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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.

that meet the apical margin at an acute angle. Hind tarsus, claw excluded, very nearly
of the same length as the tibia ; the leg, as a whole, rather longer than the fore leg.
Length of body 8, setfE 4 mm.

Bah. Puno, Peru ; from a spring (A. Agassiz, Mus. Comp. Zool. Cambridge, Mass.).

CENTROPTILUM, Etn., 1869.

Illustrations. Adult (details), PI. XVII. 30, a-c, and LXIV. 21 ; (whole figure) see
citations of Pictet (1843-5) under C. lideolnm {Cloe translucida), and C. lituratum.
Nymph., PL XLVI.

Adult. — Hind wing oblique, elongate, and narrow, with the apex commonly obtuse,
rarely acute, and usually with the costal projection acuminate [acute in C. stenopteryx] ;
neuration limited to 2 simple longitudinal nervures. Pore wing devoid of colour-
ornamentation, free from cross veinlets in the marginal and submarginal areas as far
from the great cross vein as the bulla?, and with the iutercalar veinlets of the terminal
margin in a large majority of the species single [paired in C. Poeyi'] ; neuration, as a
Avhole, similar to that of species of Cloeon or Ba'etis. Porceps-limbs of d mostly after
the j)attern of Cloeon, which differs froin that of tlie normal Ba'etis in the greater relative
plumpness of joint 2, in the slight terminal enlargement of joint 3, and in joint 4 being
clavate or papilliform instead of oval ; C. tenellum (PI. XVII. 30 c) is tlie only known
deviation fi'om this type of forceps in the genus. The interval between the bases of the
force])s-limbs varies in relative width with the species. Intermediate abdominal segments
of $ subcqual in length. Caudal setas in 6 im. If- 2, in ? im. about 1^, in subim. 1-1^
as long as tlie body. Pore tarsus of 6 rather longer tlian the tibia, which is about twice
as long as the femur ; its joints in diminishing sequence rank 2, 3, 4, 5, 1 ; fore tarsus of
? nearly -^q as long as the tibia, which is almost as long as the femur ; its joints in
shortening succession rank 2, 3, subequal to 5, 4, 1. Hind tarsus of 6 about | as long
as the tibia ; the joints (longer in the ? ) rank 1, 4, 2, 3. Nymph. — Abdominal tracheal
branchite acute, the foremost narrowly obovatc-lanceolatc, tlie others more broadly ovate,
each traversed lengthwise by an irregularly pinnately branched trachea. Antennge
longer than the head and thorax combined. Outer caudal setse almost ^ as long as the
body, the median about f as long as it, all shortly tail-pointed in the typical species. Man-
dibles armed with slender fang-like teeth ; endopodite absent, or represented by a minute
tuft of hair. Palpus of maxilla i. slightly longer than thelacinia, 3-jointed, with slender
joints of nearly equal length ; the lacinia terminated by fang-like teeth, preceded on the
inner edge by an even series of setulae inserted at nearly equal intervals. Lacinise of
maxillae ii. falcate, scarcely wider than the somewhat subulate lobes of the labium;
proximal joint of the palpus rather shorter than the remainder, which are compressed;
terminal joint squarely truncate, oblong, quadrangular, and barely more than | as long
as the second. Tongue similar in form to a closed ecclesiastical biretta ; the median lobe
broader than the paraglossae, and minutely mucronate. Hind tarsus, claw excluded,
subequal in length to the tibia ; the leg altogether about 1^ as long as the fore leg.
Habits, those of Baetis.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 175

Type. C. luteolum (in Ephemera), MiiUer.

Distribution. Eurojie ; Hudson's Bay Territory, Arizona, and Cuba.

Etymology. Kevrpd^Toc and ■n-riAo.-, from the usual spur-like form of the costal jirojection
of the hind wing.

The nymph of the typical species was identified by observation in the field ; but probably
I reared it also. The older description was based upon specimens in ill condition, still in
my possession. The foremost tracheal branchiae were described as " subulate ; " but this
was due to their having been deformed by the preservative fluid. ,

Centroptilum luteolum, Midler. PL XVII. 30 « (wings, d , head tfc forceps).

Ephemera luteola, MiilL, Zool. Dau. Prodr. 113 (177G). — E. caudata, Strom, N. Saml. Kongl. Dansk.
Vidensk. Sflsk. Skrift. ii. 91 (1783) ; Wallengreii, Christ. Vidcusk. Forliandl. No. ii. 21 (1880).

Cloeun ochraceum, ! Steph., 111. Brit. Ent. vi. 68 (1835); Walk., List of Neiiropt. Ins. iu Brit. Mus.
part iii. 578 [C. ochracea] (1853).— C hyalinatum, ! Steph., 111. Bnt. Ent. vi. 69 (1835) ; Walk., List
&c. 579 [C. hyaUnata] (1853).— C. albipeime,\ Steph., 111. Brit. Ent. vi. 69 (1835; ; Walk., List &c.
579 [C. albipennis] (1853).— C. trmisludda, Walk., op. cH. 574 (1853).— C. haUerata, id., 577 (1853). —
C. Ibioculutam, Ilag., Ent. Ann. (1863) 31; ! Etii., Ann. & Mag. Nat. Hist. (3) xviii. 117, fig. [hind-
wing] (1866).

Cloe halterata, Burm., Haudb. d. Ent. Bd. ii. Abth. ii. 798 (1839); ! Ramb., Hist. Nat. d. Ins. Ne-
vropt. 299 (1812).— 6'. translucida, ! Pict., Hist. Nat. Nevropt. ii. Ephera. .255, pi. xl. 3, 1 (184.3-5).—
C. ochracea, hyaUnata §- albipentiis, Pict., op. cit. 271 (1843-5).

Baetis luteolus, ! Etn., Ent. Mo. Mag. v. 88 (1868).

Centroptilum luteolum, ! Etn., op. cit. vi. 132 (1869) ; ! id., Trans. Ent. Soc. Loudon (1871) 108,
pis. ii. 8 [part of fore wing] & v. 13, 13 a [details] ; Hag. & Etn., op. cit. ( 1873) 400 ; Mcyer-Diir, Bull.
Soc. Ent. Suisse, iv. 310 (1874) ; Rostock, Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 86 (1878).

Snhimago {lichig). — Wings very faintly grey-tinted, sometimes very slightly tinged
with the palest yellow-ochre. Peniora light yellow-ochre, tibiae cinereous, tarsi dusky.
Setae greyish white or cinereous.

Imago {living). — 6 . Turbinate eyes bright light red ; lower eyes subolivaceous.
Notum either bistre-, or pitch-brown, or black. Abdomen vitreous in segments 2-7,
spotted faintly with raw sienna (furfuraceous) on each side near the tips of the dorsal
segments, or sometimes wholly of that colour thereabouts ; the other segments opaque,
rich brown-ochre, raw sienna, or bistre-brown above, with the distal edges of segments
8 and 9 yellow-ochreous ; beneath pale, tinged with very light Mars-yellow distally.
Setae and forceps white. Femora cretaceous ; tibiae and tarsi greyish, or smoky white.
Wings vitreous ; longitudinal nervures faintly tinged with yellowish.

? . Eyes olivaceous, greenish black, or black. Notum bistre- or olive-brown. Abdo-
men above cither raw sieuua (sometimes modified with light yellow-ochre) or Mars-
yellow, or olive-brown, with dark subcutaneous tracheaB in segments 2-6 ; venter pale.
Setae white or greyish white. Eemora either light greenish yellow, banded almost im-
perceptibly in the middle with reddish (this band is invisible in dried specimens), with
the tibiae and tarsi olive-grey ; or femora light yellowish, tibiae and tarsi greyish white.
Length of body 5-7; wing G-7"5 ; setae, <s im. 10-14., subim. 7, 2 im. 8-9, subim. 6 mm.

Hub. Europe from Uammerfest and Alten to Portugal and N. Italy : also N. America,

176 KEV. A. E. EATON ON EECENT EPHEMERID.¥. OR MAYFLIES,

in Hudson's Bay Ter. [probably St. Martin's Ealls, Albany river]. This species is abun-
dant in Great Britain, and reaches maturity in the southern counties from April to
November. It is found in Germany, Switzerland, and Erance (at Dijon, M'^Lach.), in
addition to the countries quoted above : it is common at Pallanza along the shore of the
Lago Maggiore (640 ft.), and near Cintra in the valley N. of the town (385 ft.). The
acute projecting point noticeable above the forceps [the limbs of which are nearly con-
tiguous at the base], and tlie sharpness of the hind wing are preeminently distinctive of
C. luteolum. The terminal joints of the forceps-limbs are straight. Female specimens
are sometimes distinguishable from Clo'eon rufulum only by their possessing hind wings.

Centeoptilijm lactjstre, sp. nov.

Imago {living). — d . Very similar to C. 2^efinulatum,\>vX with the turbinate eyes red,
and with the tips of the transparent abdominal segments less strongly coloured.

? . Eyes light olive-grey. Body light brownish ochre ; this colouring in segments
2-6 of the dorsum is restricted to a median triangle projecting forwards from the hinder
border of each segment, leaving the remaining parts pale ; their subcutaneous tracheae
are dark ; segments 7-10 viniformly light broMuish ochre ; venter pale. Setae white.
Legs nearly colourless, but faintly tinged with yellowish at the tips of the femora. Wings
vitreous ; the pterostigniatic portion of the marginal area of the fore wing contains 6-9
simj)le cross veinlets. Length of body 5"5-6 ; wing 6-7 ; setae, <s im. 12-14, 2 im.
about ]0 mm.

Hah. Pallanza on Lago Maggiore (640 ft.) ; at the lake side, about sunset on the 18tli
July. The forcejis and bind wing are very like those of C. pennulatmn.

Centroptilum penntjlattjm, Etn. PL XVII. 30 i ( c? , head, legs, hind wings and forceps).

Ceniroptilumpennulatum,\'Ein.,'VYans. 'Eni. Soc. London (1870) 2; \id., op. cit. (1871) 139. pi. v.
14, 14 a ; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, p. 85 (1878).

Suhimago. — Wings a very little greyer than those of C. Inteolam : distinguishable from
that species chiefly by its greater stature.

Imago {living).— d . Turbinate eyes light cadmium-orange ; lower eyes olive-grey or
black. Prouotum dusky, or light luteo-fuscous ; meso- and metanotum either light
luteo-fuscous, raw sienna, or bistre-brown. Eirst dorsal segment of the abdomen pioeo-
fuscous ; segments 2-6 vitreous, tinged at the joinings very faintly with Mars-orange;
secments 7-10 reddish brown-ochre or reddish chestnut-brown, modified with Chinese-
orange above, but ochraceous white beneath. Setge and forccjos white. Legs white, with
the tips of the femora yellowish white, and with the terminal tarsal joints faintly tinged
with very light sepia-grey.

2 . Eyes olive-grey, or greenish black ; vertex of head light yellow, with a broad
median burnt-sienna stripe from the anterior ocellus to the occiput, and with the orbits
of the ocelli black. Notum light dull brownish ochre modified with bistre-grey. Abdo-
men in dorsal segments 2-6 bistre-grey, in 7-10 reddish brown-ochre, with the usual
abbreviated median line and two short divergent pale lines in segments 2-8, with
the tips of segments 2-7 either brown-ochreous modified more or less with Mars-orange,
or deep reddish brown, or narrowly piceous, and with streaks of the same colour pro-

EEV. A. E. EATON ON RECENT EPHEMERIDJ;: OE MAYFLIES. 177

duced forwards at tlie sides in the form of triangular spots ; tracheae dark ; venter
spotless, pale, coloured in segments 8 and 9 with light ochraceous tinged slightly by the
pleurse with Mars-orange and reddish. Femora whitish amber ; tibiae greyish white ;
tarsi dark grey, with black ungues. Setae white. Wings vitreous ; the marginal area
of the fore wing, beyond the bulla, contains in the pterostigmatic region of 2 11-18
sub-simple and nearly straight cross veinlets ; in that of 6 are 7-8. Length of body or
wing 8-9 ; seta?, d ira. 14-17, 2 im. 11 mm.

Sab. Great Britain, from near Lumi^hanan in Aberdeenshire southwards ; common
near Thorncombe, Dorset, in June, and generally in trout-streams from August to
October. Hind wing somewhat ligulate, with the tip elliptical. Forceps-limbs close
together at the base ; their terminal joints pyriform, slightly incurved, smaller, and
narrower towards the base than in C. luteoluni. The edge of the penis [or penis cover ?]
is saliently curved.

CbNTROPTILUM NEMOllALE, sp. UOV.

Imago {living). — 6 . Turbinate eyes intense Mars-yellow {peropace testaceus of
Miiller's code) on the summit, jjaler at the sides; lower eyes olive-grey. Notum very
light fusco-ochraceous ; the first dorsal abdominal segment more fuscous. Abdominal
segments 2-6 translucent Avhite, their dorsal terminal margins, like segments 7-9, brown-
ochre ; segment 10 rather yellower than these ; venter in segments 7-10 whitish ochre.
Forceps (the limbs are nearly in mutual contact at the base), setse and legs translucent
white ; femora very faintly tinged with yellowish just at their distal extremities. Wings
vitreous ; in the pterostigmatic portion of the marginal area of the fore wing are 1-5
simple cross veinlets with indistinct rudiments of one or two others. Length of body
6'5 ; wing 7 ; setae 14 mm.

Sab. Italy ; in the chestnut-wood below Gaviuana, San Marcello, Apennino Pistojese,
near a streamlet (2550-2750 ft.) ; captured, by beating, at about 10 a.m., 26 July. The
hind wings and 6 genitalia resemble those of C. penmilatum ; but the colour of the tur-
binate oculi, and the smaller number of cross veinlets in the pterostigmatic portion of
the fore wing sufiice to distinguish C. nemorale.

Centroptilum pulchrum, sp. nov.

Imago {living). — d. Turbinate eyes bright chrome-lemon yellow; lower eyes light
olive-grey or olive-green. Notum furfuraceous or raw sienna, with the peak of the
mesonotum chrome-lemon. Abdomen in segments 2-6 perspicuous, narrowly tinged
with raw sienna by the joinings at the tips ; the other segments above either brown-ochre
modified with Chinese orange, or else raw sienna, with the usual pale paired dorsal
lines ; venter in segments 7-10 very light brown ochre or yellow ochre in the middle,
setae translucent white; forceps dull whitish. Femora white; tibite and hinder tarsi
greyish white ; the smaller ungues black. Wings vitreous ; in the pterostigmatic por-
tion of the marginal area of the fore wing are 4-10 almost invariably simple cross
veinlets.

$ {dried). — The colour-differences of this sex are quite of the ordinary description,

5EC0ND SERIES. — ZOOLOGY, VOL. III. 24

178 EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES.

and need not be detailed. Length of body, d $ 5'5-8 ; wing 6-8-5 ; setse, d im. 11-16,
2 im. 11 mm.

Hab. France ; in a tributary of the Loire, near Brive (Hante Loire), 24th Sept. ; the
Garonne by the Pont d'Empalot, Toulouse, 21st Aug. The hind wing and 6 genitalia
resemble those of C. 2}enmilatum ; but the terminal joints of the forceps-limbs are rather
stouter and shorter than those of that species, and are more like the terminal joints of
the forceps of Cloeou simile.

Centroptiltjm lituratum.

Ephemera % culiciformis, Scop., Eut. Carniol. 264 (1763).
Cloe liturn, Yict., Hist. Nat. Nevropt. ii. Ephem. 260, pi. xli. 1-3 (1843-5).
Cloeon lifura, Walk., List of Neuropt. in Brit. Mus. part iii. 574 (1853).
Centroptilum lituratum, Etn., Traus. Ent. Soc. London (1871) 109.

Suhwiago. — Wings dull yellowish grey. Setae fuscous (brun).

Imago. — d . Turbinate eyes light cadmium or sulphur-yellow. Metathorax traversed
lengthwise by a black streak, which does not quite reach the hind border ; the meso-
thorax [? metathorax] has two dots of the same colour. Abdomen light rufo-fuscous,
rather darker towards the tip, and with a row of spots on each side. Setse lutescent,
annulated with black. Eore and hinder legs uniformly lutescent. Wings vitreous with
pale neuration.

? . Eyes black. Body yellow-ochreous, with two little reddish lines on the meso-
thorax, and some spots on the sides of the abdomen. Length of body 8 ; setoe, <s im.
12 mm.

Sab. At the base of Mt. Saleve, in autumn. [After Pictet.] The streak on the
mesothorax distinguishes the d of this species from C . pulchrum.

Centroptiltjm stenoptebtx, Etn.

? Ephemera alhipes &^- parvula, Sco^., Eut. Carniol. 264 (1763); Vill., C. Lin. Ent. iii. 22 (1789);
01., Eucycl. Meth. vi. 421 (1791).

Cent7'optilum stenopteryx,\ Etn., Trans. Ent. Soc. London (1871) 110, pi. v. 15, 15a [details].

Subimago {dried). — Wings and setae light sepia-grey.

Imago {dried). — Notum light brownish ochre, browner in the 6 . Body very much
discoloured through age. Setae white. Wings vitreous ; the stronger nervures slightly
tinted with dull yellowish amber near the roots ; in the pterostigmatic portion of the
marginal area of the fore wing are 6 or 7 cross veiulets, which are nearly always simple
and straight, besides occasionally one or two rudiments at the costa ; but one of the S
examples has most of them forked and anastomosing with each other. Length of body,
d 4, 2 4'5 ; wing 4-5-5 ; setae, 6 im. 9, ? im. 5 mm.

Sab. Carinthia (Zeller MS. in M^Lach. Mus.).

Centroptiltjm tenellum, Alb. Plate XVII. 30 c (forceps).
Centroptilum, tenellum, ! Albarda, Ent. Mo. Mag. xv. 128 (1878).
Imago {dried), (^ . — [Turbinate eyes during life, E,oman sepia or clove-brown ; lower eyes

EEV. A. E. EATON ON EECENT EPHEMEEIDJi OE MAYFLIES. 179

black-brown.] Notum either fuscous or pitch black. Dorsal segments 1 and 7-10 of the
abdomen either deep chestnut-brown or pitch-brown ; segments 2-6 either translucent,
light sepia or Cologne-earth grey with the joinings dark, or else cretaceous ; venter m
segments 7-9 light Roman sejjia-brown. Seta? and forceps whitish. Legs translucent
whitish ; fore leg faintly tinted with brownish, varying with change of light to whitish
amber ; the femur with a well-defined pitch-brown band at the tip separated by a short
clear space from an ill-defined greyer band a little beyond the middle ; tibia brownish in
the vicinage of the distal articulation ; ungues in some lights brownish : hinder femora
banded with pitch-brown at the knee only, the adjoining part of the tibia brownish at
the articulation, the tarsal joinings and ungues also light pitch-brownish. Wings
vitreous : the great cross vein and the bases of the nervures included between it and the
thorax pitch-brown ; in the pterostigmatic portion of the marginal area of the fore wing
are 5 or 6 simple cross veinlets, and between them and the bulla are rudiments of 2 or 3.
Length of body 3-4 ; wing 4 '5 ; setae, 6 im. 7-8 mm.

Sab. Holland, near Arnhem (Van Medenbach de Rooy, 8tli Sept.). I subsequently
met with it there, between the town and the railway bridge below the town on 26th July,
and at first mistook the species for Ba'etis niger, on account of its coloration and its
finger-like forceps-limbs.

AMERICAN SPECIES.

Centroptilum PoiiYi, sp. nov.

Imago {dried), 6 . — Thorax above lutescenti-fuscous or pitch-brown ; abdominal
segments 2-6 transparent whitish ; the spiracles and tracheal trunks darker in individual
specimens ; segments 7-10 purple-sepia brown above, paler beneath ; seta? white, with
their joinings towards the base brownish. Wings vitreous ; the principal longitudinal
nervvires brownish near tlie wing-roots ; the costa, subcosta, and radius, very faintly brown
amber ; the terminal margin and finer nervures, in certain lights, brownish grey ; about
6 nearly straight and simple cross veinlets in the pterostigmatic space; interneural
veinlets of the terminal margin mostly in pairs. Legs whitish ; the fore femur throughout,
the hinder femora distally, slightly yellowish ; fore tibia and tarsus light sepia-grey,
hinder tarsi and ungues less distinctly so. Length of body 4, wing 4 mm.

Eab. Rangel Mountains, Cuba (Poey & Ch. Wright) [Hag. Mus.]. The wings of a
carded snbimago are of a light sej^ia-grey.

A small undescribed species of Centroptilum from Arizona (1 S im., 2 subim., in
M^Lach. Mus.) has likewise paired interneural veinlets along the greater part of the
terminal margin of the fore wing.

CLOEON, Leach, 1815.
Illustrations. Adult (details) PL XVII. Zla-d ; (whole figures) see under C. diptermn,
citation of Stephens (1835) and iCloe] Pictet (1843-5). Nymph PI. XLVII. ; see also
under C. dipterum, citations of [Ephemera'] De Geer (1771), Goring and Pritchard (1829),
Bowerbank (1833), Blanchard (1840), of [Cloe'] Calori (1848), and of [Cloeopsis] Vayssiere
(1882) ; also under C. rufulum of iChloeon'] Lubbock (1863 & 1865).

