB acute

laterally, rounded in front. Abdomen slender, the hinder lateral angles of the inter-

mediate segments shortly and acutely produced. Caudal setae about twice as long as the

body. Hind leg a little the longest ; the tarsus nearly J as long as the tibia (the claw

excluded).

Type. Cli. Picteti, Etn.

Distribution. Europe southwards of Belgium and Saxony ; America (undescribed sp.),

Arizona.

Etymology . yo^oc, and regxw, delighting in the dance.

The figures of the tracheal branchiae do not display the peculiar trending of the cusps

of the laminae, owing to then' having been subjected to pressure, when drawn, in order

to exhibit their outline. The species from Arizona is represented by two subimagines in

Mr. M'Lachlan's collection. Identification of the nymph was accomplished by dii-ect

observation in the field.

Choboterpes picteti, Etn. Plate XII. 19 (wings, legs, forceps, and penis).

Potamanthus % maryinatus, Pict., Hist. Nat. Nevropt. ii. Epliem. 208. pi. xxv. 4, 5 (18i3-5) ; Walk.,

List of Neuropt. in Brit. Mus. part iii. 540 (1858) ; ? Ouliauiue, Neuropt. & Orthopt. of Prov. of Moscow,

27(1867).

LeptophleUa Picteti, Etn., Trans. Ent. Soc. Loncl. (1871), 87; ! if/., op. cit. (1873), 395; ! Rostock,

Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 84 (1878).

HabropJilebia Picteti, \ Etn., Ent. Mo. Mag. xvii. 196 (1881) [citation].

Clioroterpes [type] limtanica,\ id., op. cit. xvi. 194 (Feb. 1881).—! Cti. Picteti (Etn. MS.), M<^Lacli.,

Compt.-rend. Soc. Ent. Belg. xxv. 135 (1881).

SuMmago {Hmny).—\N\n^s, uniformly purplish black. Legs and setae dark piceous;

tibiae and tarsi at first reddish piceous.

Imago {living), d .—Upper portion of eyes intense warm sepia-brown. Thorax jet-

black above. Abdomen pitch-black, with pale rufescent joinings ; penultimate ventral

segment distinctly, and a few of the segments anterior to it faintly, tinged posteriorly

with rufescent ; forceps-limbs rufescent interiorly and distally ; penis and setae pitch-

106 EEV. A. E. EATON ON RECENT EPHEMEEID^ OE MAYFLIES.

black. Legs pitch-black ; fore tarsus scarcely paler ; hinder tibite and tarsi rufescent-

piceous, the latter somewhat darker than the former. Wings vitreous with a somewhat

talcose gloss ; fore wing tinged with blackish (or in the dried insect, with fuscous) in.

the marginal and submarginal areas ; neuration piceous, the costa somewhat testaceous

at the base ; cross veinlets numerous in the marginal area of the fore wing, numbering

about 6 before the bulla and 16 beyond it ; those in the pterostigmatic region anas-

tomose irregularly with one another. Length of body 10; wing 10; setae, <S im. 12,

subim. 9 & 12 mm.

Hab. Widely distributed in Europe, ranging from Belgium and Heidelberg (M°Lach.),

Dresden (Herr C. Schiller), and Switzerland (Pict.), to southern Italy and Portugal.

The nymph inhabits gently flowing shallow water, and attains maturity in summer

and autumn.

THRAULUS, Etn. 1881.

Illu8tratio7is. Adult (details), PI. XII. 20, and XIII. 20*, 2, 3. Nijmph, PI. XXXV.

Adult. — Hind wing strongly and obtusely angulated in front, the angle in normal

species more nearly right-angled than in Ghorulerpes, placed almost in the middle of the

fore margin, and followed directly by a well-defined sinus at the termination of the sub-

costa (2) ; marginal area oblong, truncate distally, and, after the great cross vein, of

nearly uniform width ; submarginal area trilateral, the radius (3) somewhat undulated

in the typical species, the angles adjacent to it very acute, that subtended by it rather

obtuse : in the marginal area, and in direct proximity to the salient angle, a single

strong cross veinlet (or two at the most) communicates between the costa and the sub-

costa ; in the submarginal area are 2 or 3 between the subcosta and the radius, seldom

followed by a few others between the radius and the fore margin. Cross veinlets in the

normal species numerous in the fore wing, excepting near the terminal and inner margins,

which have no isolated veinlets ; they are absent also from the marginal and sub-

marginal areas l)efore the bulla. The nervures of both wings in the typical species are

generally 'branchless at the terminal margin ; when any branchlets do occur, which is

bul; seldom, they are very -scanty, simple, and peculiar to the individual wing. [Devia-

tions from the normal type of neuration are described below in the paragraph following

the definition of the genus.] The anal-axillar interspace of the fore wing contains

2, 4, or 5 intercalary nervures, two of them long, the others short ; when there are

two only, they extend | of the distance towards the wing-roots, and communicate by few

cross veinlets with both of the nearest nervures ; when 4 are present, the two shorter are

placed as in Choroterjies, all communicate more or less both mutually and with the said

nervures by cross veinlets, and all terminate abruptly ; when there are 5, the fifth shares

with another the intersj)ace between the longest two. The orifice of the mesothoracic

spiracle has valves only and lacks the guard. Porceps-limbs of cf 3-jointed ; the proximal

joint much longer than the remainder, and more or less dilated towards the base ; the

dilatation gradual in normal species. Eorceps basis short, entire ; homologous ventral

lobe of ? obtusely rounded at its extremity. ., Caudal setce 3, subequal in. length to each

other, mutilated in the typical specimens. Ungues in every tarsus dissimilar each to the

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE JMAYFLIES. 107

other ; fore tarsus of d subequal in length to the tibia, which is nearly twice as long as

the feniLir; the joints in diminishing sequence rank 2, 3, 4, 5, and 1. Hind tarsus

(including joint 1) nearly ^ as long as the tibia; its joints rank 5, 2 subequal to 3,

1 and 4; the proximal joint is ill defined in dried examples. Nymph latent ; abdominal

tracheal branchise all bipartite ; those of segment 1 with simple tiliform divisions beset

with short minute hairs ; those of the other segments decumbent upon the sides of the

dorsum, with simple oblong-ovate foliaceous divisions, fimbriate simply at the margins.

Caudal sette about as long as the body, similar to those of LeptopJdebia. Mandibles,

labium and second maxillae, tongue and paraglossae, very similar to those of Choroterpes ;

but the last are abrupt and emarginate, instead of acute, at the tips. MaxiUa i. also

subsimilar to that of Choroterpes ; but there is no spine below the subterminal series of

pectinate setulre on the lacinia, the palpus proportionally is rather shorter, and joints

2 and 3 together are subequal to 1 in length. Abdomen slender, slightly dilated at

the sides ; the hinder latei'al angles of segments 8 and 9 shortly prolonged and acute.

Hind leg rather the longest ; the tarsus (claw excluded) about \ as long as the tibia.

Type. Th. bellus, Etn.

Distribution. Portugal ; Central America (an undescribed sp.) ; also (provisionally

referred species) Columbia and Lahat.

Etymology, OpavXoc, fragile.

The nymph of the typical species was identified, chiefly by inference from the local

fauna of the stream where it was found, and partly by the structure of the genitalia

of advanced specimens. The neuration of the fore wings of certain Central- and South-

American species provisionally referred here {Th. mexicimas &c.) departs slightly from

the type in the following particulars :— Cross veinlets are plentiful in proximity to the

terminal margin, and the longitudinal nervures terminating in that margin are more

frequently branched than in normal species. The intercalar uerviu-es of the anal axillar

interspace towards their anterior extremities curve forwards to uoite each with the

nervure next in advance, in the manner usual in species of Atalophlebia. Some of these

species have cross veinlets before the bulla in the marginal area.

Thraulus belltjs, Etn. Plate XII. 20 (wings, legs, forceps, and penis). Nymph,

Plate XXXV.

Thraulus bellus, ! Etn., Ent. Mo. Mag. xvii. 195 (1881).

Subimago. — Wings light blackish grey.

Imago {living), <3 .—Eyes intense warm sepia-brown. Body blackish piceous ; thorax

jet-black above, with pale sutures. Legs piceous ; the fore tarsi blackish, the hinder

tibice and tarsi lighter. Wings vitreous, with light pitch-brown neuration ; the margmal

area of the fore wing contains about 12 weU-defined and 3-4 very indistinct straight

cross veinlets in the pterostigmatic region, but none before the bulla. Length of body,

d 8, ? 7 mm.

Hab. Portugal, in the stream below Cintra. The nymph was discovered at the end of

April 1880.. To find the imago, I revisited the locality on the 1st of June, early in the

108 EEV A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES.

morning (8-10 a.m.) before the sea-breeze arose. The only specimens of the adult and

subimago obtained were struggling in a spider's web.

Thraulus signatus, Hag.

Cloe signata, ! Hag., Verh. zool.-bot. Gesells. Wien, viii. 477 (1858), & ix. 206 (1859) ; [Gen. ?],

Etn., Trans. Ent. Soc. London (1871), 131, note.

Leptophlebia (Etn.) signata, Hag., op. cit. (1873), 395.

Subimago (dried). — Wings talcose, transparent, dark sepia-grey, with concolorous

neuration. Seta? of a Hke colour, with dark joinings. Thorax dull pitch-brown ; legs of

duller colour than those of the imago.

Imago {dried). — s . Thorax polished, bright pitch-brown or rufo-piceous ; dorsum of

abdomen purplish sepia-brown ; segments 2-6 translucent, paler at the base and sides,

but opaque at the joinings, and blackish at the stigmata; venter subochraceous with

darker joinings, excepting the ninth joint and the inwardly dilated base of the forceps,

which are somewhat rubiginose ; setse light sepia-grey, with blackish joinings. Wings

transparent colourless, iridescent ; their longitudinal nervures translucent, very faintly

tinged with pale brownish or amber colour, the wing-roots piceous ; about 5 simple

nearly straight cross veinlets in the pterostigmatic space of the fore wing. Fore legs

lost ; femora and tibiae of the hinder legs the palest Vandyke-grey, the former banded in

the middle and at its extremity with black, the tarsus and ungues faintly tinged with

testaceous.

? very similar but darker ; the ventral joinings of the abdomen more widely opaque;

the pterostigmatic space of the fore wing sometimes contains 7 simple nearly straight

cross veinlets. Length of body 5 ; wing, d 6, ? 7 ; setge, 6 and 2 im. about 6 mm.

Mab. Rainbodde, Ceylon, at altitudes of upwards of 4000 feet (Hag. Mus.). I do not

think that the dilated portion of the base of the forceps is a separate joint.

With the types of Thraulus signatus stood single examples of two other species, perhaps

of the same genus, from the same locality, numbered respectively 32 and 37.

Compared with Thratdus signakis, no. 32 presents the following differences : — none of

the femora have a median black band, but only the terminal band ; the dimensions of the

insects in length of wing and body being the same, the legs of 82 are proportionally

longer, and their colour generally is more flavescent ; the wings have a stronger neura-

tion, the longitudinal nervures are distinctly browner ; in the pterostigmatic space are

10 simple and straight cross veinlets, of which the four nearest to the bulla are very

faint.

No. 37 has the binder legs uniformly pallid (fore legs lost), and 5 simple straight, or

nearly straight, cross veinlets in the pterostigmatic space liner than those of Th.

signatus.

Theaulus exigutjs, sp. nov. Plate XIII. 20*" (forceps, penis, wings, and hinder foot).

Imago {dried), s . — Thorax above luteo-piceous. Abdomen discoloured, fuscescent.

Hinder legs whitish, with femora banded very broadly with black in the middle, the

extremities of the femora and bases of the tibiae also blackish, and the tarsi somewhat

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES. 109

amber-coloured or subtestaceous. Wings vitreous, with light pitch-brown nervures ; the

marginal area of the fore wing contains about 11 simple and straight cross veinlets in

the pterostigmatic region, but none before the bulla. Length of body G, Aving 6-5 mm.

Ilab. Lahat, Palenburg, viii. 22. Communicated from Leyden by Mr. Ritsema.

Thratjlus mexicanus, sp. nov. Plate XIII. 23* * (hind wing and genitalia).

Calliarcys (provisional) mexicanus, ! Etn., iu the writing of the plate quoted.

Imago {dried), 6 . — Thorax fuscous above. Abdomen white, with segments 8-10 and

the apical margins of segments 2-7 fuscous. Setse white with black joinings. Fore

wings vitreous ; 10 slightly curved and mostly simple (rarely anastomosing near the

costa) cross veinlets exclusively in the pterostigmatic portion of the marginal area of the

fore wing. Length of body 6, wing 7, setie 15 mm.

Sab. Mexico (Brussels Mus.). The neuration of the fore wing conforms to the type

of the following species.

Thraulus, sp. . Plate XIII.* - (wings).

Calliarcys (provisional) sp. , ! Etn., in the writing of the plate quoted

A nameless species represented by two ? subim. (M°Lach. Mus.), communicated by

Messrs. Godman & Salvin, has well-defined cross veinlets in the marginal area of the

fore wing both before and beyond the bulla.

Rab. Irazu, Costa Rica, at an altitude of 6000-7000 feet (H. Rogers).

Thratilus lepidus, sp. nov.

Imago [dried), s . — Thorax rich brown-ochreous above, changing in some lights to raw-

umber brown. Abdominal segments 2-6 transparent whitish, each with the tip and an

oblique stripe on each side recurrent therefrom, fuscescent ; segments 7-10 rich brown-

ochre, lighter or pale yellowish ochreous towards the sides and beneath, and narrowly

edged with black at their distal dorsal border. Forceps light dull yellowish ; the limbs

inserted rather near to one another upon the basis, whose lower edge is only slightly

prominent in the middle ; the upper distal margin of the forceps-basis is prolonged into a

prominent rounded lamina about half the length of the penis : peuis hidden by dirt in

the type specimen. Setse white, with some of the joinings nearest the roots piceous, and

others in the remainder of the seta black, viz. towards the base of the seta every alternate

joining, about the middle of the seta every third joining, and beyond the middle of the

same every fourth joining. Fore leg in opaque view, with the femur, tibia, and joints 3 and

4 of the tarsus pitch-brown, the remainder of the tarsus dull light yellowish ochreous, the

tip of the tibia slightly tinged with pitch-black. Hinder legs in opaque view, with the

femur light reddish brown or rufo-piceous, tlie tibia and tarsus opaque amber-yellowish.

In transmitted light the dark portions of the legs are translucent rufo-piceous, the lighter

portions translucent yellow-amber. Wings vitreous, their neuration and the submarginal

area of the fore wing varying in colour with change of light from pitch-brown to raw-

umber brown ; the cross veinlets interjacent between tlie costa and the first half of the

SECOND SERIES. — ZOOLOGY. VOL. III. 15

110 REV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

pobracliial nervure, and the nearest to the wing-roots of those posterior to it in the fore

wing, are slightly thickened ; the submarginal area of the same wing for a short space

beyond the bulla is somewhat deticieut in colour ; the said area contains about 4 cross

veinlets before the bulla, and 14 beyond it, which are mostly straight and simple, only

one or two of them forking near the costa. Length of body 7, wing 8, setse 17 mm.

Hab. Chiriqui, Panama (M^Lach. Mus.). The neui'ation of the fore wing is of the

same type as that of the wings rej)resented in PI. XIII. 23*^' and 23*^.

Theatjlus colomble. Walk. Plate XIII. 20*-^ (hind wing).

X Ephemera colombicB, ! Walk., List of Neuropt. in Brit. Mus. part iii. 537 (1853).

Palingenia colombice, Hag. MS., Smithson. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 304 [list].

Leptophlebia Colombia, !Etn., Traus. Ent. Soc. London (1871), 84.

AdenophleUa Colombia, ! Etn., Eut. Mo. Mag. xvii. 194 (1881).

Subimago {dried), ? , — Thorax very light brown-ochreous above. Abdomen light rufo-

luteous above ; segments 1-8 bordered with black at the apical margin, segments 2-7

marked on each side with a broad black stripe descending obliquely from the distal

border. Setae intense warm sepia-brown, dark at the joinings and in the midst of the

joints. Fore femur lutescent reddish-brown, almost light clove-brown, the tibia pitch-

brown, the tarsus lighter or more lutescent than the tibia ; hinder legs dull, subluteous

or dark testaceous, the coxse and trochanters paler. Wings transparent light brown-

ochreous-grey ; in the fore wing, the longitudinal nervures, the cross veinlets in advance

of the radius, and most of those posterior to it in the proximal half of the disk of the

wing, are light brown-ochreous ; the cross veinlets posterior to the radius in the remain-

ing portion of the disk are black. In the marginal area of the fore wing are 1 or 2 very

faint cross veinlets before the bulla, and beyond it 18-19 oblique, curved, and near the

costa sparingly forked. Length of body, ? , 10, wing 15, setae 19 mm.

Sab. United States of Colombia (Brit. Mus.). The length of the setse and habitat

were misstated by me in 1871.

Thraultjs l^tus, sp. nov. Plate XIII. 23*^ (wing [part] genitalia and liinder foot).

Calliarcys (provisional) leetus, ! Etn., in the writing of the plate quoted.

Imago {dried), s . — Thorax rich brown-ochre above. Abdomen in segments 2-6 white,

with a series of small triangular spots on each side of the dorsum, and with the spiracles

black ; segments 7-10, above fusco-rufescent, the 8th narrowly edged in the midst of its

distal margin with light yellow ochre, the bordering enlarged abruptly on each side into

a triangular spot, whose point reaches the base of segment 7 ; segments 9 and 10 have

a small oblong yellow-ochreous spot on each side of the dorsum and a black dash

at the lateral border. Beneath, segments 7-10 are light yellow-ochreous, with theii*

lateral borders rufescent, the tips of the forceps also rufescent; ventral ganglia light

warm sepia brown. Pemora whitish, with a grey-black band before the middle and a very

broad conspicuous rufescent band near the tip : tibiaj and tarsi in some lights very pale

pitch-brown, in other lights very pale lutescent, the former grey-black at the tip, and the

REV. A. E. EATON 'ON RECENT EPHEMERID^ OR MAYFLIES. Ill

latter narrowly edged with grey-black at the joinings. "Wings vitreous, their nervnres

in opaque view testaceous, changing in transmitted light to yellowish amber-colour, their

membrane slightly fuscescent by the wing-roots and great cross vein ; the marginal area

of the fore wing contains about 9 simple curved cross veinlets, exclusively in the

pterostigmatic region. Length of body 6, wing 8 mm.

Hab. New Granada (M°Lach. Mus.).

ADENOPHLEBIA, Etu., 1881.

Illustrations. — Adult (details), Plate XIII. 21.

Adult. — Hind wing obtusely and very strongly angulated in front ; tlie angle placed

at about the first \ of the wing's length, and followed by a wide sinus ; the sinus,

extended as far as the extremity of the radius (3) and close to the tip of the wing, is

nearly straight-edged from the angle to the termination of the sul)costa (2), where it

attains its greatest depth, and from thence to the end of the radius its margin is very

gently convex; marginal area obtusely subtriangular, with the angle at the extremity of the

subcosta very acute ; submarginal area much narrower than the preceding, elongated,

irregularly quadrangular, acuminate at both ends, and with the hinder of the obtuse

angles situated nearly midway between the wing-roots and the tip of the wing; the

lines containing this angle [viz. the radius, and the common trunk of the radius and

cubitus (5)] are gently arched ; the marginal area contains 2-4 cross veiulets, the sub-

marginal a few more ; the nearest of those to the wing-roots is in immediate proximity

to the saHent angle of the front margin. Cross veinlets plentiful in the fore Aving,

excepting towards the inner margin ; most of the nervures at the terminal margin have

curved simple branchlets. The arrangements of the intercalar nervures of the anal

axillar interspace of the fore wing cannot be described fully through lack of an adequate

series of specimens ; in the wing figured they are 4 in number, and (counting from front

to rear) 1 and 3 are long, 2 and 3 annex themselves to 1, and this to the anal, 4 is

isolated and short ; sometimes 1 and 3 project abruptly a little in front of the cross

veinlets adjacent to their terminations, while 4 is much abbreviated ; cross venilets

continue to be plentiful as far as the first intercalary nervure, and then become scarce.

Probably other combinations occur similar in general plan to those displayed in

figs. 23*- and 23*- of the same plate. Orifice of the mesothoracic spiracle furnished with

a small oval guard. Porceps-limbs 2-jointed in the type ; the proximal joint compressed,

many times longer than the other, and in its basal half broadly dilated. Eorceps-basis

short and entire ; the homologous ventral lobe of ? obtuse and entire. Median caudal seta

subequal to the others ; those in 6 about twice as long as the body. Tarsal ungues

uniformly narrow and hooked ; fore tarsus of i scarcely longer than the tibia, which is

little longer than the femur ; its joints in diminishing sequence rank 2, 3, 4, 5, and 1.

Intermediate leg little more than half as long as the hind leg. Hind tarsus (excluding

joint 1) about ^ as long as the tibia and joint 1 together ; its joints rank 2, 3 subequal to

5, 4 ; joint 1 is ill defined. Nymph unknown.

Type. A. dislocans (in Ephemera), AValker.

10*

112 REV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

Distribution. South Africa.

Etymology. qSjjv and ^\e^iov, from the abundance of cross veinlets in the wings.

Adenophlebia dislocans, "Walker. Plate XIII. 21 (wings, legs, forceps, and penis).

XEphemera dislocans, ! Walk., Trans. Ent. Soc. Loudon, N.S. v. 198 (1860).

Leptophlebia dislocans [$im.], and auriculata \_^\m.'], ■ Etn., op. cit. (1871), 83, pi. iv. 24-246

[details] .

Adenophlebia dislocans, ! Etn., Ent. Mo. Mag. xvii. 194 (1881).

Imago (dried). — 6 . Thorax above black. Abdomen light pitch-brown, the dorsal

joinings opaque, the darker colour produced obliquely downwards and forwards at the

sides of the segments. Setae in some lights pitch-black, changing to intense sepia-brown

in others. Fore legs in opaque view either pitch-brown or rufo-piceous, in oblique view

either very intense opaque raw-umber brown, or reddish brown, and in transmitted light

either translucent dark brownish amber or rufescent amber ; hinder legs rufo-piceous in

ojoaque view ; femora each with a dark submedian band, and with the extreme tip dark.

Wings vitreous, the hind wings posterior to the subcosta (2) tinged with piceous-grey ;

nearation piceous, becoming blacker or browner when the posture is varied ; cross

veinlets strongly defined in the marginal and submarginal areas of the fore wing ; in the

former area are about 6 cross veinlets before and 10 beyond the bulla ; those in the

pterostigmatic region are simple and slightly curved.

? . Thorax piceous above. Abdomen discoloured ; the apical borders of the inter-

mediate dorsal segments piceous or blackish, the dark colouring produced forwards into

a pair of oblique triangular streaks on both sides of the back of each (viz. a streak at the

postero-lateral angle, and another between that and the median line), so arranged that

each streak of the inner series is continuous with a streak of the outer series in the

antecedent segment. Setae piceous at the base and intense sepia or warm sepia-brown

towards their extremities. Pemora luteo-piceous, banded nearly in the middle with black,

and pitch-brown at the extremity ; tibiae and tarsi rufo-piceous. Wings vitreous, their

neuration in opaque view piceous, in transmitted light browner ; cross veinlets of the fore

wing (excei)ting those adjacent to the terminal margin, and those in the extremity of the

pterostigmatic space) bordered with Vandyke-brown or dark warm sepia-brown, which

gives rise to small irregular spots in the midst of the wing between the base and the

middle, and to rounded spots just behind the radius (3) and in some other situations ; at the

base of the costa a spot of a like colour occupies the space between the wing-roots and

the cross veinlet nearest to the great cross veui : in the marginal area are about 7 cross

veinlets before the bulla, and 15, mostly simple oblique and straight, beyond it. The

cross veinlets of the hind wings are narrowly bordered, and the membrane distally is

tinged with light reddish brown-grey. Length of body, s 9; wing, d 9, ? 6 ; setae,

d 20, $ 18 mm.

Scib. Cape Colony, Graham's Town. As the hind wings of the ? (in Brit. Mus.) are

exactly like those of the d (in M°Lach. Mus.), I referred both to a single species in 1881.

Sexual differences in the marking (and even the neuration) of the wings, are met with

in some other Ephemeridce, notably iu Cloeon dipterum and (coloration only) in

Hagenulus.

EEV. A. E, EATON ON RECENT EPHEMERID^ OR MAYFLIES. 113

HAGENULUS, Etn., 1882.

Illustrations. — Adult (details). Plate XV. 21 bis.

Adult. — Hind wing angulated in front very strongly indeed, almost midway between

the wing-roots and the tip ; the angle, acuminate (and in the typical species prolonged

more or less into a slender projection turned over sideways as a hook), precedes directly

a very deep sinus which extends far beyond the termination of the radius, and attains its

greatest depth in the interval between the subcosta (2) and the radius (3) at about f of

the shortest distance between the apex of the wing and the costa ; marginal area sub-

triangular, with the angle at the extremity of the subcosta obtuse ; submarginal area

narrower than the preceding, somewhat obcuneate, but not quite rectilinear, the subcosta

being strong and straight, the radius fine and subsinuous, and the margin between them

concave ; posterior to the radius two longitudinal nervures meet the margin, one a little

before the obtuse apex, the other at the apex of the wing ; cross veinlets limited almost

to a single dislocated series extending transversely from the extremity of the sub-

costa to the middle of the inner margin, the marginal area containing none. In the fore

wing cross veinlets are plentiful as far back as the second of the intercalaries in the anal-

axillar interspace, and some of them at the terminal margin constitute simple branchlets

to a few of the longitudinal nervures ; the intercalary nervures in the interspace men-

tioned are 2 in number and long ; the foremost (the longer) is prone to annex itself to

the first axillar. Forceps-limbs of d 3-jointed, with the proximal joint longer than the

remainder, compressed and broadly dilated towards the base. Forceps-basis entire ; the

homologous ventral lobe of ? bifid and acutely excised. An egg-valve of extraordinary

dimensions is produced from the apical border of segment 7, broad at the base, narrowed

ellipsoidally from thence to the middle, and terminating in a spout or a tube split open

along its upper side, resembling an ovipositor, projecting a little beyond the extremity of

segment 10. Caudal sette 3, subequal to one another, and in ? about twice as long as

the body. Tarsal ungues all dissimilar each to the other ; fore tarsus 6 subequal in

length to the tibia, which is more than twice as long as the femur ; its joints in diminish-

ing sequence rank 2, 3, 4 5, and 1. Fore tarsus $ less than \ as long as the tibia, which

is nearly 1^ as long as the femur ; hind tarsus $ (excluding joint 1) little more than \ as

long as the tibia and joint 1 (which is ill defined) together ; theii- joints rank 5, 2 subequal

to 3, 1 and 4<. Nymph unknown.

Type. S. caligatiis, Hag. MS.

Distribution. Cuba.

Etymology. Dr. H. A. Hagen, the eminent neuropterist.

Hagentjlus caligatus, Hag. MS. Plate XV. 21 bis (wings, legs, forceps, and penis).

Hagenulus (in Potamanthus, Hag.) caligatus, ! Hag. MS., Etn. Ent. Mo. Mag. xviii. 207 (1882, Feb.).

Subimago {dried), rf .—Wings transparent light bistre-grey ; neuration slightly opaque,

most of the discal cross veinlets of the fore wing faintly bordered with greyish, some in

the first three areas marked with black ; 7 cross veinlets in the marginal area before the

bulla. Setae annulated with black.

114 EEV. A. E. EATON ON EECENT EPHEMEEID.5: OE MAYFLIES.

Imago [teste Gundlach, has in life olive-brown oculi, and a light brown-ochreous body,

with a small black or brown spot on each side of every abdominal segment, Hag. MS.],

S (dried). Thorax kiteo-fuscous above ; abdomen discoloured, the segments darker at the

tips, the venter paler than the dorsum. Setae white, or greyish white, with black bands

and joinings, the bands being placed at every joint near the base of the seta, then at every

alternate joint, and ultimately, still farther away from the base, at every third joint.

Wiags vitreous ; the marginal area of the fore wing, slightly discolom-ed from the base

to at least as far as the middle, contains about 7 simple cross veinlets before, and 11

beyond the nodal point ; neuration piceous, nearly every cross veinlet marked with a

roundish blackened spot. Legs dull pale lutescent, each with two piceous bands on the

femur, the tibia black at the tip, and the tarsus sublutescent [" with darker tip to the

tarsus," Gundlach, MS.]. Length of body 5-7'o, wing 7"5-8, setae about 10 mm.

Sab. Eangel Mountains, Cuba, in June (Hag. Mus.). Four ? imagines in the col-

lection differ from the d subim, above described in having 0 cross veinlets in the marginal

area before, but 9 beyond, the bulla. Their wings are spotless, and their thorax, seem-

ingly, is piceous above. They may represent another species.

HABROPHLEBIA, Etn., 1881.

Illustrations. — Adtilt (details), PI. XIII. 22 a, b, & LXIV.- (whole figures); consult

Pictet, oj). cit. under Potamantlms, pis. 27 & 28 (1843-5). Nymph, PL XXXVI. ; also

Pictet, loc. cit., and Vayssifere under H. fusca (1882) [who both omit the tracheal bran-

chife of the firsta bdominal segment],

Adidt. — Hind wing angulated strongly and rather obtusely in front, nearly midway

between the wing-roots and the tip ; the angle, almost right-angled, is followed abruptly

by a strong sinus, the margin retiring perpendicularly from the A^ertex of the costal

protuberance, usually to about halfway towards the subcosta, and thence following a

semielliptical curve round the apex of the wing ; the subcosta (2), arising in a gradual

curve from the wing-roots, diverges from the common trunk of the radius (3) and cubitus

(6), and then with diminished curvature, running subparallel with the radius, usually

passes obHquely into the margin shortly before the tip of the wing ; the radius terminates

quite in the extremity of the wing ; hence, distally, the marginal area is usually acu-

minately prolonged in proximity to the subcosta, and the submarginal is semi-parabolic ;

but sometimes, in individual examples of certain species, the hind wing conforms essen-

tially to that of Thraulus (PI. XII. 20), the subcosta meeting and terminating in the

margin at the sinus, and the marginal area being cori'esjiondingly truncate distally.

Cross veinlets variable in number and distribution in both A^dngs ; in small specimens

they are commonly placed as in PI. XIII. 22 a, not approaching the terminal margins

of the wings, and amounting to a very limited number in the hind wing ; in the ? fore

wing they are sometimes weU defined in the marginal area before the buUa, where in

small specimens they are usually obsolescent ; in large examples they are often nearly as

numerous in both wings as in Calliarcys (PI. XIV. 23), and then those forming branch-

lets to the longitudinal nervures at the terminal margin of the fore wing are somewhat

deficient in regularity, and are usually curved. The anal-axillar interspace of the fore

EEV. A. E. EATON ON EECENT EPHEJIERn)^ OR MAYFLIES. 115

wing contains from 2 to 5 intercalar nervures ; when there are five, 1, 3, and 4 are abbre-

viated or obsolescent ; when four are present, intercalar 3 is absent ; Avhen there are three,

1 is the short one : intercalars 2 and 5 are constant, they communicate by cross veinlets

with each other, and usually with the anal (seldom the first axillar) nervure, and either

of them may terminate abruj)tly or else (combining intimately with a cross veinlet) may

bend suddenly aside to join an adjacent nervure ; for example, intercalar 5 may be

isolated, or may bend suddenly aside to intercalar 2 or to the anal ; and intercalar 2 may

be abrupt and communicate by cross veinlets with the anal nervui-e alone, or may bend

suddenly aside to join either the anal or intercalar 5. Orifice of the mesothoracic spi-

racle usually closed in the dead insect ; when open, the aperture is small, gaping in front,

and without a guard. Forceps-limbs of d 3-jointed, the proximal joint shorter than the

others combined, and suddenly dilated or tuberculated on the inner side of the base ; the

second and third joints rather long, and like those of a finger. Forceps-basis bifid,

narrowly or acutely excised in the middle ; the homologous lobe of ? also bifid and

acutely excised. Caudal setae in both sexes 3, mutually subequal, and thrice as long as

the body. Ungues in every tarsus dissimilar each to the other ; fore tarsus in s little

longer than the tibia, which is nearly ^ longer than the femur ; its joints in diminishing

order rank 2 subequal to 3 ; 4, 5, and 1. Hind tarsus about ^ as long as the tibia ; its

joints rank 5, 2, 3, and 4 ; 1 is ill defined ; hind leg not much longer than the inter-

mediate leg. Fore tarsus $ (exclusive of joint 1) about f as long as the tibia and joint 1

combined, which are about 1^ as long as the femur ; its joints rank as in the d hind

tarsus ; 1 is indistinctly defined, j^ymph latent in places where the current of shallow

streams is gentle, or where the ripple from rapids is greatly diminished amongst stones

at the brink. Abdominal tracheal branchiae nearly uniform in shape, bifid, with the

divisions filiformly dissected, and each with fewer segments in the upper division than in

the lower ; when extended they slant backwards and outwards, with the smaller divisions

ascending ; then- segments vary in number with the age of the nymph, and are most

numerous in the intermediate pairs ; theii- surface is sparsely beset with minute hairs.

Mandibles, labium, and maxillte ii. very similar to those of Blasturus ; maxillae i. nearly

as in Tlwaulus. Tongue obcordate-oblong ; paraglossse narrow, curved, oblique and

acuminate laterally, with a slight indentation in the margin a little before the point.

Body slender ; antennae of moderate length ; posterior lateral angles of segments 8 and 9

of the abdomen shortly and acutely produced ; caudal setae about f as long as the body,

and beset with minute spreading hairs at the joinings. Hind leg about as long as the

fore leg ; the tarsus (claw excluded) almost \ as long as the tibia.

Type. S.fusca (in Ephemera), Curt.

Distribution. Europe, temperate and southern ; N. America, New Hampshire (im-

described sp.).

Etymolorjy. k^pic and <pAe/3iov, in reference to the prevailing delicacy of the cross

veinlets of the wings.

The figures in PI. XIII. of this volume do not display the mutual dissimilarity of the

tarsal ungues ; they were drawn from dried specimens. This feature of the ungues was

stated correctly in Trans. Ent. Soc. Loudon (1871), p- 90, but not in Ent. Mo. Mag.

116 EEV. A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES.

(1881), p. 195. I have seen living nymphs of H.fusca and lauta, besides other species

in Portugal and Italy.

Owing to the colours being transparent, those of the legs, wing-nervures, &c., are

liable to vary greatly with the direction in which they are viewed ; and as the species of

this geniis are in a large measure distinguishable from each other by slight differences

in the colouring of these parts, it is well to state what is the position of the specimen

when such and such colours appear. The following terms are employed for this pur-

pose : — opaque view, when the examiner standing back to light holds the specimen

directly away from the light ; oblique view or reflection, when the object held towards a

dark back-ground is examined under an oblique light, the examiner either facing the

light with the specimen below the eye, or standing sideways to the light with the object

nearly on a level with the eye; in transmitted lUjht the insect is interposed between the

eye and the window.

Habbophlebia fusca, Curtis. Plate XIII. 22 a (wings, c? legs, forceps, and penis).

Ephemera fusca, Curt., Lond. & Edinb. Phil. Mag. ser. 3 (1831), 120.— £. minor, ! Steph., 111. Brit.

Ent. vi. 60 (1835).

X Ba'etis cingulata, ! Steph., op. cit. vi. 67 (1835).

Potamanthus brunneus, Pict., Hist. Nat. Nevropt. ii. Eph{:;m. 217, pi. xxvii. (1843-5); Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 512 (1853).— P.>scms, Pict., Hist. &c. 235 (1843-5) ; Walk., List

&c. 543 (1853) ; Hag., Ent. Ann. (1863), 19.— P. minor, Pict., Hist. &c. 237 (1843-5) ; Walk., List &e.

546 (1853).

CM cingulata, Pict., Hist. &c. 271 (1843-5).

Cloeon cingidata, Walk., List &c. 578 (1853).

Leptophh'bia fusca, ! Etn., Ent. Mo. Mag. v. 87 (1868); id., Trans. Ent. Soc. London (1871), 90,

pis. ii. 2 c, V. 2-2 6 [details] ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 318 (1874) ; ! Vayssiere, Ann. des

Sc. Nat. (6), Zool. xiii., pi. i. 1, 2 (1882).

Habrophlebia [type] /wsca, ! Etn., Ent. Mo. Mag. xvii. 196 (1881) [citation].

Subimago {living). — Wings light blackish grey, the nervures, at first opaque whitish,

becoming tinged with pitch-brown. Thorax pitch-brown, with pale sutures. Fore

femur dull pitch-brown or pitch-black ; tibia and tarsus in opaque view blackish grey,

changing in some lights to warm sepia-grey. Hinder femora dull light greenish Vandyke-

grey or greenish sepia-grey, tibise light sepia-grey, tarsi light blackish grey. Setge light

warm sepia-gi'ey, the joinings slightly opaque. Upper portion of eyes dull reddish-

brown, polished ; lower part intense sepia-black.

Imago [living). — 6 . Upper portion of oculi intense burnt-umber brown, the lower

blackish. Thorax jet-black or pitch-black above, with light reddish-brown tegulse.

Abdomen pitch-brown, growing darker with age; segments 2-7 translucent, excepting

at the joinings, and narrowly whitish at the base ; the remaining segments opaque, the

extreme distal edges of 7-9 often orange or light yellow above ; venter dark sepia-grey

or blackish grey, often modified to some extent in segments 8 and 9 with dull orange.

Seta3 light sepia-grey, Avith light brownish joinings. Last two joints of the forceps-limbs

liwht sepia-grey ; penis during life somewhat Y-shaj)ed, with slender recumbent spurs

beneath the lobes. Fore femur and both ends of the tibia pitch-black, the intermediate

EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. Il7

portion of the latter pitch-brown, the tarsus lighter, varying with change of posture to

brownish-hlack-grey : [iohe7i dried, in oblique view the tibia reflects a liglit madder-brown,

or (in specimens from Biron) a liglit Venetian-red, and the tarsus is light testaceous ; in

transmitted liglit the former becomes translucent rufo-piceous or amber-brown, and the

tarsus yellowish amber.] Hinder legs {dried) translucent amber-brown in transmitted

light, changing in opaque view to a nearly uniform light pitch-brown, and in oblique

view to a liglit translucent bronze or bistre-brown, the tarsi in certain positions appearing

light greyish, with opaque edges to the intermediate joints, but usually concolorous

with the tibife. Wings vitreous ; the longitudinal nervui'cs and the cross veinlets of the

pterostigmatic region of the fore wing in opaque view pitch-brown, in oblique view light

brownish ; in transmitted light the stronger nervures become yellowish amber, and the

finer whitish. The marginal area of the fore wing contains about 4 obsolescent cross

veinlets before the bulla, and beyond that 11 ; of these, 4-8 in the pterostigmatic region

are well defined, simple, and slightly curved; the remaining cross veinlets of the wing

are more delicate, and are deficient in colouring, excepting sometimes those in the distal

half of the submargiual area.

$ similar generally to d" , with the fore tarsus lighter, and the setre with darker

joinings. In the fore wing the neuration, on the whole, in a slight but appreciable

degree is better defined than in the d , and the cross veinlets in the outer half of the

wing situated between the radius (3) and the proebrachial (6) nervures exhibit the same

colours as those in the pterostigmatic region. Length of body 5-7; wing G-7 ; setae,

d im. 8 & 12-11 & 12, ? 6 e% 8-8 & 9, subim. 5-5 & 7 millim.

JIab. Generally common in Western Europe during the summer months, frequenting

brooks and rivcr^s of moderate temperature, and ranging from Great Britain and the

Vosges (jM'Lach.) southwards to the lowlands of Switzerland and southern Prance.

Specimens from this last district (where I have met with it in the neighbourhood of

Toulouse and abundantly at Biron near Orthez) have the wings of the subimago more

of a sepia-grey than a black-grey, and the legs of the d imago rather brighter in tint

than those of normal examples; the thorax also of a 2 im. from Toulouse, in my

collection, is pitch-brown instead of pitch-black ; but this 2 may have been prematurely

killed, and the difFerences in colouring of the 6 im. and the subim., mentioned, are not

sufficiently marked to be accounted specific.

Habkophlebia nervulosa, sp. nov.

Subimago (r/r/Vf/).— Wings sepia-grey, with pitch-brown neuration. Setae warm sepia-

grey, with opaque joinings.

Imago {living and f/r/^f/).— Difficult to distinguish from R. fitsca without actual com-

parison of specimens; chiefly characterized by the cross veinlets of the wings being

usually more strongly defined than in that species, and by the hinder femora lieing dark

at the tip in opaque view. — s . Upper portion of eyes castaneo-piceous, the lower sub-

piceous. Thorax jet-black above, sometimes dark piceous when dried. Abdomen dark

piceous above, with the apical margins of the segments narrowly yellowish, and with the

bases of segments 4-7 in some examples partially translucent ; venter slightly paler and

SECOND SEMES. — ZOOLOGY, VOL. III. 16

118 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

duller. Setce either piceous, or with their bases piceous and their remainder whitish

warm sepia, with the joinings alternately broadly and narrowly piceous. Forceps piceous

at the base, with their last two joints smoky grey. Eore legs {during life) pitch-l^lack,

with brownish-black tarsi, these changing in some lights to smoky grey ; hinder legs

2iiceous, with the tips of the femora dark, the tarsi blackish grey, and the tibiae in some

lights smoky grey, excepting towards both of their extremities. When dried, the fore

legs become dark piceous in opaque view, changing in oblique view to intense pitch-

brown, with the tarsus lighter brownish or almost light burnt-umber brown ; and viewed

with light transmitted the femur is dark piceous amber, the tibia less opaque, and the

tarsus testaceous amber. The hinder legs, lohen dried, are raw-umber brown, with the

tips of the femora dark, changing in transmitted light to translucent yellowish amber,

with the tips opaque. Wings vitreous, with pitch-brown neuration ; cross veinlets

generally well defined, excepting in the marginal area of the fore wing before the

pterostigmatic region, in the submarginal area before the bulla, and in the adjacent

portion of the followdng area ; but some of the lowland specimens have those in the

remaining portions of the fore wing scarcely stronger than the weaker cross veinlets of

the average Avius?. The mar2:inal area of the fore wing contains about 4-6 ill-defined or

obsolescent cross veinlets before the bulla, 3-4 beyond it, also obsolescent between that

and the pterostigmatic space, while this contains 7-12 well-defined simple straight or

slightly curved cross veinlets.

$ {dried). — Thorax pitch-brown above. Wings transparent, with a slight brownish-

grey tint, and with the neuration more strongly defined than in the 6 . In one of the

specimens all of the cross veinlets of the fore wing are very distinct ; in other specimens

tliose corresponding in position with such as are obsolescent in the 6 are weaker than

Ihe remainder: the marginal area contains about 5-6 before the bulla, and 14-17 beyond

it, which are nearly all simple. Length of body 7-8 ; Aving 7-9 ; setae, d ini. 8 & 8"5-

9-5 & 10-5, 2 8 & 9-5 millim.

Hub. Common in Algarve and Portugal, in May and June ; ranging from altitudes of

200-400 ft. near Silves, up to 2000-2850 ft. on Eoia in the former, and in the latter

from 380-1280 ft. at Cintra and 640 ft. at Ponte de Morcellos, up to 1800 ft. in the

Estrella, and 1600-2500 ft. near Villa Real in Traz-os-Moutes.

Habrophlebia modesta, Hagen. Plate XIII. 22 b (penis, two views).

Potamanthus modestus, ! Hag., Anu. Soc. Eut. Fr. scr. 4, iv. 31) (1864).

Leptophlubia modesta, ! Etn., Traus. Ent. Soc. Loiulou (1871), 91, pi. v. 3-3 i [details].

Subimago {dried). — Eore wings sepia-grey, lighter than those of S. nervulosa, with

opaque neuration ; hind wings dull pale yellowish grey. Setse light warm sepia-brown,

with opaque joinings.

Imago {dried), <S . — Very similar to U. nervulosa, but larger; not so distinctly pale at

the joinings of the al)dominal segments, but on the contrary uniformly dark above, in

the majority of specimens. Legs nearly of the same colours as those of H. nervulosa,

but in most lights the fore tarsus appears concolorous with the remainder of the leg :

EEY. A. E. EATOX OX EECEXT EP1IEMEEID.E OE IMATTLIES. 119

again, the hinder femora are just perceptibly lighter in tint than those of the species

referred to, and the dark colour at their extremities is more narrowly restricted to the

knee. In transmitted light the legs of H. modesta appear more translucent than those

of H. nervidosa. In the marginal area of the fore wing (counting along the suhcosta)

are 4-6 obsolescent cross veinlets before the nodus, and beyond that 3-4 obsolescent

followed by 11-16 well defined in the pterostigmatic region ; of these last many are

simple and straight or curved, but in many specimens some amount of irregularity is

noticeable in the veinlets of the widest part of that region, some of them forking near

the costa, and a few anastomosing with each other. 2 very similar, according to Dr.

Hagen, with brown eggs. Length of body, 6 6-7, 2 9 ; wdngs, d 8, 2 9 millim.

Sab. Corsica (Hagen) ; Carinthia (Zeller, in M'Lach. Mus.). The above diagnosis is

founded upon Carinthian specimens, captured in June.

HaBROPHLEBIA UilBRATILIS, sp. nov.

Subimago [dried). — Wings light blackish grey, with opaque neuration.

Imago, 6. — Upper portion of oculi reddish during life. — (Dried.) Tlioras piceous,

appearing pitch-brown or pitch-black according to the direction and the amount of light

in which it is viewed. Abdomen above pitch-brown, with segments 2-7 to a slight

extent translucent towards their bases, the pleural margins sometimes remaining dark

throughout ; the same segments beneath are more extensively translucent, with their

joinings pitch-brown and their ganglionic cord subtestaceous, their general colour during

life being probably greyer than that of the dorsum. Setce greyish white or warm sepia-

grey, with their alternate joinings warm sepia-brown. Basis and proximal joints of the

forceps concolorous with the venter ; the remaining joints greyish white. Penis trans-

lucent yellowish white, with well- developed reelinate slender spurs beneath. Fore femur

and tibia in opaque view pitch-black, the latter darker at the tip, the tarsus testaceous ;

the femur reflects pitch-brown, the tibia a browner tint than the very light testaceous

tarsus ; in transmitted light the femur becomes warm translucent pitch-brown, the tibia

light brown-oclireoiis amber, with its extremity somewhat opaque, the tarsus whitish

yellow-amber. Hinder legs of lighter colour ; the trochanter yellowish white ; in opaque

view the femora appear bistre-brown or piceous-grey, more opaque towards their distal

extremities than elsewhere, and the remainder of the legs dull liglit brownish testaceous ;

the femora reflect a translucent light piceous-grey, darker distally, and the remainder of

the legs a uniform dull brownish white, of nearly equal depth with the colour of the

femora ; in transmitted light the whole of the leg is translucent whitish brown amber.

TTings vitreous ; in the fore wing the longitudinal neuration, the cross veinlets of the

pterostigmatic region of the marginal area, and the adjoining cross veinlets of the

adjacent area, viewed against an opaque background, appear either bistre-brown or

whitish, according to the direction in which the light falls upon them, the former colour

persisting longest (during the change of posture) in the cross veinlets specified, the

radius, suhcosta, and in the distal half of the costa, whilst the remaining cross veinlets

are transparent ; in transmitted light, a slight yellowish-amber tint is perceptihle in the

radius, suhcosta, and the great cross vein ; the marginal area contains about 3 almost

16

*

120 EEV. A. E. EATOX ON EECEXT EPHEMEEID.^ OE MAYFLIES.

imioerceptible traces of cross veinlets before the bulla, and beyond that 6-7 well-defined,

simple, nearly straight cross veinlets.

? differs from 6 in the usual manner. Fore leg piceous, the tarsus whitish, with the

apical edges of the intermediate joints narrowly darkened ; in some lights the tibia as

well as tbe tarsus appears brownish white. AVings tinted almost imperceptibly with

greyish ; their neuration more distinctly bistre-brown than in the d ; in the disk of the

fore wing, between the costa and the upper branch of the prsebrachial (6) nervures, the

cross veinlets are well defined ; the marginal area contains about 3 almost effaced cross

veinlets before the bulla, and beyond tliat 9, usually all simple and slightly curved.

Length of body 5-5'5 ; wing, cJ 5, $ 6-7 ; setse, 6 ira. 8 millim.

Mab. Common at the end of July and beginning of August iu the Appennino Pistojese,

near San Marcello, at altitudes of 2100-2700 ft. During the afternoon, the flies throng

together along the borders of streams in the shade of alders (Alnus) : hence the name.

They are obtainable at other times by beating. The nymphs abounded under suitable

stones in the grounds of the Villa Margherita. A d im., captured at an altitude of

4-100 ft., near Abetone, has the brownish colour of the hinder legs well marked.

Habrophlebia. mesoleuca, Brauer.

Potamanthus mesoleucus, ! Brauer, Neuropt. Austr. 74 bis (1857).

LiplophlMa mesoleuca, ! Etn., Traus. Ent. Soc. London (1873), 397; Eostockj Jahresb. d. Ver. f.

Naturk. Zwickau, 1877, p. 81 (1878).

Imago {dried), 6 . — Thorax jet-black above. Abdomen in segments 2-7 pellucid

white, the remainder reddish brown above. Setoe white [with darker joinings] ; forceps

white ; penis spurred beneath, the spurs rather longer than the lobes, reclinate and

slender. Fore legs greyish white ; hinder legs white, pellucid [their femora tinged with

fuscous]. Wings vitreous; subcosta and radius of the fore wing subpiceous; cross

veinlets of the pterostigmatic region curved and mostly simple. Length of body 5,

wing 6 ; setfe, 6 im. 7 millim.

Ilah. Austria, marshy places in the Prater, near Vienna, iu June, and in Styria

(Brauer); Saxony, very common near Dretschen (Uostock). The foregoing is based upon

Dr. Brauer's description, supplemented by original notes made in 1873 of a specimen

named by E-ostock, and forwarded for ins2)ection by Mr. Albarda. The darker fore femora

of H. lauta enable it to be separated at a glance from the present species.

Habrophlebia LArxA (renamed).

Potamanthus J ductus, Pict., Hist. Nat. Nevropt. ii. Epliem. 219, pi. xxviii. 1-G (1813-5); Walk.,

List of Neuropt. Ins. in Brit. Mus. part iii. 513 (1853).

Habrophlebia lauta, ! M'Lach., Eev. d'Ent. iii. 19 (1884) [undcscribed] .

Subimago {dried). — Wings whitish sepia-grey, with concolorous neuration.

Imago {living), d . — Upper eyes flesh-red [this colour modified iu some examples with

testaceous], lower eyes black. Thorax jet-black above, varied with a lighter colour at

the sides. Abdomen, from segment 2 to the base of segment 7, pellucid white, with the

tips of the segments sometimes tinged very faintly with light reddish; the remaining

segments subpiceous above, modified beneath more or less, from segment 8 to the tip,

EEV. A. E. EATON OX EECEXT EPHEMEEID.E OR MAYFLIES. 121

with rusty yellow or dull orange. Seta3 and forceps white ; penis pitch-brown, changing

to testaceous when dried. Pore leg, with the trochantei', femur, and both extremities

of the tibia piceous, and the remainder white ; hinder legs white, with tlie tarsus, the

extreme base of the tibia, and the extremity of the femur very light dull amber-colour

or greyish. Wings vitreous, with pellucid neuration; marginal area of the fore wing

with 4-6 hardly perceptible traces of cross veinlets before the nodus and 3-4 beyond it,

followed in the pterostigmatic region by 7-10 that are well defined, simple, and almost

straight.

$ [living). — Thorax fusco-piceous above. Dorsum of abdomen piceo-fuscous ; venter

lighter; sette white. The stronger of the longitudinal nervures of the fore wing are

faintly tinged with olive-grey. Length of body 5-6 ; wing 6'5-7 ; sette, im. <j 9 & 8-11

& 10, ? 6-5-7 millim.

Hab. France, at and near Pau (under 600 ft.), June; common in the Vosges, and at

Bouillon, Belgium fM'Lach.), July. Switzerland, Miinciienbuchsee, Canton Berne, and

the stream at ^'ersoix, near Lake Leman, August ; near Troinex ixnder Mt. Sal5ve near

Geneva (over 1300 ft.), September. Some remarks concerning this species are given

above under Leptophlebia cincta.

CALLIARCYS, Etn. 1881.

Illustrations. Adult (details). Pis. XIV. 23 (typical). [KB. PL XIII. 23*, 2, 3

(provisional), are referred to Thraulits.']

Advlt. — Hind wing very similar to that of species of Habrophlebia, with plenty of

cross veinlets and a comparatively narrow form. Cross veinlets numerous in the fore

wing, excepting near the inner margin ; those in the marginal area before the bulla

distinct ; some at the terminal margin (which has no isolated veinlets) occasionally con-

stitute here and there simple curved branchlets to longitudinal nervures in individual

wings. In the typical specimens, the intercalary nervures of the anal-axillar interspace

of the fore wing establish communication with the anal (8) nervure; they are four in

number (not counting as one an occasional simple branchlet of the anal nervure), and

3 and 4 are long, 1 and 2 short ; intercalars 1, 2, or 3 may terminate abruptly ; 1 may be

shorter tlian 2, may curve towards 2 instead of towards the anal, and may be linked hy

a series of cross veinlets to 3, 2, and the anal ; when 3 is abrupt, it is similarly linked to

the anal. Aperture of the mesothoracic spiracle without a guard. Forceps-limbs of S

3-jointed; the proximal joint much longer than tlie remainder, and gradually dilated

towards the base. Eorceps-basis excised in the middle ; the homologous ventral lobe of

$ bifid and acutely excised. Median caudal seta subequal to the others ; those of d

nearly 1^ as long as the body. Ungues in every tarsus each unlike tlie other; fore

tarsus of 6 about 1^ as long as the tibia, which is about \\ as long as the femur; its

joints, in diminishing sequence, rank 2 and 3 subequal, 4, 5, 1 ; hind tarsus little more

than ^ as long as the tiliia combined with joint 1, which is ill defined ; its joints rank 5,

2, 3, 4. Pore tarsus of ? little more than i as long as the tibia, which is little longer

than the femur; its joints rank 2, 5, 3 subequal to 4, and 1 fairly defined [the proximal

joining is too strongly defined in the wliole-figure of this leg]. Kymph unknown.

Type. C. humilis, Etn.

122 EET. A. E. EATOX OX EECEXT EPHEMERID.E OK MAYFLIES.

Distribution. Algarve and Portugal.

Etymologij. koXoc and apKvc, from the completeness of the reticulation of the wings.

Upon reconsideration, I am disposed to transfer to Thraulus, provisionally, the species

referred provisionally to the present genus in the writing of PI. XIII., because the

relative lengths of the intercalary nervures of the axilar-anal interspace of their fore

wings correspond more nearly with those of the typical Thraulus than with those of

the typical Calliareys, and also because their 6 forceps-bases are entire. The oblique

acuminate prolongation of the marginal areas of the hind wiugs of these species led,

doubtless, to their being classed otherwise in the first instance. It is exti-emely probable

that they constitute a genus of their own ; but the materials at hand do not suffice for

its definition.

Caxliarcys HmiLis, Etn. Plate XIV. 23 (wings, legs, and genitalia).

Calliareys humilis, 1 Etn., Ent. Mo. Mag. xviii. 21 (June 1881).

Siibimago (dried). — Wings ivory-black grey.

Imago (dried), d . — Thorax jet-black above. Abdomen pitch-brown, with joinings 2-6

narrowly pale. Setae light warm sepia, with piceous or reddish joinings. Porceps in

opaque view light pitch-brown, changing in transmitted light to translucent bistre-brown ;

the divisions of the forceps-basis singularly prolonged at the points. Fore legs in opaque

view piceous, in oblique view reflecting rufo-piceous, and in transmitted light translucent

golden-brown amber (like resin or treacle) ; hinder legs somewhat lighter. Wings trans-

parent, with light pitch-brown neuration, changing to brownish atnber in transmitted

light ; the membrane is tinted perceptibly with a similar but faint light-brownish grey :

in the marginal area of the fore wing are 6-7 cross veinlets before the bulla, and 13-18

almost always simple and slightly curved beyond it, all well defined. Lengtb of body,

(S 2 7-9; wing, d 7-8-5, $ 9; setse, d im. 10-11-5 millim.

Sab. Algarve, on the northern slopes of Poia near Monchique, at altitudes of little

over 2000 ft. (e. g. common near the waterfall at the foot of the final slope, at about

2150 ft.), at the end of May ; also in Portugal, in the Estrella, on a hill south of Sabu-

gueiro, at an altitude of about 4100 ft., early in June ; in streams having a temperature

at that season of o& Pahrenheit.

Section 6 of the Genera. — T\-pe of Ephemerella. Adult. — Pronotum of $ traversed

lengthwise by a raised median line or ridge ; its posterior border arched, and either

truncate or slightly depressed in the middle. Hind tibia rather shorter than the femur ;

the tarsus about f as long as the tibia. In the fore wing the anal (8) and first axillar (9^)

nervures are connivent and mutually contiguous at the wing-roots, apart from the second

axillar (9-) and pobrachial (7) nervures. Penis-lobes distinct ; orifices of the seminal ducts

terminal; no stimuli apparent, ^yrnph \_Teloganodes \xnknovfn\. Terminal margins of

the fore wings connected with the peak of the mesonotum, each by a distinct triangular

membrane. Palpus of the 1st maxilla (when present) shorter than the lacinia, which is

crowned with a sparse tuft of hair and armed with spinules along its inner edge. Lobes of

the labium small, rounded, and subequal to the laciniae of the 2nd maxillae. Abdominal

tracheal branchiae fewer than the maximum number in the Familv, beins' absent from the

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE JIATFLIES. 123

2nd segment and usually from the first as well; when they exist on segment 1 they are

minute, erect, hirsute, and filiform, unlike the others ; these, issuing from the posterior

margins of the segments at the bases of the pleurae, arc recuml)ent upon the sides of the

dorsum and either imbricated or stratified, and are formed each of a broad pergamentosc

lamina (or a memln-anous lamina, if the branchia be wholly obtected), concave on the

luiderside, covering and in some extent coherent Avith a forked appendage, the support of

membranous lamellae, which are numerous and closely imbricated in the large branchiae,

but very scanty in the small. Many of the pleurae are dilated so as to form acute serra-

tures at the sides of the abdomen, and their edges, like some other parts of the body

{e. g. the femora or setas), are l^eset witli remarkable hairs, which commonly resemble in

their structure the peculiar hairs of certain Troml)idiid Acar'ma in being filiform or

clavate, and in many instances microscopically velutinous or otherwise roughened.

Natation laboured, aided by movements of the legs.

The genera of this section display afiinity with the type of Ccenis in the particulars

detailed in the last sentence but one of the foregoing paragraph.

North America has yielded several nameless nymphs referable to tbis section, whose

ultimate development needs investigation. Their characteristic diiferences chiefly reside

in the arrangement and fonu of the tracheal branchiae, the length of the palpus of the

1st maxilla (when present) and the proportions of its component joints, and in the form

of the body — -tabulated hereunder. The indications of wing-neuration delineated in

their figures are largely conventional. Being for the most part very nearly akin to

Ephemerella, their detailed descriptions are inserted immediately after the descri])tive

letterpress of the species of this genus, preceding the description of the Cingalese genus

Teloganodes, whose nymph is unknown. Those are the only two genera in the section

that are named.

Tabulation of Nymphs ranked in Section 6 of the Genera.