24*

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

Adult. — Hind wings absent. Wings, of some species only, in the $ ov in both sexes,
varied with colour in the marginal and submarginal areas, and provided with cross
veinlets between the great cross vein and the bulla ; but other species have the wings of
the 6 or of both sexes devoid both of colour and of cross veinlets in the parts specified ;
intercalar rudimentary veinlets of the terminal margin single in a large majority of the
species ; cross veinlets of the disk disposed, as in Ba'etis, mainly in 3 dislocated sei'ies in
front of the cubitus (5) and 2-3 behind, many of them thickened slightly in the females
of some of the species. Forceps-limbs of 6 4-jointed ; the basal joint short, relatively
very stout, gibbous at the base and suddenly contracted near the distal joining on the
inner side ; the second joint less stout and larger at its base than at its further extremity;
the third joint comparatively long and slender ; swollen a little at the end ; the fourth
joint minute, clavate or papilliform. Penis not yet observed. Intermediate abdominal
segments of ? subequal in length. Caudal setse in im. s about 2, in $ l-lj '^^ loiig
as the body, in subim. s about f , ? about f as long as it. Fore tarsus of s nearly 1^
as long as the tibia, which is almost of the same length as the femur ; its joints in order
of lessening length rank 2, 3, 4, 5, 1 ; fore tarsus of ? (exclusive of joint 1) little more
than f as long as the tibia, which is about \-^ as long as the femur ; its joints rank 2, 3
subequal to 5, 4, — 1 being extremely short and intimately combined with the tibia. Hind
tarsus of 6 about f as long as the tibia ; its joints, shorter than in the $ , rank 1, 1, 3, 2.
iSlymph. — Abdominal tracheal branchiae all foliaceous and slightly oblique, and all double
excepting the hindermost ; each of the double ones is formed of two unequal divisions
slightly connate at the base, containing somewhat palmately partite tracheae with long
branches and short branclilets ; of these divisions the larger, broadly subrotundate, is
more or less subtruncate along the costal border and displays a small contracted sinus at
its posterior base ; the smaller division exhilnts a similar sinus thereabou.ts, and a wide
shallow sinus or excision on the opposite side near the tip ; the single one of each series
is subrotundate, with a shallow recess in place of the basal sinus, and with the opposite
margin towards the tip slightly refuse, and is supplied by a single trachea divided nearly
to the roots into two main branches with unilateral branchlets. Antennae longer than the
head and thorax combined [in C. rufulum of equal length with the body]. Setae subequal
to each other and to the body in length, fringed for at least halfway to the tips from
the roots, with the ends of the fringes gradually shortened to points, and then tail-pointed,
the proportionate length of the fringeless tail-points varying with the species. Mandibles
terminated by compressed denticulate teeth ; endopodite absent. Palpus of maxilla i.
longer than the lacinia, 3-jointed ; first joint as long as the second, and almost twice as
long as the third ; the lacinia armed with slender fang-like teeth at the tip, preceded by
two evenly arranged divergent series of setulae along the inner edge. Laciniae of maxillae
II. falcate, narrower than the acutely lanceolate lobes of the labium ; proximal joint of the
palpus a little shorter than the remainder, which are dilated distally and slightly
compressed ; the terminal joint obliquely truncate at the end and acute at the extremity.
Median lobe of the tongue obtusely rounded, broader than the paraglossaj. Hind tarsus,
claw excluded, a little shorter than the tibia, and tliis scarcely more than ^ as long as the
femur ; the whole leg about \\ as long as the fore leg. Resident in still or sluggish

EEY. A. E. EATON ON EECENT EPHEMEEID.E OE MATELIES. 181

water; two-brooded. In southern Europe C. dipierum inhabiting warm sites has been
observed to be ovi-viviparous.

Ti/i^e. C. d'qjterum (in Ephemera), Linn.

Distribution. Temperate and tropical regions of the northern hemisphere ; Australia ;
southern Africa ; the Argentine Republic, and Chili.

Etymology obscure.

The nymph has been reared ; those of C. dipterum, C. rufidum, C. simile, and of one
of the Portuguese species have been examined by me. Through some oversight, the
proximal joint of the tarsus of the d intermediate leg has been omitted in PL XVII.
In the original camera-lucida drawing its length corresponds exactly with that of the
homologous joint of the hind tarsus.

CINGALESE SPECIES.
CLOiiON MARGINALS, Hagen.

Clo'e marginalis, ! Hag., Verli. zool.-bot. Gesells. Wien, viii. \:7~ (1858) & ix. 206 (1859) [excl. $ im.] ;
Etn., Trans. Ent. Soc. Londou (1871) 132, note.

Subi^nago {dried). — Thorax dull luteous ; abdomen dull pitch-brown above, lighter at
the sides ; venter testaceous ; setae sepia-grey with black joinings. Wings transparent,
tinted throughout very faintly with light bistre-grey, excepting in the marginal and
submarginal areas, which are fuscous ; neuration light brownish. Hinder legs testaceous
in opaque view, changing in transmitted light to yellow-amber; fore femur luteous.
[Nos. 38 and 39 in Hag. Mus.]

Imago {dried 8f fragmentary). — 6 . Thorax above fuscous or bistre-brown. Dorsum
of abdomen in segments 8-10 either of a similar or else of a redder brown ; segments
2-7 translucent whitish anteriorly, edged with bistre-brown at the tips, and extensively
suffused with bistre-grey before the tips, the dark colouring appearing in some examples
to project forwards in a pointed streak on each side from the tip of the segment ; venter
of a light colour, narrowly edged with a dark colour at the joinings, but apparently free
from other markings. Porceps similar to those of C. dipterum; a small dark acute
projecting point is visible above the interspace between the forceps-limbs, as in that
species. Fore femur, in opaque view, light brown-ochreous, with a dark band before the
tip ; tibia and tarsus of a rather dark amber tint. Hinder legs in opaque view of a light
yellowish amber tint, with dark ungues and sometimes faintly obscured tarsi, and with
a faintly defined dark spot, or fine abbreviated longitudinal streak, a little before the tip
of the femur ; knee opaque. Wing vitreous, very faintly amber-tinted in the marginal
and submarginal areas ; the great cross vein pitch-brown, or rufo-piceous, towards the
subcosta ; longitudinal neuration light brownish amber ; cross veinlets whitish. In the
marginal area are no cross veinlets before the bulla, but usually 2 or 8 straight ones in
the pterostigmatic region.

? . Wing vitreous, coloured with light bistre-brown in the marginal and submarginal
areas. Neuration light brownish, excepting such of the cross veinlets as are distributed
in advance of the sector (4), which are whitish in most lights; those situated in the
coloured areas have extremely narrow translucent edging. The marginal area contains

182 EEV. A. E. EATON OX EECENT EPnE]\£ERID^ OE MATELIES.

no cross veinlets before the bulla, and usually 2-5 straight ones in the pterostigmatic
space. Length of body or wing, d im. 4-4i"5, 2 im. 5'5 mm.

Jlab. Rainbodde, Ceylon, at altitudes of 4000 ft. and upwards (Hag. Mus. & M^Lach.
Mus.). The 2 imago (No. 40, Hag. Mus.) formerly attributed to this species is a
Telogaiiocles trlstis.

Cloeon, sp. (nameless).

Suhimago {dried), 6 . — Mesothorax dark brown-ochre in the middle, lighter at the
sides ; body discoloured, reddish brown or reddish piceous. Wings transparent, uniformly
pale warm sepia-grey ; neuration translucent, brown ; some of the interneural adventitious
veinlets in the neighbourhood of the pobrachial and anal nervures spring from the
terminal margin in pairs ; 4 cross veinlets in the pterostigmatic space, and 7 in the nearer
portion of the marginal area {i. e. before the bulla). Fore leg with the femur luteous, the
tibia and tarsus lutesceut, and the extreme terminal edges of the tarsal joints darker :
hinder legs very pale lutescent ; the femur banded with greyish before the tip, and marked
with a grey spot or dot on the outer side jvist by its extremity. Length of body 5,
wing 6 mm.

JSah. Kainbodde, Ceylon, at upwards of 4000 ft. (No. 33 in Hag. Mus.).

Cloeon bimaculatum, sp. nov., Etn. MS., in the writing of PL XVII. 31 d (wing 2 im.).

Imago [dried). — 6 . Thorax above piceous ; abdomen discoloured ; setae whitish or
brownish white, with black joinings and annulations. Pore femur reddish brown, the
tibia and tarsus lighter and rather yellower ; hinder femora brownish amber, the tibia
and tarsus nearly of the same colour. Wings transparent with light brownish longi-
tudinal neuration (excepting the costa, subcosta, and radius, which are dull light yellowish
in tint, and only faintly coloured) and white cross veinlets ; at the base of the costal area
is a reddish brown spot extending to the wing-roots ; in the pterostigmatic region a
light bistre-brown spot, containing a clear space and traversed by white cross veinlets,
occupies the marginal and submarginal areas to their extremities ; the space intervening
between these two spots along the front of the wing is faintly tinged with light yellowish
brown : in the marginal area are about 4 cross veinlets between the great cross vein and
the bulla, and 7 or 8 beyond this, all simple.

2 . Very similar. The cross veinlets in the front portion of the wing thickened as in
C. dipterum, 2 . Length of body 5-5"5 ; wing" 5'5-6 ; setae, d 13 mm.

Hah. Ceylon (Thwaites, in M^Lach. Mus.).

EUROPEAN SPECIES.
Cloeon diptebum, Linn. Pis. XVII. 31 a (forceps and 2 fore-leg and hind feet),
XLVII. 22 (caudal seta?, nymph).

Ephemera diptera, or [_Ephemerci] , [Reaum., M^m. pour serv. a I'hist. des Ins. vi. pi. xlv. 1 (1742);
? Poutop. (1753 & 4), and Naturliist. Dan. p. 223, pi. xvii. (1765)] ; Linn., Fn. Suec. ed. ii. no. 1477
(1761) ; id., Syst. Nat. ed. xii. pars ii. 906 [excl. obs.] (1767) ; [De G., Mem. d. Ins. ii. pars ii. 656,
pi. xviii. 1-9 (1771)] ; Fab., Syst. Ent. 304 (1775) ; id., Sp. Ins. i. 385 (1782) ; Retz., Gen. & Sp. Ins.
no. 184 (1783) ; Fab., Mant. Ins. i. 244 (1787) ; Raz., Hist. Nat. du Jorat, p. 210 (1789) ; VilL, C. Lin.
Entom. iii. 20 (1789) ; [ZscL., Mus. Lesk. i. 150, no. 19 (1789)] ; Gme'L, Linn. Syst. Nat. ed. xiii. i.

EEV. A. E. EATON O]^ EECEJ^T EPHEMEEID.E OE MAYFLIES. 183

pars V. 2630 (1790) ; Eos., Fn. Etrusc. ii. 9 (1790) ; 01., Encyc. Meth. vi. 420 (1791) ; Fab., Ent. Syst.
emend, iii. pars i. 71 (1793) ; Schr., Pn. Boica, ii. pars ii. 199 (1798) ; Lat., Hist. Nat. Crust, et Ids. xiii.
99 (1805) ; Shaw, Gen. Zool. vi. pars ii. 253 (1806) ; Lat., Gen. Crust, et Ins. iii. 184 (1807) ; Cuv.,
Eegn. An. ed. 1, iii. 130 (1817) ; Lamarck, Hist. Nat. An. s.-verteb. ed. 1, iv. 221 (1817) ; Sam., Ent.
Comp. p. 259 (1819) ; Cuv., Eegn. An. ed. 2, v. 244 (1829) ; Zet., Ins. Lap. col. 1046 (1840) ; Voigt,
Lekrb. d. Zool. v. 311 (1840) ; Blancli., Hist. Nat. lus. iii. 55 (1840) ; Dufour, Mem. par divers savans,
lust, de France, viii. 580 note (1841) j Lat., Nouv. Diet, d'liist. Nat. x. 349 (1847) ; Verloreu, Mem.
Couron. Acad. Eoy. Belg. xis. 49, pi. i. (1847); Blanch., Cuv. Rt^gn. An., ed. Crochard, xiii. 92 (1848);
Carus, Icon. Zootom. tab. xv. 6 [anatomy] (1857). — E. annulata k, E.X striata, Mull., Zool. Dan. Prod.
143 (1776).—^. X marginata, Gor. & Prit., Nat. Hist. Obj. for Micros. [*ed. i.] ed. iii. 01-9, pi. ii. 4-6
(1829) ; Bowerb., Ent. Mag. i. 239-44, pi. ii. 1-6 (1833) ; Lacord., Introd. JlTEnt. ii. 77 (1838) ; Brulle,
Blanch. Hist. Nat. Ins. i. p. xxiv. (1840) [nymph]. — E. % culiciformis,Yons,co\., Ann. Soc. Ent. Fr. (2) iv.
49 [misprinted calciform'is] (1846).

Cloeon pallida, Leach MS., Brewst. Edinb. Encyc. ix. 137 (1815); Sam., Ent. Comp. 259 (1819).—
C. marmoratum [ ? im.] & obscurum [subim.]. Curt., Lond. & Edinb. Phil. Mag. (3) iv. 121 (1834). —
C. cognation], J dimidiatum\, & consohrrnum\, Steph., 111. Brit. Ent. vi. 69 (1835) ; Walk., List of
Nem-opt. lus. in Brit. Mus. part iii. 579 [misprint, cognata'] (1853) [J" im.] . — C. virgo, ! Steph., 111. &c.
p. 70 (1835) ; 'Walk., List &c., p. 580 (1853) [S im-]- — C. dipterum, Leach IMS., Brewst. Edinb. Encyc.
ix. 137 (1815) ; Curt., Lond. & Edinb. Phil. Mag. (3) iv. 121 (1834) ; ! Steph., 111. Brit. Eut. vi. 68,
pi. xxix. 3 (1835) [misprint, diptera) ; Walk., List &c. p. 575 (1853) ; Hag., Ent. Ann. 1863, p. 29 ;
Etn., Ent. Mo. Mag. v. 87 (1868) ; id., Trans. Eut. Soc. Lond. (1871) p. 102, pi. v. 10 [forceps] ; Hag.,
op. cit. (1873) p. 399 [nymph] ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 311 (1874); ! M-^Lach., Trans.
Ent. Soc. Lond. (1875) 171 ; Palm^n, Morphol. Trach.-Syst. SS. 1-21 &28, taf. i. 7-9 [anatom.] (1877) ;
Eostock, Jahresb. d. ver. f. Naturk. Zwickau (1877) p. 80 (1878); Palmen, Paar. Ausf. gauge d. Geschl.
org. b. Insect. S. 64 [anatom.] (1884).

Cloe dlptera, Bm-m., Haudb. d. Ent. Bd. ii. Abth. ii. 798 (1839); ! Pict., Hist. Nat. Nevropt. ii.
Eph^m. 266, pi. xliii. (1843-5) ; Schn., Stet. Ent. Zeit. vi. 340 (1845) ; Calori, Nouv. Ann. Sc. Nat.
Bologna (2) ix. 38-53, pis. ii.-iii. [viviparition] (1848) [translat, Joly, Bull. Soc. d'Etud. Sc. Nat. Nimes,
5" ann. No. 8 [Sep. pp. 1-18] pis. ii, iii. (1877) ; Brau., Neuropt. Austr. 26 (1857) ; Leunis, Synop.
Naturgesch. Thicrreichs, ed. 2, p. 636 (1860) ; Karsch, Die lusecteuwelt, v. 400-2 (1863) ; Gerstiick.,
Handb. d. Zool. ii. 59-61 (1863) ; Hag., Ann. Soc. Ent. Fr. (1864), p. 39; id., Ent. Mo. Mag. ii. 25
(1865) ; Ed. Pict., Nevropt. d'Espag. 25 (1865) ; Ouliauiue, Neui'opt. & Orthopt. prov. Moscow, p. 27
(1867) ; Ausser., Ann. del. Soc. Natur. Modena, Ann. iv. 135 (1869) ; ! Joly, Bull. Soc. d'Et. Sc.
d'Augers, 1876 [Sep. p. 42] note d [vivipar.] (1876) ; ! id., Bull. Soc. d'Etud. Sc. Nat. Nimes, 5' Ann.
no. 8 [Sep. pp. 21-25] notes b-i (1877) ; ! id.. Bull. Soc. d'Etud. Sc. d'Augers, 1878-80, pp. 169 & 172
(1880) ; Ciaccio, Rendicont. del. session, del. Accad. d. Scien. ec. di Bologna (1880) [anatom.]. —
C. «^/M*, ! Ramb., Hist. Nat. Nevropt. 298 (1842) [^ im.'j.—C. cognata & ot>v/o, Pict., Hist. Nat.
Nevropt. ii. Ephem. 272 (1843-5) [ ^ im.] .— C. apicalis, ! Costa, Atti d. R. Acad. d. Sc. fisic. e mathemat.
diNapoli, ix. 34 (1882) \_^ subim.].

Chloeon dipterum, Lubbock, Trans. Linn. Soc. xxv. pi. lix. 19-21 (1865).

Clo'eopsis dijjtera, ! Etn., Ann. & Mag. Nat. Hist. (3) xviii. 146 [excl. var.] (1866).

Siibimago {living), ? .—Wings light blackish grey or dusky. Oculi dark fusco-
olivaceous. On each side of the venter, in segments 2-7 in the ? (2 -8 in the d ) is a
ruhiginose longitudinal line ; the lines are represented by two dashes at the base of the
9th segment in the ? .

Imago {living). — Wings colourless in the 6 , ornamented in the ? with amber-colour
along the costa ; the marginal area in the d is free from cross veinlets as far as the

184 EEV. A. E. EATON OX EECENT EPHEMEEID^ OR MATELIES.

pterostigmatic space, but this contaius 3-5 simple and usually straight cross veinlets,
and sometimes rudiments at the costa of 2 or 3 others interspersed between these ; in
the ? there are about 6 before the bulla, and 10 with a few rudiments beyond it. The
interval between the basal joints of the forceps-limbs in the 6 is moderately wide, and
behind [or above] it is a dark minute subconical point [penis ?] ; the terminal joints of
tlie forceps-limbs are proportionally shorter than in other European species.

d . Variation 1. Turbinate eyes dull light reddish, or reddish clove-brown, above ; at
the sides sulphureous or flavescent : lower eyes traversed by a dark line ; above it either
brown-black or greyish clove-brown, with a movable dark spot ; below it and towards
the orbit paler. Notum pitch-black or jet-black. Dorsum either piceous or fiiscous or
rufo-fuscous throughout, with the distal edges of the segments narrowly ochraceous or
whitish; or else only so in segments 7-10, and in segments 2-6 partly translucent, each
of these segments being whitish or cinereous towards the base and of the prevalent
ground-colour distally, the dark colour extending forwards as a triangular projection on
each side almost to the base of the segment, and sometimes also as a tapering streak in
the middle of the back ; venter dark cinereous with whitish joinings, usually marked
with two longitudinal linear stripes in every segment excepting the last ; but these stripes
are sometimes reduced to mere spots in the joinings. Setae white or greyish white, with
black joinings and annulations, the latter often coinciding with every alternate joining
towards the base of the seta, and with every fourth or fifth joining afterwards, but
sometimes the alternation is uniform throughout. Legs variable in colour : the fore
legs either dull Avhitish tinged with cretaceous in the distal portion of the femur, and
with cinereous in the tibia and tarsus ; or with the femur greenish grey and the tibia
and tarsus blackish grey ; the femur in either case has a rufescent spot or a pitch-brown
annulation near its distal extremity : hinder legs whitish or cretaceous, the femoral
marking often indistinct, the distal edges of the first, second, and third tarsal joints (or
sometimes the whole of the third joint) and all but the extreme base of the fourth joint,
black or dark grey. Wing-neuration sometimes almost colourless excepting at the
wing-roots, usually piceous. Forceps cinereous, with the proximal joint fuscous.

d . Variation 2. Differs from the preceding chiefly in being below the average in size,
and in having segments 2-7 of the dorsum greyish anteriorly and rubiginose at the tips,
with a triangular streak recurrent on each side from every dark apical border.

Hab. Belgium.

d . Variation 3. Turbinate eyes bright yellow (Jlaviis). Tergum of thorax brown-
ochreous, the peak of the mesonotum light yellow-ochreous preceded by a pair of short
brown-purple dashes tapering forwards. Abdomen in segments 2-7 translucent white,
with some fine linear streaks along the spiracular line, a spot on each side of the dorsum
of the 5th segment, a corresponding tapering stripe on each side of the 6th segment
meeting a narrow half-effaced marginal band lying along the middle of the distal edge of
the segment, a trifid spot on the 7th segment formed by a more strongly marked cor-
responding band and lateral stripes in conjunction with a median longitudinal stripe,
the stripes extending to the base of the segment, and all but the extreme lateral portions
of the dorsum in segments 8 and 9, Indian red ; the 10th segment and the 9-7th ventral

EEV. A. E, EATON OX RECENT EPHEMEEID.E OE MATELIES. 185

segments very light yellow-ochre or yellowish white, with the usual pair of linear streaks
in the 8th segment and two corresponding spots at the base of the forceps in the 9th
segment, Indian red. Setai white, with some of the joinings narrowly greyish. Legs
and wing-netiration whitish, the femora faintly tinged with yellowish distally, their
reddish markings reduced to an almost invisible dot in the hinder femora, and an almost
obHterated band in the fore femur.
Sab. Italy, at Legnano (26 July).

6 . Variation 4. Turbinate eyes dull yellow-lake. Notum piceous. Otherwise very
similar to Vars. 1 and 3.

Kah. Tessin; above Locarno (1670 feet, 15 May 1884), several examples.

S . Rather variable in general coloration ; sometimes luteous or lutescent, with a
rosy suffusion, sometimes of a rosy fawn-colour or rosy-grey, and liable (whatever the
prevalent tint may be) to a more or less extensive infiltration of chlorophyll in parts of
the head, thorax, and abdomen, and in their appendages. Eyes olivaceous, traversed by
two dark stripes ; vertex of head with a red or red-jiurple stripe on each side from the
lateral ocelli along the orbits of the oculi to the occipital margin ; a quadrangular double
spot of the same colour in the middle of the pronotum. Meso- and metanotum some-
times variegated with light fuscous, sometimes uniformly luteous or piceous. The 9th
dorsal abdominal segment is either lighter or darker in colour than the others ; segments
2-8 have reddish or piceous markings on a lighter ground-colour, viz. : — a longitudinal
tapering median streak from the base to about the middle of the dorsum of the segment,
or a continuous linear stripe down the middle of the back ; also sometimes a transverse
marginal band across the tip of the segment (but this is exceptional) ; also an unequally
bifid spot on each side extending from the base to the tip of the segment (or at least as
far as the distal joining), the longer upper division of which tapers upwards and back-
wards either as a curved linear stripe, or more usually, as a curvilinear trilateral, while
the smaller lower and linear division runs nearly horizontally a little above the spiracular
line ; the curved stripes last mentioned coalesce with the distal median marginal baud
(when that is present) and, being met by the corresponding stripes of the contiguous
segments, form together with them a kind of chain pattern along the back. All of the
ventral segments (excepting the last two) are bilineated longitudinally with reddish or
piceous, but the 9th segment has two dots at its base in the place of the stripes ; the
former segments commonly have an abbreviated longitudinal dark line on each side at
the base, close to the spiracular region, which is sometimes joined by a narrow band to
the adjacent linear stripe so as to form an L-shaped mark. Setae usually coloured as in
the s , or with the ground-colour reddish white ; but, in some examples, at a short
distance from their origin they become more strongly annulatcd, the dark colour occujiy-
ing the whole of every alternate joint and some portion of the extremities of the otlier
joints. The legs are more strongly marked than in the 6 , and when tinged with
yellowish the fore femur is of a gamboge or yellow-ochre changing to light brown ochre
in dead specimens ; the hinder femora are of a light amber-colour, and the tibite and
tarsi are of an extremely light brown-oehre or testaceous hue. The wing-membrane
from the costa to the radius, and in the distal extremity of the area enclosed between

SECOND SERIES. — ZOOLOGY, VOL. III. 25

186 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES.

the radius and the sector, is of a browu amber-colour, or light fuscous, excepting along
the borders of the cross veinlets, where it remains pellucid and white ; the costa, sub-
costa, and radius are concolorous with the membrane, excepting sometimes the subcosta
and the radius near the wing-roots, where, with the great cross vein, they are often fvxscous
or piceous ; the cross veinlets in advance of the sector, including those also in the sub-
marginal and marginal areas, are opaque Avhite ; the remainder of the neuration is
piceous, excepting sometimes that the cross veinlets nearest the wing-roots and posterior
to the pobrachial nervure (7) are also white ; the cross veinlets in the disk of the wing
are much stouter than the nervures in this sex. Length of body, d 5-10, ? 8-11 ;
wing, cf 6-11, ? 9-12 ; setae, 6 im. 13-20, subim. 9-14, ? im. 12-15, subim. 12
mm.