Nos. 3-7 of the abdominal segments bear tracheal brancliise ; of these, the

first four ou each side of the dorsum are loosely imbricate. Antenuaj

inserted

upou the disk of the frons. Terminal joint of the palpus of maxilla i.

subequal to the remainder ; joint 2 longer than joint 1. Caudal

setse narrowly plumose. Brauchial lamin;e oblique, oblong or

ovate oblong PI- XXXVII. Ephemerella.

scarcely i as long as the remainder; joint 2 subequal to joint 1.

Branchial laminre somewhat obovate PI- XXXVIII. 1-10.

scarcely I as long as the remainder ; joint 2 about | as long as

joint 1. Branchial larainse subrotuud PI. XXXVIII. 11-15.

in re-cnteTing angles at the front lateral margins of the frons. Ter-

minal joint of the palpus of maxilla i. about \ as long as the

remainder; joint 2 about | as loug as joint I. Brauchial laminae

somewhat oblong and slightly oblique. Ventral surface of the body

singularly adapted for adhesion to smooth surfaces PI. XXXJX-.

Nos. 4—7 of tlie abdominal segments bear tracheal bi'anchiae ; the laminae,

irregularly subovate, are compactly imbricate. Caudal setae plumose.

124 EEV. A. E. EATOX OX EECENT EPHEMEEID.E OR MAYFLIES.

AntennjE inserted upon the disk of tlie frons. Terminal joint of the

palpus of maxilla i. about f as long as the remainder; joint 2 less than

i as long as joint I PI. XL. 1-17.

Nos. 1 and 4-7 of the abdominal segments bear tracheal branchire; the

first is subulate and erect ; the others are of normal structure, their

lamiuse ovate-oblong and compactly stratified ; the laminse of those of

segment 4 are each traversed by a slight furrow from side to side beyond

their middle, serving as a hinge. Caudal setffi plumose. Antennie in-

serted upon the disk of the frons. Palpus of maxilla i. lost [or aborted ?] Pis. XL. 18-20 & LXIV. 3-8.

EPHEMERELLA, Walsli, 1862.

Illustrations. Adult (details), PL XIV. 21 a-c [wings, legs, d head and genitalia] ;

Etn., Trans. Eut. Soc. London (1871), pi. ii. 5 [part of fore wing] : — (whole figures) see

under E. ignita, synonyms Potanianthus, Pictet, op. cit. pis. P>0, 31, & 33, Ni/mph,

PL XXXVII. ; also Pictet, op. cit. pis. 29 & 33, and Vayssiere, Ann. des Sc. Nat. (6) xiii.

pLviii. 74 &c. (1882).

Adult. — Hind wing of moderate size, unevenly arcuate in front, with a very shallow

marginal depression just heyond the most salient portion of the costa; the subcosta (2)

advancing from the wing-roots in a bold curve towards that prominence, proceeds, in

proximity to the costa from thereabouts, almost in a direct course towards the obtuse

extremity of the wing, and meets the margin obliquely rather near the termination of

the radius (3) ; this last nervure, more gently curved, approaches the subcosta gradually,

and attains the tip of the wing : the intercalar neuration is well developed, and cross

veinlets are numerous. In both wings most of the intercalary veinlets remain isolated

and rudimental, comparatively few of them obtaining connection with longitudinal

nervures. Cross veinlets plentiful in the larger portion of the fore wing, but scarce or

absent in the immediate vicinage of the terminal margin and within tlie area bounded

anteriorly by the anal (8) nervure, and absent from the marginal area before the

buUa ; those of the pterostigmatic space, in all the described species, are for the

most part divided near the costa, and their branchlets intercommunicate so as to

enclose a series of small irregular cellules upon the costa. In the anal-axillar

interspace of the same wing are 3 long intercalar nervures, and as few or fewer short

isolated rudiments of others, one of the latter usually standing in the interval

between the first and the second of the former. Of the three longer intercalars quoted,

the intermediate is the longest ; and this is connected Avith the anal jiervure either

directly (turning aside a little, anteriorly, to unite with it as a branch) or indirectly (by

blending with a cross veinlet), and sometimes, in addition to that terminal connection, a

cross veinlet establishes further communication between them. In like manner the first

of the three may be connected directly or indirectly with the anal nervure, and the third

with the second intercalar ; otherwise the first rcmnins isolated, and the third is simul-

taneously in communication both with the first axillar (9') and with the intermediate

intercalar nervures by uniting at its inward extremity with cross veinlets [compare Etn.,

op. supra cit. pi. ii. 5. Pictet's figui'e, Pict. op. ibidem cit. pi. xxxii. 1, is untrustworthy

in detail]. Guard at the aperture of the mesothoracic spiracle small and triangular;

Eorceps-limbs of 6 3-jointedj stout, the intermediate joint long, the others ver^ short.

EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYELIE.S. 125

Abdomen of ordinary proportions ; segments 2-7 of nearly nniform length, shorter than

segment 8 (which is the longest) or 9 ; segment 10 short ; tlie postero-lateral angles of

the dorsum in segments 8 and 9 are acute and slightly prolonged ; forceps-basis entire,

the homologous lamina of the $ obtuse. Lobes of the penis without apparent stimuli.

Median caudal seta subequal to the others, which in both sexes are abou.t as long as the

body. Ungues in every tarsus dissimilar each to the other. Fore tarsus of 6 about 1^

as long as the tibia, which is nearly twice as long as the femur ; its joints, in diminishing

order, rank 2 »& 3 subequal, 4>, 5, and 1. Fore tarsus of ? (excluding joint 1) about f

as long as the tibia and joint 1 comljined ; the femur about as long as the tarsus, whose

joints rank 2, 3, 5, 4. Hind tarsus (excluding joint 1) about y as long as the tibia and

joint 1 comljined ; its joints rank 5, 2, 3 subequal to L The iirst joint in these tarsi is

obsolescent. Numph latent under stones or at the roots of water-weeds, in streams and

rivers. Body broadest at the mesothorax ; head slightly narrower than the pronotum,

and in anterior view trilateral, with the vertex arched and the oral r(^gion truncate ;

antenntie inserted about midway between the anterior ocellus and the sides of the face;

that ocellus is smaller tlian the others ; oculi moderately distant from each other in 6 .

Pronotum transversely quadraugular, arched above, nearly straight at the sides, and

obtuse at the anterior lateral angles. Abdomen plump, slightly convex beneath, and

somewhat quadrangularly arched above in segments 2-9 ; pleura? dilated considerably

in segments 3-8, slightly concave above, fringed with clavate or spathulate hairs, and

contributing to form, with the steeply sloping sides of the dorsum, a hollow for the

lodgment of the tracheal brauchia; ; those of segments 2 and 3 are obliquely truncate at

their posterior angles, but the pleura? of segments 4-7 are there acuminately pointed,

and constitute a series of uncinate serratures on each side of the body ; the pleune of

segment 8, less largely developed than their predecessors, are posteriorly more acutely

pointed in 6 than in 2 ; those of segment 9 terminate behind each in a triangular point,

which is perpetuated in the imago. The angularity of the dorsal arch, above referred to,

is due to longitudinal series of protuberances, ridges, or tubercles, one on each side of

the middle of the back, extending from segments 2-9 ; in segments 2 and 3 each promi-

nence is surmounted by an acute conical tubercle ; in segments 4-7 each ridge terminates

behind in an unciform tubercle pointing towards the tails ; in segments 8 and 9 the

ridges end abruptly. Abdomen broadest in segment 4 or 5, narrower posteriorly than

in front ; a line drawn touching the outer edges of the pleurte on each side would describe

a curve. Tracheal branchia; are borne by segments 3-7, and diminish in size successively

from the foremost ; those of segment 7 are completely obtected by the preceding pair.

The foremost lamina; are broad and obliquely quadrilateral, with^he corners obtuse or

rounded off, and have their greatest extension between the lower anterior and the upper

posterior corners ; the margin below the latter of these is slightly refuse ; the trachea

enters the lamina near the former. The hindermost of the tracheal branchia; have ovate

laminie, auricled obtusely at the base on the lower side. The other branchiae exhibit

gradations of form intermediate between these. Caudal sette nearly | as long as the

body; for some distance from the roots only their joinings are setulose and their joints

nude ; afterwards, until shortly before their extremities, the joinings are beset with

SECOND SERIES. — ZOOLOGY, VOL. III. 17

126 EEV. A. E. EATON ON RECENT EPHEMEEID.E OK MAYFLIES.

longer and sharper setulae, mingled with minute spreading hairs, while the joints become

narrowly plumose or distichously pubescent; towards their extremities the joints are

again nude, and their joinings beset with yerticils of very minute hairs. Palpus of

maxilla i. about | as long as the lacinia ; its terminal joint is subequal in length to the

remainder, and joint 2 is longer than joint 1. Lacinise of maxilla ii. broader than the

lobes of the labium. Hind leg the longest ; the tarsus (claw excluded) about ^ as long

as the tibia. Eore femur smooth underneath in the typical species ; the tarsus nearly

I as long as the tibia. Antennae setaceous, of moderate length, with minute verticillate

hairs at the joinings.

Si/nonymi/. Leptophlehia, Westwood, 1840 (part) ; Potamanthus, Pictet, 1843-5 (part).

Type. E. excrucians, Walsh.

Distribution. Northern Temperate E-egions.

Etymology. A hybrid combination of a Greek derivative with the Latin diminutive

"ella."

Nym])hs of the typical form inhabit N. America as well as Europe. E. ignita 6 im.,

Avith L. marginata 2 im., were contypical of the unrestricted Leptophlebia.

Ephemerella ignita, Poda. Plate XIV. a (legs, d head and forceps).

Ephemera ignita, Poda, Ins. Mus. Grsec. 97 (1761). — E. eryltiroplitJiahna, Schr., Fn. Boica, ii. pars ii.

197 (1798).— £. Xfusca,\ & diluta, Steph., 111. Brit. Eiit. vi. 58 (1835).— E. apicalis,\ rufescens,\ &

rosea, ! id., op.cit. vi. 59 (1835).

X Baetis obscura, ! id., op. cit. vi. 05 (1835) ; Walk., List of Neuropt. lus. iu Brit. Mus. part iii. 558

(1853).

Potamanthus erylhropht/talmiis, Pict., Hist. Nat. Nevropt. ii. Epbem. 232, pis. xxix. [written iu error

" erytlirocephalus (larvc) "] & sxx. [adult] (1813-5) ; Walk., List &c. 544 (1853) ; Hag., Eut. Ann.

(1863), 21.— ? P. ffibbus, Pict., Hist. &c. 226, pis. xxxi. &xxxii. [im. & subim.] (1843-5) ; Walk., List

&e. 544 (1853).— ? P. fcneus, Pict., Hist. &c. 229, pi. xxxiii. [egg, nymph, subim., & adult] (1843-5);

Walk., List &c. 545 (1853).— P. apicalis, Pict., Hist. &c. 236 (1813-5) ; Walk., List &c. 544 (1853).—

P. dilectus [for dilutus], Pict., Hist. &c. 236 (1843-5).— P. dilutus, Walk., List &c. 545 (1853) ; Hag.,

Ent. Ann. (1863), 19.— P. roseus, Pict., Hist. &e. 236 (1843-5) ; Walk., List &c. 545 (1853).

Ephemerella ignita, ! Etn., Trans. Eut. Soc. London (1871), 98, pis. ii. 5 [wiug] & v. 7-7 a [details] ;

Meyer-Diir, Bull. Soc. Ent. Suisse iv. 310 (1874) ; Rostock, Jahresb. d. Ver. f. Naturk. Zwickau, 1877,

p. 85 (1878).— ?£. yibba, Etn., Trans. Ent. Soc. Loudon (1871), 99; Meyer-Dur, Bull. Soc. Ent.

Suisse, iv. 316 (1874) ; Rostock, Jabresb. d. Ver. f. Naturk. Zwickau, 1877, p. 85 (1878).— ?E. (Bnea,

Etn., Trans. Eut. Soc. London (1871), 99; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 316 (1874).

Suhimago {living).— Wui^s> black-grey, the wing-roots and sometimes the hind wings

greyish white. Eernora olive-grey, often with a dark band before tlieir distal extremity ;

tibiae grey ; tarsi black-grey or grey-black. Sette brownish grey with red-brown joinings.

Imago, 6 {living). — Upper division of eyes brownish red or burnt sienna; lower divi-

sion olivaceous, or sometimes rather yellower. Head and prothorax olivaceo-fuscous ;

meso- and metanotum fuscous or jet-black. Abdomen above dark reddish fuscous, with

the opaque tips of the segments sometimes narrowly ochraceous, and often with the sides

of the segments tinged with the same colour ; the last segment paler, sometimes dull

greenish : venter sometimes light- or warm-sepia brown, sometimes fuscous or greenish

EEV. A. E. EATON ON EECENT EPHEMEEIDJE OR MATELIES. 127

fuscous, the segments sometimes each with a pair of short dark divergent lines followed

by two dots at the base, the 9th segment often brown-ochreous, with a longitudina 1

piceous streak along each side. Setre sopia-grey with darker joinings ; forceps testaceous

or greenish grey. Legs either almost sulphureous, with the fore tiliia lutescent and all

the tarsi testaceous ; or with the fore femur yellowish- or olivacoous-grey, the hinder

femora paler and tinged rather more with yellowish, the fore tibia dark olive-grey, the

tarsi and hinder tibiae grey ; a diffused obsolescent or nebulous rubigineous band is some-

times perceptible at the extremity of the femur, and the ungues are often piceous.

Wings vitreous, with the stronger nervures and sometimes the bulla almost faintly

piceous or amber-colour.

? {living). — Eyes dark olivaceous ; vertex of head marbled with black, pale ochreous

or orange, and grey. Pronotum olivaceo-fuscous varied with pitch-brown. Meso- and

metanotum pitch-brown. Abdomen more opaque and tinged with dull greenish than in

the d' , but rather similar : the borders of the dorsal vessel dark. Legs olivaceous, the

femora with a grey band just before their pale distal extremity, the fore tibia sometimes

testaceous, the tarsi greyish. Wings much as in the c7 , but sometimes with the bulla

more distinctly coloured. The ventral lobe of the penultimate segment is slightly retuse ;

and the pleurae of the 8th segment are posteriorly acute. Eggs green, becoming browner

when dried. Length of body, s 6-9, 2 6-10 ; wing, 6 7-9, ? 7-5-11 ; seta?, ? im.

7 & 8-12 & 11, subim. 8 & 7 ; setse, ? im. 7 & 8-8 & 9, subim. 7 & 9 millim.

Hab. Europe, from Portugal, near Cintra (300-400 ft. alt.), Madrid, and mid-Italy,

near San Marcello, in the Apenniuo Pistojese (2100-2700 ft. alt.), northwards to Great

Britain, and at least to Holland and Germany ; but the extent of its continental range

farther north and east is not yet ascertained. In England the fly is plentiful from June

till September ; but it was common at the end of April in Portugal. The nymph varies

greatly in colour ; the darkest and most strongly marked specimens are prevalent in

trout-streams, those of lighter colours in warmer streams and rivers, the variations being

largely determined by the nature of the bottom. I believe that Pictet was mistaken in

describing as distinct species merely colour- variations of this one ; and that some of the

differences indicated by him in the adult flies are attributable to the ordinary mutations

of colour undergone by them during their advance to full maturity, and during the

decline of life. The form of the forceps-basis in my earlier figure (1871) differs from

that in PI. XIV. 24 a, in the breadth of the extremity of the median projection ; but this

is only because the insect was then not adjusted so well for drawing as the more recent

subject. The part which is shaded thereabouts in the former figure was hidden when

the newer drawing was made, and the acute unshaded portion was brought into full view,

by throwing the extremity of the insect further back.

Ephemerella inermis, sp. nov.

Suhimago {dried). — Pore wings transparent, light brownish grey, with neuration in

some lights dull greenish grey, changing in other lights to duU light yellowish, the

membrane and opaque longitudinal nervures becoming dirty brownish white near the

wing-roots ; hind wings rather pale. Setse dark sepia-grey, with black joinings. Legs

17*

128 EEY. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES.

dull light-brownisli yellowish, the fore tarsus and distal portion of the tibia, and in the

hinder tarsi the ungues, tip of the terminal joint, and distal borders of the other joints

brownish, the brown being sometimes modified with reddish.

Imago {dried), 6 . — Thorax above polished, and of a rich deep pitch-brown, the anterior

half of the mesonotum in one example much lighter in the midst. Abdomen above either

pitch-brown, with the last 3 segments rufescent, and the lateral borders of tbe dorsum

light yellowish; or dark rufo-piceous, with tlie last segment yellowish; the joinings

opaque. Venter lighter than the dorsum ; genitalia light yellowish. Setae whitish sepia-

grey, with black joinings. Wings vitreous; the neuration in some lights colourless, the

longitudinal nervures in other lights becoming faintly tinged with light greenish grey,

changing in other positions to very light amber ; at the wing-roots of the fore wing is,

ajiparently, a light pitch-brown spot. Fore leg, as an opaque object, dull greenish grey,

with the coxa, trochanter, and knee lighter, the tarsus dirty whitish or greyish white,

with the joinings and ungues brownish ; in transmitted light the femur becomes light

yellow-amber. Hinder legs in opaque view, Avith the femur and base of the tibia,

yellowish amber, the distal portion of the tibia, and the tarsus dirty whitish, the latter

liaving the ungues, the end of the terminal joint, and the distal borders of the other

joints light reddish-brown.

?. Thorax above polished brown-ochreous ; the pronotum destitute of raised dots.

Abdomen discoloured ; ventral lobe of the 9th segment broadly rounded and almost

entire, the pleural points obtuse. Wings as in 6 , but with the longitudinal nervures

rather more definitely colovired. Legs very similar to the hinder legs of tlie d , but in

one of the specimens only the ungues and not the joinings of the hinder tarsi are light

brownish. Length of body, 5-G ; wing, 6-8 millim.

Hub. Colorado, at Denver, Arkansas Canon, and Colorado Springs (Mus. Comp. Zool.

Cambridge, Mass.).

Ephemekella guamdis, sp. nov. Plate XIV. 2i b (neuration).

Subimago {dried). — Wings dark sepia-grey, or sometimes of a slightly blacker grey,

with dark neuration, excepting at their extreme base, where both nervures and mem-

brane are more or less of a dull greenish-yellow, varied witb brownish. Coxa^, trochanters,

hinder tibiae and tarsi, fore tarsus, and sometimes the fore tibia very pale reddish

(burnt-umber) brown : femora pitch-brown. Setae pitch-black at the base and then

sepia-brown.

Imago, ? [dried). — Thorax bright brown-ochreous. Abdomen shrunken through desic-

cation, and discoloured ; in one example the colours along the middle of the dorsum

have considerably changed, but on both sides the segments are narrowly bordered

with dull ochraceous along the pleurae, and a series of large rounded blotches of a dark

purplish brown colour [pitch-brown modified with intense burnt-carmine] occupies the

immediately adjoining parts of the intermediate segments (perhaps excepting segment 9).

Setaj in opaque view pitch-black near the roots and then pitch-brown ; in transmitted

light the black changes to pitch-brown, and the lighter parts appear whitish warm sepia-

grey, with rufescent joinings. Ventral lobe of segment 9 emarginate ; the jdeui-al points

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 129

short and acute. Wings vitreous, the fore wings tinged slightly with light hrownish

grey in the pterostigmatic region of the marginal and submarginal areas ; neuration

piceous, strongly defined (excepting the cross veinlets in a large extent of the marginal

and submarginal areas, and those in a small portion of the next area of the fore wing),

the longitudinal nervures becoming lighter at the wing-roots. Fore legs in opaque view

pitch-brown, ligliter or more nearly raw-umber brown from the coxa to the base of the

femur ; in transmitted light the tibia and tarsus are less opaque than the femur, the

dark parts become rufo-piceous, and the lighter parts somewhat of an amber-colour.

Hinder femora similar in colour to the fore femur ; but the tibiae and tarsi are uniformly

whitish yellow-ochre, with the ultimate joints and ungues, or in some lights the whole

of the tarsus, clove-brown. Length of wing, ? 15-18 ; setse, ? im. 16-17, subiiu. 15 millim.

Hah. Colorado (M'^Lach. Mus.) ; The Geysers, Yellowstone, 4th of May (Mus. Comp.

Zool. Cambridge, Mass.). The arrangement of the colouring matter of the abdomen in

the specimen described above is not to be implicitly trusted.

Ephemerella Walkeri (renamed).

XBaetis\\fuscata,W\a\\s., List of Neuropt. Ins. in Brit. Mus. part iii. 570(1853) [part]: Hag.,

Smithson. Miscell. Coll. (18G1), Syiiop. Neuropt. N. Am. 47.

Imago, S {dried). — Thorax above dark pitch-brown, varied on the pleurae and sternum

with light burnt-umber brown. Abdomen discoloured, dark pitch-brown. " Fore legs

piceous " {teste Walk.) ; hinder femora dark rufo-piceous, the tibia? and tai'si dull pale

subtestaceous. Wings transparent, their longitudinal neuration in some lights pale

fuscescent. Length of wing 8 millim.

Hal). St. Martin's Falls, Albany Iliver, Hudson's Bay (Dr. Barnston) ; one example

in Brit. Mus. The 6 subimago doubtfully referred to this species by Mr. F. Walker is

still in the collection, and is most probably a llhithrogena. The name given by Walker

to this species, having been preoccupied in Ba'etls, is superseded : had lie not published

a description of the type-specimen, it might Avell have remained nameless and uudescribed.

Ephemerella invaria, AValker. Plate XIV. 24 c (penis).

{ Ba'etis invaria, ! Walk., List of Neuropt. Ins. iu Brit. Mus. part iii. 568 (1853) ; Hag., Smithson.

Miscell. Coll. (18U1), Syuop. Neuropt. N. Am. 48.

Ephemerella invaria, \ Etn., Ent. Mo. Mag. v. 87 (18G8) ; ! id., Trans. Eut. Soc. London (1871), 100,

pi. V. 8, 8 a [details] .

Imago, d {dried). — Thorax above light rufo-piceous ; abdomen discoloured, — dorsum

fuscescent, the joinings opaque, the last two segments modified with light dull reddish

orange, — venter greyish, the base of the forceps, and the two or three segments imme-

diately preceding it, light brown ochre. Fore femur and tibia reddish golden brown, the

latter with a dull light reddish spot near its distal extremity, the tarsus yellowish wiiite ;

hinder femora translucent, very light straw-colour or pale yellowish-fuscescent, the tibise

and tarsi dull whitish, with the apical edges of the joints and the ungues fuscescent.

Wings transparent, their neuration usually colourless, but in one instance distinctly pale

fuscescent. Length of wing 8-10 millim.

130 EEY. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES,

Sal). St. Martin's Falls, Albany River, Hudson's Bay (Dr. Barnston) ; 3 examples in

Brit. Mus.

Ephemeeella excrucians, Walsh.

Ephemerella [type] excrucians, ! Walsh, Proc. Acad. Nat. Sc. Pliilad. (1862), 377; Hag-, Proc. Ent.

Soc. Pliilad. ii. 178 [im^).—E.Xinvana (part), 1 Etn., Trans. Ent. Soc. London (1871), 100.

Subimago [dried). — Wings very light ochraceous grey, changing in some postures to

whitish grey, with suhopaque neuration of a similar whitish- or faintly whitish yellow-

amber tint, c? femora in opaque view light yellow-ochre, changing to light yellow-amber

in transmitted light; tibia; and tarsi dull whitish, the ungues and ends of the tei-minal

joints of the hinder tarsi brownish, the fore tibia and tarsus in opaque view dull brownish,

but in some lights dull yellowish ; legs of ? lighter, with pale brownish ungues. Setae

light sepia-grey, their joinings at most opaque.

Imago, (S . [Oculi in life [fide "Walsh) egg-yellow above, pale fuscous below.] —

{Dried) : — Thorax above piceous or light rufo-piccous : abdomen rufo- or fusco-piceous

above, with opaque joinings, the last two segments tinged with dull light reddish orange ;

venter greyish or yellowish, the last two or three segments and the bases of the forceps

light brown ochreous. Setoe whitish, with fuscous joinings. Wings vitreous, with

colourless neuration. Hinder femora very light yellow-amber ; fore femora darker, and

of a browner yellow-amber in opaque view; hinder tibice and tarsi dull yellowish or

brownish white, the tips of the tarsi and the ungues light brownish ; fore tibia in opaque

view dull yellowish brown, with a light brownish spot at the tip, the tarsus rather lighter,

with brown ungues, but in transmitted light they are both brown-ochreous white, the

tibia becoming light yellowish amber towards its base, but marked at the tip, as before,

with the opaque brown spot.

2 (dried). — Body yellow-ochreous, the head, pronotum, and abdomen sometimes red-

dened, the abdominal joinings subopaque or darker than the rest of the segments : on

each side of the pronotum, close to the hinder border, directly in front of the sutural

ftirrow in advance of the wing-roots, is a raised reddish-brown dot. Legs similar to the

hinder legs of the d . Wings \dtreous, with colourless or whitish neuration, the fore

wings with 9-11 cross veinlets in the marginal area beyond the bulla (counting them

along the subcosta). Setae white, sometimes with the first 2 or 3 joinings reddish.

Venter nearly of the same colour as the femora in segs. 1-7, and then darker ; the lobe

of the 9th segment broadly rounded off and almost entire. Length of body (after

Walsh), B-5-7-5 ; wing, 6-8 ; setae, 6 im. 11-13, 2 9-12-5 millim.

Eab. Eock Island, 111. (Walsh) ; Detroit, Mich. (Mus. Comp. Zool. Cambridge, Mass.).

Two 6 im. in the Brit. Mus. were named by Mr. Walsh.

Ephemerella consimilis, Walsh.

Ephem.erella consimilis, Walsh, Proc. Acad. Nat. Sc. Philad. (1862), 378 ; Etn., Trans. Ent. Soc.

London (1871), 100.

According to Mr. Walsh, this insect differs from E. excruoiaiis in the form of the

mesothorax, which in E. consimilis is 4-5 times as long as wide instead of less than thrice

EEV. A. E, EATON ON EECENT EPHEMEELD.E OE MAYFLIES. 131

as long as wide, and has the prsBscutum half as long again as wide instead of scarcely-

longer than wide. Sternum ferruginous, legs immaculate, hut the tip of the fore tibia

and the adjacent joint of the tarsus in the d fuscous. Length of body, <d 5, sets about

5 ; expanse of wings 14 millim.

Hab. Hock Island, IlL Described from a single defective specimen.

Several undescribed North- American species of Ephemerella are scantily represented

in the collections referred to, which it seems undesirable to characterize.

Ephemerella elongatula, M'^Lachlan.

Lepiophlebia elongatula, ! M'Lach., Trans. Eut. Soc. London (1875), 169 (pai-t).

Imago {dried), $ . — Body intense jecinoreus. Sette blackish fuscous. Wings vitreous,

with the costal margins of the fore wings narrowly brownish yellow ; neuration fuscescent,

the longitudinal nervures towards the wing-roots, and the proximal halves of the sub-

costa and radius of the fore wing, yellowish. Length of wing 14 millim. [Abstracted

from M^Lachlan's description.]

Sab. Yokohama (Pryer, in Wormald's Mus.). The ? subimago attributed to this

species in 1875, prolmbly through an error on my part, is apparently a Meptageuia.

Five Nymphs allied to Ephemerella, sedis incertce.

Nymph No. L— PI. XXXVIII. 1-10 (whole figure & details).

Perhaps an Ephemerella, but differing from the nymph of the typical form in the

following particulars. Abdomen broadest in front, tapering gradually to the end of the

9th segment ; the plevirse nearly straight along their outer sides, their hinder corners in

segments 4-7 nearly right-angled, those in segments 8 and 9 shortly ^^rolonged into acute

triangular points ; a line drawn touching the outer edges of the pleura? on each side

would be curved only in a very slight degree. Tracheal branchite obtusely rounded off

distally. Anterior, or inferior, edge of the fore femur minutely denticulated. Joints 1

and 2 of the palpus of maxilla I. subequal to each other ; joint 3 rather shorter. Length

of body 8-5, setie C millim.

Uah. AVashington Territory ; Wenass V., W. T., Taylor's, 6th July ; Klikitat V.,

W. T., Thorpe's, 10th July, S. Henshaw (Mus. Comp. Zool. Cambridge, Mass.).

Nymph No. II.— PI. XXXVIII. 11-1.5 (whole figure & details).

Perhaps an Ephemerella, tuberculate on the vertex of the head and the notum, and

with rows of spines instead of tubercles on the dorsum ; also with tlie abdominal plem-ae

wider than in the typical species, and the proximal joint of the palpus of maxilla i. rela-

tively longer. — Head vertical, with an erect elevated and acute triquetrous tubercle on

each side of the crown above the inner orbit of the oculus, terminating a low blunt ridge

ascending in a curve from near the posterior ocellus, and with a small rounded wart-like

protuberance on the vertex, intermediate between that and the median longitudinal

ridge ; occipital border slightly prominent. Pronotum narrower in front than behind,

132 EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES.

sparingly tul)erculated at the sides, and posteriorly near the middle. Mesonotum with

a pair of small tubercles on the praescutum, anotlier tubercle at each of the lateral angles

of the scutum, and a single tvibercle on the scutellum. The dorsal spines on segments 3-9

are slender and somewhat unciform, with their points directed posteriorly. Length of

body 14 ; outer sette about 9 millim.

nah. Klikitat V., W. T., Thorpe's (10. vii.; S. Henshaw, in Mus. Comp. Zool. Cam-

bridge, Mass.).

Nymph No. III.— PL XXXIX. (whole figure & details).