Hub. Europe, from Scania and Norway (Wallengren) southwards to the borders of the
Euxine and Mediterranean ; Madeira, in pools left in the lower parts of the beds of
streams in the neighbourhood of Funchal (22 Nov. 1880), first collected by Wollaston ;
TenerifFe, common near the Jardin Botanico, Orotava (15 Dec. 1880) ; Egypt (Savigny,
and F. Walker !) ; Armenia (Hag. Mus.) ; Japan (M^Lach. Mus.). In Great Britain,
clean ponds that acquire a rather high summer temperature are frequented by this
species ; at Paris, tanks for Nymphfeacese and other water-plants in the Jardin des Plantes
are its favourite resorts. Hitherto instances of viviparation on the part of C. dipterum
have been observed only in the warmer parts of Italy and France.

The occurrence of species closely related to C. diptertmi in N.W. India, and in the
Knysna, S. Africa, was recorded by me in Trans. Ent. Soc. Loudon (1871), p. 103; there
is also one in Australia.

CLOiiON SIMILE, Etn. Plates XVII. 31 b (adult wing, d legs and forceps), XLVII. no. 2
(details of nymph).

Che II obscura, ! Ramb., Hist. Nat. d. Ins. Nevropt. 297 (1842).

Clo'con II obsmrum, ! Etn., Trans. Eut. Soc. London (1871) 104. — C. simile, ! id., op. cit. (1870) 2; \id.,
(1871) 103, pis. ii. 7 & V. 11 [details]; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, 81 (1878).

Subimago {living). — Wings mouse-grey, tinged with yellowish in a slight degree along
the costa and at the base ; the nervures somewhat raw sienna in colour. Setae piceous.
Oculi of <s subolivaceous.

Imago {living). — <3 . Turbinate eyes olivaceous or dark greenish sulphureous; lower
eyes either joitch-black or greenish black. Notum either jet-black or fuscous. Abdomen
pitch-brown above ; venter cinereous, faintly tinged with yellowish towards the tip. Setae
rusty white, with reddish joinings. Forceps greenish white ; the limbs nearly contiguous
at the base ; penis-cover (or penis ?) gently curved distally, not acute like that of
C. dipterum. Legs olivaceous with greyish or blackish tarsi ; the fore tibia greenish
grey. Wings vitreous ; the subcosta and radius of the fore wing somewhat straw-colour
or bright amber-yellow ; the pterostigmatic portion of the marginal area contains nume-
rous (about 9-11) cross veinlets, slightly irregular in their curvature and sparingly
conjoined ; there are none before the bulla in either sex.

? . Eyes black. Head castaneous in the vicinage of the ocelli, with two longitudinal

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 187

lines or stripes of the same colour upon the vertex • the facial carina has two small
piceous tubercles on each side. Abdomen luteo-fuscous or raw umber above, with the
terminal edges of the segments testaceous or very light brown-ochreous, and with dark
subcutaneous tracheae ; venter olivaceous, with the last two segments tinged somewhat
with straw-colour or light yellow-ochre. Legs olive-green, with darker tibige and tarsi.
Length of body 9-10 ; wing, c5' 8, ? 10-11 ; setae, 6 im. 14-15, subim. 9, ? im. 10-14,
suhim. 7-9 mm.

Sab. Great Britain, in still water and in sluggish streamlets, during September and
October. France, Autun (M'Lach.). Portugal, at Almodovar, Alemtejo (600 ft., 7 May),
water 65° F. ; Sao Marcos da Serra (580 ft.) ; and Silvcs, Algarve (about 130 ft., 16 May).
Also in Switzerland at the Statzer-See, near St. Moritz in the Engadine (about 6000 feet,
16 August; M'^Lach.). The name obscurum was preoccupied in this genus by Curtis
[under C. diptermii].

Cloeon conciknum, sp. nov.

Imago {living). — 6 . Turbinate eyes dull liglit yellow or chrome-lemon (JIavits) ;
lower eyes olive-grey. Notum raw sienna or furfuraceo-luteous. Abdomen in seg-
ments 6-10 concolorous above with the notum, with paler joinings ; segments 2-5 dirty
white, suffused with the same colour as the remainder, the main tracheae conspicuously
dark; venter in segments 8-10 somewhat ochraceous. Setae and forceps whitish ; the
limbs of the latter almost contiguous at the base. Hinder femora yellowish white ;
hinder tibiae and tarsi smoky white or whitish sepia-grey ; fore leg rather darker. Wings
vitreous. When dried the neuration acquires a faint dull amber tint in certain lights ;
the pterostigmatic region of the wing, likewise very faintly amber-tinted and of slightly
turbid trauslucidity, contains usually 11-13 rather irregular cross veinlets (of which a
few are forked towards the costa and some anastomose witli one another), seldom so small
a number as 7-9 (counted at the subcosta) : the fewer the cross veinlets, the more they
are branched and anastomose ; there are none before the bulla in either sex.

$ (dried). — Very similar to the s . The cross veinlets of the pterostigmatic portion
of the marginal area, more regular in this sex, are usually 10-12, seldom 8 in number ;
and the membrane thereabouts is more transparent than in the d ; between the strictly
pterostigmatic region and the bulla are sometimes a few (about 4) indistinct rudiments
of cross veinlets. In dried examples of either sex the legs become more opaque than
those of living specimens ; femora sublutescent in opaque view, changing in transmitted
light to light yellowish-amber ; fore tibia and tarsus of 6 in some lights olive-grey ;
hinder tibiae whitish amber in transmitted light, nearly concolorous with the femora in
other lights ; hinder tarsi of 6 rather yellower than the tibiae, with the terminal joint
either brown-ochreous or olive-grey, and black ungues ; tarsi of ? often suffused with
green. Setaj dull whitish, with faintly opaque joinings ; in c? examples tlie setaj some-
times become faintly tinged with light brown-ochre. Length of body 7-5-8 ; wing 8-9 ;
setae, 6 im. 14-16, ? im. 11 mm.

Sal). Portugal : the stream near Porcalhota, at the junction of the road from Mafra
with that between Lisbon and Cintra (480 ft., 1st June 1880, shortly before sunset, water'

25*

188 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

66° F.). Distinguishable from C. simile by the colour of the legs and the bright colour
of the 6 oculi ; and from C. rnfuhtm by having the d forceps-limbs close together at
their insertion, by the greater irregularity of the pterostigmatic cross veinlets &c. In
the absence of the subimago, and without direct comparison of dried examples with
Rambur's type, it is impossible to pronounce an opinion as to the likelihood or otherwise
of this species being identical with the following.

Cloeon subinfuscatum, Rambur.

Cloe subinfuscata, ! Ramb., Hist. Nat. d. Ins. Nevropt. 298 (1842).

Cloeonl halterata, var., Walk., List of Neiu-opt. lus. in Brit. Mus. part iii. 577 (1853). — C. subinfus-
catum, !Etn., Trans. Ent. Soc. London (1871) 104.

Subimago [dried). — ? . Wings tinted with dark ivory-black-grey, with luteous longi-
tudinal nervures ; the pterostigmatic portion of the marginal area contains about 12
sparingly forked cross veinlets; there are none before the bulla. Thorax lutescent;
legs rather light brown-ochre. The joinings of the setae dark. Length of body, ? 9 ;
wing 11 mm.

Sab. Provence {Ramb.).

Cloeon rtjfulum, Miiller. Plates XVII. 81 c (forceps), XLVII. no. 1 (nymph and
details).

Ephemera rufula, MiilL, Zool. Dan. Prodi-. 143 (1776). — E. % culiciformis and J striata, Blanch., Hist.
Nat. des Ins. iii. 55 (1840). — E. J bioculata, Blanch., Metamorph. &c. des Ins. p. 127, fig. [misdrawn]
(1868). — E. X rw/f/ate, Gegenhaur, Griuidz. d. Vergleich. Anat. 438, fig. 112 a (1870) [tracheal syst.],
reproduced in Balfour, Comp. Embryol. i. 339, fig. 188 a (1880).

Cloeon dimidiafum, Curt., Loud. & Edinb. Phil. Mag. (1834) 121 ; Hag,, Ent. Ann. (1863) 32.— C.
diinidiata, Walk., List of Nenropt. Ins. in Brit. Mus. part iii. 580 (1853). — C. russu/um, ! Etu., Trans.
Ent. Soc. Loud. (1871) 105, pi. v. 12 [detail] ; Hag. & Etn., op. cit. (1873) 400; Rostock, Jahresb. d.
Ver. f. Naturk. Zwickau, 1877, p. 81 (1878).

CloeXpumila, !Ramb., Hist. Nat. d. Ins. Nevropt. 298 (1842).— C. dimidiata, Pict., Hist. Nat.
Nevropt. ii., Ephem., 272 (1843-5).— C. f iiocw/ff^ff, Blanchard, Metamorph. &c. des Ins. p. 127, fig.
(1868).

ChJoeon dimidiatum, Lubbock, Trans. Linn. Soc. Lond. xxiv. 61-67, pis. xvii., x^dii. (1863), and op. cit.
XXV. 477-92, pis. Iviii., lix. (1865).

Clo'eopsis t diptera, var., ! Etn., Ann. & Mag. of Nat. Hist. (3) xix. 401 (1867).

Snbimago {living). — Wings extremely light greyish or greyish white, often tinged with
bright green [green oxide of chromium] along the stronger nervures. Setae ligbt
greyish.

Imago {living).— 6 . Variation 1. Turbinate eyes Iloman-sej)ia brown. Thorax jet-
black above. Abdomen dark fuscous, with pale yellowish joinings, and with the tracheal
ramifications black. Setae white, with dull reddish joinings. Forceps white, light
blackish grey distally. Legs pale greenish-yellow, with light dusky tarsi.

6 . Variation 2. Turbinate eyes dull lemon-yellow, or dull suljjhur-yellow ; lower eyes
fuliginose, or olive-grey, or glaucous. Thorax above pitch-brown, or fusco-luteous, or
brown-ochreous, or almost raw-sienna yellow. Abdomen in segments 2-6 or 7 translu-

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 189

cent white, with the edges of the dorsal vessel, a spot on each side of it on every joining-,
and a clond over the tracheal ramifications, dull reddish ; the tracheal trunk pitch-
black ; segments 7-, or 8-10, above, either pitch-brown, or fusco-luteous, or fuscous, or
almost burnt-sienna red, sometimes with the joinings ochraceous ; venter in segments 7-
10 ochraceous Avhite, sometimes with a pair of abbreviated dark lines beneath the
ganglionic cord at tlie base of each segment but the last, and with a dark line immedi-
ately beneath the spiracular ridge. Eorceps and setge white. Legs either wholly white,
or with the fore femur greenish grey, the fore tibia and tarsus grey or greyish white,
the hinder femora white tinged with very light yellow or sulphureous, and the hinder
tibiae and tarsi dull white. Wings vitreous ; the marginal area in its pterostigmatic
portion contains 6-8 oblique cross veinlets, sometimes sparingly forked near the sub-
costa ; there are none before the bulla in either of the sexes.

$ (liviny). — Eyes caisious, or dark olive-grey, or light greenish grey, or brown-black.
Vertex of head light yellow, with a double longitudinal median reddish or brown-ochreous
stripe from the frons to the occipital mai-gin. Thorax above sometimes very light dull
brown-ochre, sometimes very light yellowish, sometimes bistre-brown, sometimes jet-
black ; the peak of the mesonotum often tinged with bright green. Abdomen sometimes
fuscous, sometimes olive-grey, sometimes in such examples tinged distally with light
brown-ochre, and sometimes uniformly of this last colour : the lighter segments (2-7)
either have each a small spot in the middle, two at the apical margin, and an indistinct
curved line on each side of the back, or have a small spot in the middle of the back, and
a larger triangular spot on each side distally, of the same yellowish or furfuraceous
colour ; the subcutaneoi;s tracheae, and a streak close by every spiracle, are black.
Venter lighter tlian the dorsum, and sometimes paler anteriorly than in the hinder
segments, sometimes reddish white. Setse white. Fore femur sometimes greenish- or
olive-grey ; hinder femora greenish white ; tibiae and tarsi white, with the terminal tarsal
joints cinereous. Wings vitreous, often tinged at the base with bright green. Length
of body 5-9 ; wing 6-10 ; setse, <s im. 13-15, subim. 9, ? im. 10-12, subim. 6-8 mm.

Hah. Europe from Scania (Wallengren) and Great Britain to Switzerland and southern
France ; profusely abundant in Holland near Gouda &c. and in Belgium ; common in
Saxony (Rostock) ; also at Basle (M^Lach.), near Visp in Canton Valais ; and in the
leighbourhood of Orthez in the Basses Pyrenees. The forceps-limbs are wider apart
it the base than in our other native species, and their terminal joints more slender.
The identity with this species of the Chinese specimen referred to below is open to
luestion.

^LOEON siNENSE, Walker [Catalogue-name only].

X Ctsnis sinensis, ! Walk., List of Neuropt. Ins. in Brit. Miis. part iii. 584 (1853).
Cloeon X russulwm, ! Etn., Trans. Eut. Soc. London (1871) 105, var. 2 [part.].

Hab. Northern China. A single adult 6 in the British Museum, insufficiently
escribed, is very similar to, if not identical Avith, C. rufulum.

190 EEV. A. E. EATON ON EECENT EPHEMERID^ OE MATELIES.

AMERICAN SPECIES.

Cloeon mendax, Walsli.

VMmendax, Walsh, Proc. Acad. Nat. Sc. Pliilad. (1862) 381.
Cloeon mendax, Etu., Trans. Ent. Soc. London (1871) 106.

Subimago, 6 . — Wings and their neuration subopaque and slightly dusky. Setae pale.
Turbinate eyes pale ; lower segment of oculi blackish (Walsh).

Imago, 6 . — Pale ferruginous ; sternum and venter pale greenish hyaline, the latter
opaque at the tip. Legs pale, tips of tarsi cloudy. Wings and neuration hyaline ; isolated
veinlets of the tei'minal margin all single. The 2 sometimes has the thorax tinged with
green, and is always paler above. (After Walsh.)

? {dried). — Body light yellowish ochraceous above, sometimes very light, and com-
monly liable to infiltration of chlorophyll, especially at the roots of the setae, the peak
of the mesonotum, the wing-roots, the knees, and the tarsi. Venter whitish ochraceous ;
the main tracheae of the abdomen often blackened. Setae white. The marginal area of
the wing has no cross veinlets between the great cross vein and the bulla ; in the ptero-
stigmatic space are 4-8 cross veinlets (usually 6) from the costa, mostly simple, rather
oblique, and almost straight, very rarely anastomosing with one anotlier to any extent,
many of which do not reach the subcosta ; and usually, between them, a few rudiments
of others issue from the costa. Length of body 4-6, wing 5-6 mm.

Bab. Rock Island, 111. (Walsh) ; Denham, Mass. (M^Lach. Mus.) ; Detroit, Mich.
(Mus. Comp. Zool., Cambridge, Mass.). May and June.

Cloeon vicintjm, Hagen.

Cloericina, Hag., Sraithson. Miscell. Coll. (1861) Synop. Neuropt. N. Am. 5i; id., Proc. Ent. Soc.
Philad. ii. 178 (1863).

Cloeon vicinuni, Etn., Trans. Ent. Soc. London (1871) 107.

Imago {dried). — d . Thorax fulvous (Hag. 1861) or reddish brown {id. 1863) ; abdomen
whitish hyaline, with the last 3 segments fuscous above ; setae whitish. Wings colomdess.
Legs whitish, the fore legs fulvous at the base.

? . Body yellowish white ; setae and legs whitish ; wings hyaline. Length of body 4 ;
expanse of wings 10 ; setae, 6 10, $ 6 mm. (After Hagen.)

Hab. Washington (Osten-Sacken).

? Cloeon dubium, Walsh.

Cloe dubia, Walsli, Proc. Acad. Nat. Sc. Philad. (1862) 380; Hag., Proc. Eut. Soc. Philad. ii. 178
(186.3).

Cloeon dubium, Etn., Trans. Ent. Soc. London (1871) 100.

Mr. Walsh diagnosed this species from BaHtis lyropinquus (which it closely resembles)
by its smaller dimensions &c.

Imago. — 6 . Thorax and last 4 dorsal segments piceous : these last, beneath, opaque
whitish ; the intermediate abdominal joints transparent whitish, each with a dark dot
on each side, whose centre is hyaline. Legs pale, the tips of the tarsi cloudy. Wings

EEV. A. E. EATON ON EECENT EPHEilERlD^ OK MAYFLIES. 191

and their neuration colourless ; the iutercalar veiulets of the terminal margin in
pairs.

S . Thorax, sternum, and abdomen above pale ferruginous ; venter pale yellowish or
greenish ; femur of the fore leg always more or less ferruginous. Length of body 2"5-4 ;
expanse of wings 8-10*5 ; setae, d 4*5-5 -5, 2 3-4!*5 mm. (After Walsh.)

Hab. Kock Island, 111. (Walsh).

? Cloeon Oldendorfpii, Weyenbergh.

Oxycypha 0/dendorffii, Weyeub., Tijdsclir. v. Eiit. sxvi. 1882-3, p. 173, pi. x. 6 (1883; [wing].

Imago {living). — Eyes dark brown ; head and thorax glossy sepia-brown, the colour
changing to fallow-grey on the scutellum [schildje] and passing into a greyish brown on
the dorsum of the abdomen. Underside of the body of a very light colour. Setae
translucent, light grey. Legs grey. Wings vitreous, with dark nem-ation ; the sub-
marginal area in the figure is shaded, and two straight cross veinlets, remote from
one another, are shown in the pterostigmatic space, lludimentary intercalar veinlets
of the tei'minal margin of the mesothoracic wing paired. No mention is made of hind
wings. Length of body 5-5*5, wing 4*75, setae 6 mm.

Hab. Cordova, Argentine Hepublic ; in the autumn, found at rest on walls. (After
Weyenbergh.)

CALLIBiETIS, Etn., 1881.

Illustrations. — Adult (details), PI. XVI. 28 a-d ; (whole figures) see citations of Pictet
(1843-5) under C. tmdatus and C.fasciatus. Nym/ph, PL XLVIII.

Adult. — Hind wing oblique, widened rapidly in front from the roots to the costal pro-
tuberance, usually rather broad, and oblong, with the tip ellipsoidally rounded off ; costal
protuberance large and very obtuse ; neuration limited to three main longitudinal
nervures, a few rudimentary intercalars from the terminal margin between the second and
the third of these, and (at least in the marginal area) a considerable number of cross
veinlets. Fore wing in the majority of the species variegated in one or both of the sexes
in front, and sometimes in the disk ; but in others without colour-ornamentation ; cross
veinlets numerous throughout the whole of the marginal area, and either pluriserial
in the disk or arranged in a few dislocated series, as in Baetis ; rudimentary intercalary
veinlets of the terminal margin single or paired, according to the species. Forceps-limbs
of 6 conformable to those of Cloeon. Penis not observed hitherto. Of the ? abdominal
segments 6-9 are a little the longest. Caudal setae of 6 im. 2-2^, ? im. l^i as long
as the body. Fore tarsus of 6 about 1-^- fis lo^o ^^ the tibia, which is nearly 1^ as long
as the femur ; its joints in diminishing succession rank 2 subequal to 3, 4, 5, 1. Fore
tarsus of $ about -f as long as the tibia, which is about as long as the femur ; its joints
in order of lessening length rank 2 subequal to 5, 4, 3, 1. Hind tarsus of 6 about \ as
long as the tibia ; its joints rank 1, 4, 2, 3. Nijnipk. — Abdominal tracheal branchiae all
iouble, with unequal divisions : the first and second are each formed of a large somewhat
Dblong lamina obtusely rounded at the tip, contracted transversely in some measure about
aaidway from the roots, and slightly contorted, connate with a smaller underlying division

192 EEV. A. E. EATON ON EECENT EPHEjVIEEID^ OR MAYFLIES.

placed obliquely with regard to the larger ; the next four are each composed of a large
subovate lamiaa, with a flap turned over on one side close to the base, which constitntes
the much smaller division ; the seventh has the larger lamina narrowly ellipsoidal and a
much smaller turned-over flap than the others ; each of the larger lamiuce is supplied with
a single main trachea with long branches and short brauchlets. Antennae about as long
as the head and thorax comliined. Seta) subequal to one another and about f as long as
the body, fringed for about f of their length, with the fringes gradually shortened to a
point, and then tail-pointed. Mandibles terminated by slender, compressed fangs, with a
tuft of hair in place of the endopodite. Palpus of maxilla i. longer than the lacinia,
slender, apj^arently 2-jointed, with joints of very nearly equal length ; lacinia armed at
the tip with slender fangs, and with other slender fangs mingled with hau* along the inner
edge. Laciuise of maxillae ii. obtusely falcate, rather shorter than, but nearly of equal
width with, the obtusely lanceolate lobes of the labium : proximal joint of the palpus stout,
compressed, narrowed slightly and evenly from the base distally; second joint about
thrice as long as the third joint, slightly gibbous at the base on the inner side as far as
the oblique line of muscular attachment ; third joint almost as broad at the base as the
end of the second joint, and subacute at the tip. Tongue somewhat similar in form to a
closed ecclesiastical biretta ; median lobe subrotund, bluntly mucronate, and broader tban
the rounded paraglossae. Hiud tarsus, claw excluded, little shorter than the tibia,
which is not quite § as long as the femur ; the whole leg not much longer than the
fore leg.

Ty])e. C. pictus (in Baetis), Etn.

Distribution. America from Canada to the Argentine Republic and ChUi ; also [unde-
scribed sp.] Australia.

Etymology. koXoq and Bcetis, a proper name, with reference to the beauty of many of
the species.

The generical identification of the nymph was ascertained by examination of the hind
wings of one of the alcoholic specimens received from Dr. Hagen, subsequent to the
phot olithogra piling of Pis. XVI., XVII. It then became evident that the genus had
better be ranked at the close of the section, instead of at the beginning,

Callib^tis Hageni (renamed), Etn. MS., in the writuig of Plate XVI. 28 a (wings and
part of femur).

Baetis \\ tessellata, ! Hag., Smithson. Miscell. Coll. (1861) Synop. Neuropt. N. Am, 50; Etn., Trans.
Ent. Soc. London (1871) 84 [note to Lept. Colombia'], and 150, note ; Hag., op. cit. (1873) 395.

Subimago (dried). — Wing-membrane cinereous, or blackish grey ; cross veinlets white,
and narrowly bordered with white ; the pale borders of a few that may happen to be close
together side by side near the base or the middle of the wing are occasionally confluent,
but only sparingly so ; in some lights the longitudinal nervures also in great measure
appear to be whitish, especially towards the terminal margin. Legs sublutescent, with
the tarsi somewhat blackened. Setse pale sepia-grey, with black joinings.

Imago (dried). — ?. Wings ornate; femora densely, minutely, and inconspicuously
dotted ; tarsi to a large extent black. — Body piceous ; the dorsal sutures of the thorax

EEV. A. E. EATON ON EECENT EPJrEMERID.E OR MAYFLIES. 193

paler and yellowish ; the abdomen discoloured, but rather uniformly coloured and orna-
mented throughout ; its integument densely, minutely, and irregularly rugulose on the
back, and foveolate ventrally ; setre white with black joinings (but these are reddish in
imperfectly developed seta>). Wings vitreous, brilliantly iridescent ; the fore wing
ornamented with piceous, broadly along the costa, very narrowly along the terminal
margin, and very variously in the disk ; the costal markings may be described as a
longitudinal stripe, deeply and ii^regularly eroded posteriorly, and varied diversely in
different specimens with pellucid spots enclosing the cross veinlets ; the terminal margin
is white or jiellucid at the terminations of the longitudinal nervures, but elsewhere pitch-
brown, and the interneural veinlets arising from it are similarly dark, and sometimes are
enveloped in little nebula? of the same colour, or spots ; the irregular spots of the disk are
in connection with dark portions of the longitudinal nervures ; these are mostly white,
banded with piceous, only tjie costa, subcosta, and radius being piceous throughout ; cross
veinlets opaque white ; the marginal area contains about 8 cross veinlets before, and 13
within the pterostigmatic space, mostly simple, though a few are forked. Femora fusco-
lutescent, minutely and densely punctulate with darker, especially towards their distal
extremities; tibiae slightly paler, darkened at their distal joinings; basal joint of the
tarsus almost concolorous with the tibia, but the extremity of the tibia, together with
the rest of the tarsus, is dull black. Length of body, $ 12; wing 12; setae about
17 mm.

Hal). Puget Sound and other parts of Washington Territory (Ilag. and M'Lach. Mus.)
and California (M^Lach. Mus.).

Callib^tis feR-RUGINEUS, AYalsh. Plate XVI. 28 b (wings 2 im.).

Cloe X iindata, ! Hag., Smithson. Miscell. Coll. (1861), Synopt. Neuropt. N. Atn. 53 [part] .— C./e;--
ruginea, Walsh, Proc. Acad. Nat. Sc. Philad. (1862), ZTd.—C. fluctuans, id., loc. cit. (1862); Hag.,Proc.
Ent. Soc. Philad. ii. 178 (1863).

Baatis fluctuans, Etn., Trans. Ent. Soc. Loudon (1871), V22.—B. (?) undatus, id., op. cit. (1871), 123
[part] ; Hag., op. cit. (1873), 402 [part]. — B. ferrugineus, Etti., op. cit. (1871), 121 ; Hag. & Etn., op.
cit. (1873), 402 [part].

Subimago (dried). — Wing-membrane sepia- or bistre-grey ; cross veinlets white, narrowly
bordered with transparency in a manner very similar to those of C. Hageiii ; longitudinal
neuration for the most part pale and similarly edged with transparency, the costa, sub-
costa, and radius of the fore wing (and, in parts, some of the other nervures) darkened
uniformly with the ground-colour of the membrane. Legs sublutescent ; the apical
borders of the first three tarsal joints, and the extremity or sometimes the whole of the
terminal joint, also the fore tibia, brown. Setae pale sepia-grey, their joinings either
)paque or blackened.

Imago (dried). — Wings colourless in the 6 , ornate in the 2 ; femora usually quite
'ree from dots, and then normally pale lutescent in both sexes ; or in the <^ Avhitish, but
douded with pale lutescent before their extremities ; sometimes in the c? they are dotted
ninutely in part or throughout ; tarsi of the d in great measure white. — 6 . Thorax
lormally piceous or fusco-piceous ; abdomen normally with the dorsum uniformly rufo-

SECOND SERIES. — ZOOLOGY, VOL. III. 2G

194 EE\". A. E. EATON OX EECEXT EPHEMEELD^E OK MAYELIES.

piceous or intense warm sepia, and the venter light reddish white, densely and rather
uniformly dotted with dull dark reddish, and generally with the several pairs of subgan-
gKonie streaks well defined ; but the bases of the doi"sal segments above the dorsal vessel
are sometimes marked each with a pale streak. Forceps-limbs white, excepting the basal
joint, which is yellonish and irrorated with reddisli. Setae white, sometimes with their
joinings towards their insertion opaque. Wings vitreous throughout; the marginal area
of the fore wing contains about 6 faint simple cross veiulets before the bulla, and 7-12
better defined beyond it ; and the intervals of these last in the pterostigmatic space are
occupied by variously disposed, more or less plentiful, granulations ; most of the inter-
neural veinlets of the terminal margins are in pairs. Femora pale, somewhat lutescent,
slightly darkened a little before the tip, or more nearly white, and in some specimens
dotted ^"ith minute inconspicuous pale reddish specks ; fore tibia usually white, with
its extreme tip brown, but in one example sepia-grey with the tip piceovis ; fore tarsus
white, sometimes with brownish ungues ; hinder tibiae and tarsi wliite, sometimes
slightly tinged with yellowish, with the imgues, and most commonly the joinings also,
light red, or piceous.

Variation, d im. (dried). — Thorax above fuscous, varied with flavescent, and slightly
dotted with darker near the insertion of the fore wings. Abdomen above closely punc-
tulate with black, somewhat fusco-griseous, varied with reddish and greyish white ; the
whitish markings comprise in each segment a streak from the base of the segment along
the dorsal vessel, a larger triangular spot at the base of the segment that terminates a
little before its dark apical border, and another rounded impressed spot at the base of
the segment, adjacent to the spiracular line, forming regular series of markings ; venter
whitish, tinged faintly with reddish, closely and minutely puuctulate with reddish, more
coarsely and sparsely punctulate with black, with a short small black acutely triangular
streak at the base of each of segments 3-8, adjacent to the spiracular line, and indistinct
traces of the usual series of pau's of curved linear sti-eaks adjacent to the ganglionic
cords.

2 (dried). — Body variously coloured during life [ranging, according to Walsh, from
whitish brown mingled with brown to pale brown with the sixth abdominal segment
brown], mostly piceous afterwards ; surface very similar in detail to that of tlie body of
C. Sayeni. Setae white, with black joinings. Wings usually ornamented with pale
piceous, in nearly the same manner as those of C. Kageni ; but sometimes the disk of the
fore wing is spotless ; the costa, subcosta, and radius are whitish and ti-anslucent in the
pellucid spots ; there are about 6-9, mostly simple, cross veinlets before, and 12-14
beyond the bulla in the marginal area of the fore wing. Femora pale lutescent, or pale
luteous ; the coxse, tibise, and tarsi much paler ; the last tarsal joint, and the apical
borders of the others, as dark as the femora, and ochreous brown. Length of body 6-9o ;
wing 6-9 ; setae, 2 im. 10-5-12, 6 15-17 mm. (teste Walsh).

Hah. Widely distributed in N. America ; Red River ; Quesnel Lake, British Columbia;
Vancouver's Island ; AVashington Territory ; Montana ; Oregon (M'^Lach. Mus.) and The
Dalles, Or. (23 June, 1882, S. Henshaw, Hag. Mus.); San Jose, Cal. ; Colorado; Rock
Island, and A'ormal, 111. ; also New York. Two 6 im. from Montana have a small cloudy

EEV. A. E. EATON OX EECENT EPHEMEEID.E OE MATTLIES. 195

fuscescent spot at the junction of the radius (3) with the subsequent two nervures of the
fore wing, and in the hinder legs the unirues, the last two tarsal joints, together with the
extremities of the other joints and that of the tibia, are black-brown : in one of them the
10th dorsal segment of the abdomen is pale. [Numerous specimens in Ha?., and in
M'^Lach. Mus.]

Cailib^tis , sp. nov. ?

Imago [dried), 6 . — Wings ornate in this sex, as strongly and nearly in the same
manner as those of C'.ferrugineus, 2 [compare PL XVI. 28 5]. Neuration of hind wing
less sparse than in that species, closely resembling that of the liind wing of C montanus
\loc. cit. 28 f/]. Legs much darker in colour than those of C.ferrugineus; the fore leg
quite as dark as that of C. Hageni, being, in opaque view, either light pitch-brown, or
warm sepia-brown, with the trochanter and base of the femur rather lighter; hinder
legs very light yellowish brown, almost whity-brown, marked in the femur with very few
and verv indistinct round dark dots, the tarsi duskv or corvinous. with the un2rues and
the terminal edges of the joints black. Abdomen intense warm sepia-brown above,
inclining to pitch-brown in parts, and varied with much lighter groundinsr similar in tint
to the predominant light yellowish-brown of the venter; the dorsal joinings of a light
colour ; the sides of the dorsum are distinctly shagreened, or impresso-punctate, with
pitch-brown ; the venter is more densely inipresso-punctulate with intense warm sepia--
brown, and has depressions corresponding in size and situation with the pairs of abbre-
viated longitudinal streaks at the bases of the segments. Forceps whitish ; the basal
joints of the limbs uniform with the venter in colour and stippling. Setfe dusky, with
black joinings. TVin^s vitreous; longitudinal neui'ation of the fore wing fuscous, varied
in places with white ; cross veinlets white, excepting sometimes a few of those contained
within the dark markings adjacent to the costal margin, which markings are varied with
various rounded pellucid spots in the customary manner ; the marginal area contains
about 10 nearly straight, oblique cross veinlets in the pterostigmatic region, pai-tly con-
joined by a longitudinal line of irregular granulations ; the terminal margin itself is
aniformly dark, and the interneural veinlets upon it are mostly in pairs. Length of body
)r wing 6o-7 ; sette 13-16 mm.

nab. Colorado (^M'Lach. Mus.). In the absence of the subimago one can hardly
lecide whether this should be regarded as a distinct species or not.

^ALLiB^Tis Picxrs, Etn. Plate XTI. 28 c (wings and two femora).

Baetis pictus, !Etn., Trans. Ent. Soc. London (1871), 12.2, pL v. 27 [hind wing] ; Hag., op. cit.
1873), 402.

Callibxtis [type] pictus, !Etn., Ent. Mo. Mag. xvii. 196 (1881).

Subimago (dried). — "Wing-membrane sepia-grey, transparent ; neuration (including
ross veinlets) brownish, the cross veinlets sometimes narrowly and indistinctly edsred
ith dim obscurity. Legs pale dull yellowish brown, the femora spotted, the tarsal
linings and ungues brown. Sette sepia-grey, with dark joinings.

26*

196 EEV. A. E. EATON OX EECENT EPHEMEEID.E Olt MAYFLIES.

Imago (dried). — Wings colourless in d , ornate in ? ; femora marked with a row of
6-8 or more round spots, and witli a few dots (most distinctly so in the hinder legs), some-
times confluent iu part ; tarsal joinings, ungues, and the last 1-3 joints blackish- or
reddish-brown. — Body greatly discoloured ; thorax above pitch-brown in d , dark lutescent
in $ ; abdomen closely punctulate above, and still more so beneath ; the venter and
some parts of the dorsum rosy whitish-brown, with the punctulatioas dark red-brown;
the remainder of the dorsum pitch-brown. Setm white or reddish white, sometimes
banded with grey; the joinings greyish in the d , black in 2 . Wings vitreous; ptero-
sligmatic space slightly fuscesceut in d ; in ? the marginal and submarginal areas, and
the base of the fore wing are marbled with light umber-brown somewhat faintly and more
evenly than iu the two preceding species, the disk and terminal margin are also irregularly
clouded with faint tints of a like colour ; neuration pitch-brown, the terminal margin in
2 , and nervures 1-4 in both sexes, white here and there ; cross veinlets dark in <S , white
in 2 ; the marginal area in d has no cross veinlets before the bulla, but has 6-8 beyond
it ; in $ there are 6-9 vex-y faint before, and 11-16 beyond it, which are mostly simple,
and have no granulation interposed between them. Length of body 5-6'5 ; wing 5"5-7;
setae, d im. about 14, 2 about 15 mm.

Hab. Widely distributed in the southern parts of N. America ; California, at Brooklyn,
San Jose, San Raphael (31 March, Osteu-Sackeu), and San Gerouimo (20 April, idem);
Texas iu Bosque Co. (Belfrage) ; Guatemala (5000 feet) ; and Aceytuno (5100 feet).
[Many specimens in M^Lach. Mus. and Mus. Comp. Zool. Cambridge, Mass.

A very small undescribed species of Callibcetis (in M'^Lach. Mus.) from Florida has
whitish grey wings. The fore wing of the 5 is faintly amber-tinted in the marginal and
submarginal areas ; but in the d the membrane is devoid of ornamentation. I have seen
only 7 immature examples.

Callib^tis rxDATUs, Pictet.

Cloeundata, Pict., Hist. Nat. Nevropt. ii. Epliem. 26i, pi. xli. 5 (1813-5) ; Hag., Sraitlison. Miscell.
coll. (1861) Synop. Neuropt. N. Am. 5 [part.].

Cloeon undata, Walk., List of Neuropt. las. ia Brit. Mus. part iii. 575 (1853).

A Mexican species, insufficiently described, and figured questionably ; but perhaps
admitting of re-identificatiou by collectors at some future time. Two kinds of Callibcetis
captured in Cuba by Poey, Gundlach, and Chas. Wright, are represented in Dr. Hagen's
collection, but too imperfectly for description. Pictet alludes to a species from the
same island.

Caxlib^tis montanus, sp. nov. Etn. MS. in the writing of Plate XVI. 28 d (wings &
femur).

Imago {dried), 2 . — Fore wings viti^eous, ornamented in the marginal, submarginal, and
the next adjoining areas with light raw umber-brown (fusco-luteous), the same colour
extending acro.ss the base of the wing iu proximity to the wing-roots, and varying in
mtensity distally, as well as in the proximal portion of the marginal area : nem-ation of
a like colour, or lutescent, excepting the rudimentary cross veinlets preceding the bulla

EE\^ A. E. EATON ON EECEXT EPHEMEEID^ OE MAYFLIES. 197

in the marginal area, which are more or less whitish ; hefore the bulla are 6 or 7 rudi-
mentary cross veinlets, beyond it about 7 rudimentary and 7 Avell-defined simple and
almost straight cross veinlets : the intercalary veinlets of the terminal margin are mostly
single. Legs, in opaque view, somewhat of a dull light Vandyke -brownish grey, stippled
or irrorated minutely and densely in the femora with very light burnl-umber brown ;
tarsal joinings also of this latter colour ; terminal tarsal joints darkened; ungues black.
Body discoloui'ed ; notum testaceous, irrorated on each side with brown-ochre, and
traversed lengthwise by a median brown-ochreous sti'ipe intersected by a light yellowish
line. Sette white, with the joinings and basal joints lutescent. Length of body, 2 6;
wing 8 mm.

Hah. Central America ; Aceytuno (5100 ft.) [in M°Lach. Mus.).

Callib^tis fasciatus, Pictet.

Cloe fasciata, Pict., Hist. Nat. Nuvropt. ii. Epliem. .202, pi. xli. 4 (184.3-5) [wbole figure].— C.
Lorentzii, Weyenh., Tijdscb. v. Eut. 1882-3, p. 167, pi. x. 4 (1883) [wings].
Cloeon fasciata, AV^alk., List of Neuropt. lus. iu Brit. Mus. part iii. 575 (1853).
Ba'etis fasciatus, Etn., Trans. Eut. Soc, London (1871) 123.

Subimago {dried), d . — Wings transparent, very light brownish- or fawn-grey, striped
and spotted with light brown : fore Aving mottled along the costal border, and traversed
obliquely, from the costa in the neighbourhood of the bulla to the anal curve of the
inner-terminal margin, by a fascia somewhat irregular in outline, but broadest and sub-
angulated near the costa ; between this fascia and the wing-roots are two large spots
extending at least from the costa to the prsebrachial (6) nervure, and in the disk, midway
towards the wing-roots, a small spot contiguous with, or intersected by, the long inter-
calar nervure that follows the anal (8) nervure : along the costa beyond the fascia are a
large fiexuous spot, followed by a smaller straighter spot, and several other small ones,
all of irregular form and apt to be more or less continent Avith one another ; and near
the terminal margin an irregularly broken fascia exteods from just below the tip of the
wing almost as far backwards as the termination of the first-mentioned fascia. The
markings are dark-edged throughout the wing, and in the marginal area are broken up
by clear spaces bordering the cross veinlets. Legs pale dull brownish-lutescent ; the
fore tarsus, and the joinings and extremities of the hinder tarsi fuscous. Setae light
sepia-grey, with reddish joinings. Thorax light dull brownish-lutescent. Abdomen
faded, dark above, jialer beneath ; each of the first six ventral segments is marked with
a pair of abbreviated, longitudinal, linear, black dashes, each followed by a black dot,
and also with a reddish spot at the middle of the terminal margin. [After Pictet, and a
d subim. in Hag. Mus.]

Imago {lirbig). — 6 . Upper i:)ortion of eyes dark reddish brown. Thorax and legs grey ;
he former somewhat darker above, and more yellowish in colour at the sides. Abdomen
ibove reddish brown, sometimes nearly blood-red, or suff"used Avith dark brown on the
)ack, with very dark tips to the segments ; venter similar in colour to the sides of the
horax. Setae translucent, with darker joinings, especially towards the roots ; the joints
horter than in Q. Sellacki. Wing-markings somewhat darker in tint than those of that

198 EEV. A. E. EATON ON EECENT EPHEMERID^. OE MAYFLIES.

species, but of a similar colour : front margin of the fore wing mottled, in the manner
prevalent in the genus, as far as the radius (3) ; posterior to this nervure, from the
neighbourhood of the bulla of the subcosta, a curved narrow fascia extends transversely
to about the anal angle ; this fascia is partly confluent with an irregular blotch of mode-
rate dimensions, seated upon the pobrachial (7) nervure and spreading on both sides to
the neighbouring intercalary nervures, but not nearly to the terminal margin ; the same
fascia is preceded by a blotch at the wing-roots, and another smaller blotch in the vici-
nage of the conjunction of the sector (4) and cubitus (5), and is united to the latter by
a narrow projection of the colouring along the cubitus : immediately after the fascia is a
large subtriangular blotch, which extends outwards along the radius as far as the com-
mencement of the pterostigmatic region of the wing, and transversely from the radius to
the sectorial intercalar next to the cubitus ; this blotch contains a clear space ; a band
of colouring, parallel with the terminal margin, extends from the sector (4) to the prae-
brachial (6), and touches the lowest extremity of the last-mentioned blotch. The rudi-
mentary intercalar veinlets of the terminal margin of the fore wing are paired. Hind
wings similar to those of C. Sellackl, but somewhat clouded.

$ . Eyes olive-brown. Abdomen light yellow, or at most brownish yellow. Wing-
nervures brownish. [Weyenbergh ; abstract translation.] Length of body 6-7 ; wing
5"5-9 ; seise, 2 iui. from 8 to 9 mm. and upwards.

Ilab. Brazil (Pict.) ; Cordova, Argentine Republic (Weyenbergh & Hag. Mus.). In
autumn ; comparatively scarce ; not associated with C. Sellacki (Weyenb.). Dr. Hagen's
specimen was no longer with me when Prof. Weyenbergh's paper arrived. This species
is smaller than the following, and has the cross veinlets of the fore wing rather diffe-
rently arranged {cf. Weyenbergh's figures).

CALLiBiETis Sellacki, Weyenbergh.

Cloe Sellacki, Weyenb., Tijdschr. v. Ent. xxvi. 1882-3. p. 161, pi. x. 3 (1883) [wings].