Body stouter than in the typical Epliemerella, and with neither tubercles nor spines

upon the dorsum ; sternum and venter apparently adapted for adhesion to smooth sur-

faces ; antennte remote from the ocelli, and inserted in the angles of right-angled excisions

at the sides of the prominent front border of the frons ; first joint of the palpus of

maxilla i. about 1^ as long as the second, the terminal joint about \ as long as these

combined. — Body broadest at the mesothorax, narrowed in front ; abdomen somewhat

oniscoidal, broadest at the third and fourth segments ; the pleurte in segments 2-8 broad

and relatively short, concave above, strongly rounded off in front, their outer margins

less curved and meeting their oblique posterior margins at an acute angle ; the

pleurae of segment 9 naiTower and posteriorly more acute, the segment in dorsal view

resembling somewhat a mitre with the cleft choked seen sideways ; dorsum strongly

arched, furrowed obliquely at the sides in segments 2-7 by grooves which ascend singly

from their front margins at the bases of the pleura?. These grooves are displayed in

fig. 2. Venter densely velutinous, and ('exclusive of the pleuree) elongate-ovate, almost

plane behind (the pleurae being only very slightly jjrominent), but with a deep arclied

depression in front of the third segment, wherein is situated a smooth nude curved

transverse furrow immediately adjacent to the anterior velvety boundary of the adhesive

surface. This furrow is probably the channel for the readmission of water into the

enclosure when the insect desires to be free after adhesion has been established. Beneath

the thorax are two large and deep nude concavities, bounded by prominent sharply

defined even margins, and divided from one another in front of the mesosternum; the

anterior is widened angularly close behind the fore coxae; the posterior resembles the

impressure of an axe-head laid flat, edge towards the tail. Pronotum transverse, widest

behind ; its posterior lateral angles acute. Head vertical, transverse ; in front view

quadrilateral, slightly oblong and flattened ; frons prominent and truncate in front

(where it projects in advance of the mouth-parts), angularly excised at its anterior

angles, and with nearly parallel sides ; antennae short ; mouth-parts similar in type of

construction to those of Epliemerella. Legs moderately long ; femora flattened behind,

spinulose or denticulated along their edges ; hind tarsus about f as long as the tibia.

Tracheal brancliise arranged as in Ephemerella, but their laminae more obtuse. Length

of body, ? , 11, seta3 4 millim.

Hah. Colorado, in a brook at Idaho, adhering to the underside of a board, 5th July;

Roaring Water Fork, Col., 2nd August, Lt. Wheeler (Mus. Comp. Zool. Cambridge,

Mass.).

EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES. 133

Nymph No. IV.— PL XL. 1-17 (whole figure & detaas).

Synonymy. ? Heptagenia t pudica {njm^ha.-skm) , ! H3g. Ann. Rep. U. S. Geol. & Geograpli. Survey

of the Terr. 1873, part iii. Zool. 582 (1875) [not subimago, p. 581].

Nymph-slough. — Mouth-organs and tracheal branchite of a type similar to tliose of

Ephemerella ; body stouter, the abdomen in its broadest part wider than the thorax, the

dorsum unarmed, the venter convex; antennae inserted about midway between the

anterior ocellus and the sides of the face; first joint of the palpus of maxilla i. upwards

of twice as long as the second, the terminal joint about f as long as these combined;

tracheal branchiae borne by segments 4-7 of the abdomen, but probably absent from

segment 1. — Body broadest at about the fifth abdominal segment, narrowed thence

in both directions, but nearly as broad in the mesothorax ; abdomen broadly oniscoidal,

the pleurae strongly developed in segments 2-9, and produced into slender acuminate

recm'ved teeth, w4iich are pilose where the tracheal branchiae do not overlap them ; the

penultimate segment the longest, in dorsal view somewhat similar to a mitre with the

cleft partly choked seen sideways. Caudal setse of $ mutually subequal in length, and

very nearly ^ as long as the body ; median seta plumose ; outer setae ciliated on the

inner side near the roots, and plumose distally. Pronotum transverse, quadrangular,

rather broader behind than in front, gently arched, slightly compressed on each side, and

armed with a short conical tubercle on each side in the middle near the boixler. Le£;s

pilose, very similar in their proportions to those of Ephemerella ; femora prolonged at

the knee each into a short acute spine ; intermediate coxae each armed above with a

short conical tubercle. Head small, transverse, narrower than the pronotum, wider in

front than behind, slightly constricted at the junction of the frons and vertex; integument

minutely spinulose on the frons, pilose at the sides and in front ; vertex transverse, oculi

contiguous in 6 ; frons prominent at the base in the vicinage of the ocelli and antenna»,

and then broadly flattened out so as to form a transverse and projecting ledge or guard

over and in advance of the mouth-parts, which ledge is truncate in front, rounded off

at the fore corners (where it is broadest), straight-sided, narrowed posteriorly, and much

wider than long. Length of body 15, setae 7 millim.

Sab. Colorado, mountains and plains (Lieut. W. L. Carpenter ; Mus. Comp. Zool.

Cambridge, Mass.). The laminae of the tracheal branchiae of segments 4 & 5 are emar-

ginate below the tip on one side ; those of the other segments are entire. The palpi of

maxillse ii., formerly described as 2-jointed, have 3 joints ; but the small terminal joint

is difficult to trace in tbe cast slough. The sloughs of the hind wings are separate from

those of the fore wdngs, and are attached in the usual manner to only the hind border of

the metanotum ; their tips attain the base of the second abdominal segment. They were

formerly described as being incorporated into the notal hood, in a manner similar to the

hind winsis of Bcetisca.

-'»'-

Nymph No. V.— PI. XL. 18-20, & LXIV. 3-7 (whole figure & tracheal branchiae).

Body moderately stout ; mouth-organs and hinder pairs of tracheal branchiae similar

in type of construction to those of Ephemerella ; abdomen in its broadest part wider

SECOND SERIES. — ZOOLOGY, VOL. III. 18

134 EEV. A. E. EATON ON EECENT EPKElMEEID-i: OE MAYFLIES.

than the thorax, the dorsum tuberculated as in Ephemerella, the venter convex ; insertion

of antennae intermediate between the anterior ocellus and the sides of the face ; palpus

of maxilla I. lost (or aborted ?) in the specimen examined ; tracheal branchiae borne by-

segments 1 & 4-7 arranged as in C<enis. — Body broadest at about the fifth abdominal

segment, narrowed thence towards the thorax and tails ; abdomen oniscoidal, the

segments very similar in form to those of Nymph 'Ko. IV, having the intermediate

pleurse produced in like manner into curved acuminate retrorse serratures (which are

spinulose along their front edges and beset with long, fine scattered hairs), but having a

series of uncinate tubercles on each side of the median line of the dorsum, extending

from the first to the sixth segment, the tubercles standing singly at the hinder edges of

the segments pointing backwards, and represented in the following three segments by

small marginal teeth. Caudal setae acutely and narrowly plumose, about f as long as

the body. Pronotum transverse, quadrangular with almost straight sides, about as broad

as the head in front, and very little broader behind. Legs very like those of Ephemerella.

Tracheal branchiae of segment 1 minute, erect, 2-jointed, Avith the first joint short and

the second joint more slender, filiform, and distally pilose or pubescent, arising from the

dorso-pleural region rather behind the middle of the segment and near the lateral borders ;

those of segments 4-7 inserted in sinuses at the hinder bases of the pleurae, and com-

posed, like those of Ephemerella, each of a lamina sheltering lamellae, but differing from

their homologues in that genus in being compactly stratified rather than imbricated,

those of segment 4 elvtroidallv shielding the others. Moreover, the branchial laminae

of at least segments 4-6 are each traversed by a crease from side to side, situated at about

f of the distance from the roots to the tip ; and while the foremost is pergamentose in

texture, all the other laminae are papyraceous or membranous ; whereas in the genus

quoted the laminae are not creased, and only the hindermost in each series is papyraceous.

The laminae diminish successively, chiefly in length ; their form in segment 4 is narrowly

suboval, somewhat abrupt at the base ; in segment 5 each is broadly oval, truncate at

the base ; in segment 6 the laminae are rotundate-subquadrate ; the hindermost are

almost semi-rotund. Length of body, 6 12, setae 5 millim.

Kah. Detroit, Mich. (Mus. Comp. Zool. Cambridge, ]\Ias.) ; M'CoUam's Lake, M'Henry,

111. (May ; Foster in Mus. State Lab. Nat. Hist., 111.). The eyes of the adult must be

ascalaphoid ; but the hind wings of the nymph differ from those of described genera of

this section.

TELOGANODES, Etn. 1882.

Illustrations. Adult (wings), PI. XV. 24 bis.

Adult. — Hind wing minute, obovate-oblong, angular in front nearly in the middle,

with the apex of the angle inverted, and with the margin beyond the angle slightly

concave ; ncuration very simple, consisting of the subcosta (2), radius (3), cubitus (5),

and praebrachial (6), with or without a sector, and with scarcely a cross veinlet ; subcosta

nearly straight, terminating abruptly near the salient angle without meeting the costa ;

the common stem of the radius and cubitus makes an acute angle with the subcosta, and

is met by the cubitus at a distance of about ^ of the wing's length from the wing-roots;

EEV. A. E. EATOX OX EECEXT EPHEMEEID.E OE MAYFLIES. 135

the irregularly sublinear marginal area is broadest in proximity to the great cross vein ;

the submarginal area, widest at the anterior angle of the wing, and subtriano-ular in

form, with its outer side slightly concave, contains a few traces of obsolescent cross

veinlets, of which another is sometimes distinguishable in the next area subjacent.

In the fore wing, most of the intercalary nervures are rudimental and isolated ; the cross

veinlets are absent from the portion of the marginal area preceding the pterostio-matic

region, as well as from the terminal margin, but are numerous elsewhere in advance of

the anal (8) nervure, although obsolescent in parts. The intercalar neuration of the

anal-axillar interspace of the same Aving is less scanty in larger specimens than in the

small example figured ; but the series of adults available for comparison is too limited

for descriptive purposes. Forceps-limbs of d 3-jointed ; the proximal joint stout, taperino-

distally from the base, and rather longer than the slender second joint ; terminal joint

short and small. Porceps-basis entire, and seemingly very short ; ventral lobe of 2

segment 9 obtusely rounded off and entire. Penis-lobes linear or subulate, and con-

tiguous. Median caudal seta aborted ; outer setae about twice as lona; as the 2 bodv.

Tarsal ungues each unlike the other in every leg. Fore tarsus shorter than the d tibia ;

its joints in diminishing sequence rank 2, 3, 5, 4, 1 ; the other proportions of the legs

are unascertainable.

Nymph unknown.

Type. T. tristis (in Cloe), Hag.

Distribution. Ceylon.

Etymology. rt-Xo? and -yaiwSijc, in allusion to the wings becoming clear and bright in

the imago. The type was named tristis from the dinginess of the wings of the sub-

imago, — heretofore the only grade described.

Teloganodes tristis, Hagen. Plate XV. 24- bis (wings).

Cloe tristis, \ Hag., Yerli. zool.-bot. Gesells. Wien, viii. 476 (1858); Etn., Trans. Ent. Soc. London

(1871), 131, note.

Leptoptilebia [Etn.] tristis, Hag., op. cif. (1873), 394.

Teloganodes [type] /m^is, ! Etn., Ent. Mo. Mag. xviii. 208 (1882) [undescribed] .

Subimago {dried), 2 . — Wings translucent, talcose, deep Avarm-sepia brown verging

upon sooty black ; neuration sometimes like-coloured, but at others many of the longi-

tudinal nervures are black : the pterostigmatic space of the fore wing contains about 9

nearly straight simple cross veinlets at some distance from the bulla. Legs pale, sub-

lutescent varied with piceous ; the fore femur, the base and a subterminal band or spot

of the fore tibia, and the terminal joints, ungues, and the extreme apical borders of the

other joints of all the tarsi, besides the apical projections of the hinder femora, pitch-

brown; the apical spinule, and a streak along the upper terminal border of every coxa

black. Setaj pale sepia-grey, with black joinings. Abdomen discoloured ; thorax pitch-

brown ; oculi during life {teste Isietner's MS. ticket) black.

Imago, ? (f/;v'e(7).— Wings transparent, very faintly tinted with extremely pale smoke-

grey : longitudinal nervures (excepting near the wing-roots), the extreme edges of the

wing, and the cross veinlets of the pterostigmatic space of the fore wing, black ; wing-

18*

136 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES.

roots piceoiis. Abdomen piceous with opaque joinings. Setae brownisli- or greyish-

white, with deep-black joinings. Length of body, 2 5-6 ; wing 8-8'5 ; setae, im.,

upwards of 15 millim.

JIab. Rainl:)odde, Ceylon, at upwards of 4000 ft. altitude. An adult c? in the British

Museum, perhaps of this species, captured in Ceylon by Mr. G. Lewis, was noted by him

as luminous at night. Being carded, it cannot well be described.

Teloganodes major, sp. nov.

Snblmago [dried), ? . — Wings very similar to those of T. tristis ; neuration concolorous

with the membrane, the longitudinal nervures opaque ; the pterostigmatic space of the

fore wing contains upwards of 14 nearly straight, simple cross vcinlets. Legs varying

in colour, perhaps with age; fore femur pitch-black or pitch-brown; hinder femora

pitch-brown or deep luteo-fuscous, with a dark longitudinal median streak ; fox'c tibia

lutescent ; hinder tibiae dull testaceous ; tarsi either entirely blackish, or else only the

terminal joint and ungues blackish. Body discoloured ; setse light sepia-grey, with black

joinings. "Oculi during life red" {teste Nietner, MS.). Length of body, ? [shrunken)

8 ; wing 10-12 ; setae about 25 millim.

Sab. Rainbodde, Ceylon, at an altitude of 4000 ft. and upwards. Two examples

(Nos. 17 & 18) in Dr. Hagen's collection, and one (mistaken by me for T. tristis in 1871

[Trans. Ent. Soc. London, 1871, p. 131 note]) in the British Museum.

Third Series of Group Ii. of the Genera.

Adult. — The anal (8) and second axillar (9^) nervures, together with the margin of the

fore wing, enclose a trilateral space, truncate or abrupt at its apex, and curved at the

sides ; anal nervure either contiguous with, or nearly approximated to, a pobrachial (7

or 7^) nervure at the wing-roots ; first axillar (^9) curved or arched, sometimes falling

short of the wing-roots. Hind wings absent, or small [fide Vayssiere), with the costa

sharj)ly angulated near the base, and the subcosta nearly straight. Thoracic spiracles

relatively small, usually open in dried specimens ; orifice of the metathoracic spiracle

oval ; that of the mesotlioracic spiracle angular and short, without a guard, its upper lip

convex externally, vaulted within, much larger than the lower lip, and with its edge

bent almost at right angles in the middle. Forceps-limbs sessile upon the segment, at

the sides of a large immovable lobe, which is represented by a lamina in the ? . Eyes

alike in both sexes, evenly contoured, round or oval, small and far apart. Subimago

restless until the moulting is imminent, which is speedily effected within a few minutes

of the preceding ecdysis, when not retarded by torpor induced by exposure to cold.

This series of genera has affinity with the sections typified by Ephemerella and Poly'

mitarcys. It is conveniently grouped with the former on account of the character of the

nymphs of the section of Ccvnis. Where these differ essentially from those of the two

sections already mentioned, they resemble nymphs of the section of Leptoplilebia.

Their relationship to the section of Polymitarcys is traceable in the imago, viz. in the

formation of the head, the sexual disparity in the proportional length of the setse, the

REV. A. E. EATON ON RECENT EPHEMEEIDiE OR MAYFLIES. 137

texture of the wings and approximation of the anal (8) to the pobrachial (7) nervure at

the base of the mesothoracic wing, and the brevity of the subimago period. The pro-

notum of the adult, similar in some respects to that of Epliemerella, has also an appreci-

able likeness to that of Lachlania and its allies; and it is noteworthy that free epinotal

prolongations of the membrane continued from the wing-roots along the hind margin of

the mesonotum, similar to theirs, exist in Leptohyplies — Lachlania and its kindred ranking

next to the section of Polymitarcys, in the present system of arrangement. In marshal-

ling European collections I have sometimes placed Ca;nis between Oligoneuria and Foli/-

mitarcys ; and I believe Dr. Hagen and Mr. M'Lachlan are disposed to assign it that

position.

But, on the other hand, at the present time no genus unquestionably referred to

Group I. is known to have palpi conformable to the Leptophlehia type. Even Jolia, so

similar in aspect to nymphs of the Baetis and Siphlvriis sections, has palpi of the Palin-

gen'ia type ; and Enthyplocki, while deviating slightly from the normal, clearly maintains

through Ephemera a close connexion with the same group. If the transfer has to be

effected eventually, on account of anything learned about nymphs yet to be discovered

of genera in Group I., the consequent disturbance in the grouping of the sections may

attain very considerable dimensions.

Section 7 of the Genera. — Type of Ctenis. Adult. — Pronotum of $ transverse and

short, closely appressed to tlie mesonotum, prominent and somewhat smooth above, and

witli a deep sinus in the middle of its hinder border. Hind tibia about f as long as the

femur, the tarsus little more than h as long as the tibia. In the mesothoracic wing the

longitudinal neuration is fully developed ; the first and second axillary nervures (9^ & 9")

enclose a narrow space, whicli for some distance from the inner margin maintains an

almost even width, and docs not extend to the wing-roots ; wing-membrane ciliated

along the inner and terminal margin, as in the subimago [except, perhaps, in Lepto-

hyphes]. Hinder ocelli unusually large ; the foremost extremely small [excepting^

perhaps, in Tricorythiis maximus]. Nymph \Leptohyphes unknown]. — Terminal margins

of the wings free [excepting, probably, in Leptohyphes]. Palpus of the 1st maxilla 3-

jointed, longer than the lacinia ; the latter crowned with a sparse tuft of hair, armed

with spinous teeth at the tip, and ciliate on the inner edge. Lobes of the labium well

developed, subovate, nearly as large as the lacinige of the 2nd maxilte, which are ovate

and acute. Abdominal tracheal branchiae on segments 1-6; those of the first segment

minute and erect ; those of the 2nd segment elytroid, shielding the remainder, and

differing from all the others in form and texture. Hinder lateral angles of the segments

more or less prolonged. Natation laboured, aided by movements of the legs.

Nymphs of two genera in this section are known— Cmiis and ? Tricorythus. Ccenis

has plumose caudal seta?, sparingly branched fringes to the hinder tracheal branchiae,

and has no appendages beneath their laminne. The other nymph has the setse minutely

pubescent and setulose, like those of Ephemerella, laxly pectinate fringes to the obtected

tracheal branchia?, and an appendage on the underside of each lamina of the hinder

pairs.

138 EEV, A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES.

TRICORYTHUS, Etn. 1868.

Illustrations. Adult (details), PI. XV. 25 ; (whole figure) see citations of Saviguj

and Pictet under T. varicauda. Nijmfh (?), PI. XLI.

Adult. — Hind wings absent. Caudal setie 3, mutually subequal in length, about ai

long as the body in ? , and twice as long in 6 . Cross veinlets multiserial, numerous ii

the midst of the wing and of the marginal area (but rudimentary in the latter), remot(

from the terminal and inner margins ; these margins are devoid of isolated rudiments o

veinlets, and the longitudinal nervures of branchlets. The anal-axillar interspace contain

two well-developed intercalar nervures ; the nearest to the anal (8) nervure describes ;

simple curve, and meets the first axillar (9^) at a point nearly in a line with the junctioi

of the branches of the pobrachial (7) nervure, and of the sector (4) with the cubitus (5)

and at a distance from the inner margin of about f of the interval between its owi

extremity and the costa ; the hinder intercalar meets the anterior near its inward termi

nation, and its extremities are curved slightly in opposite directions, somewhat like th

stem of an italic y*; hence the intercalars simulate a deeply forked nervure annexed t

the first axillar. The recurrent membrane of the wing-roots does not extend beyond th

point of the scutellum. Ventral lobe of ? segment 9 obtuse. <s unknown to me ; pre

portions of legs unascertained. Ni/nqih [Ccenis maxima, Joly, is perhaps a Tricorythut

and is provisionally described as such, pending identification]. — Body broadest at th

mesothorax ; head slightly narrower than the prouotura, and somewhat similar in contou

to that of an Ephemerella. Pronotum quadrangular, oblong, with sharply defined angle:

Abdomen slender in comparison with the anterior portion of the body, broadest about tli

4th segment, and tapering slightly posteriorly, but nearly as broad in front ; segmeni

2-5 combined are about \ as long as the posterior segments united ; dorsum arched

venter slightly convex ; pleurae somewhat dilated, and similar in character to those (

Ephemerella, but less obviously cUiated, their hinder angles acute in the anterior sej

ments, but gradually more and more prolonged and acuminate in the posterior segment

Dorsal tracheal branchiae issue from the antero-lateral angles of the 1st segment, froi

the posterior margins at the bases of the pleurce of segments 2-5, and from the disk (

the 6th segment at a point in line with the insertions of the four preceding ; those (

segment 1 [teste Vayssiere], lost in examples examined by me, are minute, subulat

hirsute, jointed close to their insertion, and erect ; those of segment 2, large, elytro:

and coriaceous, obtect the hinder pairs completely, and are hitched together by the

adjacent inner edges, where a row^ of short stiff ascending hairs inserted along the margi

of the right elytron is caught by a flange projecting from beneath the margin of the le

elytron ; moi'eover the same elytroid laminae are securely held down anteriorly by tl

hind margin of the segment, which is bevelled or under-cut to receive their front edge

and has a small projecting triangular tooth in the middle, affording further support ; eac

elytron, subquadrate in the main, with the outer side and the angles adjacent therei

rounded off, is externally convex and nude, ciliated with hairs of peculiar form along i

outer and terminal margins, and is traversed obliquely by a ridge running from the pla(

of attachment towards its inner posterior angle ; each on the imderside is largely concav

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 139

and supports a short lax filiformly dissected appendage, projecting diagonally from tlie

point of attachment into the concavitJ^ The other tracheal branchiajare smaller, closely

imbricated, decumbent, pergamentose, ovate-triangular, concave beneath, and fringed

with crowded, long, unilaterally branched, lax fiilamentose fimbria? ; and [teste Vayssiere]

each of them shelters in its concavity a filamentosely dissected appendage. Caudal setae

about f as long as the body, rather similar to those of Ephemerella in the quality and

disposition of their hairs, but lacking pilosity. Various parts of the body are beset with

peculiar hairs resembling those of Ephemerella and Troml)idiid Acarina. Hind leg the

longest, the tarsus (claw excluded) about f as long as the tibia ; fore tarsus nearly as

long as the fore tibia. Antenna? of moderate length, subulate, almost nude.

Type. T. varicauda (in denis), Pict.

Distribution. Upper Egypt and Cape of Good Hope ; also (undescribed sp.) the Malay

Archipelago. The nymph described inhabits the south of France.

Etyniologij, TpiKopvOoc, with triple plume.

Tricortthus varicauda, KoUar, MS.

Ephemera [Savigny, Descript. de I'Egypt. Hist. Nat. i. 194 (Explic), ii. Nevropt. pi. ii. G, 7 (1817)].

Ccenis varicauda, Pict., Hist. Nat. Nevropt. ii. Ephem. 281, pi. xliii. 5 (1843-5); Walk.^ List of Neuropt.

Ins. in Brit. Mu,. part iii. 581 (1853).

Triconjthus varicauda, Etn., Ent. Mo. Mag. v. 82 (1868) ; id.. Trans. Ent. See. London (1871), 92, pi. ii.

3, 3 a [wing, after Savigny] .

Adult {dried), 3 . — Body" pale yellowish ; eyes and a spot on the frons black. Meso-

thorax i*ather darker laterally, with some longitudinal black marks [sutures ?]. The

last five segments of the abdomen have each a black dot (" point ") above. Setaj white

finely annulated w ith black. Legs yellowish, with some greyish clouds. "Wings and

neuration slightly yellowish, except the subcosta and radius (" la costale et la sous-

costale "), wdiich are rather darker, without being quite so dark as in Ccenis argentata

and C. haUercda. Length of body, d 4, expanse of wings 10, length of seta? 9 mm.

llab. Upper Egypt. [After Pictet.]

Tricorythus discolor, Burmeister.

Oxycypha discolor, Biirm., Handb. d. Ent. Bd. ii. Abtli. ii. 797 (1839).

Clo'eon discolor. Walk., List of Neuropt. Ins. in Brit. JIus. part iii. 577 (1853).

Ccenis discolor, Etn., Trans. Ent. Soe. London (1871), 96; ! Hag., op. cit. (1873), 399 [C. a/iiaTfl,

Winthem, MS.] .

Suhimago {dried), $ .—Head dull dark grey above ; pronotum greyish fuscous, meso-

and meta-notum dull lutescent or brown-ochre; dorsum of abdomen dark cinereous,

venter and eggs ochraceous ; seta? white, pubescent. Wings throughout very pale sepia-

grey, translucent ; longitudinal nervuros subopaque, slightly brownish ; cross veinlets

very indistinct ; the darkened appearance of the costal border is due merely to the sub-

costa and radius being closed together by shrinkage of the membrane. Legs pale flaves-

cent ; the fore-femur edged with fuscous, the tibia and tarsus dark sepia-brown. Length

140 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

of body, S (eggs discharged, and therefore shruuken) about 5'7 ; wing 10 ; setae about

8-9 mm.

Hab. Cape of Good Hope (Burm.j. Described from a specimen in Dr. Hagen's collec-

tion (Winthem). The comparative elongation of the wings noticed by Dr. Hagen (1873)

is doubtless due to the sex of this example.

Tricorythtjs (?) sp. (nymph). PL XLI. (whole figure and details).

Ctenis or C(Enis maxima, Joly, Bull. Soc. Hist. Nat. Toulouse, iv. 144, pi. ■ — ? (1870) ; id. Rev. d. Soc.

Savants, ser. 2, iii. G9-72 (1873) ; id. Feuil. d. jeun. Nat. ann. 6, 53-4, pi. ii. 7 (1876) ; ! Etn., Ent.

Mo. Mag. xvii. 190 (1881).

Tricorythus, ! Vayssierc, Arm. d. Sc. Nat. 6" s6v. Zool. xi. 3, 4, pi. i. 1 (1881) ; id., op. cit. xiii. 65,

pis. vi. 54, viii. 81-90 bis, & ix. 94-97 (whole figure aud details).

Adult unknown.

Nymph of mature age ; length of body 10, outer setae 7 mm.

Hab. The Garonne near Toulouse (Dr. E. Joly). I am disposed to suspect that this

nymph has been too hastily referred to Tncorytlius ; the adult may be of a genus at

present unknown ; but I could not distinguish the neuration of the wings satisfactorily

in the nymph, and therefore this is only a conjecture.

LEPTOHYPHES, Etn. 1882.

Illustrations. Adult (detail), PI. XV. 25 bis.

Adult, ? . — 'Uind wings absent. Caudal setae 2, about as long as the wings. Cross

veinlets multiserial, numerous in the larger portion of the wing, but absent from the

marginal area and from the vicinage of the terminal and inner margins ; these are devoid

of isolated rudiments of veinlets and perhaps of fringes, and the longitudinal nervures

have no brauchlets at their terminations. The anal-axillar interspace contains two well-

develojied intercalar nervures, each of which, like the 1st axillar (9^), is met at its anterior

extremity by two cross veinlets, — one from each of the nearest adjacent nervures ; the

anterior of these intercalars is a little the larger, nearly straight, and is connected by

several obsolescent cross veinlets with the anal (8) nervure, to which it is subparallel ;

the hinder intercalar is almost imperceptibly curved, nearly bisects the area intervenient

between the first intercalar and the first axillar nervures, and is connected more strongly

with the former of these than with the latter. The recurrent membrane of the wing-

roots projects as a subulate point beyond the peak of the scutellum. Other particulars

unascertained. <s unknown.

Type. L. exlmius, Etn.

Distribution. Argentine Republic.

Etymology. XeTTTow^/jc, finely woven ; referring to the tenuity and relative abundance

of cross veinlets.

Leptohyphes eximius. pi. XV. 25 bis (wiug).

Leptohijphes ezimius, ! Etn., Ent. Mo. Mag. xviii. 208 (1882, Feb.).

Adult (dried), $ , — Body discoloured dull pitch-black. Wings talcose, transparent,

REV. A. E. EATON ON RECENT EPHEJIERID.E OR MAYFLIES. 141

slightly dimmed with very light sepia-greyish ; neuratiou pitch-brown. Fore legs and

hinder femora greyish black; hinder tibiie and tarsi greyish white. Setae dull whitish.

Length of body (shrunken) 4 ; Aving 8 ; setae about 8 mm.

Hub. Cordova, Argentine Eepublic (Mus. Comp. Zool. Cambridge, Mass.).

C.ENIS, Steph. 1835.

Illustrations. Adult (details), PL XV. 26 a, h ; (whole figures) Steph. (1835) under

C. halterata (macrura), and Pictet under C. haltcrata {grisea) and lactella (J lactea).

Nymph, PL XLII.