Imago {Umng). — 6 . Eyes dark brown above. Thorax yellowish green, with a broad
longitudinal median green stripe on the notum, which often appears sepia-colour edged
with darker. Abdomen very light brown above, darker or reddish brown at the tips and
in the midst of the segments, and with oblong black spots at the stigmata ; venter very
pale, with colourless forceps. Setae [whitish ?] annulated distinctly at the joinings with
light sepia-colour towards their roots, but less distinctly so towards their extremities.
Legs light brown, with the femora almost colourless above [ ? towards their bases] ; fore
legs of 6 almost yellow. Wings ornate in both sexes : neuration light brown. The
light brown markings of the fore wing are mottled, in the usual manner, with rounded
clear spots enclosing single cross veinlets along the costal border, and occupy a very
large proportion of the remainder of the wing posterior to the radius ; they comprise a
blotch at the wing-roots, nearly contiguous with another protuberance from the said
border, which just overlaps the prsebrachial (6) nervure, followed closely by a broad
transverse fascia, nearly in the middle, which crosses the wing and terminates at the
anal angle ; that fascia is followed directly, at the costal border, by two abbreviated
confluent bands, which by their combination compose a large irregularly triangular

EEV. A. E. EATON OX EECENT EPHEMEEID.E OR MATELIES. 199

blotch that encloses a clear space ; another irregular band extends some distance in
proximity to the terminal margin and subparallel therewith. At the terminal margin,
the interneural veinlets are single. Hind wings perfectly clear.

$ . The markings of the wings correspond somew hat with those of the other sex ; but
the bauds are more perfectly defined, though faiuter in colour, and both they and the
blotches are broader ; hence the clear spaces are much smaller. Posteriorly the whole
of the wing-membrane has a smoky tint. Eyes pearl-grey, each traversed horizontally
by a black line; the remainder of the head and thorax yellow-grey, with the 'appendi-
cular organs ' almost colourless. Length of body 8-10 ; expanse of wings 16 ; length
of setfe, d im. 15, $ im. 12 mm.

Hab. Cordova, Argentine Republic ; commonly, but not exclusively, in the autumn.
[After Weyenbergh, abstract translation, and partly based upon his figures.]

Group III. of tue Genera of the Ephemerid^.

Adult. — At the fore-wing roots the anal (8) communicates with the pobruchial (7)
nervure by a well-defined channel of circulation in the membrane ; and the first axillar
(9^) nervure, detached from its own group of nervaires, either meets or is very closely
approximated to the anal nervure at the l)ase of the wing. [In Bcetisca it is subparallel
with the anal, but nearer to it than to the second axillar nervure.] Legs all functional ;
hinder tarsi distinctly 5-jointed [the fifth joint in Colohnras is less distinct than is
usualj ; ungues rather small. Contour of 6 oculi either evenly rounded or obsoletely
ascalaphoid. Ni/i/ijjh. — the structure of the palpi varies with the Series.

Firsi Series of Groiq) HI.
Adult. — Anal-axillar interspace [\>. 81, 1. G from bo(tom~\ of the fore wing curvilinear-
trilateral, subtended by the outer half of the inner margin and the anal angle [in BcBtlsca
closed by the terminal margin, and narrowly su1)linear in form] ; the intercalary
nervures of this interspace, varying in number with the individual, constitute simple or
divided branchlets of the anal [in Bcetisca tlie second axillar (9-)] nervure, and as a rule
are entirely free from cross veinlets distinctly recognizable as such. The structure of
the thoracic spiracles of many of the genera (owing to their valves being closed in the
dried examples exclusively obtainable for examination) has not been ascertained in a
manner sufficiently satisfactory for descriptive purposes, and is therefore taken only
tacitly into account here. Pronotum of $ , when Avell developed, transverse, longitu-
iinally carinate, appressed closely to the mesonotum, and more or less broadly retiexed
it the sides to a maximum not exceeding double its minimum extent. Eorceps-basis of
S , and the homologous ventral lobe of ? , usually well developed ; but the latter is small
n Siphlurus and absent in Oniscigaster. Oculi of S either evenly contoured or
)bsoletely ascalaphoid ; anterior ocellus rather smaller than the others. Subimago
[uiescent many hours ; its posture has been observed in only a few of the genera.
\"ymp]i. — Palpi of both pairs of the maxilla triarticulate. Abdominal tracheal branchiae,
t^hen exposed, foliaceous, friugeless, and without fasciculated fibrils at the base; those

200 EEV. A. E. EATON ON EECENT EPHEMERID^ OE MAYELIES.

of BiBtisca are concealed by a larg-e notal shield when the insect becomes adolescent,
and their structure is j)eculiar.

Section 10 of the Genera. — Type of SipJdurns. Adult. — In the fore wing, the first
axillar nervure (9') meets the inner margin at or before the middle ; the anal nervure
(8) terminates close to the anal angle and receives sevei'al simple or divided branchlets
[intercalaries] from the outer half of the inner margin. Pronotum well developed.
Nymph. — Palpus of maxilla i. as long as the lacinia, or longer. Pronotum and sutures
of the mesonotum well defined. Terminal maro:ins of the fore win2:s free.

The affinity between the genera of this section and those of the type of Baetis has
already been remarked upon at page 15i. i?<g^/«c«, ranked apart in Section 11, is rather
similar to genera of the Sqjhliirus type in aspect.

Tlie relative dimensions of legs, sette, or segments, indicated in the definitions of
the genera, are employed, in the absence of whole figures, to convey an approximately
definite idea of the aspect of typical examples of the insects concerned, so far as this
may be dependent largely upon those proportions. But yet the descriptions must not
be interpreted rigidly in these particulars ; because the geuerical likeness of species can
l)e maintained and be appreciated at a glance, where the standard proportions have been
departed from in some points.

Nymphs of only three of the genera of- this section are known ; that of Chirotonetes
(as it is supposed) has tracheal branchiae on segments 1-7 of the abdomen, all of which
are single obovate lamellte ; SipIUio'us has similarly situated tracheal branchiae, but those
of segments 1 and 2 are double. Onlscigaster has tracheal hranchiye on segments 1-6
only, of which all but the foremost are produced each on the inner side into a curiously
foliated lobe.

Tabulation of the Genera of the Siphlurus Tvpe.

Tibiae of the liiuder legs longer than, or at least subequal in length to, the tarsi. Prox-
imal joint of the hind tarsus
shorter than the 2nd joint. Tarsal claws mutually

dissimilar. Costal dilatation of the hind wing acute. In ? abdomen the
ventral lobe of segment 9 is bifid and acutely excised ; pleurae
of segments 7 and 8 squarely truncate, each with a minute
spinule at the point, those of segment 9 produced each into
a short acute triangular tooth. Diminishing gradation of
tarsal joints : — fore tarsus ,$ 2, 3, 4, 5, 1, ? 5, 2 sub-
equal to 3, 4, 1 ; hind tarsus ^ and ? 5, 2, 1 subequal to

3, 4 [in ? PL XVIII. 32 b, 5, 2 subequal to 3, 1, 4] Coloburus.

alike, narrow and liooked. Costal dilatation of the hind wing obtuse. In
$ abdomen, the ventral lobe of segment 9 is
roundly emarginate with acute points ; pleurae of segments 7 and 8
squarely truncate, of segment 9 narrowly dilated outwards
and produced each into a short acute tooth behind. Grada-
tion of tarsal joints: — fore tarsus (J 1, 2, 3, 4, 5, ? 5, 1,
2, 3, 4 ; hind tarsus (5' 5, 2, 1 subequal to 3, 4, ? 5,1

subequal to 2, 3, 4 Chirotonetes.

acutely excised, with short acute points; pleuraj of segments 7-9

EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES. 201

squarely truucate. Gradation of tarsal joints : — fore tarsus
(J 3 and 2 subequal to 4, 1, 5, ? subim. 2, 1, 3, 4, 5 ;
hind tarsus ^ 2, 5, 1, 3, 4, ? subim. 2, 1, 5, 3, 4.
[PL XX. ?346] Metamonius.

subequal to the 2nd joint. Tarsal claws mutually dissimilar. Costal dilatation
of the hind wing almost right-angled. In J abdomen the
ventral lobe of segment 9 is subtriangular with the vertex
retuse ; pleurse of segments 7-9 squarely truncate. Grada-
tion of tarsal joints : — fore tarsus ^ 2, S, 4^ Ij 5, $ 2, I, 3,
5, 4; hind tarsus <S and ? 2, I, 5, 3, 4.— [PI. XVIII.
?34e] Ameletus.

longer than the 2nd joint. Tarsal claws mutually alikcj narrow and hooked.
Costal dilatation of the hind wing obtuse. $ unknown.
Gradation of tarsal joints : — fore tarsus 1 equal to 2, 3, 4,

5; hind tarsus 1, 2, 5 subequal to 3, 4 Dipteromimus.

Tibiae of the hinder legs shorter than the tarsi. Proximal joint of the hind tarsus

longer than the 2nd joint. Tarsal claws mutually

aUke. Costal dilatation of the hind wing obtuse. In $ abdomen the ventral
lobe of segment 9 is very short, parabolic or obtusely trian-
gular ; pleurae of the segments 7-9 obtuse behind. Grada-
tion of tarsal joints : — fore tarsiis ^ 2 equal to 3 and sub-
equal to 4, 1, 5, ? 1, 2, 5, 3, 4 ; hind tarsus J" 1, 2, 3 sub-
equal to 5, 4, ? 1, 2 subequal to 5, 3, 4 Siphlurus.

dissimilar. Costal dilatation of the hind wing very small and obtuse. In $
abdomen the ventral segment 9 is lobeless ; pleurfe of
segments 1-6 truncate behind^ of 3-6 slightly dilated
posteriorly, those of 7-9 broadly dilated laterally and pro-
duced posteriorly each into a short acute tooth. Gradation
of tarsal joints : — fore tarsus (J 1, 2, 3, 4, 5, $ 1, 2 sub-
equal to 5, 3, 4; hind tai'sus ^J and ? 1, 5, 2, 3, 4 Oniscigaster.

COLOBURUS, Etn. 1868.
Illustrations.— Adult (details) Pis. XVIII. & XIX. a-c.

Adult. — Fore leg of d about as long as the body [when dried 1 nj as long] ; tarsus

about as long as the tibia, and this about If as long as the femur ; diminishing sequence

of tarsal joints 2, 3, 4, 5, 1, the first joint nearly ^ as long as the second. Fore leg of

the typical S about -j^ as long as the body ; tarsus about f as long as the tibia, which

s about IJ as long as the femur ; tarsal joints in lessening length rank 5, 2 subequal to

J, 4, 1, the first joint about ^ as long as the second. In an undescribed N. American

species [PL XVIII. 326] the ? tarsus is about y as long as the tibia, and this about If as

ong as the femur. Hind tarsus of the typical d about -^ as long as the tibia, and this

ibout 1-^ as long as the femur ; the first joint is abovit f as long as the second, but both

if them are short. Ungues in every tarsus each unlike the other. Hind wings weU

'eveloped, oblong-oval, with the dilatation of the marginal area acute in front, and -with

datively scanty neiu*ation in the narrow axillar region. In the ? abdomen the relative

jngths of the 2nd-9th dorsal segments may be formulated approximately thus : — 5, 8,

SECOISn) SERIES. — ZOOLOGY, VOL. III. 27

202 EEV. A. E. EATON ON KECENT EPHEMEEID^ OE MATELIES.

10, 12, 13, 13, 11, 8, 5 ; tlie first segment is thoracoid. The squarely truncate pleurae of
segments 7 and 8 are minutely mucronate ; those of segment 9 are produced posteriorly
each into a short acute triangular point. Porceps-basis of d divided almost completely
into two broad divisions ; the limbs 3-jointed, the proximal joint subcylindrical, slightly
enlarged or gibbous at the extreme base, and not mvich longer than the remaining joints
combined. Ventral lobe of 2 bifid and acutely excised. Penis-lobes narrow, obliquely
pointed ; orifices of the seminal ducts placed in proximity to the extreme points of the
lobes ; their armatu.re is not obvious in dried specimens, but may resemble in some degree
that of the penis-lobes of SijMuriis. Median caudal seta rudimentary, only xV-4 as long
as the outer setse ; these are about twice as long as the body in the <s , and 1| as long as it
in the ? . OciJi of d contiguous, or nearly so, above, obsoletcly ascalaphoid, with the>
upper segments hemispherical and the lower relatively very small. Vertex of ? head
transverse ; the occipital border raised in the middle above the level of the posterior orbits
of the oculi. Median ocellus smaller than the others ; not isolated, but situated upon the
foremost prominence of the upper sm?face of the head. Prouotum of $ broadly reflexed
upon the mesopleura?, and in the middle deeply excavated behind. Nymph unknown.

Type. C. humei'alis (in Palincjema), Walker.

Distribution. New Zealand and (undescribed sp.) N. America.

Etymology. Ko\oj3ovpoG, in allusion to the rudimentary median seta.

CoLOBURTJS HUMERALis, Walker. Plate XVIII. 32 a (wings, legs, and <S genitalia).

Palingenia humeralis, ! Walk., List of Neuropt. lus. in Brit. Mus. part iii. 552 (1853).
X Baetis remota, id., op. cit. part iii. 564 (1853).

Coloburus [type] humeralis, ! Etii., Eut. Mo. Mag. v. 89 (1868) ; ! id., Traus. Ent. Soc. London (1871),
132, pis. iii. 1 & vi. 6-6 b [detail].

Subimago [dried). — Wings very light grey, with rather darker narrow mouse-grey
borders to the cross veinlets in the greater part of the disk ; but in the fore wing the
cross veinlets of the first three areas (excepting those of the pterostigmatic space) and
also those in the first ^ of the wing's length between the cubitus (5), prsebrachial (6),
and pobrachial (7) nervures are more distinctly edged with sepia-brown; the wing-roots
and great cross vein, together with the bases of the principal nervures, are of a duU,
very light ochreous tint ; but elsewhere the neuration is dull piceous. Setse light warm
sepia- or Vandyke-brown ; the joinings opaque in some examples.

Imago {dried). — 6 . Notum either pitch-brown or fuscou.s. Abdomen rufo-piceous or
opaque burnt-umber. Setie pitch-brown. Pore legs in opaque view pitch-brown;
hinder femora and tibiae in opaque view very light raw-umber- or yellowish-brown,
changing in transmitted light to pale yellowish amber ; hinder tarsi dull bistre-brown.
Wings vitreous, tinged in proximity to the wing-roots with light raw-umber, and in the
pterostigmatic region of the fore wing from the costa to the radius with light bistre-
brown ; neuration pitch-brown, with the roots of the longitudinal nervures light raw-
umber ; cross veinlets of the fore wing edged narrowly with warm sepia-brown between
the cubitus (5) and pobrachial (7) nervures in the first ^ of the wing's length, and
between the costa and sector (4) in its first | ; those of the pterostigmatic portion of
the marginal area branch near the costa and mostly anastomose with one another.

EEV. A. E. EATO:\' ON EECENT EPHEMEEIDJi OE MATl'LIES. 203

S Very similar to the d . Fore leg iu opaque view pitch- or dark bistre-brown, Avith
the end of the tibia darker. Hinder legs in opaque view light bistre-brown, with tarsi
of a duller colour ; in one example the colour is more of a raw-umber ; in transmitted
light the bistre changes to light raw-umber and to brownish amber, and the raw-umber
of the exceptional specimen to yellow-amber. The cross veinlets of the pterostigmatic
portion of the marginal area of the fore wing branch about midway between the costa
and the subcosta. Length of body 10-11 [shrunken] ; wing, d 13, 2 14-16 ; setge, 6 im.
15-20 & 2, subim. 14 & 1, ? im. 15 & 1, subim. 14 & 1 mm.

Hub. New Zealand; common at Christchurch (Fereday) and Otago [Brit. Mus. &
M'^Lach. Mus.].

CoLOBURTJS HALEUTicus, Etu. Plate XVIII. 32 c (penis), XIX. 32 (fore wing).

Coloburus haleuticus, ! Etn., Traus. Ent. Soc. London (1871), 133, pi. vi. 7, 7 a [detail].

Imago {dried), 6 . — Notum raw-sienna [furfurosus]. Abdomen rufo-fuscous above,
rather darker at the joinings ; pleurae testaceous ; venter rufo-lutescent. Setse fuscous ;
forceps testaceous, tinged distally with piceous. Fore legs rufo-piceous ; hinder legs
light brownish ochre. Wings vitreous, with pitch-black neuration, excepting that the
membrane and nervures close to the wing-roots are suffuscous, and the marginal and
submarginal areas of the fore wing in the pterostigmatic region are greenish grey.
Length of body, 6 im. 11 ; wing 15 ; setse 20 and 5 mm.

Sab. Australia ; probably near Melbourne [M'^Coy]. Well distinguished by the shape
of the penis.

CHIROTONETES, Etn. 1881.

Illustrations. Adult (details), Pis. XVIII. 33 (Z-e & XIX. 33 «, h,'^c. Nymph,
PI. XLIX.

Adult. — Foi'e leg of 6 from about § to ^^ as long as the body ; tarsus scarcely longer
than the tibia, which is nearly If as long as the femur; diminishing sequence of tarsal
joints 1, 2, 3, 4, 5, the first nearly 1^ as long as the second joint. Fore leg of ? nearly
as long as the body [when dried about ^o as long] ; tarsus about |- as long as the tibia,
and this about 1| as long as the femur ; sequence of tarsal joints 5, 1, 2, 3, 4, the first
1^ as long as the second. Hind tarsus of d nearly f as long as the tibia, and this about
I as long as the femur ; sequence of joints d 5, 2, 1 subequal to 3, 4; ? 5, 1 subequal
to 2, 3, 4. Ungues mutually alike ; those of the d fore tarsus terminate each in a
narrow obtuse squamiform point, creased lengthwise in the middle and concave beneath ;
those of the hinder tarsi and of the ? fore tarsus are narrow and uncinate. Hind
wings well developed, obtusely oblong-ovate, with the summit of the dilatation of the
marginal area obtuse ; axillar region largely developed and Avith abundant neuration, of
which a large portion is composed of nvimerous long branchlets of the hindermost
axillar nervure. In PI. XIX. 33 b the functions of the first axillar (9) have been
usurped by the intercalar nervure intervening between it and the second axillar. In
the 2 abdomen the relative lengths of segments 2-10 may be formulated thus : — 8, 11,
12, 12, 12, 13, 11, 11, 5 ; the first segment is thoracoid ; the pleurce of segments 7 and 8
are squarely truncate ; those of segment 9 are very narrowly dilated laterally, and are
each produced posteriorly into a short acute tooth ; the ventral lobe of the 9th segment

27*

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

is roundly emarg'inate Avith acute points. Porceps-basis of d variously excavated or
excised according to the species ; forceps-limbs 3-jointed, with the proximal joint
gibbous or slightly enlarged at its extreme base, and longer than the remaining joints
combined. Penis of various form, without apparent stimuli. Median caudal seta
sometimes totally aborted, and sometimes extremely rudimentary in the same species ;
outer setae about twice as long as the body in both sexes. Oculi of d obsoletely asca-
laphoid, contiguous above ; their inner orbits concave. Vertex of $ head longer than
broad, very little broader in front than behind, with the occipital border only slightly
raised and projected little beyond the level of the posterior orbits of the eyes. Median
ocellus rather smaller than the others and isolated, occuj)ying a small shallow depression
in front of and below the anterior edge of the upper surface of the head. Pronotum of
? somewhat narrowly reflexed upon the mesopleurse ; its posterior margin opposite the
interspace between the eyes is almost straight, but minutely emarginate in the middle,
and retires to form a shallow recess thereabouts. Nymph [generical identification
doubtful]. — Abdominal tracheal branchiae borne by segments 1-7, all obovate and single.
Antennae shorter than the head and pronotum, abou.t 14.-jointed at maturity. Stipes of
the mandibles unusually short ; endopodites absent ; fangs slender, two in number.
Lacinia of maxilla i. unusually short and broad, beset on the crown with numerous
slender curved pectinate spines [somewhat in the same manner as that of Thraulus is
crowned with a tuft of hair], and ciliated for some distance from the point along its
inner edge; palpus equal in length to the lacinia, its first joint nearly of the same length
as the second, and longer than the third joint. Laciuise of maxillae ii. somewhat falci-
form, much narrower than the lobes of the labium ; these are unusually broad, trilateral,
with the outer side saliently rounded off and the other sides nearly straight, and are
spinulose along their distal borders. Paraglossae roundly expanded distally, and longer
than the subrotund median lobe of the tongue. Abdominal pleurse narrowly dilated,
and with short acute points behind. Hind leg nearly of the same length as the fore
leg ; tarsus (claw excluded) about as long as the tibia. Setae subequal in length to one
another, and i as long as the body ; median seta plumose, the others ciliated on the
inner side ; their fringes taper towards the points.

Type. Ch. ignotus (in % Baetis), Walker.

Distribution. Continental Europe, in large rivers ; N. America ; Sumatra (undescribed
sp.).

Etymology. -^eipoTovriTriQ, one that stretches out the hands, from the attitude of the
imago in repose.

Synonymous with % Ba'etis (B), Walsh, 1862, and \\Isonychia, Etn., 1871.

The nymphs referred here provisionally were sufficiently matured to show that the
tarsi of the imago are 5-jointed ; and so far as their wing-neuration could be ascertained,
there was nothing adverse to their being placed here. Length of body 9, setae 4'5 mm.
Five specimens collected by Mr. Hubbard at Trenton Falls, N. Y,, on 20th May, 1874
[the typical set], and one captured hj Lieut. Oarpeuter near Denver and Colorado
Springs in the Foot HiUs, Color., in 1873 [Mus. Comp. Zool. Cambridge, Mass.], are the
materials studied.

EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. 205

Chirotonetes ignotus, Walker. Plate XIX. 33 b (wings, J , head, and forceps).

%Ba.etis iynota^ ! Walk., List of Neuropt. Ins. iu Brit. Mus. part iii. 571 (1853).

II Isonychia iynota, ! Etu., Traus. Eut. Soc. London (1871), 135, pi. vi. 29. — /. ferruyinea, ! Albarda,
Ent. Mo. Mag. xv. 128 (1878) ; ! Etn., op. cit. xvi. 36 (1879).

ISipMurus, sp. , ! Rostock, Jahresb. d. Ver. f. Natm-k. Zirickau, 1877, p. 88 (1878).

Sub'miago {living), 6 . — Eyes subolivaceous. Wings somewhat fawn-colour, becoming
{ivhen dried) dull light brownish ochre or yellowish brown, bordered narrowly along the
terminal margin with ivory-black grey, and marked in the anterior wing with two or
three evanescent dusky nebulae or abbreviated transverse streaks from the fore margin,
due to the grouping of the cross veinlets, which are very narrowly edged with black (or
when dried with light grey) ; neuration yellowish (like the membrane), with the
exception of a few cross veinlets in the marginal and submarginal areas between the
great cross vein and the bulla, which are black.

Imago (living), 6 . — Eyes light red or brownish red, with the orbits ochreous, and
with a movable black round spot or curved streak. Xotum pitch-brown or (when dried)
rufo-piceous. Abdomen purple-brown above (when dried dull \'enetian-red brown), with
the joinings of the segments very narrowly brownish, the terminal segments rather paler
than the others, and the edges of the pleuraj ochraceous ; venter spotless, unless (as in
dried examples) marked in segments 2-8 with a median light brownish Venetiau-red
triangular spot pointing forwards and extending from the hinder margin to the base of
the segment, leaving on each side a pale triangular space of the lighter ground-colour.
Setse whitish, but piceous near their insertions, with this darker colour gradually shaded
off. Eorceps dusky, paler at their joinings. Fore leg piceous ; the tibia and tarsus
pitch-black, excepting the bases of the tarsal joints and the ungues, which are pale.
Hinder legs lutescent straw- colour, or [when dried) bright amber-yellow, with the ter-
minal tarsal joint and the outer claw dusky. Wings vitreous, with almost pellucid
neuration, some of the longitudinal uervures being sometimes very faintly amber-
tinted.

$ . Very similar to the 6 . Vertex of head and pronotum pale ; the mesothoracic
sutures in front of the wing-roots yellow-ochreous. Venter paler than in the 6 ;
segments 2-7 marked on each side with a black dot beside the spu-acle, and each with
large twin acute obtriangular light subochraceous spots enclosing a chaKce-shaped or
cup-like purple-brown spot in the vicinage of the ganglion (often obliterated when,
dried). Setse ochroleucous, pui-ple-brown at the roots. Eore tarsus dusky, with the
tips of the joints black ; hinder tarsi very narrowly edged at the joinings with reddish ;
the terminal joint and ungues dusky. Length of body or wing 12-13 ; setse, 6 im. 27,
subini. 12, ? im. 20 mm.

Sab. Western Europe, from Holland to Southern France ; Arnliem, Vasserbeck (Van
Medenbach de Rooy) ; South Holland (Van Walcheren) ; Rotterdam (Fransen) ; Amboise
(Lelievre) ; Saxony (Rostock) ; Mariensee (5th September, M'Lach. Mus.). Also
Toulouse ; common at gas-lamps at the lower extremity of tlie lie du Grand Eamier by
the Pont suspendu de St. Michel (l7-20th July) ; iu flight after sunset near the Pont
d'Empalot (3rd September).

206 EEV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES.

Chirotonetes mancus, Etn. Plate XIX. 33 a (wings and legs).

\\Isonychia manca, ! Etn., Trans. Ent. Soc. London (1871), 134, pis. iii. 4 [wing] & vi. 5, 5 « [detail].

Subimago {dried). — Wings light sepia- or Cologne- earth grey, lighter for some distance
inwards from the inner margin, with narrow dark borders to most of the cross veinlets.
Setae somewhat of a dull light yellowish ochre.

Imago {dried). — ? . Head and notum of a colour inclining to light yellow-ochre
or light Roman-ochre, modified or toned down in a slight degree Avith light brownish;
the markings of the upjier surface of the head comprise narrow piceous orbits of the
ocelli ; a conspicuous triangular streak or piceous spot on each side of the vertex, which
extends from the base of the posterior ocellus, and in contiguity with the orbit of the
oculus, nearly halfway towards the occiput ; and a broad faintly defined median longi-
tudinal brown-ochreous stripe on the vertex, intersected lengthwise by a line of the
lighter ground-colour. Abdomen light ruf o-piceous ; venter spotless ; setae whitish
yellow-ochreous, sometimes with the joinings opaque, or light reddish, towards the
roots. Wings vitreous, with very light brownish neuration ; in some lights the cross
veinlets show out more strongly than in other lights. Fore femur in opaque view rufo-
piceous ; tibia less translucent than the femur, but otherwise concolorous with it ;
tarsus in opaque view light Vandyke-brown throughout in most of the specimens, but in
some of them the first joint to a large extent is lighter and more translucent than the
remainder. Hinder legs in opaque view dull greenish yellow, approaching yellow-lake,
changing in transmitted light to pale yellow-amber ; the ungues sometimes slightly
brownish.

6 . Undescribed ; the specimens of this sex referred to this species in 1871 are Ameletm
dlssitus. Length of body, $ im. 7-12 ; wing 9-13 ; seta3 15-22 mm.

Hab. North America ; W. Texas (Belfrage) and Montana (M'=Lach. Mus.), May to
July.

Chirotonetes aridtts. Say. Plate XVIII. 33 e (genitalia 6 ).

XBactis ar'ula, Say, Journ. Acad. Nat. Sc. Philad. viii. 42 (1839) ; Walk., List of Neuropt. Ins. in
Brit. Mus. part iii. 562 (1853) ; Lc Coute, Complete Writings of T. Say ii. 412 (1859) ; Hag., Smitlison.
Miscell. Coll. (1861) Synop. Neuropt. N. Am. 46 j ! Walsh, Proc. Acad. Nat. Sc. Philad. (1862) 370;
Hag., Proc. Ent. Soc. Philad. ii. 170 (1863) ; ! Walsh, op. cit. ii. 191, notes 8 & 192, note 11 (1863).

XSiphlurus aridus, Etn., Trans. Ent. Soc. London (1871) 129 [after Walsh].

Subimago (after Walsh). — "Wings clouded with dusky, especially towards the tips;
the hind wings broadly bordered with fuscous along the terminal margin ; neuration
dusky, the cross veinlets edged with fuscous. Fore legs fuscous, excepting at the base
of the first and sometimes of the second tarsal joints."

Imago. — <s {dried). " Head light ferruginous, with the orbit of the anterior ocellus
black behind, and those of the posterior ocelli black on the inner sides. Thorax and
abdomen piceous above, except the last segment ; segments 2-9 occupied severally on
each side by a pale ferruginous triangular or semicircular spot extending halfway from
tlie base ; venter piceous in the middle throughout its length ; setae pale greenish white ;
forceps sometimes fuscous towards the tips. Wings hyaline, with pale greenish hyaline

EEV. A. E. EATOX ON EECENT EPHEMEEID.E OE SIATELIES. 207

neui'ation, tinged sometimes Avith fuscous towards the costa [Walsh, 1863], or at tlie
extreme base of the costa [id., 1862]. Pore leg, as a rule, about as long as the body,
variable in coloration; femur obscure greenish at the base, fuscous in its terminal half;
tibia varying from a pale greenish with both its extremities obfuscated, to a uniformly
dark fuscous or brown black ; tarsus fuscous, with the basal halves of the joints pale.
Hinder legs greenish white, with the tips of the tarsi a little cloudy. [After Walsh.] —
The forceps-basis terminates distally in a shallow sinus, which leaves on each side of the
distal border a short, moderately broad projection terminated by the forceps-limb. Penis-
lobes obliquely acuminate.

? . Eyes in life ferruginous, bisected by a broad yellowish band. Vertex yellow,
sometimes with a yellowish vitta. Body, when different in markings from the d , almost
uniformly ferruginous. Wing-nervures pale fuscous, excej)ting those meeting the inner
margin of the fore wing. Pore leg entirely fuscous, excepting the basal halves of the
tarsal joints, which are pale. Length of body 9-13 ; wing, d 10'5-12, ? 11-15 ; setse,
6 im. 18-23, subim. 12-11, ? im. 17-26, subim. 10-11 mm.

Hab. North America ; Rock Island, 111. (Walsh); Washington, D.C. (Hag.); Indiana
(Say), about the middle of June.

Chirotonetes intermedius, sp. nov.

Imago (dried), d . — Notum intense raw-umber brown, rather lighter in the middle in

advance of the peak of the mesonotum (perhaps in consequence of pinning). Abdomen

intense burnt-carmine purple, marked with yellowish white on the dorsum and venter ;

the dorsal markings are in segments 2-8, a large spot at the base of every segment on

each side, and a very small indistinct spot or abbreviated streak in the middle of the

base ; the lateral spots of the dorsum increase successively in size jiosteriorly, those in

segments 2-4 are somewhat rounded behind, and those of segments 5-8 (oblique, subtri-

angular and obtuse) extend from the base to about f of the length of the segment, and

leave in the hinder lateral angles of the dorsum triangular patches of the dark grovind-

coloiu" in continuity with the colouring of the hinder border; in the corresponding

ventral segments the anterior lateral angles are occupied each by a small yellowish white

triangular spot ; segment 10 and the forceps-limbs light dull yellowish brown, mingled

ivith reddish purple ; forceps-basis and the nearer portions of the setae light reddish

Dm-plish, the joinings of the setse thereaboiits opaque, or burnt- carmine, the remainder

)f the setae imiformly dull yellowish white. Porceps-basis similar in form to that of

Uh. siccus ; but a difference from that species is noticeable in the penis, the lobes being

nore rounded at the tip, and less broad, so that their form is recognizable within the

?ap in the forceps-basis. Pore leg about f as long as the body ; the femur and tibia in

•paque view pitch-brown, except the inner side of the former from the base to about the

oiddle, which is translucent light raw-umber ; in oblique view the pitch-brown becomes

ighter; tarsus in opaque view light brownish Indian-red, changing in oblique light

Imost to light bm-nt-sienna ; in transmitted light the ungues, first tarsal joint, and the

ale part of the femur are equally translucent whitish amber, the tibia and remainder of

tie tarsus opaque, and the femur is largely tinged with reddish purple. Hind legs in

208 EEV. A. E. EATON ON EECENT EPHEIMEEID^ OE MATTLIES.

opaque view very light yellow-ochre, with the ungues and, in a less degree, the distal
edges of some of the tarsal joints light purplish brownish ; in transmitted light the ochre
changes to very pale amber. Wings vitreous, with bistre-, or light pitch-brown neuration ;
the principal nervures towards the base, and (in some lights only) the costa, subcosta,
radius, and some other of the longitudinal nervures, to a larger extent paler. Length of
body or wing 12, setoe upwards of 17 mm.

Hah. North America ; Arizona (M°Lach. Mus.).

Chirotonetes siccus, Walsh. Plate XVIII. 33 d (genitalia c? ).

XBaetis sicca, ! Walsh, Proc. Acad. Nat. Sc. Philad. (1862) 371 ; Hag., Proc. Ent. Soc. Philad. ii.
170 (1863) ; ! Walsh, op. cit. ii. 191-2, notes 10, 11 (1803).

ISip/ilurus siccus, Etn., Traus. Ent. Soc. London (1871) 130 [after Walsh].

Suhimago hardly distinguishable from that of Ch. aridus ; but in the present species
the 6 oculi are contiguous during life.

Imago. — 6 . Head light ferruginous. Thorax and abdomen piceous above, spotless;
setae pale gi'eenish white, usually with the joinings nari'owly fuscous, but sometimes only
so at the base ; forceps a little darker towards the tijis. Wings hyaline, with fuscous
neuration. Fore leg usually about § as long as the liody, rarely as long as it, variable in
coloration, commonly piceous, with the tip of the tibia and the base and tip of the 1st
tarsal joint (which elsewhere is conspicuously pale) black or fuscous, and with the
remainder of the tarsus entirely fuscous, excepting rarely the basal halves of joints 2 and
3, which in one example are pale. Hinder legs pale greenish, with the extreme tips of
the tarsi cloudy. [After Walsh.] — Eorceps-basis deeply, broadly, and somewhat squarely
excised behind, in such a way that the projections terminated by the forceps-Hmbs are
longer than broad ; the margin of the basis in the middle of the excision is produced
into a short subacute salient projection, which is concave beneath. Penis-lobes broad,
obliquely truncate, moderately acute at their outer distal angles.

$ . Very similar to the 3 . Pore tarsus pale fuscous, Avith the first joint conspicuously
pale. Length of body 8-5-11-5; wing, d 9-11-5, ? 11-13; setae, 6 im. 19, ? im. 15 mm.

Hah. North America ; Rock Island, 111. (Walsh), api^earing a month later than
Ch. aridus. Also North Carolina (M'^Lach. Mus.).

Chiuotonetes (?) ouNATTJS, Etn. MS., in the writing of Plate XIX. 33 ? c (genitalia 6 ).
This species must be dealt with and descrilied in the Supplement as one of undeter-
mined genus. My discrimination of generical differences in the present Section (the type
of Sipldurus) has been matured very recently ; whereas the drawings and description of
the insect were made in the year 1876, and I have not subsequently seen a specimen.
The plate Avas lithographed in 1882.

METAMONIUS, gen. uov.

Illustrations. Adult (details), PI. XX. ?34 6.

Adult. — Pore leg of 6 about If as long as the body ; tarsus a little more than twice

EEV. A. E. EATOX ON EECENT EPHEaCEEID.E OE MATELIES. 209

as long as the tibia, and this nearly 1-J as long as the femur ; gradation of tarsal joints in
order of diminution 3 and 2 each suhequal to 4, 1, 5 ; the first scarcely more than A as
long as the second joint. Hind tarsus about f as long as the tibia, and this subequal in
length to the femur ; sequence of <3 tarsal joints 2, 5, 1, 3, 4 ; the first joint f as long
as the second. Ungues mutually alike in every tarsus, narro\y and uncinate. Hind
wings well developed, ovate-trilateral ; the dilatation of the marginal area moderately
obtuse in front ; the axillar region narrow, and with scanty neviration. In the $ sub-
imago the relative lengths of the abdominal segments counting from the 2nd to the 10th
may be formulated thus : — 5, 12, 12, 12, 15, 17, 11'5, 11-5, 9 ; segment 1 is thoracoid.
The pleurae of segments 7-9 are squarely truncate [7 appears to be branchiate in the
nymph] ; the ventral lobe of segment 9, acutely excised, has short acute points. Forceps
basis of c? angularly and widely emargiuate; forceps-limbs, as in Sq^hliiriis, 4<-jointe([,
with a short basal joint tuberculate on the inner side distally, and with a curved sub-
cylindrical second joint longer than the remainder. Penis-lobes narrow, somewhat like
those of Siiohlurus. Median caudal seta rudimentary, about ^ as long as the others,
which in 6 are about 1| as long as the body. Oculi apparently ascalaphoid, and conti-
guous above in the s ; anterior ocellus rather smaller than the others. Nymph
unknown.

Type. M. anceps, sp. nov. (in ? Slphlurus, Etn. MS. 1883, in writing of PL XX.).

Distrihtition. S. America.

Etymology, jnernnwi'ioc, borne by the wind.

Metamonius anceps, sp. nov.

Siphlurus (?) anceps, ! Etn. MS., in the -writing of PI. XX. 34 b (wings & legs) .

Snbimago (dried). — Wings light sepia-grey, with piceous or pitch-brown neuration ; in
some lights only, the longitudinal nervures appear light warm sepia-brown, and the cross
veinlets black ; cross veinlets narrowly edged with darker grey. Setee sepia-grey, with
dark joinings. *

Imago {dried), c? . — Notum brown-ochreous. Alidomen in opaque view either light

raw-umber, or else reddish brown ; segments 3-8 paler on each side from the base nearly

to the terminal border ; in some examples the pale spaces in segments 3-6 are each

obtusely triangular and translucent, and a dark triangle of the ground-colour occupies

the hinder lateral angle below the space [but the pallor of these species may be partly

due to Psocida:'], and the corresponding spaces in segments 7 and 8 are very pale

yellowish ochre. Venter bordered laterally with very pale yellowish ochre, leaving in

the midst a broad longitudinal dark burnt-umber or purplish brown stripe. Setse warm

jepia-grey, with opaque joinings. Legs, in opaque view, light raw-umber ; the knee and

dp of the tibia of the fore leg, and the knees and tarsal joinings of the hinder legs dark

■aw-umber or bistre-brown. Wings vitreous, with the pterostigmatic region of the fore

ving almost imperceptibly dusky ; neuration pitch-black, the cross veinlets in the ptero-

tigmatic portion of the marginal area of the fore wing sparingly conjoined near the costa.

iicugth of body 10-13 ; wing, d 13-14, $ 17 ; setae, 6 im. 17 & 2, subim. 10 & 2 mm.

Sab. Chili (Reed, in M^Lach. Mus.). The adult ? is not represented.

ECOND SERIES. — ZOOLOGY, VOL. III. 28

210 REV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

AMELETUS, gen. nov.

Illustrations. Adult (details), PI. XVIII. ? 34 a and LXIV. 22-24.

j^dulf. — Fore leg of d as long as the body ; tarsvis nearly If as long as the tibia,
and this nearly to ^^ long as the femur ; the joints in diminution rank 2, 3, 4, 1, 5, and
the first is abou.t \ as long as the second joint. Fore leg of 2 between | and § as long
as the body ; tarsus very nearly of equal length with the tibia, which is about ^o as long
as the femur ; the joints in decreasing length rank 2, 1, 8, 5, 4, and the first is very
nearly f as long as the second joint. Ungues mutually dissimilar in each tarsus. Hind
wings well developed ; dilatation of the marginal area angular in front ; axillar region
moderately narrow, and with rather scanty neuration. In the $ abdomen the segments
are proportioned somewhat as in Chirotonetes ; the first is thoracoid. Pleurge squarely
truncate in segments 7-9 ; ventral lobe of the ninth segment subtriangular, with the
apex refuse. Forceps-basis of d widely and angularly excised ; its posterior corners by
the inner sides of the proximal joints of the limbs are shortly produced ; the limbs are
4-jointed, with a short basal joint tumid interiorly, and with the next joint, longer than
the remainder, slightly gibbous on the inner side at the base. Penis-lobes narrow,
with terminal superior stimuli, as in Slphlurus. Median caudal seta completely
aborted ; outer setae about as long as the body in both sexes. Oculi of d obsoletely
ascalaphoid, contiguous with each other above. Vertex of ? head a little longer than
broad, distinctly wider in front than behind ; occipital margin level with the posterior
orbits of the eyes. Median ocellus of ? much smaller than the others, isolated in a
small deep depression in advance of and below the anterior edge of the upper surface
of the head. Pronotum of $ broadly reflexed upon the meso-pleurge ; its posterior
margin (viewed from above) somewhat evenly arched and not receding in a very marked
degree in the middle.

Nijm])h unknown.

Type. A. suhnotatus, sp. nov.

Distribution. N. America.

Etymology. ayueAjjroc, neglected, or overlooked.

Ameletus dissittjs, sp. nov. Plate LXIV. 22 (forceps-basis).

\\Iso7iychia Xmanca S ™., ! Etn., Traus. Ent. Soc. London (1871) 134, pi. vi. 5 [excl. ?] (genitalia
misdrawn) .

Imago {dried), d . — Predominant colour of the body bright brown-ochre (perhaps fer-
ruginous in life) ; pronotum piceous ; metanotum piceoiis behind ; dorsal segments 2-8 of
the abdomen bordered distally with pitch-brown, each with extensions of the same
colouring forwards at the sides in the form of triangular spots, which, at least in
segments 6-8, occupy the hinder lateral angles of the dorsum and extend to the base
of the segment ; the ninth segment has corresponding streaks from the hind border.
Ventral segments rather lighter than the dorsum, and seemingly marked each with a
light pitch-brown blotch at the base in the middle : forceps-basis, posterior to the oval
depression, light yellowish ; forceps-Limbs piceous. Setae medium warm sepia-brown

REV. A. E. EATON ON RECENT EPHE]MERID.^ OR MAYFLIES. 211

with opaque joinings. Fore leg, in opaque view, pitcli-broT^-n ; hinder legs in some lights
bronze-brown, in other lights dull yellowish with the femora tinged with bistre-brown,
and in transmitted light brownish yellow. Wings vitreous, very faintly tinted with
greenish grey ; neuration pieeous. Length of body or Aviug, c? 10-12-5 ; setse, <S im.
17-18 mm.

Sab. North America ; California (Edwards ; M^'Lach. Mus.) ; San Geronimo, Cal.,
April 20 (Ostcn-Sacken ; Mus. Comp. Zool. Cambridge, Mass.).

Ameletus subnotattjs, sp. nov. Plate XVIII. ? 34 a' (legs) and LXIV. 23 (forceps-basis).
Siphlurus? %femoratus, ! Etn. MS., in the writing of PI. XVIII. loc. cit.

Subimago (dried), c? . — Wings light sepia-grey with pitch-brown neuration, the latter
colour varying with change of light to bistre-brown ; cross veinlets margined with sepia-
brown. Setce warm sepia-brown, with ojoaque joinings.

Imago (dried). — d . Body pitch-brown ; metanotum pitch-black ; the dorsal segments
of the abdomen appear to be largely occupied with pale light brownish yellow subtrian-
gular blotches, one on each side in segments 2-7, which leave in each of them the
terminal border, a median longitudinal stripe, and a triangle that extends along the
pleura from the hinder lateral angle to the base, of the dark ground-colour ; pleurae
narrowly coucolorous with the venter, which is rather paler than the light dorsal
blotches, and is marked in segments 2-6 with two short dark dashes from the base of the
segment, and a dark dot on each side of the median tract nearly midway between the
base and tip ; the ninth ventral segment, of a light brown-ochreous tint, has indications
of two corresponding dark streaks at the base in the form of triangular spots, and is
bordered laterally with pitch-brown as far as the joining of the forceps-basis ; the
depressions of the forceps-basis are shaded with bistre-brown ; forceps-limbs light bistre-
brown. Setse raw-umber brown at the base, lighter distally. Fore leg in opaque view
dark rufo-piceous, banded with pitch-black before the knee, the general colour changing
in other lights to dark bistre-brown. Hinder legs in opaque view light bistre-brown,
varying towards light raw-umber with change of postm*e ; femora banded with pitch-brown
before the knee ; tarsi browner than the tibiae in certain lights, especially the terminal
joint and ungues. Wings vitreous ; the fore wings close to the wing-roots, and the hind
wings to a slightly larger extent at the base, clouded with intense bistre- or pitch-brown ;
longitudinal neuration, in opaque view light pitch-brown, in oblique view light raw-umber
(excepting the stem of the praebrachial, which in most postures remains pitch-brown) and
in transmitted light translucent pieeous ; cross veinlets in opaque view intense pitcli-
brown, bordered narrowly with pitch- or bistre-brown, which bordering gives rise to small
specks in the fore wing, viz. : — one near the Inilla of the radius (3), one at the proximal
3xtremities of each of the two pairs of shorter sectorial intercalary nervures, one at the
fork of the prsebrachial (6), and another near the proximal termination of the intercalary
lervure contained within that fork : the pterostigmatic portion of the marginal area
jontains about 17 branched cross veinlets (counted at the subcosta), which, mutually
mastomosing, form a rather dense reticulation, preceded towards the bulla by about 5
nore distant simple cross veinlets.