Adult. — Hind wings absent. Caudal set?e 3, mutually subequal, the median being

sometimes a little longer or shorter than the others, which in 3 im. are from 3| to 5 or

6 times as long as the body, and in 2 about f as long as it ; in neither sex are the setae

of the subimago much more than ^ as long as the body, and therefore their joints in the

cf undergo excessive elongation during the last moult ; in e im. they are uniformly

glabrous, but in ? im. the seta3 are pubescent from near their roots to the tips. Cross

veinlets almost exclusively uniserial, remote from the margin and absent from the mar-

ginal area ; terminal and inner margins of the wings devoid of rudimentary veinlets ; no

branchlets to the longitudinal nervures. The anal-axillar interspace contains two long

intercalar nervures of nearly equal length, either of which is met by the other just before

annexing itself to the anal (8) nervure near the series of cross veinlets, and at a distance

from the inner margin of about f of the interval between its own extremity and the

costa ; the fork formed by their conjunction is narrow and deep, and the curvature of its

sides nearly uniform. The recurrent membrane of the wing-roots does not extend beyond

the scutellum. Homologue of the forceps-basis undeveloped in ? . Pleura3 prolonged

posteriorly in segments 7, 8, and 9 of the abdomen into setaceous-acuminate or subulate

teeth. Forceps-basis entire ; forceps-limbs jointlcss and short ; penis exposed, undivided,

without apparent stimuli. Ungues of the hinder tarsi of 6 , and of all the tarsi of 2 ,

each unlike the other ; those of the d fore tarsus alike, rotund. Fore tarsus of 6 ,

exclusive of joint 1, about f as long as the tibia, which is about twice as long as the

femur ; its joints in diminishing order rank 2, 3 subequal to 4, 5 ; joint 1 is not distinctly

marked off from the basis. Fore tarsus of ? 4-jointed, about f as long as the tibia ;

this and the proximal joint of the former together are very little more than f as long as

the femur. Hind tarsus ? f as long as the extreme length of the tibia ; its joints rank

4 (the terminal), 1, and 3 subequal to 2. The theoretical first joint in these tarsi is

imdeveloped ; the femora are relatively broad. During quiescence the subimago stands

upon all its feet, with the caudal setaj laid together, and the wings usually widely

outspread, rarely erect. Nymph. — Body broadest at about the mesothorax, but not so

in a marked degree ; head a little narrower than the pronotum, varying slightly in contour

with the species. Pronotum transverse, its lateral borders sometimes dilated, and pro-

longed somewhat in front. Abdomen narrowed gradually in its hinder half, the anterior

segments difi'ering little from one another in breadth ; 1st ventral segment thoracoid,

2-5 shorter than the succeeding segments ; ventral segments 2-6 together about as long

as 7-10 together ; pleurte dilated, posteriorly acute or acuminate. Tracheal branchiaj

SECOND SERIES. — ZOOLOGY, VOL. IIL 19

142 EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES.

placed as in Tricorytlms maximus, and of a very similar character, but the laminae of the

hinder pairs are more rounded in form, and are not provided with an appendage on their

under surface. Moreover the elytroid pair are beset with short pubescence on the upper

surface, and ciliated with fine hair along their lateral and posterior borders ; the pairs

succeeding them are membranaceous, and their fringes are subdivided more sparingly

than in Tricorythus, the fibrils of the costal border and of the proximal portion of the

inner border of each lamina being simple or only bipartite, instead of pectinate, and

those of the distal margin having only two or three short branches apiece, arranged uni-

laterally. Caudal setae about | as long as the body, beset at the joinings with fine rigid

hair arranged piunately. The hairs of Ccen'is are not flattened like those described under

Tricorythus. Hind leg the longest ; the tarsus (claw excluded) about as long as the

tibia. Femora slender, or broad, according to the species. Antennae of moderate length ;

joint 2 rather long and pubescent ; the remainder of the flagellum beset at the joinings

with minute spreading hairs.

Type. C. Imlterata (in Ephemera), Fab.

Didrihution. Northern Europe and America, southwards to Egypt (Savigny), Mogador

(undescribed sp.), and Florida; lakes of East Ceuti-al Africa; Cape Town (undescribed

sp.) ; and the Indo-Malay region.

Etymology . A mythological proper name.

The adult flies take wing during the cool of the day, and during the warmer hours of

the night, when light is attractiA^e to them. Their life is fugitive in dry air. The Cape

Town and Mogador species were found there by me in 1874. and 1881 respectively ; but

in each case only a single drowned adult 2 was obtained. I have seen nymphs of C. dimi-

diata, halterata, Harrisella, and of some Portuguese and Italian species alive. My dis-

covery of the nymph occurred at Cambridge in the spring of 1866 ; but the genus and

species ( C. dimidiata) of the specimen captured were not ascertained until a year or two

later.

C^Nis DIMIDIATA, Steph. Plate XV. 26.

lEphemera minhnu, Liun., Syst. Nat. ed. v. p. 62 (1747) ; Mill., Zool. Dau. Prodr. 142 (1776) ; Schr.,

Fn. Baica, ii. pars ii. 198 (1798).— [Sy/emera] or E. horaria, Linn., [Act. Upsal. (173G),p. 27; id., Fn.

Suec. ed. i. no. 754 (17-16)] ; id., Syst. Nat. ed. x. i. 547 (1758) ; id., Fn. Suec. ed. ii. 376; [Geof.,

Hist. Abreg. d. Ins. Paris, ii. 240, no. 8 (1761);] Pontop., Naturh. Dan. 223 (1765); Linn., Syst. Nat.

ed. xii. pars ii. 907 (1767) ; Fab., Syst. Ent. 304 (1775) ; Mill., Zool. Dan. Prodr. 143 (1776) ; Fab.,

Sp. Ins. i. 358 (1782) ; Fourc., Ent. Paris, ii. 352 (1785) ; Fab., Mant. Ins. i. 214 (1787) ; Berkcnh.,

Outl. Nat. Hist. Gt. Brit. & Ireland, ed. ii. i. 150 (1789) ; Vill., C. Linn. Ent. iii. 20 (1789) ; Gmel.,

Linn. Syst. Nat. ed. xiii. i. pars v. 2630 (1790) ; Ros., Fn. Etrusc. ii. 9 (1790) ; 01., Eneycl. Meth. vi.

419 (1791) ; Fisch., Vers. e. Naturgcseh. v. Livland, 566 (1791) ; Fab., Ent. Syst. emend, iii. pars i. 71

(1793) ; Schr., Fn. Boica, ii. pars ii. 199 (1798) ; Ccderb., Fn. Ingrica; Prodr. 135 (1798) ; Walck., Fn.

Paris, ii. 10 (1802) ; Lat., Hist. Nat. ed. ii. 226 (1817).— £. j^tumosa, Miil., Zool. Dan. Prodr. 142

(1776). — E. \\albipennis, Atkinson, Zoologist, i. 272-5 (1843). — E. lactea, Landois, Jahresb. Westf.

Prov. Ver. f. "Wissensch. u. Kunst. (1878), 3.

? Brachycerais minima, Curt., Lond. & Edinb. Phil. Mag. ser. 3 (1834), 122.

C<enis dimidiata, ! Steph., 111. Brit. Ent. vi. 61 (1835) ; Pict., Hist. Nat. Nevropt. ii. Ephem. 286

REV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 143

(1843-5); ^Valk., List of Neuropt. Ins. iu Brit. Mus. 582 (1853); Hag., Ent. Ann. (1863), 12;

Oulianine, Neuropt. & Orthopt. of Prov. of Moscow, p. 27 (1867) ; ! Etn., Trans. Ent. Soc. Loncl.

(1871), 95, pi. ii. 4 [ala] & v. 5 [genital. ^J] ; Hag., oj). cit. (1873), 397-9; Mocsary, Rev. d. Inhalte der

Termeszetrajze Fuzctek, ii. 124-5 & [German text] Naturh. Heft ii. Bd. ii. u. iii. 181-2 (1878);

Rostock, Jahrcsb. d. Ver. f. Naturk. Zwickan, 1877, p. 80 (1878).— C. brevkauda, ! Steph., 111. Brit.

Ent. vi. 01 (1835) ; Pict., Hist. &c. 280 (1843-5) ; Walk., List &c. 582 (1853).— C. peimata, ! Stepli.,

111. Brit. Ent. vi. 01 (1835) ; Pict., Hist. &c. 286 (1843-5) ; Walk., List &c., 583 (1853).— C. ladea,

Gerstacker, Handb. d. Zool. ii. 01 (1803) ; Hag., Stet. Ent. Zeit. sxvi. 229-32 (1865) ; id.. Trans.

Ent. Soc. Lond. (1873), 397.

Oxycypha lactea, Burm., Haudb. d. Ent. Bd. ii. Abth. ii. 796 (1839).

?Clue horaria, Ramb., Hist. Nat. d. Ins. Nevropt. 299 (1842) ; Pict., Hist. Nat. Nevropt. ii. Ephem.

270 (1843-5) ; Oulianine, Neuropt. & Orthopt. of the Prov. of Moscow, p. 29 (1867).

^Cloeon horaria, Walk., List of Neuropt. in Brit. Mus. 576 (1853).

Subimago {Ihiug). — Wiugs greyish white, with the marginal and submarginal areas

tinted with warm sepia almost to their extremities. Setae white.

Imago {living). — Head and pronotum fuscous, antennae white. Meso- and metathorax

piceous. Abdomen whitish, varied with grey ; iu j white above, with markings corre-

sponding in 2>osition with those of the ? , but only faintly tinged with grey ; in $

cretaceous, with segments 1-5, and sometimes the extreme base of 6, grey above, but with

tlris colour broadly interrupted at the joinings by the ground-colour, and widely so iu

the middle of segment 1 ; moreover the patches of grey are intersected l)y a fine longi-

tudinal cretaceous line, and are invaded by the same colour in the neighbourhood of the

pleurse, where a series of grey dots is distinguishable, placed singly in the segments

close to their anterior lateral angles ; the dots are present also in the hinder segments,

which otherwise are uniformly cretaceous. The ventral segments of ? are often marked

on each side with a grey dot. The 6 genitalia are pale throughout, and when dried

have a light yellowish testaceous tint. Setae white. Eore leg in some lights tinged witli

Eoman sepia-grey, and with femur simply grey, becoming when dry whitish with the

femur bistre- or light sepia-grey in 2 , and greyish or brownish grey in d . Hinder legs

greyish white (the ? with yellowish-white femora when dried), with a black dot on the

upper edge of the femur a little before the knee, visi])le also on the ? fore femur. The

stronger portions of the longitudinal nervures, and the usual coloured part of the front

border of the wings, are greyish iu the dried s and sepia-grey in the ? . Length of

body 3-5 ; wings, d -4, ? 5 ; sette, 6 im. 18 & 13, subim. 3 & 2-5-3 & 3-5 ; seta?, $ im. 3,

subim. 2"25 millim.

Rab. Great Britain to Moscow, and Scania (Wallengren) to Lago Maggiore, where I

have taken it at Pallauza. It abounds in Belgium and Holland, as well as in lowland

Switzerland. Pastor Wallengren adopts the prevalent surmise that this was the species

which Linne meant to describe as E. horaria in 1758. I have not adopted the name (on

account of the vagueness of the diagnosis) in the absence of authentic types. Vague

diagnoses are, at the most, essentially generical.

Var. nivuLORUM.

Imago {lioing), 2 ■ — Head and prothorax translucent whitish grey, varied with dark

19

,»

144 EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES.

black-grey. Meso- and mefcanotum light umber-hrown, with black sutures. Abdomen

white, segments 1-3 partly shaded above very slightly with greyish. Legs white ; the

fore coxa, femur, and base of the fore tibia dark grey ; hinder femora white.

d {living). — Similar; meso- and metanotura lighter than in the $ , and with sutures

less distinctly black. Costa, subcosta, radius, sector, and cubitus blackish grey to rather

beyond the middle. Length of wing 3, setse about 12 millim.

Hub. Dorsetshire, in the Syndeford brook, near Shedrick, in the parish of Thorncombe,

Cliard; also the Dove, near Mayfield, Ashburne, Derbyshire (June). I suspect this is

the insect quoted as. English by Pictet under C. % lactea in 1843-5.

C^Nis LACTELLA (renamed).

Canis if lactea, Pict., Hist. Nat. Nevi-opt. ii. Epliem. 27G, pi. xliii. 1-4 & xliv. (1843-5) ; Hag., Trans.

Eut. Soc. London (1873), 397.

Imar/o (after Pict.). — Head grey, with the vertex a little lighter. Thorax light ochreous,

with the sides of the prothorax and the mesonotum fuscescent ; the latter marked with

a cruciform spot of the ground-colour. Abdomen white, with very slightly defined spots

on the sides of the segments. Sette whitish. Legs tinged very faintly with lutesceut.

Wings vitreous, colourless ; subcosta and radius black ; the other nervures lutesceut,

colourless in the d .

(S {dried). — Vertex of head pitch-brown. Thorax translucent ; the pronotum rather

greyer than the remainder in some lights ; meso- and metanotum pervaded with a light

brownish amber-colour, the metathorax viewed sideways rather yellower amber. Ter-

minal segments of the abdomen very light yellowish am])er or light brown ochreous ; the

remainder whitish amber, with traces of the same yellowish colour at the sides of the

back; legs and setae uniformly whitish, or whitish amber with a faint yellowish tint.

Length of body, $ 4, d (dried) 3 ; wing, ? 4, d 3"5 ; setaj d 11 millim.

Kal). Lakes of Geneva and Zurich, in the middle of summer. I obtained it at Geneva

(1230 ft. alt.) on the 10th August, in profusion at gas lamps. Pictet's fig. 1 is a very

good likeness of the living 6 im.

Cjcnis halterata, Pab. PI. XV. 2G.

Ephemera halterata, Fab., Gen. Ins. 24,4 (1777) ; id., Sp. Ins. i. 384 (1782) ; id., Mant. Ins. i. 243

(1787) ; Vill., C. Linn. Ent. iii. 18 (1789) ; Gmel., Linn. Syst. Nat. ed. xiii. i. 2G29 (1790) ; 01., Encyc.

Metb. vi. 418 (1791) ; Fab., Ent. Syst. emend, iii. pars i. 69 (1793) ; Schr., Fn. Boica, ii. pars ii. 198

(1798) ; Lat., Hist. Nat. Crust. & Ins. xiii. 95 (1805) ; Zet., Ins. Lap. 1045 (1840) ; Hag., Trans. Ent.

Soc. London (1873), 396. — E. brevicauda. Fab., Ent. Syst. emend, iii. pars i. 69 (1793) ; Walck., Fn.

Paris, ii. 9 (1802) ; Lat., Hist. Nat. Crust. & Ins. xiii. 96 (1805) ; Zet., Ins. Lap. 1045 (1840).

Brachijcercus chironomiformis, Curt., Lond. & Edinb. Pbil. Mag. ser. 3 (1834), 122.

Cmiis chironomiformis, Steph., 111. Brit. Ent. vi. 62 (1835); ! Etn., Trans. Ent. Soc. (1871), 94.—

C. macrura, ! Stepb., 111. Brit. Eut. vi. 60, pi. xxix. 1 (1835) ; Walk., List of Neuropt. in Brit. Mus.

583 (1853); Hag., Ent. Ann. (1863), 10; ! Etn., Trans. Ent. Soc. London (1868), 279-82 [nympb] ;

\id., op. cit. (1871), 93, pi. v. 4 [details]; Hag., op. cit. (1873), 397; Meyer-Diir, Bidl. Soc. Ent.

Suisse, iv. 308 (1874) ; Rostock, Jabresb. d. Ver. f. Naturk. Zwickau, 1877, 80 (1878). — C. interrupta,

Stepb., 111. Brit. Ent. vi. 62 (1835) ; Pict., Hist. Nat. Nevropt. ii. Epbem. 287 (1843-5) ; Walk., List

EEV. A. E. EATON ON RECENT EPIIEMERID.E OR MAYFLIES. 145

&c. 583 (1853).— C. grisea, Pict., Hist. &c. 278, pi. xlv. 1, 2 {18i3-5) ; Walk., List &c. 581 (1853) ;

Brau., Neuropt. Austr. 25 (1857) ; Aiisscr., Ann. A. Soc. Nat. Modena, Ann. iv. 133 (18G9) ; ! Joly,

Bull. Soc. Hist. Nat. Toulouse, iv. 147 (1871) ; id., Bull. Soc. d'Et. &c. Augers, 41-2, Note B (1876).—

C. halterata, ! Hag., Eut. Ann. (18(33), 11.

Subimago [Umng). — Wiugs tinted with greyisli, especially towards the costa. Setae

light blackish grey.

Imago {Uc'ing). — d . Head gi'ey-black, with the stipes of the antennae and the cervical

joining sepia-grey. Pronotum medium ivoiy-black ; meso- and metanotum jet-black,

changing to pitcli-ln-own when dried. Alidomen of 6 grey, tinged towards the sides

with medium ivory-black ; each dorsal intermediate segment has the track of the dorsal

vessel, and a spot on each side of it at the base of the segment, pellucid, and each of

those segments beneath has a pellucid spot on each side near the middle; the dorsal

joinings of the segments are opaque, with the extreme overlapping edge of the integu-

ment whitish. Setce grey, with light blackish-grey joinings. Legs pitch-black ; the

tibiae, tarsi, and under edges of the femora light blackish-grey and translucent. Wings

transparent, smoky, slightly greyish in the vicinage of the costa for some distance from

the wing-roots ; costa, subcosta and radius, and in some lights the other longitudinal

nervures pitch-black ; but viewed with transmitted light, in some positions, most of the

nervures mentioned, excepting the thicker parts of the three foremost, become trans-

lucent whitish.

2 [living). — Fore femur grey ; hinder femora yellowish white. Abdomen above

l)lackish grey, becoming ochreoiis towards the joinings and sides of the segments ; venter

tinged with greenish grey. Length of body, 6 4-5, ? 6 ; wing, d 4-5, $ 7 ; setae,

6 im. 14 & 15-15 & 16, subim. 3; ? im. & subim. 2-3 millim.

Hub. Europe, from Scania and Smalaud (Wallengren) or Lapland (Zet.) to Portugal

and Italy ; and from Great Britain to Germany and Switzerland. Abundant at Cintra,

27th April (400-COO ft.) ; Toulouse (430 ft.) ; Bale and Geneva ; and near San Marcello,

in the Apennino-Pistojese (2200 ft.). The form of the spot on the forceps-basis varies

considerably in dried examples, and sometimes the spot disappears in drying.

CtENis kobusta, sp. nov.

Imago {dried), d .—Thorax lucent raw-umber or light pitch-brown, the pronotum

rather paler laterally, the vertex of the head rather redder brown, approaching light

burnt-umber. Abdomen greyish white above; the joinings very narrowly grey-black,

liordered narrowly with whitish at the bases of the segments ; the dorsal vessel and the

sides of tlie dorsal segments pale, the lighter space encroaching largely upon the darker

in segment 7 ; genitalia stained slightly with brown-ochreous ; venter and forccps-ljasis

uniformly whitish ; setae white. Legs whitish ; fore femur and base of fore tibia varied

with sepia-grey ; ungues and hinder femora whitish yellow-amber. Wings transparent,

slightly smoky along the costal margin ; costa, subcosta, and radius for some distance

from the wing-roots dark sepia-grey.

2 . Head and thorax rather similar in colour to those of the 6 . Abdomen opaque

with light greyish dorsal markings (dark grey in the subimago) upon a dull light brown-

146 EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

ochreous ground-colour, of a similar pattern to those of the 6 . Setse white. Legs

nearly as in d , but in some lights the fore tibia and tarsus appear sepia-grey. Length

of body, cJ 4, ? 6; wing, d 4, 2 6 ; sette, d im. about 15, subim. 2-5 & 3-3 & 4, 2 im.

4-5, subim. 3 & 4 millim.

Hub. Holland, the Ijssel, near Gouda, by the nearest lock on tlie way to Stein ; end

of July.

C^Nis Harkisella, Curtis.

Brachycercus Harrisella, Curt., Lond. & Edinb. Phil. Mag. ser. 3 (1834), 122.

Ccenis Harrisella, Stepli., 111. Brit. Ent. vi. 61 (1835) ; Pict., Hist. Nat. Nevropt. ii. Ephcm. 286

(1843-5) ; Walk., List Neuropt. iu Brit. Mas. part iii. 583 (1853).— C. luduosa, Pict, Hist. &c. 283,

pi. xlv. 3 (1843-5) ; Walk., List &c. 582 (1853) ; Hag., Stet. Eut. Zeit. xxyi. 229 (1865) ; ! Etn., Trans.

Ent. Soc. Lond. (1871), 97, pi. v. 6 [forceps] ; Hag., Trans. Eut. Soc. Lond. (1873), 399; Meyer-Dur,

Bull. Soc. Ent. Suisse, iv. 308 (1874); Rostock, Jalircsb. d. Ver. f. Naturk. Zwickau, 1877, p. 79

(1878).— C. Xhalterata, ! Etn., Trans. Ent. Soc. Lond. (1868), 279-81 [nymph].

Oxynjplia luduosa, Eurm., Handb. d. Ent. Bd. ii. Abth. ii. 797 (1839).

Ephemera I brevicaitda, Blanch., Hist. Nat. dcs Ins. iii. 54 (1840).

Suhimago {living). — Head and pronotum greyish black; meso- and metanotum black.

Abdomen light brown-ochre or light cinnamon ; setse black. Wings tinted with l)lackish

grey ; their neuration dark. Legs white, sometimes smoky white ; the tarsus, tibia, and

estrenyty of the femur of the fore leg carbonaceous black.

Imago, $ & d {living). — Head and thorax pitch-black, with the sutures and pleurye

of the latter Roman sepia-brown. Abdomen Roman or warm sepia-brown, with a short

dark line on each side at every joining, and pale elongated spots near the bases of the

setaceous pleural prolongations of segments 7-9 ; forceps and setse grey or light blackish

grey. Wings whitish, with grey nervures, excepting the piceous su1)costa and radius.

Fore tarsus warm sepia ; hinder legs light blackish grey, with the joinings black. Length

of body, 6 6-5, 2 5-7 ; wing 5-5-6 ; setse, d im. 25, subim. 4, 2 subim. 3 & 4 millim.

Sab. England, in the Kennet, near Reading, and in Somersetshire; Berlin (Burm.);

St. Petersburg (Hag.) ; Lake of Thun (Pict.). The nymph is easily recognized by its

strangely subcorneal ocelli : on one occasion I caught one in the part of the Garonne flowing

between St. Michel and the lie des Grands Ramiers, Toulouse. It probably flies by night.

CyENIs oophoba, Kollar MS.

Ca-nis oophvra, Pict., Hist. Nat. Nevropt. ii. Ephedra. 284, pi. xlv. 4 (1843-5) ; Walk., List of Neuropt.

Ins. in Brit. Mus. part iii. 582 (1853) ; Etn., Trans. Ent. Soc. London (1871), 97.

Adult, 2 {dried). — Brilliant brown; legs lutescent, spotless. Wings Avhitish, with

their neuration more distinct than iu ordinary species of Ccenis, and the radius stouter

and darker. Length of body 4 ; expanse of wings 11 millim.

Hab. Sardinia (after Pictet). Described from a defective 2 example.

CiENIS ARGENTATA, Kollar MS.

Canis argentata, Pict., Hist. Nat. Nevropt. ii. Ephem. 279, pi. xliii. 6 (1843-5); Walk., List of

Neuropt. Ins. in Brit. Mus. part iii. 381 (1853) ; Etn., Trans. Ent. Soc. London (1871), 96.

EEV. A. E. EATON OX RECENT EPHE.AIERID.E OR MAYFLIES. 147

Si(U)nago {dried), 2 .—More delicate and slender than C. halterata and C. lactella.

Head and thorax grey, witli silvery reflections, the prothoras a little lighter. Abdomen

grey at the base and brilliant white at the tip. Fore legs grey ; liinder legs brilliant

white. Setae white, faintly auuulated with blackish. Wings slightly greyish, the sub-

costa and radius black. Length of body -i, setae 3 ; expanse of wings 8 milUm.

Hah. Sicily (after Pictet).

C.EXIS HiLAKis, Say.

Ej^hemera hilaris, Say, Jouru. Acad. Nat. Sc. Philad. viii. 43 (1839) ; Le Coute, Complete Writings

ofT. Say, ii. 413 (1859).

C(Bnis hilaris, Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 583 (1853) ; Hag., Smithson.

Miscell. Coll. (1861), Synop. Neuropt. N. Am. 54; Walsh, Proc. Acad. Nat. Sc. Philad. (1862), 381 :

Hag., Proc. Eut. Soc. Philad. ii. 179 (1863) ; Etn., Trans. Ent. Soc. London (1871), 96.

Imago (abstract after Say). — Thorax pale fulvous. Abdomen white ; each of the

apical segments with three fuscous dots on each side. Length of body 2 millim.

Hub. Indiana ; September.

CzENIS DIMINUTA, Walk.

Canis dimimita, ! Walk., List of Neuropt. Ins. in Brit. Mus. part. iii. 584 (1853) ; Hag., Smithson.

Miscell. Coll. (1861), Synop. Neuropt. N. Am. 55; ! Etn., Trans. Ent. Soc. London (1871), 95.—

C. arnica, Hag., Smithson. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 55.

Imago {dried), <s . — Thorax above for the most part bronzy brown-ochreous. Abdomen

whitish, varied with grey anteriorly on the back, posteriorly yellowish white ; the joinings

of the segments and a dark longitudinal line near the spiracular border on each side of

the back in the intermediate segments black. Genitalia and setai white. Wings trans-

parent whitish grey ; the subcosta and radius purple-black to beyond the middle. Legs

whitish: the fore femur warm sepia-grey, with a dark spot above close to its distal

extremity : hinder femora dull whitish, with a grey band or a black spot on their uppei-

part just before the knee. Length of body, c^ 2-2-5, wing 3, setae 10 millim.

Hab. St. John's Bluif, East Florida (E. Doubleday; Brit. Mus.); Pennsylvania

(Zimmermann ; Berlin Mus.). By using a lens of suitable power, instead of a Coddington,

I can distinguish the femoral spots or bands in Walker's type, which formerly were sup-

posed by me to be lacking, but were mentioned by Hagen in his description of C. arnica.

He indicates perhaps a distinct species from the same locality (Pennsylvania) in the

Berlin Museum, with a yellow thorax, whitish yellow abdomen, and white legs, grey at

the distal extremities of the fore femur and tibia.

I have seen several other N. -American species of Cceuis, but have left them, to be

described by entomologists resident in that country.

Cj5Nis perpusilla, Walk.

Canis perptmlla,\ Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 585 (1853); Hag., Verh. zool.-

bot. Gesells. Wien, viii. 477 (1858) ; ! Etn., Trans. Ent. Soc. London (1871), 96.

Imago {dried), d .— " Testaceous; " wings transparent, the marginal and submarginal

148 EEV. A. E. EATON ON RECENT EPHEMEEID^ OE MAYFLIES.

areas, from the base of the wing to beyond the middle, faintly tinged with light grey ;

tlie subcosta and radius black. Hinder legs and seise white. Length of body 2-5 ;

wing 3 ; setae 12 millim.

I£ab. Ceylon (Brit. Mus.). The above is hardly an adequate description of the species,

and therefore the name may rank as a mere catalogue name. The unique specimen is

gummed upon card, back downwards, and consequently little can be added to Walker's

diagnosis.

C^NIS CIBARIA, Etn.

Cisnis cibaria, ! Etn., Ent. Mo. Mag. xv. 208 (1879).

Imago (dried). — Head black, grey above. Thorax light bistre-brown, with the sutures

and point of the scutellum black, and the metanotum, as M^ell as the first abdominal

segment, grey, with their distal borders black. Abdomen of 6 in segments 7-10, and

of 2 throughout blackish grey, Avith the joinings and sides of the dorsum widely whitish,

and with segments 2-6 of ? less dark ; these segments are whitish in d , and so also,

sometimes, is the track of the dorsal vessel in the dark segments ; venter uniformly pale.

Legs whitish ; the outer side of the coxa3, and a large triangular preapical spot or

abbreviated streak on the upper part of the femur black. Wings vitreous, with the

coarser nervures and the interjacent cross veinlets more or less opaque blackish-grey.

Length of body, d 2-5-2-75, 2 4'0; wing, c^ 2-0-2-75, 2 3-0 miUim.

Sab. In company with C. kuiign, 25th January, 3877 (H. B. Cotteril).

Cj^nis kungu, Etn.

Canis ku7igu, ! Etn., Ent. Mo. Mag. xv. 268 (1879) ; cf. Elton, Travels . . . East. & Cent. Africa,

p. 292 & Append, p. 415 (1879) [no descript., but note of habits] .

Imago [dried) — Head and thorax light brown-ochre, or farfuraceous above, and very

light yellow-ochre beneath ; abdomen yellower, with the joinings pale. Femora browu-

ochreous, the fore tibia of 6 light blackish-grey, the tarsi and hinder iWAse whitish.

Wings vitreous, in 6 very faintly tinted towards the costa with light warm sepia-

greyish ; the costa and a few of the neighbouring nervures, with the intervening cross

veinlets, pitch-black, becoming with change of light warm sepia-brown where they are

thinnest. Length of body, d about 3'5, $ 4-5-5'0 ; wing, d 3, $ 3'5-3"75 ; setae, c?

subim. 1'75 millim.

Hah. Lake Nyassa, about the middle of the lake, between Livingstonia and Makan-

jeras, 25. i. 1877 (H. B. Cotteril). The packet containing specimens of this and Ccenis

cibaria {supra) was endorsed " Edible midges, which the natives of Nyassa make into

cakes," sold in their markets by the name of " Kungu." The specimen of Kungu

examined by me was composed almost exclusively of a species of the Citiicidce ; and

therefore it is probably made of whatever mild-flavoured insect happens to be in suffi-

cient profusion at the place and time of its manufacture.

EEV. A. E. EATON ON EECENT EPHEMERID^ OE ilATFLIES. 149

Section 8 of the Genera. — Type of Prosopistoma. Adult. — Similar to Ccenis and its

allies, bvit with 4 wings instead of 2 only. Figured by Vayssiere under very dis-

advantageous circumstances ; the figures consequently do not admit of exact comparison.

Nymph. — Fore wings immersed in a notal shield, which conceals the tracheal branchiae

and most of the abdomen : pronotum undefined. Palpus of maxilla i. 4-jointed, longer

than the lacinia ; the latter nude on the crown, armed with a few strong spinous teeth

at the tip and a few setulte on its inner side. Labium not differentiated into lobes and

lacinise of second maxillae. Hinder lateral angles of abdominal segments dilated and

produced. Natation agile, effected by the setae exclusively (which are capable of com-

plete retraction into the interior of the abdomen), the legs being closely folded up.

PROSOPISTOMA, Lat. 1833.

Illustrations. Suhimago (details), PI. XV. 27 (after Vayssiere, 1881), Nymph,

PL XLIII. ; see also citations under Binocle, Geoffrey (1764), Frosopistoma, Joly (1872,

Sept., and 1876 Mars), Westwood (1877), and Vayssiere (1881).

Suhimago (in alcohol). — Wings 4; hind wings with the costal shoulder placed close to

the wing-roots ; neuration in both wings plentiful, but no cross veinlets are delineated.

Hinder ocelli relatively much smaller than in Ccenis. Abdomen proportioned somewhat

as in Ccenis, with the pleurfe of segments 7 -9 similarly produced into slender points ; the

ventral lobe of ? segment 9 entire and truncate. Caudal setas of ? ^ as long as the

body. The recurrent membrane of the fore wing-roots does not extend beyond the point

of the scutellum. S and adult fly unknown. Proportions of legs not ascertained

(after Vayssiere, 1881). Nymph. — Broadly ovate, tapering posteriorly, flattened beneath,

and highly convex above. Notal shield imperfectly peltate, being excised in front and

behind to fit with extreme exactitude the adjoining surfaces of the head and 7th abdo-

minal segment ; laterally its borders are broadly expanded, flattened beneath, and trun-

cate obliquely in front and behind ; dorsally, along the median suture, a narrow depression

or shallow furrow is apt to be produced, the integument thereabout being apparently of

a texture sufficiently yielding and elastic to allow considerable variation in the defini-

tion of the furrow. Possibly this part may be concerned in some way with the trans-

fusion of water through the branchial chamber underlying the shield ; but this is merely

my conjecture. At the hinder extremity of the median suture, a small aperture is tlis-

cernible at the edge of the shield, affording an exit from the branchial chamber. The

plastron (so to speak) truncate in front and behind, and nari'owed in advance of the

metasternum, is slightly countersunk in relation to the sternum and traversed by shallow

grooves for the lodgment of the legs when they are folded up during adhesion or nata-

tion. The sutures of the mesosternum, with the pro- and meta-sterna, are liable to

become effaced in alcoholic specimens ; neither the artist nor myself could distinguish

them in the subject of PI. XLIII. The sternum terminates behind in an acuminate point,

very near the margin of the plastron, and has a very smooth flattened surface. A narrow

ovate aperture exists on each side of the plastron close to the acute hinder angles ;

S'ECOND SERIES. — ZOOLOGY, VOL. III. 2Q

150 EEV. A. E. EATON ON RECENT EPHEIMERID^ OR MAYFLIES.

through these inlets the water enters the branchial chamber. Head transverse, flattened

beneath, arched in front and above. Labrum small. Mentum oblong-oval, crenulated

behind, and with a truncate- triangular median excision in front, into which the labium

fits closely. The labrum and epistoma, with the labium and mentum, enclose the

remaining mouth-parts completely, and often conceal them. Antennae short, subulate,

6-jointed ; the joints in order of diminishing length rank 3, 4>, 5, 6 subequal to 2, and 1 ;

joint 1 is the stoutest, and joint 3 is nearly as long as all the others put together.

Mandible tapering from a l)road oblique subtriquetrous base to a pungent tridentate

crown ; fangs conical, the intermediate very little smaller than the others, just below the

bases of which the edges of the crown are minutely denticulated ; endopodite strong

and relatively long, subcyliudrical, bidentate at its extremity, with a row of denticula-

tions on each side just below the fangs ; its base is immediately preceded by a tuft of

velutinous or puberulose setae [their puberulence is not distinguishable in a figure drawn

to a scale of enlargement as low as 90], about 5 in number, and rather longer than the

endopodite ; molar region absent. The mandibles, as well as the 1st maxillae, are

virtually symmetrical ; the latter terminate each in 4 strong, flattened, acuminate,

chitinous teeth, the innermost of which are the strongest, and have 2 or 3 microscopically

puberulose seta? close to their inner base ; a short, solitary, smooth setula arises from the

inner face of the lacinia near the transverse suture ; the palpus, geniculated at the first

joining, has the proximal joint strongly reflexed ; its joints in sequence of lessening

length rank 3, 1, 2, 4 ; the first two are stout, the others slender. Labium truncate-

obtriangular, slightly rounded off at the corners, and bevelled at the sides to fit into the

gap in the mentum ; tongue and laciniae of 2nd maxillae absent ; palpi geniculated,

tapering distally, the proximal joints divaricate, and each nearly as long as the next

joint. The joinings of the anterior ventral segments are sometimes dimly discernible

through the plastron. Dr. Vayssicre describes and figures (1882, figs. 106 & 108) 5 pairs

of obtected tracheal branchiae ; his figures should be consulted. Caudal setae pliimose,

indistinctly articulated, and about f as long as the body. Legs slender ; the fore tibia,

in about ^ its length from the tip, is armed interiorly with a row of articulated spines,

denticulated on their inner sides. Hind leg rather the longest; the tarsus (claw

excluded) less than ^ as long as the tibia ; this last about f as long as the femur.

Type. P. variegatum, Lat.

Distribution. Rivers of continental Europe, and Madagascar.

Etymolo(jy. -Kpoau-niov and (TTo^to, from the mouth-partS being well concealed by the

large mentum &c. as with a little mask.

Prosopistoma foliacetjm, Fourcroy. Pis. XV. 27 [wings, after Vayssiere] & XLIII.

[nymph].

Le Binocle h queue en plumet [Hist, abreg. des Ins. dc Paris, ii. 660, pi. xsi. 3 e. f. g. (1764)] ; Geoff.,

op. cit. ed ii. loc. cit. (1785) & ed. iii. (1799).

Binoculus foliacens, Fourcroy, Ent. Paris, ii. 539 (1785). — B. pennigerus, Lat. Hist. Nat. Crust. & Ins.

iv. 122 (1802). — B. pisciforme, Dumeril, in Diet. So, Nat. iv. 106, Paris, Lenormant, art. Binocle (1816).

EEV. A. E. EATON OX RECENT EPHEMERIDiE OR MAYFLIES. 151

Limulm peymigerus, Miill., Eatom. p. 127, no. 62 (1800?) [cited by Lat. 1802].

Prosopistoma punctifrons, Lat., Nouv. Ann. du Mus. (3), ii. 33 (1833) ; id., op. cit., iii. 40 (1843);

Lucas, Diet. Univ. Hist. Nat. d'Orbigny, ed. ii., art. Prosopistoma (18G9); Joly, Rev. d. Soc. Savants

(2), V. 4-6 (1870) ?; id., Mem. Soc. Nation. Sc. Nat. Cherbourg, %\\. 329-336 (1871) ; MuL, Ent. Mo.

Mag. viii. 227 (Feb. 1872) ; id., Zoologist, 2955 (1 Feb. 1872) ; id., Proc. Ent. Soc. London, 1st Jan.

1872, p. xlvi. (19 Feb. 1872) ; Wcstw., Athena;um (Feb. 24th, 1872) ; N. Joly, Mem. de FAcad.

des Sc. Inscript. et Belles-let. de Toulouse (7), vol. iv. Bulletin, pp. 437—138 (1872) ; id., op. cit. pp. 440-

441 (Mars, 1872) ; id., in Le Progres Lib. de Toulouse (19 Mars, 1872); Westw. & IV^Lach., Ent.

Mo. Mag. viii. 279 (1 April, 1872) ; iidem, Proc. Ent. Soc. London, 19 Feb., p. vi. (April 1872) ; E. &

N. Joly, Ann. d. Sc. Nat. (5), Zool. xvi. Art. no. 7, pp. 16, pi. xiii. 1-16 (Sept. 1872); M^Lach., Ent.

Mo. Mag. X. 109 (Oct. 1873) ; id., Rep. Brit. An. for 1873, p. 118 (1874) ; id., Journ. Linn. Soc,

Zool. xii. 145 (1874) ; Joly (' Separate' of). Rev. des Soc. Sav. (2), iii. 69-72, p. 7, Note E (Digue

Dec. 1874) ; N. &. E. Joly, in Le Prog. Lib. de Toulouse (17 Mars, 1875) ; iidem, Mem. de FAcad. des

Sc. Inscript. & Belles-let. de Toulouse (7), via. 606-607 (1875) ; Joly, Feuil. d. Jeun. Nat. v. 68

(1875); id., op. cit. vi. 53-54, pi. ii. 1-5 (Mars 1876); id., Bull. Soc. d'Etudes &c. d' Augers, 1874-5,

pp. 44-45, Notes E & G (1876) ; N. & E. Joly, Rev. des Sc. Nat., Montpellier, v. 307 &c., pi. viii. 32

[tracheal branchise] (Dec. 1876) ; Westw. Trans. Ent. Soc. London (1877), 189-194, pis. iv. B 1-5 & v.

1-12 [after Joly] ; Joly, Ann. Soc. Ent. Fr. (5), viii., Bull., pp. 70-71 (Avril 1878); id., Feuil. d. Jeun.

Nat. no. 92, pp. 99-100 (Juiu 1878) ; Joly & Vays., Compt. Rend, des Seauc. de I'Acad. des Sc. Paris,

Ixxxvii. 263-5 (Aout 1878) ; Joly, Pet. Nouv. Ent. ii. no. ccv. 265 (Oct. 1878) ; id., Feuil. d. Jeun.

Nat. no. 98, pp. 24-25 (Dec. 1878); Joly & Vays., Bull. Soc. d'Etud. Sc. Nat. Nimes, no. vi.-vii.

(1878) ; Joly, op. cit. (1879), pp. 3-7 ; id., Proc. Ent. Soc. Fr. (1880), Bull. no. xi. 109 ; id.. Bull. Soc.

d'Etud. Sc. d' Angers, 1878-9, pp. 157 note 2, 158 note 1, 164 notes, 167 Note B (1880) ; Vays. Anu.

des Sc. Nat. (6), Zool., xi. 1-15, pi. i. 3-17 (1881) [nymph, subim., & details] ; id., op. cit. xiii. 77, pis.

vi. 57, X. 105-109, si. lOi & 110-114 [nymph and details] & 116 [diseased nymph] (1882).— P./o/(«-

ceum, Lucas, Ann. Soc. Ent. Fr. (6),ii., Bull. Eut. xcv. (Sept. 1882).

Chelysentomon or Ch. pennigerum, N. & E. Joly, in Le Prog. Lib. de Toulouse (Fev. 1872) ; iidem,

Mem. de I'Acad. des Sc. Inscript. & Belles-let. de Toulouse (7), iv., Bull., pp. 437-438 (Fev. 1872) ;

N. Joly, in Le Prog. &c. (19 Mars, 1872) ; id., Mem. de I'Acad. &c. (7), iv., Bull., 440-441 (1872) ;

N. & E. Joly, Mem. de I'Acad. &c. (7), iv., pi. figs. A-G & R (1872) ; id. Compt. Rend. Paris, Ixxiv.

1413 (1872).

2 Suhimago {in alcohol). — Wings dark iron-grey, especially the anterior. Body

reddish brown, darker above than beneath, and pale at the insertions of the legs. Length

of body 3-78, wing 4-85, setee 0-42 millim. (Vayssierc).

Sab. France ; the Garonne near Toulouse, chiefly to the right of ile des Grands-

Eamiers, not far from the powder-mills below the Pont d'Empalot (Joly) ; the Ehone

at Avignon (Vayssiere) ; the Seine above Paris (Geoif.), in the neighbom-hood of Epone,

Mantes, Bas-Meudon, and Point-du-Jour (Lucas). Germany : the Rhine at St. Goar,

between Coblentz and Mayence (Dr. Noll, teste Prof. Leydig). Bohemia, in the Moldau,

a tributary of the Elbe (Purkinje, teste Blanchard & Joly). The nymph inhabits swiftly

flowing water from a few inches to 6 ft. deep, harbouring in irregularities of the vmder

sui-face of rough stones, and shunning the light. It swims with agility, propelled solely

by the caudal seise, holding its legs closely folded up under the body. When desirous of

repose, it is able to attach itself by adhesion, like a Patella, to a smooth surface ; the

joinings of the segments and of the head and thorax are then tightly contracted, to

152 KEY. A. E. EATON ON KECENT EPHEMERID^ OE ilATFLIES.

prevent leakage, and the caudal setae withdrawn more or less completely into the visceral

cavity. The terminal segment also is partly retractile. What appear to be the perineal

lobes form with the dorsum of that segment the extremity of the sheath of the setae ;

and whilst these are passing into its aperture during retraction, the fringes of each seta

collapse upon the rhachis successively. Dr. Vayssiere conducted me to the river at

Avignon, and captured a specimen without entering the water, — the only one that I have

seen alive. He reared the subimago early in June at Avignon, and states that the fly is

nocturnal.

About fifty literary references to P.foliaceum are cited above ; of these only one relates

to the subimago and egg, aU the others to the nymph exclusively. The most important of

them are Vayssiere (1881 & 1882), Joly (1872, Sept.), and Westwood (1877, Oct.). This

catalogue of Prosopistoma literature is very nearly exhaustive, and although many of

the passages cited are tautological, yet the reiterated statements are not verbatim reprints

of one another. Some of the ' Notes ' designated by capital letters are special additions

to the extracts reprinted as ' Separates."

Prosopistoma variegatum.

Prosopistoma variegatum, Lat., Nouv. Aim. du Mus. d'Hist. Nat. (3), ii. 23(1833); Gueriu-Men., Ic.

Reg. An. iii. 40, pi. xxxv. 4 (1829-44); Westw., Proc. Ent. Soc. Lond. (1872), p. vi.; idem, Trans. Ent.

Soc. Lond. (1877), pp. 189-194, pi. iv. B 1-4.

Hub. Madagascar. Length of body of nymph 6 millim. (Latr.). An undescribed

species.

In accordance with my usual custom, I refrain from passing criticisms upon the work

of previous authors, preferring that it should be understood that where om- conclusions

may happen to differ upon any point concerning Prosopistoma, my not concurring with

their opinions respecting it is not due to oversight of their observations.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 153

Part III. Read February 10th, 1885.

Fourth Series of Group II. of the Genera of the Ephemeridce.

Adult. — The anal (8) and second axillar (9-) ncrvures, together Avith the inner margin

of the mesothoracic wing, enclose a curved, trilateral, somewhat leg-of-mutton sliaped

space, which is abrupt at its anterior extremity ; anal nervurc distinctly separate from

the pobrachial (7) at the base of the wing; first axillar (9^) more or less curved, and

rather long ; second axillar approximated to or united with the first at the base, where

this is distinctly independent of the anal uervure ; prtebrachial nervure (C) essentially

simple. Hind wings small or absent ; costal border spurred or protuberant at about the

first f of the wing's length ; neuration incomplete, the subcosta somewhat curved.

Thoracic spiracles straight-lipped, usually closed in the dried insect ; mesothoracic

spiracle without a guard, its valves unequal ; when open, the apertures of both spiracles

are oval. Pronotum of ? closely appressed to the mesonotum. Hinder tarsi absolutely

4-jointed, with the proximal joint long. Forceps-limbs sessile upon the segment, with a

short fleshy protuberance from it between their proximal joints, which is not represented

in the ? . Penis normally retracted and invisible, very rarely protruded by captured

living specimens. Median caudal seta aborted. Oculi of 6 divided into two unequal

parts ; the upper segment, cylindrical or somewhat turbinate, is facetted solely on the

terminal surface ; tlie lower and much smaller segment, oval in form, is annexed to the

under (or rarely to the anterior) orbit of the former', and is facetted all over with facets

of less diameter than those of the turbinate part. Hinder ocelli large ; the foremost

much smaller. The virgin imago can live many days if kept in a moderately damp cool

place. Subimayo usually quiescent for at least twenty-four hours, standing upon all its

feet with wings erect and setae divergent.

Section 9 of the Genera.— ly^a of Baetis. Adult .—Vionoiwm. of ? transverse and

short, prominent above and somewhat smooth, closely appressed to the mesonotum and

receding in the middle behind. Hind tibia at least | as long, and sometimes nearly of

the same length as the femur ; the tarsus from about I to about f as long as the tibia.

Ungues in every tarsus dissimilar each to the other. Mesothoracic wings large, ovate-

oblong, gradually rounded off from the terminal to the inner margin ; the first and

second axillary nervures (9^ and 9^) enclose a narrow space, which usually maintains an

almost even width for some distance from the inner margin and (leaving cross veinlets

out of account) commonly extends to the wing-roots. [In tig. 31 d, through individual

aberration, the functions of 9^ have evidently been usurped by an intercalar nervure, to

which the numeral has therefore been assigned, whilst the true first axillary nervure is

abbreviated and isolated.] Prtebrachial nervure of the fore wing separate from the

second of the following intercalar nervures, and therefore simple. iVyw^j A.— Terminal

margins of the mesothoracic wings free. Palpus of maxilla i. 3-jointed [probably

2-jointed in Callihcetis], not shorter than the lacinia ; the latter terminated at the tip

with either spines or strong teeth, and near the tip nude externally, but armed with

rigid setulte, diversely in different genera, along the adjoining portion of the inner

SECOND SERIES. — ZOOLOGY, VOL. III. 21

154 EEV. A. E. EATOX OX EECENT EPHEMEEID.E OE MAYFLIES.

edge. Tracheal brancliise borne by segments 1-7 of tlie abdomen, all exposed, foliaceous,

fringeless, and without fasciculated fibrils ; those of segment 1 smaller than the inter-

mediate pairs, sometimes minute and erect. Hinder angles of the abdominal pleurae

hardly produced at all. Setas natatorial ; the outer setae ciliate along their inner side,

and the median seta plumose, either throughout or in the greater part of their length.

Natation agile, effected solely by undulations of the body and seta% the legs trailing

through the water extended at full length close to the sides.

The genera of this type have near relations with the Leptophlehia section of the second

group of the Ejihemeridas. A common, though not universal, feature in the neuratiou

of the fore wing in this group is noticeable in the order of shortening of the sectorial

intercalary norvures, which are usually five in number. Their ordinary rank in diminish-

ing length, when numbered successively from the foremost, is 5, 1, 4, 2, 3 ; or occasion-

ally 5, 1 subequal to 4, 2, 3. In the third group of the genera, and also in some genera

of the first group, their most frequent gradation is 5, 4, 1, 2, 3. Differences in the

tarsi, and in the oculi of the males, disguise their affinities with the section of SipMurus

when adult ; but their essential approximation to that type is manifest in the nymphs.

The number of joints in the antenna; of nym^jhs of the Baetis type largely exceeds the

maximum hitherto observed in those of that section.

Comjjsoiiciirla, a genus of the Ecdijurus section of the third group of the Ephemeridse,

has the cross veinlets of the fore wings arranged very much in the same manner as in

those of most of the genera of the Baetis type. But, without looking at its hind wings

and tarsi, and ajiart from other important differences, the forked prsebrachial nervure (6)

in the fore wing is sufficient to distinguish it from every genus of this type.

Summary of Generical Characteristics. — Type of Baetis.

Among miscellaneous representatives of the genera, adult and in good condition, Cloeon

is easily distinguished by the absence of hind wings ; Callibcetis by the large rounded

costal projection and numerous cross veinlets of its broad, oblong, obtuse hind wings ;

Baetis by hind wings as broad and obtuse as those of the preceding genus, but with the

costal projection (if any) small and acute, and with scarcely a cross veinlet at all ;

Centroptilum by the extreme narrowness of its very small hind wings, and usually by

the slenderness of their costal projection.

But to discriminate from Cloeon defective specimens of the other genera deprived

accidentally of their hind wings is a task attended often with insurmountable difficulty.

Satisfactory determinations of the genera of such examples may, however, be arrived at

sometimes by means of the following indications afforded by the fore wings ; or, when

absolute determinations are impossible, a near approach may be made to their identifica-

tion sufficient to facilitate the comparison of the defective specimens with better examples

of the same insects. In the first place, it may be noted that in genera of the present

type the rudimentary intercalar veinlets of the terminal margin of the mesothoracic

wing are disposed either singly or in pairs. In a large majority of the species of Cloeon

■ and Centroptilum, as well as in many of Callibcetis, these veinlets are single. As a rule,

the species of this last genus have more numerous cross veinlets than the others

EEV. A. E. EATON ON EECENT EPilEMEEID.E OR MAYFLIES. 155

in their fore wings, and this is especially noticeable in advance of the cubitus (4) in the

proximal half of the wing. Cloeon and Centroptilum cannot be distinguished from one

anotlier absolutely by their mesothoracic wings ; but several species of the former

genus can always be recognized by peculiarities of minor detail not essential character-

istics of that genus. The aforesaid iutercalar veinlets are paired in Baetis, in a few

exotic species of Centroptilum and Cloeon, and often in Callihcetis; their relative len"-th

is usually greatest in Baetis and Centroptilum, which, like Cloeon, have fewer cross

veinlets than CalUhcetls in advance of the cubitus in the proximal half of the winf. In

Baetis a short veinlet from the inner margin of the fore wing almost invariably meets

the second axillar uervure (9-) so as to form a small fork ; but the corresponding nervure

is simple in Centroptilum.

In the Appendix will be found a statement of the classification of these genera, adopted

by me in 1868, which was accidentally omitted from page 20.

The nymphs may be tabulated as follows : —

Tabulation of Nymphs of Section 9 of the Genera. — Type of BAiins.

Abdominal tracheal braucliice all simjjje ; the laminse

broadly obovate, obtuse. Terminal joint of the palpus of maxilla ii.

rotund, forming with the penultimate a clavate mass indented on the

inner side at the joining. Terminal joint of the palpus of maxilla i.

long PL XLIV. Baetis.

partljr oblong and partlj' ovate-lanceolate, oblique and acute. Terminal

joint of the palpus of maxilla ii. short and elhpsoidly rounded at the

tip, forming with the penultimate joint a simply clavate mass.

Terminal joint of the palpus of maxilla i. very short PI. XLV. Nameless Gen.

partly Hnear-obovate-lanceolate, and partly broadly so, acute. Ter-

minal joint of the palpus of maxilla ii. quach'angular, forming with

the penultimate joint a compressed clavate mass broadly and abruptly

truncate at the end. Terminal joint of the palpus of maxilla i. long

and slender PI. XLVI. Centroptilum.

Abdominal tracheal branchiae mostly, or all, conduplicate with unequal

segments ; the larger segments of the laminas

irregularly subrotund ; the laminse of the hindermost branchiae single.

Terminal joint of the palpus of maxilla ii. large and compressed,

forming with the penultimate joint a compressed clavate mass

obliquely truncate and acute at the extremity. Palpus of maxilla i.

triarticulate, with the terminal joint long and slender PI. XLVII. Cloeon,

of the first and second of the series somewhat contorted ; those of the

3rd to 6th obliquely subovate ; that of the seventh elongate-oval ; all

of the laminae are duplicate, but the lesser lobes arc much smaller in

most of the series than those of Cloeon. Terminal joint of the palpus

of maxilla ii. small, forming with the penultimate joint a narrow

slightly compressed mass, acute at the point. Palpus of maxilla i.

(in alcoholic specimens) 2-jointed, with the last joint loag; but if

ever triarticulate, the terminal joint would be minute [the joining

might have been obliterated in the samples examined] PI. XLVIII. Callibcetis.

21*

156 EEY. A. E. EATOX OX EECEXT EPHEMEBID.E OR MAYFLIES.

BAETIS, Leach, 1815;

Illustrations.— Adult (details), Pis. XVI. & XVII. 29 a-f, also LXIV. 9-20 ; (whole

figures) see citations, under Baetis, of Clo'e 'Siciet passim. Nymph, PI. XLIV. ; see also

Pictet, op. cit. pis. 34 & 36 (1843-5).

Adnlt. — Hind Ming oblique, widened rapidly in front from the roots to the costal

projection, usually rather broad and obtusely ovate, but sometimes oblong or ovate-

lanceolate with the tip ellipsoidally rounded ; costal projection in general small and

acute, but in B. atrehai'mus suppressed ; neuration very sparse, comprising only 2 or 3

distinct longitudinal nervures (of which the intermediate is forked in some instances),

the great cross vein, and in certain species very scanty feeble traces of rudimentary

cross v.einlets or intercalar veinlets that are liable to much individual variation. Pore

wing [except B. Salvini, PL XVI. 29 a] devoid of colour ornamentation ; marginal and

submarginal areas [Avith the same exception] free from cross veinlets fi'om the great

cross vein to the bullae ; terminal margin beset with paired ru.dimentary intercalar

veinlets ; cross veinlets in the disk disposed mainly in two dislocated series between

the subcosta and the cubitus (5), and two, also dislocated, behind the latter nervure,

with occasional sparse indications, near the base and tip of the wing, of others irregular

and defective, aU at some distance from the terminal margin. Of the series in advance

of the cubitus, the innermost commences at the subcosta or radius shortly beyond the

buUfe and extends quite to the cubitus, if not farther, often blending with the outermost

of the posterior series ; the second series in advance of the cul^itus starts abreast of the

former just before the pterostigraatic dilatation of the marginal area, and terminates at

the hindermost of the sectorial iutercalars ; the defective third anterior series nearer

the apex of the wing is usually represented l^y only a single cross veinlet uniting the

shortest of the sectorial intercalars with the one immediately in front of it. Of the two

main series of cross veinlets posterior to the cubitus the outermost is the longest, ex-

tending most commonly from this nervure to the first axillar, but sometimes to the

second axillar ; between the cubitus and the pobrachial (7) nervure the cross veinlets

composing it are liable to displacement outwards so as to be nearly in even line with

the innermost of the anterior series, above described, rather than with the remainder of

their own series : the second of the series posterior to the cubitus is liable to a similar

dislocation outwards between the same two nervures, and to displacement inwards

posterior to the anal (8) nervure ; its first portion reaches from the pobrachial to the

cubitus [in B. Salvini it is prolonged to at least the sector (4)] somewhere near the

proximal extremity of the fifth sectorial intercalar ; its intermediate portion is a single

cross veinlet between the pobrachial and anal nervures, in a line with the junction of

the sector and cubitus ; its third portion lies nearer the wing-roots between the anal

and second axillar nervures ; sometimes a third posterior series is indicated by a few

cross veinlets quite close to the axilla, which commences at the anal nervure. Porceps-

limbs of 6 4-jointed; basal joint short and comj)act, considerably the stoutest, and

suddenly contracted towards the distal joining; second joint rather stout and usually

tapering gradually from the base ; third joint comparatively slender, subcylindrical,

EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. 157

often somewhat curved, and usually much the longest ; fourth joint commonly suh-

globular or oval and much the shortest, seldom elongate-oval and as long as the third.

The interspace between the basal joints of the forceps-limbs varies in relative width with

the species. Lobes of the penis without apparent stimuli. The intermediate segments

of the S abdomen are mutually subequal in length. Caudal setre in c? im. 2-2i, in

2 im. li-2i, in S subim. IJ-ly, in $ subira. -I-lf as long as the body. Fore tarsus

of d very nearly of equal length with the tibia, Avliich is about 1^ as long as the femur ;

its joints in diminishing succession rank 2, 3, 4, 5, 1 : fore tarsus of 2 about f as long as

the tibia, which is jast as long as the femur ; its joints rank 2, 5, 3, 1, 4. Hind tarsi of

<S about § as long as the tibia; the joints, shorter than in the $ , rank ], 4, 2, 3.

Nymph. — Abdominal tracheal branchioe all somewhat alike in form, each obtusely ovate

or obovate and traversed lengthw ise by a pinnately branched, irregularly subdivided

trachea. Antennsc about as long as the head and thorax together. Outer caudal seta)

about f as long as the body ; median seta commonly f as long as it, but in some s[)ecies

(e. g. _B. melanoHyx) of shorter proportions ; the fringes narrowed acuminately to the

extremities of the setre. Each mandible terminates in a slightly prolonged, compressed,

and obliquely abrupt lobe, eroso-denticulate at its termination ; endopodite absent.

Palpus of maxilla i. as long as the lacinio, 3-jointed ; the terminal joint slender and

about as long as the other two together : the lacinia armed with compressed teeth at

the point, that are preceded by a scries of setula) on the inner edge, arranged evenly and

gradually increasing in length aw"ay from the teeth, so as to constitute an acute oblique-

pointed ilatteued beard. Lacinia? of maxillteii. narrow and cultriform, broader than the

subulate lobes of the labium ; proximal joint of the palpus about as long as the remainder,

which are compressed and combined into a clavate piece rounded at the tip and slightly

indented on the inner side just before the tip, the terminal joint being subrotund and

somewhat imperfectly delimited by suture from the penultimate joint. Tongue, as a

whole, cuneate, with the narrower extremity truncate ; the median lobe narrower than

the paraglossce and bluntly mucronate. Hind tarsus, claw excluded, about f as long as

the tibia ; the leg altogether about as long as the fore leg. Resident in running water

and lakes ; two brooded in temperate regions.

Type. JB. binoctilatns (in Ephemera), Linn.

Distribntion.. Europe, including Egypt and Greenland; Northern and Central

America, the Argentine Republic, and perhaps Chili; Asia; Indo-Malay region and

Australia.

Etymology doubtful; probably a misreading of Bsetis, the classical name of the

Guadalquivir.

Synonymous with Brachyphlehla, "Westwood (18-iO). At p. 20 ante reference is made

to the identity with Bactis of the nymphs partly figured in detail l)y M. Vayssiere (1882)

under the name % Centroptilmn; and also to the probability of those quoted by him as

X Gloeoii being only junior grades of the same. The difference in form of the lamina) of

their tracheal branchia?, judging from the description, is such as might readily be pro-

duced by the alcoholic solution in which the specimens were preserved. Distention of

these laminte by endosmosis, to a large or small extent, is an accident of common

158 EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

occurrence ; and M. Vayssiere is not the first nor the second entomologist who has been

misled by it.

The nymph of Baetis has probably been reared by others besides myself. I have

identified and examined those of B. vernus, B. rhodani, B. gemellus, B. melanonyx, and

B. 2onrnilus, in addition to many undetermined species.

The species of this genus being numerous are arranged geographically in the following

order : — European, North American, Central American, South American, and Cingalese.

The figures of wings and forceps of European species published in 1871 w'ere engraved

after a photograpli on reduced scale of my original drawings ; but the engraving was not

faithfully executed in facsimile, and consequently the value of the figures was impaired.

I therefore deem it advisable to reissue some of them, on the scale of the original

drawings.

EUROPEAN SPECIES.

Baetis binoculatus, Linn. Plate XVI. 29 b (wings and forceps).

[Ephemera] or E. bioculata, Linn., [Act. UpsaL (1736) 27, no. 2; id., Fn. Suec. ed. i. no. 751 (1746)];

id., Syst. Nat. ed. x. i. 547 (1758); id., Fn. Suec. ed.ii. no. 1473 (1761); [Geof., Hist. Abr. d. Ins

Paris, ii. 239, no. 5, pi. xiii. 4 (1764)]; Mul., Fn. Ins. Fried, no. 556 (1764) ; Linn., Syst. Nat. ed. xii.

pars ii. 906 (1767) ; Fab., Syst. Ent. 304 (1775) ; id., Sp. Ins. i. 384 (1782) ; Str6m. N. Saml. Kongl.