28*

212 EEV. A. E. EATON ON EECENT EPHEMElilD^ OR MAYFLIES.

? . Wings free from the basal discoloration, and nearly so from the specks noted
in d , but yet with dark-bordered cross veinlets. Fore leg in opaque view pitch-brown,
in some lights intense bistre-brown, paler at the base and at the knee, but not dark-
banded. Hinder femora raw-umber brown, with a single ill-defined dark band before
the knee. Setse light Cologne-earth brown, with the joinings and bases of an intense
shade of the same colour or piceous. Abdomen discoloured : the median dorsal stripe
apparently is represented by a longitudinal line on each side of the track of the dorsal
vessel, and the lighter blotches seem to be less conspicuous than in the d : instead of the
ventral dashes and dots of the other sex, the $ has only small, conspicuous twin oval
dark-edged spots in the places of the ganglia. Length of body 11-12; wing, 6 13,
? 14 ; setoe, d im. about 17, $ im. 13 mm.
Sab. Colorado (M'^Lach. Mus.).

Ameletus exquisitus, sp. nov. Plate LXIV. 24 (forceps-basis).

Imago (dried), d . — Mesonotum brown-ochreous ; metanotum pitch-brown. Abdomen
in segments 2-6, and sometimes in a large part of 7, translucent at the sides : the dorsum
in these segments, in a large measure tinged with a rich brown-ochre, is bordered along
the tei'minal margin with light pitch- or with Vandyke-brown, this darker colour occu-
pying the hinder lateral angles of the segments so as to form a series of right-angled
triangular spots extending each from the hind margin of the segment to the point of
origin of the segmental trachege ; the tracheae themselves are slightly brownish ; again
from the dark terminal border in every segment two slender streaks issue basewards, one
on each side of the median track, which in ill-marked specimens are represented by small
triangular spots only, at the border in question. The remaining dorsal segments are
more opaque than the preceding, but are marked in a nearly corresponding manner with
the same darker colour, excepting the terminal segment, which is almost uniformly of the
lighter colour. Venter in segments 2-6 translucent, and (like the translucent portions
of the dorsum) of a somewhat light bistre-grey colour ; in segments 7-9 very light
brownish ochre ; the ganglia brownish, and the forceps-basis tinged at the lateral borders
with bistre-brown. Eorceps-limbs pitch-brown. Seta? warm sepia-brown, dark at the
joinings throughout, and also dark near the roots. Fore leg in opaque view pitch-brown,
with the knee yellowish brown. Hinder femora bistre-brown in opaque view, with a dark
prseapical band ; the tibiae and tarsi in opaque view light bistre- or raw-umber brown,
with the ungues opaque, or sometimes the tarsi are sepia-brown ; in transmitted light
the tibiae and tarsi acquire a yellowish tint, seldom approaching brownish or dark yellowish
umber. Wings vitreous, tinted almost imperceptibly with bistre-grey throughout ; the
pterostigmatic portion of the fore wing transparent bistre-brown : neuratiou in opaque
view dark bistre-brown, in oblique view almost raw-umber, but somewhat of a redder
brown ; in transmitted light translucent rufo-piceous ; cross veinlets of the pterostigmatic
portion of the marginal area of the fore wing branched evenly near the costa, and
regularly anastomosing with one another. Length of body, d im. 14, wing 16 : setae
defective.

EEV. A. E. EATON ON RECENT EPHEMEEID.E OR MAYFLIES. 213

One specimen, perhaps a dwarf of tlie same species, measures : — length of body, d im.
8, wing 10 mm.

Sab. North America ; larger examples Washington Territory ; smaller example Mt.
Hood (M'Lach. Mus.).

DIPTEROMIMUS, M-'Lacli. 1875.

Illustrations, Adult (details), Pis. XX. 35 [N.B. — The hind wing is defective] &
LXIV. 25.

Adult. — Fore leg of d about ly as long as the body; tarsus twice as long as the tibia,
and this about f as long as the femur ; decreasing sequence of tarsal joints, 1 equal to 2,
3, 4, 5. Hind tarsus about f as long as the tibia, which is j^- as long as the femur ; its
joints rank 1, 2, 5 subequal to 3, 4, and the first joint is about 1^ as long as the second.
Ungues all narrow and uncinate. Pore wing unusually narrow and long in its proportions,
rapidly narrowed to the roots in its proximal J, and elliptical beyond that. Hind
wings very rudimentary, trilateral and elongate, with the marginal area obtusely rounded
off in front. $ unknown. Forceps-basis shallowly, widely, and angularly excised ;
forceps-limbs 4-jointed, the basal joint very short resembling a gibbous enlargement of
the second, which is longer than the remainder, curved, and bordered on its inner side
with a narrow membranous expansion. Penis-lobes narrow, unarmed. Median caudal
seta aborted in two specimens, but present in another and then (so far as as can be
inferred from the remnant preserved) at least half as long as the outer setss ; these are
minutely pubescent, and are upwards of twice as long as the body. Oculi of d obso-
letely ascalaphoid, probably contiguous above during life ; anterior ocellus rather smaller
than the others.

Nymph unknown.

Type. D. tipuliformis, M'^Lach.

Distribution. Japan.

Mymology. Sic, nTep^v, and /i?;iioc, from its similarity in aspect to a Tipula.

DiPTEROMiMUS TIPULIFORMIS, M'Lach. Plates XX. 35 (wings, legs, and genitalia d ,)
& LXIV. 25 (hind wing refigiu'ed).

Dipteromimus tipuliformis,\ M°Lach., Traus. Ent. Soc. London (1875), 170.

Imago {dried), d . — Pronotum, hinder parts of the mesonotum, metanotum, and the
thickened hind border of the first abdominal segment yellow ochreous ; the anterior
parts of the mesonotum either raw-umber or pale reddish brown. Abdomen in segments
1-6 translucent, the dorsum bistre- or light greenish grey, passing into brownish ochre
posteriorly in segments 6-9, and marked on each side in segments 2-7 with angulated
piceous stripes ; the foremost stripe lies wholly on the dorsum in segments 1 and 2, the
portion in the first segment meeting that in the second segment a little above the
hinder lateral angle of the former segment at a very obtuse angle ; the other stripes lie
partly along the jileura in one segment and partly in the dorsum of the next segment,
in this manner : — the portion in the anterior segment commences at the anterior lateral

214 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES.

ano"le of the ventral arcus, is very narrow, and terminates in the hinder lateral angle of
the dorsum of the same segment, where it is met by a much broader stripe, which, for
a short space, follows the terminal border or joining upwards, and then is suddenly
diverted into the next segment, through which it passes obliquely, and subparallel with
the lower moiety of the nest stripe, to the terminal border of that segment ; in segments
5-7 the borders of the dorsal vessel are perhaps faintly darkened, and there may be a
fine indistinct longitudinal streak from the base on each side of it, such as is common in
the Ephemeridce ; segment 10 is yellow-ochreous. Venter in the translucent segments
pale yellowish horn-colour ; in the opaque segments extremely pale yellowish ochre ;
perhaps free from markings, excepting the streaks, already referred to, by the pleurae.
Porceps-limbs reddish brown. Setse pitch-, or intense burnt-umber brown. Wings
vitreous, almost imperceptibly tinted with bistre-grey ; neuration in opaque view for the
most part pitch-black ; the costa, subcosta, and the intervening cross veinlets of the fore
wing pitch-, modified with madder-brown ; the finer longitudinal nervures pale near the
wing-roots, and the stronger nervures raw-umber brown thereabouts ; in transmitted
lio-ht the neuration as a whole becomes pitch-brown. Fore leg in opaque view raw-
umber brown ; the femur lighter than the remainder, excepting just at the kuee. Hinder
femora, in opaque view, very light raw-umber, with the knee pitch-brown ; tibia? and
tarsi darker than the femora and of a yellower tint that approaches brown-ochre.
Length of body 11-14 ; wing, d 13-16 ; outer setae (of the larger example) upwards of
24 mm.

Hah. Japan (Von Siebold, Leyden Mus.) ; Yamato, IGth June, and Tokio, 27th Sept.
(G. Lewis, M'^^Lach. Mus.).

SIPHLURUS, Etn. 1868.

Illusf rations. Adult (details), PL XX. 34c-e [excl. XVIII.? 34 «, & XX. ?34i];
(whole figure) see citation under S. flavidns [_% Baetis], Ed. Pict. (1865). Nijnupli. PL L. ;
also poorly represented in P^osel, Insect. Belust. ii. pi. xii. 4-6 (1749), and De Geer, Mem.
Sav. Etr. Acad. Paris, ii. 468, pi. xvii. 1 (1755).

Adult. — In normal species the fore leg of 6 the is usually nearly (y^) as long as the
body ; tarsus about 2x\ as long as the tibia, and this \\ as long as the femur ; decreasing
gradation of the tarsal joints, — 2 equal to 3 and subequal to 4, 1, 5 ; the first joint | as
long as the second. Pore leg of ? f as long as the body ; tarsus very nearly 1| as long
as the tibia, and this almost -^ as long as the femur; its joints in diminishing sequence
rank 1, 2, 5, 3, 4, and the first is about If as long as the second joint. Hind tarsus of
S Ii as long as the tibia, and this about f as long as the femur ; its joints rank 1, 2, 3
subequal to 5, 4, and the first is about If as long as the second joint. Ungues all narrow
and uncinate. Hind wings well developed, obtusely ovate-trilateral ; dilatation of the
marginal area obtu.sely rounded in front; axillar region somewhat ample and well
supplied with neuration. In the ? abdomen the relative lengths of segments 2-10 may
be formulated thus :— 5, 9, 10, 12, 12, 15, 17, 15, 9; the first is thoracoid. Plem'se in
segments 7-9 obtuse behind ; ventral lobe of segment 9 very short, parabolic or obtusely

EEV. A. E. EATON ON EECENT EPHEMEKID^ OR MAYFLIES. 215

triaug'ular. Porceps-basis entire, or only slightly retuse, produced shortly between the
bases of the limbs and there split along the sides to admit the edges of their proximal
joints when the forceps close. Forceps-limbs 4-jointed ; 1st joint short, slightly com-
pressed, broader than the second, and forming a prominent projection inwards ; 2nd
joint the longest. Penis-lobes narrow and shortly beaked ; the orifice of the seminal
duct on the inner side of the beak is immediately interposed between the point of the
lobe and a small mov^eable appendage [stimulus], which together form the beak. Median
seta aborted ; lateral setse of ^ about 1|, of $ about IJ as long as the body. Oculi of
d obsoletely ascalaphoid, contiguous above during life. Vertex of $ head about as
broad as long, very little wider in front than behind ; the occipital border almost level
with the posterior orbits of the oculi. Median ocellus of j much smaller than the others,
isolated in a small deep depression in front of and below the anterior edge of the upper
surface of the head. Pronotum of ? broadly refiexed upon the mesoplevu'se, and with a
shallow curved median recess behind, which is not always distinguishable as a recess
when viewed from in front.

A long-legged s])ecies in N. America \_S. tyincus] has the fore leg of the s about 1^ as
long as the body ; tarsus about thrice as long as the tibia, and this xf as long as the
femm' ; tarsal joints (as, a priori, probable in so attenuated a tarsus) slightly inconstant
in their relative lengths, but the first joint is equal in length to the second. Pore leg of
$ about -fr as long as the body ; tarsus about If as long as the tibia, and this | as long
as the femur ; the proportions of the first tarsal joint to the second are as 17 to 13.
Hind tarsus of s about If as long as the tibia, and this about f as long as the femur ;
its joints rank in lessening length 1, 2 subequal to 5, 3, 4, and the first is about ly as
long as the second joint. Median seta aborted ; outer sette in <s nearly twice as long as
the body ; in $ about If as long as the same. In other particulars this species is
normal.

During repose the suhimago stands upon all of its feet, with the wings erect and setae
divergent.

NympJi. — Very similar to Cloeon, but readily distinguished therefrom by having only
the foremost two tracheal branchiae on each side double, and by the endopodites appended
to the mandibles. — Abdominal tracheal branchiae foliaceous and diversiform, borne by
segments 1-7 and inserted each in a notch, close to the projection of the pleura, in the
posterior margin of the dorsum ; those of the first two segments formed each of tAvo
laminae narrowly connate at the base, the others of single lamintB ; their tracheae multi-
partite, except sometimes those of the hindermost. In nymphs of advanced grade the
venation, so to speak, of these organs is a useful aid to the discrimination of species ;
the figures in PI. L. illustrate sufiicieutlv the kind of dilferences noticeable. Antennae
it maturity about li-jointcd, not longer than the head and pronotum combined.
Mandibular lobes strong and fang-Hke ; the endopodite well developed ; stipes well-
oroportioned. Palpus of maxilla i. longer than the lacinia, finger-like [in fig. 1 the
irticular membrane of the proximal joining is shown as if distended by glycerine] ; the
irst joint a little longer than the second and longer than the third, the extremity of
vhich is acute ; lacinia narrow, oblique at the point, crowned with a tuft of hair and

21G EEV. A. E. EITON ON EECENT EPHEMERID^ OR MAYFLIES.

boset with cilias intermingled sparsely with spines for some distance from the point
along its inner edge, and with a small tuft of hau* immediately below ; the spines are
not symmetrical in both maxillte of the first pair. Lacini* of maxillge ii. nearly of equal
breadth with the lobes of the labium, which nearly conform to quadrants of a circle ;
proximal joint of the palpus compressed and somewhat dilated inside before its extremity;
second joint slightly curved towards the base, enlarged distally and obliquely truncate,
equal in length to the third and half as long as the first joint ; third joint acutely sub-
ovate. Paraglossse rounded distally, narrower and shorter than the median lobe of the
tongue, which is widely retuse at the tip. Hind leg rather longer than the fore leg ;
tarsus (claw excluded) about as long as the tibia. Dorsum smooth ; pleurse of the inter-
mediate abdominal segments narrowly dilated oniscoidally, their outer edges nearly
straight for some distance from their points, and gently receding in a convex curve
anteriorly. Setge subequal in length ; the median plumose ; the outer ciliated inside and
approximately -^ as long as the body; in some species the fringes are conterminous
with the setDe, in others these are tail-pointed.

Ti/2ye. S.Jlavidus (in XBaet'is), Ed. Pictet.

Distribution. Eiirope, N. America, and Japan, in streams, rivers, and lakes ; species
more numerous in America, Northern Europe, and in mountainous regions than
elsewhere.

Etymology . ai(p\oc, defective, and ovpa, tail, from the atrophied condition of the median
caudal seta.

Subsequent to De Geer, no author appears to have noticed the nymph of Siphlurm
for upwards of a century. Dr. Hagen met with it in Prussia, but did not identify the
species or genus. The generical determination of the nymph was accomplished by
observation of *S'. lacustris in North Wales at the lakelet on Suowdon in the year 1868.

EUROPEAN SPECIES.

SlPHLUBTJS FLAVIDIJS, Ed. Pictct.

XBaetis flavida, ! Ed. Pict., Synop. Nevropt. d'Esp, 24, pi. iii. 1-6 (1865).

Siphlurus [type] fluvidus, ! Etn., Trans. Eut. Soc. Londou (1871), 125, pi. v. 30 [detail after Pict.].

Imago {dried). — ^. Notum and abdomen somewhat brown-ochreous, the latter with
longitudinal fuscous [brunes] markings on the hinder segments ; the venter is marked
with a series of strongly curved horseshoe-like or U-shaped lines pointing forwards.
Setae brown-ochraceous, with fuscous joinings. Wings vitreous, with a general faint
yellowish tint, and a Avell-pronounced yellowish stain at the base and in the pterosti^
matic portion of the fore wing. Legs yellowish ochre, with fuscous joinings.

5 . Very similar, but paler. Length of body 12 ; wing, s 12-5, $ 14' 5 mm.

Sab. San Ildefonso, Segovia, Spain, in July (chiefly after Ed. Pictet).

Siphlurus armatus, Etn. Plate XX. 34 e (forceps).

Siphlurus armatus, ! Etu., Trans. Ent. Soc. London (1870) 6; \id., op. cit. (1871) 126, pi. vi. 1, la
[detail].

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 217

Imago {dried), d . — Thorax luteo-piceous above. Abdomen fuscous above, with the
joinings paler towards the sides ; venter lutescent or ochraceous, with U-shaped dark
marks in the hinder segments. Forceps piceous. Setoe either of the very lightest
warm sepia-grey, or faintly tinged with fulvous ; the joinings fuscous. Fore legs piceous ;
hinder legs lutescent or ochi'aceous. Wings vitreous tinted with greenish grey ; their
neiu'ation piceous. Length of body 14-15 ; wing 15-16 ; setoe, d im. 24-25 mm.

Sab. England and Ireland : Eallarney (M°Lach. Mus.;; Bishop's Wood, Hampstead,
Middlesex (Wormald), in July.

SiPHLTJBUS LACUSTEis, Etu, Plate XX. 34 d (head <j , legs, and forceps).

Siphlurm lacustris, ! Etu., Trans. Ent. Soc. Loudon (1870), 7; \ id., op. cit. (1871), 126, pi. vi. 2
[detail] .

Sublmago {liciug). — Wings cinereous or very light sepia-grey.

Imago {living), 3 . — Eyes dark sepia-brown above, dark greenish grey beneath. Thorax
jet-black above, pitch-brown when dried. Abdomen piceo-fuscous above, with ochraceous
joinings ; venter dai'k greenish-grey, becoming fulvescent in the last three segments,
which are marked each with a dark U-shaped streak, represented in every anterior
segment by two dark longitudinal stripes, convergent towards the base of the segment.
In dried examples of what I suppose to be the same species the venter becomes yellowish
brown, with pale joinings, and the dark markings are sometimes absent. Forceps-limbs
bistre-brown. Sette sepia-brown at the base and greenish grey elsewhere, with opaque
joinings ; when dried light burnt-umber brown. Legs yellowish brown in dried examples ;
in life the fore femur is black-green, the tibia and tarsus greyish black, and the hinder
legs are dark greenish grey. Wings vitreous, with piceous neuration ; the pterostigmatic
region of the fore wing is faintly tinted with pale greenish.

? . Similar, but with sepia-brown setse, and with the hinder tibise and tarsi light
brown-ochraceous. Length of body or wing 12-15 ; setce, $ im. 17-20, subim. 11 ;
? im. 16-18 mm.

Sab. Great Britain : Llyn Llydaw, Snowdon ; streamlets or small burns in the neigh-
bourhood of Corse, near Lumphanan, Aberdeenshire ; in August. Also the Giffre, near
Samoens, Savoie (2280 ft.), in September ; also near San Marcello in the Apennino
Pistojese (about 2500 ft.) in August.

5IPHLUIIUS LlNN^ANIJS, Etu.

SipUurus Linnceanus, ! Etu., Trans. Ent. Soc. London (1871), 127, pi. vi. 3, 3a [detail].

Imago {dried), 6 . — Thorax above bistre-brown in front, varied with light reddish ochre

iehind. Abdomen along the middle of the back broadly fuscous, darker at the tips of

he segments, light ochraceous at the sides, the dark colour extending forwards at the

ides in segments 2-9 so as to restrict the paler colour to a triangular patch above the

piracxilar line ; venter in segments 2-8 light ochraceous marked with black, viz. ; — with

le joinings of segments 2 and 3, and in each of segments 2-8 a short triangular streak

•om the middle of the base, pointing backwards, followed by a transversely placed pair

SECOND SERIES. — ZOOLOGY, VOL. III. 29

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

of dots, and flanked in segment 8 by a longitudinally elongate spot, in segments 7-4 by
an obliquely elongate spot, and in segments 3-2 by an oblique linear stripe from the
posterior angle to tbe base, on each side ; segment 9 and the forceps-basis red-brown.
Setse whitish brown-ochre, with the joinings intense sepia-brown. Fore tibia and tarsus
dark reddish brown, the femur lighter, banded before the tip with dark reddish brown ;
hinder legs light brown-ochraceous, the femora with dark median bands. Wing vitreous,
perhaps suffused with a faint bistre-grey tint (but this appearance may be due to the
overgrowth of mould) ; longitudinal neuration pitch-black, the nervures towards the
base of the wing becoming somewhat of a bistre-brown ; the cross veinlets in the ptero-
stigmatic portion of the fore wing simple. Length of body, d 13 ; wing 14 ; setse 26 mm.

Hab. Unknown. (Linn. Mus.) This may be an American species ; but there is one
rather like it in the Italian Alps, in the neighl)Ourliood of Monte Adamello.

I have seen several other European species of Siphlurus.

NORTH-AMERICAN SPECIES.

Siphlurus occidentalis (renamed). Plate LXIV. 26 (forceps-basis).

J Heptagenia % brunnea, ! Hag., Ann. Rep. U. S. Geol. & Geograph. Survey of the Terr. 1873, part iii.
Zool. 581 (1875) [ ? im. only].

Suhimago [dried). — Wings very light sepia-grey, with pitch- or dull raw-umber brown
neuration ; longitudinal nervures pale at the base. Setse pitch-brown with opaque joinings.