Dansk. Vidensk. Selsk. Skrift. ii. 91 (1783) ; Fab., Mant. Ins. i. 244 (1787) ; Vill., C. Linn. Ent. iii.

18 (1789) ; [Zsch., Mus. Lesk. i. 150, no. 16 (1789)] ; Gmel., Linn. Syst. Nat. ed. xiii. i. pars v. 2629

(1790); Ol., Encyc. Meth. vi. 419 (1791); Fab., Ent. Syst. emend, iii. pars i. 70 (1793) ; Schr., Fn. Boica,

ii. pars ii. 199 (1798) ; Cederh., Fn. Ingricte Prodr. 134 (1798) ; Walck., Fn. Paris, ii. 9 (1802) ; Lat,

Hist. Nat. Crust. & Ins. xiii. 97 (1805) ; Shaw, Gen. Zool. vii. partii. pi. Ixxxi. (1806) ; Lamarck, Hist.

Nat. d. Anim. s. Vertebr. ed. i. iv. 221 (1817) ; Stewart, Elem. Nat. Hist, of Anim. Kingd. ed. ii. ii.

225 (1817) ; Guer., Iconograph. Regn. Anim. ii. pars i. pi. Is. 9 (1829-43) ; Gray, Griffith's Anim.

Kingd. ii. pi. xciv. 9 [after Guerin] (1832) ; Zet., Ins. Lapp. col. 1046 (1840) ; Westw., Introd

Classif. of Ins. ii. 25 (1840); Blanch., Hist. Nat. d. Ins. iii. 54 (1840) ; Wallengren, Christ. Vidensk.

Forhandl. no. ii. 21 {\SSO).—E.fuscata, Linn., Fn. Suec. ed. ii. no. 1474 (1761) ; Miil., Fn. Ins. Fried.

63 (1764) ; Linn., Syst. Nat. ed. xii. pars ii. 907 (1767) ; Vill., C. Linn. Ent. iii. 19 (1789) ; Gmel.,

Linn. Syst. Nat. ed. xiii. i. pars v. 2629 (1790); 01., Encyc. Meth. vi. 419 (1791) ; Fab., Ent. Syst.

emend, iii. pars i. 70 (1793) ; Walck., Fn. Paris, ii. 9 (1802) ; Lat., Hist. Nat. Crust. & Ins. xiii. Q7

(1805). — E. diaphana, Mill., Zool. Dan. Prodr. 143 (1776). — E. flava, Schr., Beytr. z. Naturgesch.

82 (1776) ; id., En. Ins. Austr. indig. no. 605 (1781, ; Vill., C. Linn. Ent. iii. 22 (1789) ; 01., Encyc.

Meth. vi. 421 (1791J; Schr., Fn. Boica, ii. pars ii. 199 [179S).—E.% lutea, Fourc, Ent. Par. ii. 353

(1785).— £. notata, Gmel., Linn. Syst. Nat. ed. xiii. i. pars v. 2630 (1790) ; 01., Encyc. Meth. vi.

422 (1791). — E. X cuUciformis, id., op. cit. vi. 420, note [e.xcl. descript.] (1791) ; Lat., Hist. Nat. d.

Crust. & Ins. xiii. 98? (1805).— £. | striata, Walck., Fn. Paris, ii. 10? (1802).

Baetis bioculatus. Leach, Brewst. Edinb. Encycl. ix. 137 (1815) ; Sam., Ent. Comp. 259 [B. bioculata]

(1819) ; id., Ent. Cab. ii. no. 53, pi. xxiv. 1 (1834) ; Steph., 111. Brit. Ent. vi. 65 (1835) ; ! Etn., Ent.

Mo. Mag. V. 88 (1868).— 5. binoculatus, !Etn., Trans. Ent. Soc. Lond. (1871) 111, pls.ii. 9 & v. 16, 16a

[details] ; Hag. & Etn., op. cit. (1873) 401 ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 309 (1874) ; Palme'n,

z. Morphol. d. Tracheensyst., Sect. i. pi. i. 1-7 (1877) ; Rostock, Jahresb. d. Ver. f. Naturk. Zwickau,

1877, p. 86 (1878) ; ! Etn., Ent. Mo. Mag. xvii. 196 (1881) ; Palraen, Paar. Ausf. gauge d. Geschl. org.

b. Insect. S. 71 [anatom.] {188-1).— B.flavescens, Curt., Lond. & Edinb. Phil. Mag. ser. 3 (1834) 131;

EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 159

Pict., Hist. Nat.Nevropt. ii. Ephem. 193(1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii.

561 (1853). — B. autumnaUs, Curt., Lond. & Edinb. Pliil. Mag. ser. 3 (1834) p. 121 ; Steph., 111. Brit.

Ent. vi. 67 (1835). — B.fuscata, Stepli., op. cit. vi. G6 (1835).

Brachyphlebia biocidata, ! Westw., Introd. to Mod. Classif. of Ins. ii. 25 & Addend, to Gen. Syuops.

158(1840).

Cloe hioculata, Pict., Hist. Nat. Nevropt. ii. Epliem. 244, jsls. xx.\iv.-xxsv. (1843-5) ; Hag., Smithson.

Miscell. Coll. (1861) Synop. Neuropt. N. Am. 52 [exel. example in Brit. Mus.] ; id., Stet. Ent. Zeit. xxvi.

229 (1865); Oulianine, Neuropt. & Orthopt. of the Prov. of ISIoscow, p. 28 (1867). — C. autumnalis,

Pict., Hist. Nat. Nevropt. ii. Ephem. 270 (1843-5).— C. Xpunula, Oulianine, Neuropt. & OrtLopt. of the

Prov. of Moscow, p. 28 (1867).

Cloeon hioculata, Walk., List of Neuropt. Ins. in Brit. iMus. 572, exempl. 1 a-f [excl. g.] (1853).—

C. autumnaUs, Walk., op. cit. 578 (1853).— C. Xpumilum, ! Hag., Ent. Ann.(1863) 33'; ! Etu., Ann. &

Mag. of Nat. Hist. (3) xviii. 147 (1866).

Snb/maffo {living). — Wings pale grey or smoke-grey ; the hind Avings sometimes

paler or whitish ochraceous. Femoi'a greenish grey or very pale greenish yellow or

greenish white, with pale grey tibiae and black tarsi, the green tint more pronounced in

the female sometimes, and then her fore femora are pale olive-green with a dark spot

before their distal extremities, while her hinder tibiaj acquire a greenish yellow tint.

Setae pale grey.

Imago {living). — d . Turbinate eyes lemon- or bright yellow; lower eyes yellowish

green, black-green, or piceous.

<S var, 1. Thorax burnt sienna, or fuscous, or pitch-black above. Abdomen in

segments 2-6 or 7 ti-anslucent white, with a more or less slight pale yellow tint, and

with the spiracles ancf sometimes the tracheal trunks rubiginose or black ; the remaining

segments above either burnt sienna, or fuscous, or fusco-olivaceous, edged distally with

bright yellow ; the last segment sometimes lighter above than the others, and beneath

either ochraceous or olivaceous. Seta; and forceps white. Femora yellowish white, the

rest of the fore legs white or greyish white ; the rest of the hinder legs white. Wings

vitreous, with whitish neuratiou, but with the base of the subcosta and radius sometimes

fuscous.

c? and ? va7\ 2. Body either light bistre-brown or greenish bistre-broAvn or olivaceous

above, with the extreme tips of tlie abdominal segments either narrowly darker or bright

yellow, and the subcutaneous trachese black or intense sepia-brown ; venter olivaceous,

marked Avith two dark dots near the base of every segment. Setna either greenish Avhite

or else white or greyish, and tinged at the bases with greyish or dusky. Eyes of ?

either olivaceous, piceous, or black. Legs in some lights olivaceous ; in others the fore

femur becomes fusco-olivaceous, with the knee pale, and tlie tibia and tarsus either

uniformly warm sepia-brown, or the tibia brownish black and the tarsus charcoal-black ;

hinder femora and tibine much paler than the anterior, and marked before the knee Avith

a curved greyish spot ; hinder tarsi grey. Length of body 4-8 ; Aving 6-8 ; setae 6 im.

12-14, subim. 7-10, ? im. 10-12, subim. 8-10 mm.

Hab. Europe, from Portugal, near Cintra (380 ft., 27 April, 1880), eastwards to Southern

Persia and Armenia (Hagen Mus.), northwards to Moscoav and ScaudinaA-ia. North

America, in Hudson's Bay I'er. (Dale Mus.). The species is common in rivers northwards

160 HEV. A. E. EATON ON RECENT EPHEMEEID^ OE MAYFLIES.

of the Pyrenees and Alps. Amongst localities in Trance where it has been captured may

be mentioned Orthez, Blois, and the Vosges.

Baetis venustulus, sp. nov. Plate LXIV. 10 (forceps).

Imago {living). — d . Turbinate ej^es citron-yellow ; lower eyes olivaceous. Notum

greenish bistre-brown (virescenti-fuscum) varied posteriorly with bistre-brown ; the parts

adjoining the meso- and meta-sterna are of the former colour, or olivaceo-fuscous.

Segments 2-6 of the abdomen translucid white, with a cretaceous tint on the dorsum, and

black spiracles ; segments 7-9 above fusco-olivaceous with ochreous joinings and dark

stigmata, beneath more or less ochraceous ; segment 10 somewhat of a purplish tint

above. Porceps and setce smoky white. Pemora translucid white, tinted very faintly at

the tips with cretaceous ; tibiae and tarsi smoky white, with the ungues and in the

hinder tarsi the terminal joints darker. Wings and neuration colourless ; pterostigmatic

cross veinlets variable.

5 . Very like B. bmoculatiis $ . Oculi and orbits of ocelli olive-green ; a rufescent

spot on each side between the base of the antenna and the oculi. Hinder femora

spotless ; tibiaj and tarsi all dark smoky grey, with the tarsal joinings and the tips of the

terminal joints darker. Neuration of wings pitch-black. Abdominal spiracles (not the

tracheae) black. Length of body 4-4-5 ; wing d 4-5, S 5 ; setaj 6 im. about 9, ? im.

6'5 mm.

Hub. Switzerland ; the Rhone, in the vicinage of Geneva, above the confluence with the

Arve ; 25 August, 1879, on wing in the evening before dark.

Baetis scambus, Etn. Plate LXIV. 9 (forceps).

Baetis scambus, ! Etn., Traus. Ent. Soc. London (1870) 3; \id., op. cit. (1871) 112, pi. v. 17, 17 a

[details] .

Subimago {living). — Wings, setae, tibiae, and tarsi cinereous ; forceps-limbs and femora

cretaceous, or sometimes the latter are greenish white and are marked in the $ almost

imperceptibly with a cinereous spot before the knee.

Imago {living). — d . Turbinate eyes clove- or warm sepia-brown ; lower eyes black.

Notum jet- or pitch-black. Abdominal segments 2-6 translucent white or greenish

white, faintly suffused with light bistre-brown ; the others bistre-brown. Setae white,

with a few of the basal joinings darker. Wings vitreous. Pemora either cretaceous or

olive-grey ; fore tarsus smoky grey ; hinder tibiae and tarsi greenish white, with ungues

and the tarsal joinings slightly darkened.

$ . Body olivaceous-brown. Eyes intense olivaceous. Pemora olivaceous ; tibiae and

tarsi dark smoky grey. Wings vitreous, with pitch-black neuration. Setae smoky grey,

with subopaque joinings. Length of body 6-6-5; wing 6-7 ; setae, <3 im. 12, subim. 7,

? im. 9-10, subim. B mm.

Sab. England ; Ashbourne and Norbury, Derbyshire, in the Dove and in the Henmoor

Brook ; June and September. Porceps rather similar to those of B. binociilatns ; but the

limbs are more slender, and are closer together at the base. Hind wings binei'ved.

EEV. A. E. EATON ON EECENT EPHEMERID.^ OR MAYFLIES. 161

Baetis vebnus, Curtis. Plate XVI. 29 d (forceps).

?Ephemt7-a t bioculafa, Fourcroy, But. Paris, ii. 353 (1785).— ? jB. testacea [Zsch., Mus. Lesk. i. 50,

no. 17 (1789)]; Gm(51., Linn. Syst. Nat. eel. xiii. i. pars v. 2G30 (17'J0); 01., Encyc. Meth. vi. 422

(1791).— 1£. dubia, ! Steph., 111. Brit. Ent. vi. 59 (18.35).

Baetis vermis, Curt., Lond. & Ediub. Phil. Mag. ser. 3 (1831) 121 ; ! Stepli., 111. Brit. Ent. vi. 66

[B. venui'] (1835).— 5. J culiciformis, ! Steph., op. cit. vi. G6 (1835).— B. phceopa, ! idem, inter synon,

(1835).— 5. X striata, lid., op. cit. vi. 65 (1835).— B. phceops, ! Etn., Trans. Ent. Soc. London (1870) 4;

lid., op. cit. (1871) 115, pi. v. 21, 21 a [details]; Meyer-Diir, Bull. Soe. Ent. Suisse, iv. 310 (1874).

Cloeverna, Pict., Hist. Nat. Nevropt. ii. Ephein. 270 (1843-5).

Clo'eon verna, Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 578 (1853).

Siibimago {lichig). — Wings smoky or mousey grey ; setae and forceps smoky. Femora

either testaceous grey, light greenish grey, or even greenish white, each with an ill-defined

dark v-shaped mark before the extremity ; tibiae smoky, the anterior black at the tip ;

fore tarsus black ; hinder tarsi cinereous, with black joinings.

Imago (living) . — d . Turl)iuate eyes burnt-umber ; lower eyes brown-black. Notum

at first bistre-brown, changing with maturity to pitch- and jet-black. Dorsum of

abdomen variously coloured ; either bistre-brown or darker, with the extreme edges of the

joinings greyish white ; or in segments 2-7 bistre- or greenish grey and translucent, and

in segments 8-10 bistre-brown with dark tracheae ; venter cinereous. Setse white or

smoky-grey. Forceps-limbs greyish white, or more of a greyish tint towards the base,

vrith the last two joints white. Wings vitreous, with suflPuscous longitudinal neuratiou.

Fore femur subolivaceous, with a dark rounded spot before the tip ; the tibia whitish

grey, the tarsus dark grey : hinder femora either greenish grey, or cretaceous with a light

greenish tint; tibiae whitish; tarsi whitish or greyish white, with the joinings and the

uncinate claw scarcely darker.

S . Very similar. Eyes sepia-black or black. Notum at first pitch-brown, becoming

pitch-black or black. Femora olivaceous ; tibiae greyish- or greenish- white ; tarsi char-

coal-black with black joinings, the fore tarsus darker. Setae white, tinged with brown-

black basewards. Length of body 5'5-8 ; wing, d 5-7, ? 7-9; setos, rf im. 12-16,

subim. 5, ? im. 10-12, subim. 7 mm.

Sab. Great Britain ; Finmark, Hammerfest and Alten. It frequents English streams

and rivulets in May, June, September, and October. The adult d may be recognized by

the forceps-limbs having each a caUus at the interior extremity of the basal joint, no

very marked deuticulation at the inner base of the second joint, and an ovate-oblong

terminal joint.

Baetis bhodani, Pictet. Plates XVI. 29 c (hind-wing, d head), and LXIV. 12

(forceps).

Cloe rhodani, ! Pict., Hist. Nat. Nevropt. ii. Ephdm. 248, pis. xsxvi.-xxxix. (1843-5) ; Brauer, Neuropt.

Austr. 26 (1857) ; ! Hag., Ann. Soc. Ent. Fr. (4) iv. 39 (1864) ; Meyer-Dur, Mitth. Schw. Eut. Ges. i.

221 (1864) ; ?Oulianine, Neuropt. & Orthopt. of the Prov. of Moscow, p. 28 (1867) ; Ausscr., Ann. d.

Soc. Natm-. Modena, Ann. iv. 136 (1869) ; Joly, Rev. d. Sc. Nat. Montpellier, v. 310, pi. vii. 17-18

(1876) [details] .—C. maderensis, I Hag., Ent. Mo. Mag. ii. 25 (1865).

SECOND SERIES. — ZOOLOGY, VOL. III. 22

162 PEV. A. E. EATON ON RECENT EPHEIMEEID^ OE MAYFLIES.

Cloeon rhodani, Walk., List of Neuropt. lus. in Brit. Mus. part iii. 573 (1853) ; Hag., Ent. An n

(1863) 31 ; !Etn., Ann. & Mag. of Nat. Hist. (3) xviii. 14.7 (1866).

Buetis rhodani, !Etn., Trans. Ent. Soc. London (1871) 114, pi. v. 20, 20e [details]; Meyer-Diir,

Bull. Soc. Ent. Suisse, iv. 309 (1874) ; Rostock, Jahresb. d. Ver.f. Natiu-k. Zwickau, 1877, p. 86 (1878) ;

Palmen, Paar. Ausf. giluge d. Gescld. org. b. Insect. S. 64, 68, 71, taf. iii. 45 [anatom.] (1884).

Subimago [living). — Wings eitlier cinereous or dark brownish grey, with greenish grey

neuration. Fore femur greenish grey, with a dark crescentic spot or an ill-defined light

grey spot before its distal extremity, the tibia light sepia-grey, the tarsus dull black ;

hinder femora light greenish- or yellowish-white, the tibiae greyish white, the tarsi dull

black ; setae greenish grey, with reddish or warm sepia-brown joinings.

Imago {living). — d . Turbinate eyes intermediate in colour between deep sepia- and

madder-brown above, much lighter at the sides ; lower eyes deep sepia-brown. Thorax

jet-black above. Abdomen in large examples greyish bistre- or umber-brown in segments

2-6 or 7, with the joinings opaque ; the remaining segments of a richer umber- or bistre-

brown, with ochraceous joinings ; venter dark greenish grey, often with two short

divergent sepia-grey lines, each followed by a dot near the base of almost every segment.

Setge greenish grey, with sepia-brown or dull red joinings. Forceps greyish or greenish

grey, their third and fourth joints whitish, more or less. Femora light olive-green or

dark greenish grey ; tibiae and fore-tarsus light grey ; hinder tarsi light grey or black.

Wings vitreous, the nervures very faintly tinged with bistre-grey.

Variation. — Small examples have segments 2-7 of the abdomen translucent light

greyish, each of these having the usual three dorsal linear marks in the middle of its

base and the spiracles faintly darker grey, and having the edge of the distal border of

the segment in the middle of the back, and also a spot in the midst of the dorsum on

each side, orange-fuscous. Legs greyish, the tibiae in some Mghts appearing whitish with

their tips dark grey, and the hinder tarsi dark grey.

$ . Very similar to the male ; the abdomen opaque throughout. In specimens of

either sex that have only just cast the subimaginal slough, the thorax is visually pitch-

brown above; it becomes jet-black afterwards. Length of body 5 '5-9 ; wing 5'5-9 6

and -12 ? ; setae, 6 im. 13-19, subim. 105, $ im. 16 mm.

Hub. Great Britain, in streams and rivers, ascending to upwards of 1000 ft. in Derby-

shire ; in the south this species is matured on sunny days in the depth of winter where the

water has an average temperature at that season of about 51° F. Widely distributed on

the Continent : the Vosges (M^Lach.) ; lowlands of Switzerland, e. g. Lake of Geneva

(1230 ft.), Tirol (Brauer) ; also Corsica (Bellier). Common in Madeira up to 3000 ft.

and in Gran Canaria, near Sta. Brigida and San Mateo up to about 4600 ft. The terminal

joint of each of the forceps-limbs is small and globular.

Baetis Bocagii, sp. nov. Plate LXIV. 13 (forceps).

Subimago {lining). — Wings tinted with griseous.

Imago {living). — c? . Tiu-binate eyes dull light red ; lower eyes dark olivaceous. Thorax

jet-black above. Abdomen in segments 2-6 fusco-griseous, with the joinings of the

segments and an abbreviated longitudinal line from the base on each side of the median

EEV. A. E. EATON ON EECENT EPHE1MEEID.E OE MAYFLIES. 163

line of each of them darker ; segments 7-10 fuseo-lutescent ; venter greenish grey, tinged

with brown ochre in segments 8-10 ; the first two joints of the forceps lurid, varied with

fuscescent, the other two fumatose. Setae smoky white, with rusty-reddish joinings.

Fore femur greenish grey, the tibia and tarsus scpia-grey or dusky ; hinder femora paler,

the tibige and tarsi whitish grey or smoky, with black joinings. Wings vitreous ; sub-

costa and radius of the fore wang, and other longitudinal nervures towards the base of

the wing, light amber-yellow, becoming blackish in the outer part of the disk ; cross

veinlets likewise blackish. Length of body, d im. 10, wing 10, setaj 19 mm.

Sab. Portugal. The streamlet near Bemfico, which passes under Alcantara, Lisbon ;

23 May, 1880. The temperature of the water at the time was 66° F. Named out of com-

pliment to the learned investigator of the Portuguese fauna, Senhor Barboza du Bocage.

Baetis gemellus, sp. nov. Plate LXIV. 14 (forceps).

Ba'etis Xrhodani, var., ! Etn., Trans. Ent. Soc. London (1871) p. 114.

Snhimago {lmn(j).—WmQ?, dark smoky grey in 6 , darker in ? ; setfie of a like colour,

with rufescent joinings in <s . Fore femur of d dull yellowish tinged with grey, with a

dark spot inside before the knee ; tibia blackish grey or dusky ; tarsus charcoal-black ;

hinder femora pale greenish smoky grey ; the remainder of the hinder legs smoky grey,

with the tarsal joinings black. Femora of ? light yellowish grey ; tibiae and tarsi

smoky grey, with the tarsal joinings black.

Imago [Uriug). — d . Turbinate eyes bright light red ; lower eyes olivaceous or olivaceo-

fuscous. Notum either light brownish ochre streaked with fuscous or pitch -brown, or

else fuscous with the sutures raw-sienna yellow. Abdomen in segments 2-6 pellucid

white, with the joinings and rounded lateral nebulae above the pleurae suffused with

either yellowish fuscescent or raw sienna ; the remainder of the dorsum either raw sienna

throughout, or onlj' so in segments 9 and 10, w^ben segments 7 and 8 are light brown-

ochreous fuscous ; segment 10 bright yellow beneath. Setae smoky or dusky, with

medium burnt-sienna red or black joinings. Fore femur and base of the tibia in some

lights tinted with light amber-yellow, changing in other lights to a stronger yellow ; the

remainder of the tibia and the tarsus dusky or dull greenish grey, with darker joinings.

Hinder femora either dull whitish amber, or whitish tinged with olive-green ; tibiae and

proximal joints of the tarsi either whitish or light yello^"ish smoky white ; the remainder

of the tarsus dusky, with darker or black joinings ; ungues black. Forceps smoky white

or greyish fuscous ; the basal joints raw sienna. Wings vitreous ; the stronger longi-

tudinal nervures slightly amber-tinted, and towards the base of the wing of a greenish

grey tint ; the costal projection of the hind wing slightly fuscescent.

$ . Eyes pitch-black ; the space between the ocelli, the basal joints of tlie antennae,

and a spot on each side intermediate between the eye and the insertion of the antenna,

raw-sienna yellow ; epistomum ochraceous, with fuscous carina. Abdomen fuscescent

above, with the terminal margins of the intermediate segments rufo-piceous, edged very

narrowly in segments 2-5 with yellow-ochre, and with the sides of the dorsum lighter

near the pleurae ; venter lighter than the dorsum, wdth the joinings darkened ; the last

two segments tinged with raw-sienna yellow. Legs somewhat as in the 6 , but darker ;

22*

164 EEV. A. E. EATON ON EECENT EPHEMEEIDiE OE MAYELIES.

the fore tibia olivaceous. In drying, the legs acquire yellowish amber tints. (The

alpine condition.)

Length of body, d 6-8-5, $ 6-11 ; wing, 6-5-11 ; setse, c? im. 13-25, subim. 8-5, ? im.

11, subim. 8 mm.

Hah. Spring-water streams in the mountains of Switzerland, N. Italy, Savoy, and

Central Italy: July to September. Thusis and Val Anzasca (M'^Lach.) ; near Cham-

p6ry, Valais, in streamlets having at altitudes of 3700-4000 ft., between 2 and 4 p.m.

in August, temperature ranging from 54° to 62° and 68° F. ; also at a spring in the same

neighbourhood at Les Clous (4000 ft., 6*50 a.m., 18 August, 1879, water 46° F. [large speci-

men]) : also near Samoens (2280 ft., 5-30 p.m., 13 Sept., water 54° F.) ; also in Val

Montjoie between Contamines and Notre Dame de la Gorge. Common in the Apennino

Pistojese near San Marcello, in streamlets tributary to the Limestre, both in the

chestnut wood below Gavinana (2550-2750 ft.), and at a streamlet crossing the highway

nearer San Marcello (2160 ft., 3-40 p.m., 27 July, '82, water 63° F.). The temperatures

quoted give suflB.cient indications of the water-climate suitable to the species, and may

be of use in the selection of sites for collecting. The Apennine specimens are just

appreciably brighter in the colour of their bodies than Alpine examples ; but the diffe-

rence is very slight indeed.

Baetis atrebatinus, Etn. Plate LXIV. 15 (forceps).

Baetis atrebatinus, ! Etn., Trans. Ent. Soc. Loudon (1870) 4; id., op. cit. (1871) 113, pi. v. 19, 19 a

[detail].

This species (living subimago Sf imago) closely resembles B. rhodani, but is dis-

tinguishable therefrom by the almost complete suppression of the usual projection in

front of the hind wing near the base of the costa, and by an acute prominent black point

in a shallow rounded depression in the protuberant part of the segment [probably the

point of the penis] above the forceps in the middle line of the venter. Length of body

7-8 ; wing 6-8 ; setae, 6 im. 11-13, subim. 8-5, ? im. 8-10, subim. 7-5 mm.

Hab. England. The Kennet near Reading, Berkshire ; captured when in subimago

and at rest upon herbage fringing the towing-path of the canal between the mill and the

county bridge nearest the junction of the Basingstoke and Devizes railways : October.

Baetis tenax, Etn. Plate LXIV. 16 (forceps).

Baetis tenax, ! Etn., Trans. Ent. Soc, London (1870) 5; ! id., op. cit. (1871) 116, pi. v. 22, 23 a

[detail] .

Imago {living). — 3 . Turbinate eyes intense warm sepia-, or chocolate-brown ; lower

eyes sooty-black. Notum jet-black. Abdomen in segments 2-6 translucent, tinted with

olive-brown, pale at the joinings and lighter towards the pleurae, with the tracheal trunk

slightly reddish-purple grey ; the other segments opaque : venter light cinereous, tinged

with orange in segment 9 between the forceps -limbs, and in part of segment 8, and

ochreous in segment 10. Forceps-limbs whitish, sometimes darker at the base. Setae

white. Femora olivaceous or dark olive-grey, pale yellowish at the knees ; fore tibia and

tarsus cinereous ; hinder tibiae and tarsi smoky grey, with the tarsal joinings either

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 165

cai'cely darker, or else narrowly black. Wings vitreous ; neuration either pellucid

vhitish, or fuscescent [perhaps according to the age of the specimen].

2 . Very similar. Length of body 6-8, wing 7-8"5, setje, c? im. 14-16 mm.

Hab. England. Rills and streamlets on Ashbourne Green, Derbyshire, in June. Also

it Woolbridge, Ringwood, Hants, in September. Distinguishable from J5. rhodani

)y the minute dilatation or denticulation inside the extremity of the second joint of each

orceps-limb, and the distinctness of the tubercle similarly situated in the first joint.

Baetis melanonyx, Pictet. Plate LXIV. 17 (forceps).

CloS melanonyx, Pict., Hist. Nat. Nevropt. ii. Epliem. 258, pi. xl. 6 (1843-5).

Cloeon melanonyx, Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 574 (1853).

Baetis finithnus, ! Etn., Trans. Ent. Soc. London (1871) 113, pi. v. 18, 18 a [detail]. — B. melanonyx,

d., op. cit. (1871) 118 [after Pict.].

Suhimago {living) $ . — Wings smoky grey, with dull greenish grey or suffuscous neu-

ation. Setae dark smoky grey, with rubiginose joinings. Eore femur and tibia greenish

jrey, varied with black at the knee, and with a dark cloud near the extremity of the former ;

arsus dark grey, with black joinings and ungues. Hinder femora smoky cretaceous,

vith a faint nebulosity before the extremity ; tibiae smoky grey ; tarsus dusky, with the

oinings and the lesser of the ungues black. Oculi olivaceous, with a movable black spot.

Imago {living). — 6 . Turbinate eyes chocolate-brown on the summit, and narrowly so at

he base of the light yellow pedicel; lower eyes dull subolivaceous. Notu.m jet-black.

Abdomen fuscous above, darker or more opaque at the tips of segments 2-6, and through-

)ut segments 7-10 ; venter somewhat griseous in segments 2-6, lighter in segments 7-9,

)ale ochraceous in segment 10 and inside the basal joints of the forceps; the remainder

)f the forceps blackish basewards, but lighter distally. Sette somewhat greyish, with

larker joLoings near the roots. Fore femur olive-grey, the tibia and tarsus dull blackish

jrey; hinder legs rather lighter, with the tarsal joinings narrowly black; coxne olive-

jrey. Wings vitreous, with metallic gramineous (= medium green oxide of chromium)

md light carmine reflections ; pterostigmatic space of the fore wing slightly smoky or

aibopaque ; neuration translucent, the finer uervures in some lights subpiceous, the

stronger tinged with olive-grey.

$ . Eyes subpiceous. Thorax dull black, or pitch-black, with paler sutures ; tegulse

ailphur-yellow. Abdomen either fuscous or pitch-black above, with the first three

loinings conspicuously pale, the next three piceous, and the others rufo-piceous ; venter

either dark bistre-grey with pale joinings, or greyish, with the last two segments often

somewhat ochraceous, traversed lengthwise by a pale median line, and having a dark

rounded spot at the base on each side of that line in every dark segment. Sette dusky,

nith darker joinings. Eore femur olivaceous : hinder femora light greenish grey ; tibiae

and tarsi in some lights dusky, with black joinings ; in other lights those of the fore leg

appear pitch-black, and those of the hinder legs pitch-brown ; wings vitreous, with the

greater part of the neuration pitch-black; subcosta and radius olive-grey. Length of

body, 6 5-7, 2 8-5-9, wing, d 6-7, 2 8-5-11 ; seta3, <S im. 12-18, ? 13-18 mm.

Hah. A common alpine species in N. Italy, Savoy, and Switzerland : in the ueighbom--

166 EET. A. E. EATON OX EECEXT EPHEMERIDJ: OE MATTLIES.

hood of Samoens (3400-5100 ft.) and Champerv (4500—5760 ft.), in streams or torrents

having temperatiu-es ranging in August and the beginning of September from 42°-51° T.

in the early morning, to 45° and 59° F. (rarely 62°) in the afternoon : also in the Enga-

dine at Pontresina and (M'^Lach. 13 August) the Yal de Fain : also (M'^Lach.) in July

on the St. Gothard route, Yal Bedi-etta, and at Gex, Ain, &c. ; also Oberseisenthal

(Meyer-Diii-) and Yal d'Entremont (Pict. in June).

Ba£tis AXPEsrs, Pictet. Plate LXIV. 18 (forceps).

C/o'e alpina, Ret., Hist. Nat. Nevropt. ii. Ephem. 257, pi. xl. .5 (184.3-5).

Clo'eon aJpina, Walk., List of Neivropt. Ins. in Brit. Mus. part iii. 574 (1853).

Baetis amnicus, ! Etn., Trans. Ent. Soc. London (1871) 117, pi. v. 24, 24a [detail]. — B. aJpinua, id.,

op. cit. (1871) 118 [after Kct.].

Imago (living). — c? . Tui-binate eyes chocolate- brown ; lower eyes brown-blact. Xotum

jet-black, with pale sutiu'es. Dorsal segments of the abdomen fuscous, slightly paler at

the joinings : venter mostly cinereous. Eorceps black at the base, b'ghter distally.

Setae white or cinereous, with darker ioinings near the roots. Fore femui- srreenish

grey ; tibia and tarsus smoky or dusky ; hinder femora sometimes less of a greenish and

more of an ochmceous tint, with a rufescent streak at the knee, the tibiae commonly

fawn-grey, and the tarsi dusky with black joinings. Wings vitreous, tinted slightly with

extremely light brown-ochreous ; neuration olive-black ; pterostigmatic region of the

fore wing somewhat obscured.

2 . Wings clear, with sfreenish errev neuration. Femora ijreenish srev or olivaceous;

tibiap, tarsi, and caudal setae dusky. Length of body 7-10, wing 8-10 ; setae, im. d 16,

2 13 mm.

Sab. Common bv mountain-torrents in Switzerland and Savov : in the neiErhbourhood

of Mt. Blanc at Barberine, Xant Bourant (4500 ft.), and Mottet in July ; also at a stream

fi'om Mt. Brevent (Pict.) in August ; also near the Chalets de Pitty, Samoens (4700-

5100 ft.) 8 A.M. 29 August, water 51' F., and near Les Clous, Champery (4000 ft.). Also

at La Kosa in the Bernina Pass (6000 ft.) 630 a.m. 25 August, water 5r F. K<?adily

distinguished by the tint of the d wings from B. melanonyx.

BAEns BrcERAirs, Etn. Plate LXIY. 19 (forceps).

Baitls buceratus, ! Etn., Trans. Ent. Soc. London (1870) o; ! id., op. cit. (1871) 116, pi. v. 23, 23a

[detail] .

Subimago d- Imago {living). — ^^'ery similar to £. vermis and B. tenax; chiefly distin-

guishable from them by the 3 forceps. The forceps-limbs in B. biiceratus, divergent from

one another in the fii-st and second joints, again converge, and are also strongly arcuate

beneath ; the second joint of each limb is more domed than in those other species, and

the terminal joint more nearly oval. Length of body, 6 im. 8-9, wing 8-9, setae

10-16 mm.

Sab. England. The Eennet and Holy brook near Reading, Berkshire, in April and May.

Baetis primrs, Burmeister. Plates XYI. 29 e (hind-wing ) & LXIY. 20 (forceps).

? Ephemera mufica or \Ephemera], Linn., [En. Suec. ed. i. no. 752 (1746)] ; id., Srst. Xat. ed. x.

EEV. A. E. EATON ON EECENT EPHEjVIEEID.E OE MAYFLIES. 167

i. 547 (1758) ; id., Fn. Suec. ed. ii. no. 1479 (1761) ; [Geof., Hist. Abreg. cles Ins Paris, ii. 240,

no. 7 (1764)] =£. striata, Linu., Syst. Nat. eel. xii. pars ii. 907 (1767) ; Fab., Syst. Ent. 304 (1775) ;

id., Sp. Ins. i. 385 (1782) ; id., Mant. Ins. i. 244 (1787) ; Berkenh., Outl. of the Nat. Hist, of Gt. Brit.

& Ireland, ed. 2, i. 150 (1789); Vill., C. Lin. Ent. iii. 20 (1789) ; Gmel., Linn. Syst. Nat. ed. xiii. i. pars

V. 2630 (1790); 01., Encycl. Meth. vi. 420 (1791); Fab., Ent. Syst. emend, iii. pars i. 71 (1793);

Cederh., Fn. Ingricse Prodr. 135 (1798) ; Lat., Hist. Nat. d. Crust. & Ins. xiii. 99 (1805) ; Stewart,

Elem. Nat. Hist. Anim. K. ed. 2, ii. 226.— ?£■. ciliata, Strom, N. Saml. Kongl. Dansk. Vidensk. Selsk.

Skrift. ii. 91 (1783) ; Wallengren, Christ. Vidensk. Forhandl. no. ii. 22 (1880).

Clo'e pumila, Burm., Handb. d. Ent. Bd. ii. Abth. ii. 799 (1839) ; Piet., Hist. Nat. Nevropt. ii. Ephem.

253, pi. xl. 2 (1843-5) ; Bran., Neuropt. Austr. 26 (1857) ; Karsch, Die Insectenwelt, v. 402 (1863) ;

! Hag., Ann. Soe. Ent. Fr. (4) iv. 39 (1864) : Meyer-Dur, Mitth. Schw. Ent. Ges. i. 221 (1864) ;

Ausser., Ann. d. Soc. Natnr. Modena, An. iv. 136 (1809)—? C. striata, Pict., Hist. Nat. Nevropt. ii.

Ephem. 270 (1843-5) ; Oulianiue, Neuropt. & Orthopt. of Prov. of Moscow, 28 (1867).

Cloeon pumila, Walk., List, of Neuropt. Ins. in Brit. Mus. part iii. 573 (1853). — ? C. striata, id., op.

cit. 576 (1853).

Baetis pumiliis, ! Etn., Trans. Ent. Soc. London (1871) 118, pi. v. 25-25a [details] ; ! id., op. cit. (1873)

401 [mode of oviposition] ; Meyer-Diii'., Bull. Soc. Ent. Suisse, iv. 310 (1874) ; Rostock, Jahresb. d.

Ver. f. Naturk. Zwickau, 1877, p. 87 (1878).

Snbimago {living). — Wiugs tinted with charcoal blackish. Legs greenish grey with

light black-grey tarsi. Setae light black-grey.

Imago {living). — 6 . Turbinate eyes intense sepia-, or bnrnt-umber brown. Thorax

jet-black aboye. Abdomen in segments 2-7 translucent white, the remainder yellowish

pitch-brown above, umber-brown beneath. Forceps and setse white. Legs white ; the

fore femur, the tarsi, and the extremities of the tibiae light black-grey. Wings vitreous.

? . Eyes olivaceous ; vertex of head traversed lengthwise by a double median rufo-

piceous stripe. Thorax black or pitch-brown above. Abdomen above reddish pitch-

brown, with the joinings, and sometimes with an abbreviated longitudinal line from the

middle of the base between two curved lines in nearly every segment ochraceous ; venter

paler, with a series of L-shaped warm sepia-brown marks or oblong rufo-piceous spots on

each side of it. Setae very light reddish brown-grey. Legs either almost uniformly pale

grey, or else greenish grey with sepia-grey tai'si. Length of body 5-7 ; wing, s 4-6,

S 6-8 ; setae, d im. 11-13, subim. 10, ? im. 7*5-10, su.bim. 7-10 mm.

Sab. Great Britain in streams and rivers. Widely distributed on the Continent,

rnngiug from Scania and Norway (Wallengren) southwards to Portugal and Corsica

[occurring at Cintra in April at about 380 ft., water 58° P. ; at Cea in the Estrella

in June at 1800 ft., water 56° E. ; and at Villa Real, Traz-os-Montes in June at 1630

ft., water 58° E.) and eastwards to Armenia (Hag. Mus.). In Savoy and Switzerland it

ranges from the lowlands up to about 5800 ft. in the neighbourhood of Champery near

the Chalets de Pas (5.15 p.m. 19 August, water 51° E.), and it is found in Erance,

Grermany, and Austria. The terminal joint of each of the forceps-limbs is^'oval or globular.

The intermediate nerve of the hind wing is usually forked ; and the fork contains a

simple veinlet from the terminal margin,

Baetis niger, Linn. Plate XVI. 29/ (forceps).

Ephemera nigra or [Ephemera'],lAixa., Fn. Suec. ed. ii. no. 1478 (1761); id., Syst. Nat. ed. xii.

168 EEV. A. E. EATON ON RECENT EPHEMERIDiE OE MAYFLIES.

pars ii. 907 (1767) ; Fab., Syst. Ent. 304 (1775) ; [Sclisef., Icou. Jus. circa Eatisbon. inclig. ii. tab. cliv.

1, 2? (1776)]; Schr., Enum. Ins. Austr. indig. 305 (1781); Fab., Sp. Ins. i. 385 (1782); id.,

Mant. Ins. i. 244 (1787); VilL, C. Lin. Ent. iii. 19 (1789); Gmel., Linn. Syst. Nat. eel. xiii. i. pars v.

2629(1790); Rossi, Fu. Etrusc. ii. 8 (1790); 01., Eucycl. Meth. vi. 419 (1791); Fab., Ent. Syst.

emend, iii. pars i. 70 (1793); Cederli., Fu. Ingricte Prodr. 135 (1798); Walck., Fn. Paris, ii. 9 (1802) ;

Panzer in Explic. Scbsef. Icon. cliv. (1804); Lat., Hist. Nat. Crust. & Ins. xiii. 98 (1805); Stewart,

Elem. Nat. Hist. Anim. K. ed. 2, ii. 225 (1817) ; Stepb., 111. Brit. Ent. vi. 67 (1835) ; Ronalds, Fly-

fish. Ent. ed. i. pi. ix. 16-17 (1836) ; Blancb., Hist. Nat. Ins. iii. 54 (1840).

Cloel diptera, ! Ronalds, Fly-fish. Ent. ed. v. no. 16 (1856).

Baetis niyer, ! Etn., Trans. Eut. Soc. London (1870) 6 ; ! id., op. cit. (1871) 119, pi. v. 26, 26a [detail].

Siibimaffo {living). — Wings black-grey. Legs of the $ dull greyish white ; 6 femora

very light yellowish green (prasinus) ; an abbreviated line or streak at the tip of the fore

femur dark, the tibiae and terminal joints of the tarsi greyish white, and the remainder

of the tarsi fawn-colour. Setaj of s grey, of $ cinereous.

Imago {living). — d . Turbinate eyes reddish brown or light burnt-umber brown : lower

eyes olivaceous. Thorax jet-black above. Abdomen in segments 2-7 translucent, and

either white or light cinereous, with whitish or fuscescent joinings, and with the tracheal

trunks darker ; segments 8-10 either pitch-brown, reddish brown, or yellowish brown

above, and either whitish, greenish grey, or fuscous beneath ; nearly every ventral

segment has two short divergent dark lines at its base, each followed by a dot. Setae

white or greyish white, often with oj)aque joinings, or with some of the proximal joinings

faintly reddish. Eorceps with finger-Uke limbs, dark grey at the base and then light

greyish white. Fore femiir either light greyish white, or dull greenish white, or light

yellowish green ; the rest of the fore leg greyish, with the distal extremity of the tibia

reddish brown ; hinder femora white, slightly tinged distally with yellowish, greenish,

or grey ; the tibite dull whitish and the tarsi greyish white, or both of them of this latter

colour, with the distal edges of the tarsal joints black and the ungues piceous. Wings

transparent ; their neuration whitish pellucid, the subcosta and radius at the wing-roots

piceous.

? . Eyes intense sepia. Dorsum of abdomen castaneo-piceous, with the terminal margins

of the segments, and often with three short streaks at the base of each of segments 2-6,

yellow ochreous : venter warm sepia, or burnt-umber brown, often with dark lateral L-

shaped marks. Setae either uniformly smoky or greyish white, or else greyish white

with rufescent joinings. Legs greenish testaceous, with the tarsal joinings dusky.

Length of body 5-7'5, wing 6-8 ; setae, d im. 9-11, subim. 9, ? im. 6-8'5, subim. 7 mm.

Hab. Rivers in England ; May, June, and September. Also perhaps Sweden and

Courland (Brauer). The second nervure of the hind wing is usually forked, as in B.

pumilus.

NOETH AMERICAN SPECIES.

Baetis .

t Cloeon X bioculata [exenpl. g], ! Walk., List of Neuropt. in Brit. Mus. part iii. 573 (1853).

An undescribed species,

Hab. St. Martin's Falls, Albany Kiver, Hudson's Bay (Brit. Mus ).

EEV. A. E. EATON OX EECENT EPHEMERLD^ OR MAYELIES. 169

Baetis posticatus, Say.

J Cloeon post'icuta, Say, Godman's West. Quart. Rep. ii. 162 (1824) ; Le Conte, Complete Writings of

T. Say, i. 172 (1859).

Clo'e posticata, Hag., Smithson. Miscell. Coll. (1861), Syuop. Neuropt. N. Am. 53.

Baetis posticatus, Etn., Trans. Ent. Soc. Loudon (1871) 120.

Imago, d .— Ej'es reddish brown ; thorax black ; abdomen greenish white, hyaline, the

last three segments fuscous ; seta? w^hite. Legs white, the fore femur obscure. Wings

hyaline. Length of body 8, setaj 19 mm. (After Say.)

Rab. Shippiugsj)ort, 21st May. Common. (Say.)

Baetis Hageni (renamed).

Clo'e \\ unicolor, Hag., Smithson. Miscell. Coll. (1861) Synop. Neuropt. N. Am. 54; Walsh, Proc.

Acad. Nat. Sc. Philad. (1862) 380?; Hag., Proc. Ent. Soc. Philad. ii. 178 (1863) [nee CI. unicolor,

Curt. (1834)].

Baetis unicolor, Etn., Trans. Eiit. Soc. London (1871) 120.

Imago {dried), ? . — Body bronze-lirown ; legs pale luteous ; setre white; wings hyaline.

Length of body 4 ; exp. of wings 10; setse 10 mm. (After Hagen.)

Hab. Washington (Osten-Sacken). The translator of Dr. Hagen's Synopsis wrote

"brassy" for " bronze." Walsh may have confounded another species with Ilagen's.

BAiiTIS RUBESCENS, Hag.

CloeXW unicolor, Provanclier, Natural. Canad. viii. 267 (1876); id.,Yn. Ent. Canad. ii. fasc. i. 84

(1877).— C. nibcscens. Hag. MS., id., op. cit. ii. fasc. i. 82' (1877).

Imago ( ? ? dried). — Body reddish brown, the abdominal segments margined with

black behind ; setae whitish ; legs pale yellowish ; wings hyaline, reddish at the base and

along the costal margin. Long. -22 pouce = ll-8 mm. (After Provancher.)

Sab. Not stated ; probably Quebec. As this insect was taken by I'Abbe L. Pro-

vancher to be CI. II unicolor. Hag., which is a Baetis, I infer that it also has 4 wings, and

is referable to the same genus. But judging from the coloration of tlie mesothoracic

wings, it might be a Cloeon, or even a CalUbcetis, if this genus ranges so far as

Quebec.

Baetis propinqtjus, Walsh.

CloeXi:icina, Walsli, Proc. Acad. Nat. Sc. Philad. (1862) 380; id., Proc. Ent. Soc. Philad. ii. 207,

note 20 (1863).— C. propinqua, AValsh, loc. cit. (1863).

Baetis propinqutis, Etn., Trans. Ent. Soc. London (1871) 121.

Subimago.— Wings fumose, with rather coarse and dusky longitudinal neuration ; the

cross veinlets concolorons with the membrane. Tarsi sometimes dusky.

Imago, d . — Lower portion of the oculi attached to the hinder " corner " of the

turbinate portion. Thorax and last 4 dorsal segments of the abdomen piceous ; the

intermediate abdominal segments wdiitish hyaline, each with a dot at the sides ; venter

pale hyaline, the last 4 joints opaque whitish. Setae whitish, the joinings near the base

often fuscous. Legs pale, except the fore femur, which is sometimes pale ferruginous ;

SECOND SEMES. — ZOOLOGY, VOL. III. 23

170 EEV. A. E. EATON ON EEOENT EPHEMEEID^ OE MAYFLIES.

tips of tarsi cloudy. Wings and neuration hyaline ; the space included between the two

nervures of the hind wing subopaque.

? . Thorax, and abdomen above, ferrugineo-piceous, or sometimes ferruginous ; venter

reddish Avhite. Pore femur always immaculate.

Length of body, d 4-5, ? 3-5-6-5 ; exp. of wings 9-12 ; sette, J 7-5-10, ? 5-9 mm.

[After Walsh.J

Sab. liock Island, 111.

Baetis ptgm^tts, Hag.

Chi' pygnuea, ! Hag., Smithsou. Miscell. Coll. (1801) Syiiop. Neuropt. N. Am. 54 ; id., Vvoc. Ect.

Soc. Philad. ii. 178 (18G3).

Baetis pygmceus, Etu., Trans. Ent. Soc. Loudon (1871) 122.

Imago [dried), ? . — Thorax dark fuscous ; " abdouien fusco-griseous " (Hag.). Wings

vitreous, with brownish neuration ; fore wings with 6 simple straight cross veiulets, but

no granulations, in the pterostigmatic sj)ace. " Legs and setae white" (Hag.). Length

of body, ? 3, expanse of wings 6 mm.

Hah. Tlie St. Lawrence. The type reached me in an extremely fragmentary con-

dition. [No. 79 in Hag. Mus.]

CENTRAL AND SOUTH AMERICAN SPECIES.

Baetis Salvini, sp. nov. Plate XVI. 29rt (wings and forceps).

Stibimaffo {dried). — $ . Wings very light sepia-grey, with pitch-black neuration

bordered with darker (Cologne earth) grey, the bordering ti'ansversely confluent here

and there so as to form in the fore wing several (0-8) narrow fascitc, some of which have

a tendency to combine with one another in the vicinage of the most salient part of the

curve of the terminal and inner margin ; the marginal area contains usually 1 cross

veinlet before the buUa, and 15-18 beyond it, which last are oblique, strong, and for the

most part simple.

Imago (dried). — 6 . Thorax fusco-luteous above, the metanotum piceous. Abdomen

discoloured, perhaps flavescent or else light olivaceo-fuscous, with the apical borders of

the segments pitch-black. Setae very light sepia-grey, with about every fourth joint

darker, annulated at every joining with sepia-brown. Wings vitreous : the fore wing

Avith pitch-black neuration, the stronger nervures fuscescent towards the wing-roots ; the

membrane with a patch of that colour at the base of the wing, and most of the stronger

cross veinlets bordered with the same, their borderings more or less confluent in the

pterostigmatic space and the subjacent portion of the submarginal area. Pore femur

light fuscous (light bistre-brown) banded with pitch-black near the middle and at its

extremity; tibia and tarsus flavescent, the tibia just at the base and more broadly at its

extremity, the tarsal joints annulated distally, and the ungues coloured throughout with

EEV. A. E. EATON ON EECENT EPHEMERID/E OR MAYFLIES. 171

pitch-black. Hindci' legs lighter in tint, but ornamented nearly in the same manner.

Ijengtb of body, d 10; wing, d 12, ? 14; settB, c? 26, subim. 20 mm.

Sab. Irazu, Costa Eica, GOOO-7000 feet. (H. Rogers, Salvin and Godman Mus).

(?) Baetis Stelzneri, "Weyenb.

Cloe Stelzneri, Weyenbergh, Tijdscli. v. Ent. xxvi. 1882-3, p. 170 (1883).

Imago {living). — d . Upper portion of oculi dark red, the lower blackish grey. Thorax

darker than in the ? , so are the legs ; pleurae greyish yellow.

? . Thorax sepia-brown, traversed longitudinally throughout the notum by a darker

median line or stripe, and with much darker wing-roots. Abdomen pearl-grey beneath,

and somewhat darker on the back, the colour there approaching steel-blue. Seta; (? 2)

pearl-grey, the joinings as good as invisible. Wings unclouded, with almost black neu-

ration. Length of body 5-5, wing 6, setae 7'o mm.

Hab. Cordova, Argentine E,epublic ; summer and autumn, scarce. (After Weyen-

bergh). — Prom what is remarked of the wings, I conjecture this to be a species of Baetis:

INDIAN AND CINGALESE SPECIES.

Baetis .

X Clol'on dehilis, ! Walk., Trans. Ent. Soc. London, N. S. v. 199 (1860) .

Baetis II debUis, ! Etn., Trans. Ent. Soc. London (1871) 112 [nee % B. delnlis, Walk. (1853)].

Imago {dried). — 2 . "Tulva, capite nigro, abdomine testaceo ; setis pedibusque albis,

alls vitreis, venis albis." — An insufficiently described species, with 5 or 6 simple, oblique

cross veinlets in tlie pterostigmatic portion of the marginal area of the fore wing. Length

of body 5 ; expanse of wings 12 mm.

Ilab. Hindostan (Walk., in Brit. Mus.).

BAiiTIS FEMINALIS, sp. UOV.

Imago {dried). — 2 . Wings vitreous, with pale pitch-l:)rownish neuration ; 2-5, gene-

rally simple and straight, fairly strong cross veinlets in the pterostigmatic space of the

fore wing, without any interjacent granulations. Body bright reddish brown, the thorax

polished ; penultimate dorsal segment pale ochraceous, the other segments at the joinings

dark or piceous; setae pale warm sepia-brown, with grey joinings. Fore femur, for the

most part, reddish piceous-brown, its apical margin and extreme base pale dull yellowish

white ; the base of the tibia of the same pale colour, the rest of the tibia and the tarsus

light sepia-brown ; hinder legs pale sepia-grey, or whitish tinged with yellowish ; the

femora broadly banded with reddish j)iceous-brown near their extremities.

S . Snbsimilar, but having the abdomen from segment 2 up to the basal half of seg-

ment 6 translucent, with piceous joinings ; the tibiae, tarsi, and bases of the hinder femora

more nearly whitish ; the setae rather paler ; and the neuration of the wings paler than

in the 2 . Length of body, 6 4-5 ; wing, d 5-5, 2 6 ; setae, 6 about 13-5, 2 8 mm.

Sab. Raiubodde, Ceylon, at altitudes of not less than 4000 feet (Hagen Mus.). All

23*

172 "REV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES.

traces of hind wings in the 4 specimens (Nos. 34, 49, 50, 51) had disappeared, if they ever

had existed at all.

Baetis consuetus, Hagen.

CloS conmeta, ! Hag., Verb, zool.-bot. Gesells. Wien, viii. 477 (1858) ; Etu., Trans. Ent. Soc. London

(1871) 131; Hag., op. cit. (1873) 403.

Subimago [dried). — Wings transparent, tinted thronghout with very pale smoky grey;

neuration opaque light brown, the cross veinlets in certain postures seeming darker than

the longitudinal nervures. Legs pale brownish-yellowish, the fore femur tinged with

reddish brown towards its extremity. Setae warm sepia-grey or fuliginous. Mesouotum

very pale yellowish brown in the middle ; the jdeura; fuscous ; pectus and venter jiale

ochraceous ; dorsum of abdomen discoloured, but dark and paler along the middle.

Imago (drled).^ 6 . Wings vitreous ; some of the longitudinal nervures yellowish at

the base ; the pterostigmatic space of the fore wing contains 2-5 simple straight cross

veinlets, without any granulations between them. Hind wing trinerved. Mesonotum

lutescent ; sides of the thorax dark brown-ochre ; pectus and venter ochraceous ; dorsum

of the abdomen varied with dark reddish brown and pale ochraceous, — the paler colour

forms large blotches in the midst of segs. 2-7, and some longitudinal linear streaks near

the spix'acles, leaving on each side of these segments a broad dark longitudinal stripe

continuous with that of the thorax; the joinings of these segments, and the whole

dorsum of the subsequent segments dark reddisli brown. Legs pale amber-colour ; the

fore femur indistinctly annulated with reddish brown close to or at its extremity.

2 . Very similar ; but the dorsum of the abdomen is darker, with piceous joinings ;

setae sepia-grey, with some of the joinings towards their roots darker. Tibia and tarsus

of the fore leg sepia-grey. Length of body, d 3-4, ? 4"5 ; Ming, d 4'5-5, ? 5-6 ; setae

d subim. 9 mm.

Sab. Rainbodde, Ceylon, at altitudes of 4000 feet and upwards (Hagen Mus.). With

the types of this species, and from the same locality, stood a single example of probably

a different species, inarked 41, characterized as follows : —

Imago (dried). — d . Wings vitreous, with pale yellowish-brownish perspicuous neura-

tion ; 4-8 slightly curved, cross-veinlets in the pterostigmatic space of the fore wings,

linked together by a somewhat sinuous row of adventitious veinlets near the costa, which

thus give rise to a series of cellules, but there are no granulations between the cross

veinlets. Thorax polished, bright brown-ochreous. Abdomen in segments 2-6 translucent

ochraceous white, pitch-brown at the joinings ; segment 7 ochraceous ; segments 8-10

brown-ochreous ; venter pallid, subochraceous. Setas sepia-grey, with dark joinings.

Legs dull pale testaceous ; fore femur tinged slightly with golden-brown, the tibia and

tarsus fumatose. Commensurate with B, consuetus.

Baetis solidtjs, Hagen.

CM soMa, ! Hag., Verli. zool.-bot. Gesells. Wien, viii. 477 (1858) ; Etn., Trans. Ent. Soc. Loudon

(1871) 131.

Subimago [dried). — Wings transparent, pale sepia-grey ; neuration for the most part

EEV. A. E. EATON ON RECENT EPHEMEEID.E OR MAYFLIES. l73

translucent and concolorous, but sometimes subopaque ; the subcosta and radius of the

fore wing', the base of the costa, and tlie wing-roots, subopaque and pallid, or pale

yellowisli brown. Legs in 2 lutescent, rather more dingy in eolour in the d . Seta3 pale

warm sepia-brown, Avitli opaque joinings. Tliorax in s luteous or lutescent, varied with

paler ; abdomen above luteous or brown-ochre, darker or more of a reddish brown at the

sides of the segments and in the midst of their hinder extremities ; venter ochraceous

yellow.

Imago [dried).- — d . Wings vitreous, with light brown neuration ; 3-6, subregular,

mostly simple, oblique cross veinlets in the pterostigmatic space of the fore wings, some-

what attenuated or tabescent towards the subcosta ; between them, almost midway

between this last and the costa, is extended a single series of granulated rudimental

longitudinal veinlets, rarely branched, but somewhat irregular. Hind wing binerved.

Thorax yellowish testaceous, varied near the peak of the mesonotum with llavescent.

Dorsum of abdomen partially brown-ochre, with dark spots at the stigmata ; segments

2-5 or 6 translucent at the sides and towards the base, their extreme liinder borders

piceous ; segments 9 and 10 pale. Venter and forceps pale yellowisli ochraceous ; the

8th segment and the forceps towards their extremities dark ; seta? whitish, tinged with

pale sepia-grey, and having several of their basal joinings dark reddish brown. Femoi"a

amber-colour, gradually darkened and more distinctly tinged towards their tips with

reddish testaceous ; tibiae and tarsi testaceous, the ungues, and the extreme terminal

margins of the intermediate joints of the hinder tarsi, rubiginose. Length of body 4 ;

wing 4!"5-5mm.

Hab. Eainbodde, Ceylon, at altitudes of 4000 feet and upwards (Nos. 23, 27-30, and

perhaps 52 in Hag. Mus.). The specimen numbered 52 has tlie neuration and terminal

margin of the fore wings piceous ; and the neuration is stronger than that of any of the

other examples.

A Nymph allied to Centroptilum, generis iiicerti.

Nameless Nymph. Plate XLV. (whole figure and details).

Abdominal tracheal branchiaj all somewhat alike in form, ovate-lanceolate and acute,

traversed lengthwise by an irregularly piunately branciied trachea. Autennne defective in

the type specimens, shorter than the head and thorax combined. Median caudal seta

subequal to the others in length, which are about h as long as the body ; the fringes are

narrowed acuminately to the points of tlie seta?. Mandibles nearly as in Ba'etis. Palpus

of maxilla i. longer than the laciuia; the terminal joint minute, the others long and

slender, the first about | as long as the second ; the laciuia armed at the point with about

two teeth, preceded on the inner edge by fasciculated setuhe of nearly uniform length.

Labium and maxilla? ii. nearly as in Baietis; but the palpi are not indented at the joining

of the oval-pointed terminal joint Avith the penultimate joint, which is well defined; the

proximal joint of the same is subequal in length to the other two combined. Tongue

truncate at the base, broadly emarginate in front ; the median lol)e dilated distally and

mucronate ; the much narrower paraglossa? slightly expanded, with curved lateral borders

171 EEV. A. E. EATON ON EECENT EPITEMETIIDtE OE MAYFLIES.