Imu(jo (dried). — d . Notum piteh-l)rown, sometimes almost rufo-piceous along the
median sutui'c of the mesouotum. Dorsum of the abdomen bistre-brown, varied with
dull light ochraceous, nearly in the same manner as in S. tijpicus ; in segments 2-9 two
tapering streaks are projected from the darker colouring into the paler space on each
side of the segment ; the lower streak extends along the lateral border of the dorsum to
the base of the segment, and the upper streak, higher up on the side of the back, running
nearly horizontally, also attains the base ; the ligliter ground-colom' adjoining the dark
streaks remains in the form either of a pair of unequal triangular spots or longitudinal
streaks on each side of the base of the segment, of wdiich the lower streak is the larger, or
in the form of a single triangular spot corresponding with the lower of the two. Venter
very light brown-ochraceous with piceous markings, viz. : — in segment 9 a pair of broad
stripes, each tapering to a point behind, which meet in the middle of the base of
the segment at an acute angle, so as to form a V ; in segments 8-5 the corre-
sponding stripes combine at the base so as to form U-shaj)ed marks with oblique-pointed
arms ; in the more anterior segments their likeness to the letter U diminishes, owing
to increased obliquity in the stripes and consequent increase of width in the curves
resulting from their combination. The usual pairs of dark dots are recognizable, either
immersed in the ventral stripes, or else in contiguity with the inner edges of the stripes.
Forceps-basis and the proximal joints of the forceps-limbs usually pale, like the ground-
colour of the venter ; but the former is usually streaked with light brownish in the parts
overlain by the penis-lobes. Setse in opaque view either pitch-brown or raw-umber,
paler towards the tips. Fore leg in opaque view light pitch-brown, inclining to rufo-
piceous or burnt-umber. Hinder femora intense raw-umber, very slightly subopaque m

EEV. A. E. EATON ON RECENT EPHEMEEID.E OE MAYFLIES. 219

the place correspondiug with that of the praeterminal band in other species ; tibiae and
some part of the tarsi basewards rather lighter than the femora, but the remainder of
the tarsi about as dark as the femora. Wings vitreous ; nenration in opaque view
pitch-black, with the wing-roots and the bases of the longitudinal nervures very light
bistre-brown in both wings, and also with the costa of the hind wing to a large extent
pale.

? . Very similar. The ventral stripes in segments 2-6 combine to form wider curves
tlian in the 6 , and the innermost pairs of dark dots stand apart from the stripes ;
segment 7 has a pitch-black triangular stripe on each side from the base, an ochraceoiis
depression in the midst, and a broad dark-coloured ovivalvular border ; segment 8 is
bright yellow-ochreous in the midst, and is traversed by a blackish longitudinal stripe on
each side, which is continued through the following segments to the base of the seta ;
segment 9 is edged very narrowly at the sides with yellowish, and traversed longitudinally
by an abbreviated median yellowish cuneiform streak tapering forwards from the base of
the lobe ; the lobe itself is largely occupied by an ochraceous rhomboidal spot truncate
anteriorly at the base of the lobe so as to be reduced to the form of an irregular pentagon,
and its anterior lateral margins are narrowly ochraceons. Fore legs intense raw-umber.
Setae whitish sepia-grey, sometimes dark near the roots ; the joinings for the most part
blackish. Length of body, d 11-12, ? 13; wing, d 12-14., 2 16; setae, 6 im. 16-22,
2 im. 22 mm.

Hab. Colorado and Washington Territory (M°Lach. Mus.) ; also (in Mixs. Comp. Zool.
Cambridge, Mass.) Truckee, Nev. (Crotch, June 10), between EUes and Humboldt, Nev.
(S. Henshaw, June 10), Bridger Basin, Wy. (Garman), and Manitou, Col. (Morrison).
The description given above is based mainly upon specimens from Colorado in M^Lach.
Mus. Those from Washington Ter. have the forceps-basis uniformly bistre-brown ; and
their hinder legs may be almost imperceptibly of a darker shade than those of the typical
form. This last difference is slight enough to be attributable to fortuitous causes. In
accordance with prevalent usage, the name brimnea is restricted to the <s imago described
by Hagen in 1875, which is a BJiithrogena ; but in that genus also it will rank as a
synonym.

SiPHLURUS ALTERNATIJS, Say.

X Bcietis alternata, Say, Godman's West. Quart. Rep. ii. 304. (1824.) ; Le Conte, Comi)lete Writings of
r. Say, i. 204 (1859) ; Hag., Smithsoo. Miscell. CoU. (1801), Syiiopt. Neiu-opt. N. Am. 49 ; Walsh,
Proc. Acad. Nat. Sc. Philad. (18G2), 369 ; Hag., Proc. Ent. Soc. Pliilad. ii. 109 (1863) ; Walsb, o^j. cit.
189 (1863).— t B. II annulata, ! Walk., List of Neuropt. Ins. iu Brit. Mus. part iii. 567 (1853) ; Hag.,
3mitlison. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 48.— ± B. Xfemorata, Provauelicr, Naturl.
:anad. viii. 267 (1876) ; id., Fn. Ent. d. Canad. ii. fase. i. ^3 (1877).

Siphlurus annulatus, ! Etn., Tran.s. Ent. Soc. London (1871), 127, pi. vi. 4, 4:a [forceps and ventral
narkings]. — S. alternatus, id., op. cit. 129 (1871). — S.alternans [misprint in corrections for aliernatus'],
?rovanclier, Fn. Ent. d. Canad. ii. fase. i. 82 ^ (1877).

Stibimago. — Wings furaose, with coarser and more distiuct neuration than those of the
mago : nem-ation and membrane pale greenish at the tips of the hind wings (Walsh).

29*

220 EEY. A. E. EATON ON EECENT EPHEJIEEID^ OR MATrLIES.

Imago. — 6 . [Eyes in life pitcli-brown, intersected by a black line at their lowest \ :
Walsh.] — {Dried). Notum light raw-umber brown, darker along the middle. Dorsum of
the abdomen bistre-brown, varied with dull whitish yellow in segments 3-9 ; the lighter
coloiu" in segments 3-8 forms an acute triangle at the base of every segment on each side
about half as long as the segment [two triangular yellowish spots, more or less confluent,
sometimes extending to the dorsum, in segments 2- or 4-9 (Walsh)]. Venter extremely
light ochraceous, with intense burnt-umber brown markings in segments 2-8, viz. : — in
each segment two longitudinal stripes, a pair of dots, and a spot or streak ; in segments 4-8
the longitudinal stripes extend from near the hinder lateral angles of the segment almost
to the base, are gently curved outwards posteriorly, and are slightly convergent towards
each other in front ; in segments 2 and 3 the stripes are confluent at the base of the
segment ; in segments 2-8, between every pair of stripes, is a pair of dots placed trans-
versely not quite in the middle of the segment, and these are followed at a short distance
in the same segment by an abbreviated streak or lanceolate spot, half overlain at the
joining by the margin of the segment, and half projected into the following segment.
Setse ochraceous, with piceous joinings. [Fore legs pale brown (Walsh).] Hinder legs,
in opaque view, ochraceous ; a broad band before the extremity of the femur, the extreme
base of the femur, the knee, the joinings of the tarsal joints and tibia, and the ungues,
intense burnt-umber brown. Wings vitreous, with pitch-brown neuration ; the bistre-
grey tint formerly attributed to the pterostigmatic region is now no longer visible.

$ . Anterior and lateral edges of the vertex, and sometimes the median line, as weU as
two abl)reviated vittse on each side of it, yellowish. Abdominal markings occasionally
indistinct \_teste Walsh]. Length of body 10-13 ; wing, d 11-14, ? 12-16 ; setse, 6
im. 18-31, subim. 13, ? im. 18-19, subim. 14-15 mm.

Sab. Trenton Falls, N. Y. (Brit. Mus.) ; Rock Island, 111. (Walsh) ; North-west Ter-
ritory (Say); Quebec, Ca. (Provancher).

SiPHLURTJS FEMORATUS, Say [uot Etu., in PI. 18].

X Ba'etis femo7'ata, Say, Godman's^West. Quart. Eep. ii. 162 (1823) ; LeConte, Comjjlete Writings of
T. Say, i. 171 (1859) ; Hag., Smitlison. Miscell. Coil. (1861), Syuop. Neuropt. N. Am. 48 ; Walsli, Proc.
Acad. Nat. Sc. Pliilad. (1862), 368?; Hag., Proc. Ent. Soc. Pliilad. ii. 169; Walsh, o;?. d^. ii. 188?
(1863).— 5. mterUneata, id., op. cit. 190?

Siphlurus femoratus , Etn., Trans. Ent. Soc. London (1871), 128.

StiMmago. — Wings coloured exactly like those of Hexagenia hilineata [see p. 50, ante\
the bordering of the cross veinlets along the anterior margin of the fore wing forming
three dark clouds, of which the intermediate, situated about the bullae, is the most
distinct. Sette pale brown, with brown joinings.

Imago (licing). — d . Eyes pearly whitish above, with a movable black dot ; then' lower
|- (separated by a definite line from the whitish part) pale dusky. Notum piceous.
Abdomen in segments 2-6 transparent whitish, each of them, above, bordered narrowly
with piceous at the terminal margin, marked in the middle on each side with an obscure
oblong spot, and slightly pulverulescent with piceous along the upper part ; segments 7
and 8 of the dorsum piceous, each with a semi-oval whitish spot at the base on each side

REV. A. E. EATON ON RECENT EPHEMEEID.^ OR MAYFLIES. 221

extending to the middle ; the last segment has the sides of the dorsum whitish throughout.
Venter transparent whitish ; forceps-limhs sometimes whitish only in their longest joint.
Setre whitish, with the joinings alternately hroadly and narrowly fuscous. Wings
vitreous ; in the fore wing, the stronger of the longitudinal nervures, one discal sector
with its cross veinlets, the subcostal cross veinlets, and a small more or less obvious spot
at the bifurcation of the said sector, brown ; a coarse medial black line about a millimetre
long immediately beliind the radius, and sometimes a slight brown cloud in the ptero-
stigmatic region ; in the hind wing one long and one short series of cross veinlets on the
basal costa are strongly fuscous and enclose a brown cloud.

S . Differs from d in having segments 2-6 of the abdomen pitch-brown above, each
paler towards the base ; and there is no brown cloud at the base of the hind wing.
Length of body 12-14 ; expanse of wing, c? 25-28, ? 28-29 ; length of setge, 6 im.
20-24, 2 im. 13-16, subim. 10-14 mm.

mib. Rock Island, 111. (Walsh) ; Cincinnati, Ohio (Say). [After Walsh.]

SiPHLURUS BicoLOE, Walker.

Palingenia bicolor, ! Walk., List of Neuropt. lus. iu Brit. Mus. part iii. 552 (1853) ; Hag., Smithson.
Miscell. Coll. (1861), Synop. Neuropt. N. Am. 43.

Siphlurus bicolor, ! Etn., Trans. Ent. Soc. London (1871), 128.

Subimciffo {dried), 2 . — Wings light sepia-grey, the fore wing lighter and more trans-
parent at the base and within the space bounded by the anal (8) nervure ; neuration
dark ; cross veinlets of the pterostigmatic portion of the marginal area of the fore wing
about 20 in number, sparingly forked and anastomosing ; those of the disk margined with
darker grey. Vertex of the head, and also the notum, brown-ochreous. Abdomen dis-
coloured ; seta? light yellowish brown. Tore femur dark reddish pitch-brown, the tibia
rather less reddish and more piceous, the tarsus very light yellowish white. Hinder
femora, in opaque view, extremely light yeUow-ochre, changing in transmitted Hght to
pale amber ; the tibioe and tarsi more nearly white ; the ungues pitch-brown. Length
of body 11, wing 13 mm.

Eab. St. Martin's Tails, Albany River, Hudson's Bay (Barnston, in Brit. Mus.).

SiPHLTJRUS MIRUS, Sp. nov.

Imago (dried), 2 . — Thorax dark pitch-brown above, varied at and near the peak of
the mesonotum with dull light Mars-yellow. Abdomen fulvous or dull Mars-yellow
above, varied with brownish, the hinder borders of the intermediate segments black,
the bordermg produced forwards along the lateral margins of the dorsum from the
hinder amjles of the se<?ments so as to form acute triangular black spots in segments
2-8, and a black linear streak on each side in segment 9 ; the median basal dot and two
livergiug lines of the dorsal segments are visible in at least segments 9-8. Venter nearly
)f the same colours as the dorsum ; segments 2-8 broadly margined with black behind ;
.he black transverse bands, expanded just at their extremities, and narrowly conjoined
ilong the lateral border, are each shortly extended into a projecting point midway
>etween the side and the middle of the segment. Sette whitish, with reddish joinings.

222 EEV. A. E, EATON ON EECENT EPHEMEEID^ OE MATELIES,

Fore wings vitreous, their neuration pitcli-black somewhat brownish at the wing-roots.
Hind wings transjiarent at the base, but largely occupied by a broad transverse trans-
parent pitch-brown band (an hypertrophied bordering of the terminal margin) which
extends from terminal margin to rather beyond the fork of the praebrachial nervure (6),
and right across the wing from the costa, following the edge of the wing some distance
further in along the inner margin ; neuration pitch-black, Pemora and tibiae in opaque
view light bistre-brown or lu'onze-brown, the tibiae in some positions appearing light
or pale dull brownish yellowish ; tarsi brownish white, the ungues, terminal joint, and
distal borders of the other joints, light burnt-umber or reddish brown. Length of body,
? 10, wing 12'5, setae about 12 mm.

Sab. New Hampshire (Whitney, in Mus. Comp. Zool. Cambridge, Mass.). The con-
spicvious colouring of the hind wings enables this species to be distinguished at a
glance.

SiPHLTJRTJS TYPICUS, Sp. nOV.

Subimago {dried). — Wings uniformly light bistre-grey, with light bistre-brown longi-
tudinal neuration ; the nervui-es paler close to the wing-roots. Setae in opaque view
bistre-brown, with piceous joinings. Body pitch-brown.

Imago {dried). — 6 . Notum almost intense brown-ochre, but browner. Dorsum of
abdomen in opaque view bistre-brown, modified in segments 7-10 with light brown-
ochre; in oblique view the predominant colour changes from bistre- to raw-umber
brown, and segments 2-6 become more translucent than the others, especially at their
bases ; the darker colour in them occupies the middle of the back continuously as a broad
longitudinal stripe, extends laterally therefrom along the joinings, and then is suddenly
dilated midway towards the jilcurae so as to form a quadrangular sj)ot bounded behind by
the terminal margin and below by the hinder half of the lateral margin of the dorsal arc,
thus filling the posterior lateral angle ; from the upper anterior angle of this spot a dark
streak is produced horizontally to the base of the segment, dividing the pale space there-
abouts into a sub quadrangular spot at the anterior lateral angle of the segment, and a
longer portion beside the dark median stripe ; in segment 7 the corresponding pale spaces
are much more circumscribed in extent. Venter pale, in segments 8 and 9 modified with
brown-ochre or ferruginous, and marked faintly sometimes in segments 2-7 with fine
lines convergent towards the base of the segment, or U-shaped markings of the pattern
common in this genus, which in other specimens are not traceable. Porceps-basis pale
in the middle ; its lateral borders and the forceps-limbs light brownish. Setae whitish
warm-sepia, with piceous joinings. Pore femur and tibia in opaque view light raw-
umber brown, the latter opaque or redder at the tip ; tarsus whitish, with narrowly
piceous joinings, and with the terminal joint and ungues tinged very faintly with warm
sepia-grey ; in transmitted light the raw-umber changes to yellowish amber. Hinder
femora and tibiae very light raw-umber brown ; the tarsi whitish, tinged (especially in
the terminal joints) with warm sepia ; their joinings and ungues light reddish. Wiugs
vitreous, with a small brownish cloud along the axillar fold of the fore wing ; neuration
pitch-black, excepting the fore wing-roots and the bases of the main nervures, and also in

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 223

some lights the costa, subcosta, aud radius, which are pitch-brown or light i^itch-
brown.

S . Very similar. The ventral markings consist of a broad dark longitudinal stripe on
each side at a little distance from the pleurae in segments 2-5 or -6. The joinings of the
setae are more distinctly piceous than in the <^ , and this colom- seems to be liable to run
together into irregular bands, perhaps only in dead specimens. The terminal joints and
the joinings of the other tarsal joints are warm sepia-brown. Length of body, d 9, 2 10;
wing, d 10, ? 11 ; setae, c? im. 18-25, subim. 11, ? im. 15 mm.

Hub. Denham, Mass. (IVfLach. Mus.) ; Worcester, Mass. (Mus. Comp. Zool. Cambridge,
Mass.).

No Japanese Siphlums has yet been described; but in M'Lach. Mus. are 9 adult 2
specimens (captured by Pryer) of a large species. The colours of the abdomen have been
lost, and therefore it is inexpedient to describe the insect.

ONISCIGASTER, M-'Lach. 1873.
Illustrations. Adult (details), PI. XXI. 36 ; (Avhole figures) see citations under
0. WahefieUU of M^Lach. (1873 & 1874). Nijmph PI. LI. ; see also citations of M-'Lach-
(1874) and Vayssiere (1882).

Adult. — Fore leg of S shorter than the body nearly in the proportion of 14 to 17 ;
tarsus almost 1^ as long as the tibia, and this nearly ^ as long as the femur ; gradation
of the tarsal joints in the order of lessening length, 1, 2, 3, 4, 5, the first about 1^ as long
as the second joint. Fore leg of ? little less than half [^] as long as the body ; tarsus
about If as long as the tibia, and this f as long as the femur ; the rank of the tarsal
joints in order of diminution is 1, 2 equal to 5, 3, 4, and the first is twice as long as the
second joint. Hind tarsus of $ about 1^ as long as the tibia, and this little more than
\ as long as the femur ; the joints in order of shortening rank 1, 5, 2, 3, 4, and the first
is twice as long as the second. Ungues each unlike the other in every tarsus. Hind
wing well developed, obtusely subovate ; dilatation of the marginal area obtuse in
front ; axillar region well developed, largely occupied by numerous long anastomosing
veinlets from the inner margin. In the ? abdomen the relative lengths of segments
2-10 may be formulated thus :— 6, 8, 8, 8, 8, 10, 11, 10, 6 ; the first is thoracoid. Pleurae
of segments 2-5 in $ squarely truncate behind; those of segments 6-9 in 2, or 5-9
in c? , broadly and oniscoidally dilated, each narrowed and rounded oflf obtusely in front,
ind each produced behind into a short acute point separated by a smaU sinus from the
und border of the segment, so that this part of the abdomen is flanked by very con-
spicuous serratures ; the pleural projections of segment 5 in the i are narrower than
he others. The 9th ventral segment is unprovided with a lobe in the ? . Forceps-basis
)ipartite ; the divisions, explanate, quadrangular, longer than broad, and remote from
)ne another, might be reckoned as basal joints of the forceps-limbs. Forceps-limbs
lactyloid, 4-jointcd ; the first joint short, tapering from the base ; the second curved,
onger than the others, and very slightly gil)bous inside at the base. Penis smaU,
erhaps retracted partially in dried examples. Median caudal setaj of <S about \, of ?
as long as the body ; outer set?B of i about | as long as the body. In the 2

224 EEV. A. E. EATOX O^; EECENT EPHEMERID.E OE MAYFLIES.

subimago the median seta is about \ and the outer setae nearly f as long as the body.
Oculi of cJ remote above, oval and very prominent. Vertex of 2 head about as long as
broad, slightly wider in front than behind ; the occipital border raised suddenly above
the level of the posterior orbits of the oculi. Median ocellus of ? much smaller than
the others, isolated in a broad descending groove in front of and below the anterior edge
of the upper surface of the head. Pronotum of 2 rather broadly reflexed upon the
mesopleurse ; its posterior border (viewed from above) arched, with a very shallow median
recess, which is oot noticeable when viewed from in front.

Nymph. — Abdominal tracheal branchiae recumbent upon the dorsum, borne by segments
1-6, diversiform and single, each inserted in a notch in the hind margin of the segment
adjacent to the plem-a ; the foremost oblique, and somewhat resembling a truncate tri-
angle with obtusely rounded angles, placed with the longest side inwards ; the remaining
five are formed each of a somewhat broadly obovate or oval pergamentose lamina with a
lai'ge roundly expanded foliated lobe produced from its inner edge [defective in fig. 18]^
the margins of which are irregularly erosc and incised. The tracheation of the lamina
gives it a curiously marbled appearance. Antennae shorter than the head, about 12-jointed
in adolescence. Mandibular lobes strong and fang-like ; the endopodite well developed ;
stipes well developed, circumscribed distally by a shallow constriction. Palpus of
maxilla i. a little longer than the lacinia ; the third joint gradually tapering, pungent,
about as long as the second and little shorter than the first, but not quite as stout as
either of them ; lacinia somewhat lanceolate, with very few hairs on the oblique crown
close to the point, and with short eiliae mingled with a few slender curved spines on the
inner edge preceded by a few A'ery short hairs nearer the stipes. Laciniae of maxillae ii.
falcate, nearly of the same breadth as the narrowly ovate-lanceolate lobes of the labium ;
first joint of the palpus stout ; second joint less stout and slightly curved, very little
enlarged and almost squarely truncate distally, about as long as the first joint ; third joint
about half as long as the second, less stout, and somewhat elongate-oval. Median lobe
of the tongue subquadrangular, with the distal corners rounded, longer than broad and
slightly retuse, subequal in length to the paraglossse, of which the terminal margins
with that of the median lobe constitute together an arcuate curve ; paraglossse dilated
distally very moderately. Hind leg a little longer than the fore leg ; tarsus (claw
excluded) nearly 1^ as long as the tibia. Abdomen carinate above longitudinally in the
middle ; the carination in segments 2-9 produced into short jjoints, each i^rojecting a
little over the base of the next segment ; pleura3 in segments 1-9 oniscoidally dilated,
forming recurved acuminate serratures. Median seta plumose, the others ciliate inside,
each in its distal f ; outer setae about ^ as long as the body.

Type. O. Wakefiekli, M"Lach.

Distribution. New Zealand,

Etymology, oviokoc and -yaarhp, in reference to the lateral serratures of the abdomen.

Oniscigaster Wakepieldi, M'^Lach. Plate XXI. 36 (wings, legs, <S head, and
forceps).
Oniscigaster Wakefiekli, M<=Lach., Ent. Mo. Mag. x. 108-9, woodcut (1873, Oct.) ; id., Re^j. Brit. Ass.

EEV. A. E. EATON OX EECENT EPHEMEEID.E OE MAYFLIES. 225

1873, p. 118 (1874) ; id., Proc. Ent. Soc. London (1874), p. vi; id. Journ. Linn. Soc. Zool. xii. L39-
146, pi. V. l-u^r (1874).

Sitbimago {dried). — Wings, in opaque view, light sepia-grey ; neuratiou generally
piceous, but the principal nervuves become pale basewards ; the cross veinlets situated
in the portions of the fore wing bounded posteriorly by the inner and terminal margins,
and in front by the outer half of the sector (4) and the inner half of the pobrachial (7)
nervures, and all of the cross veinlets iu tlie hind wing are narrowly edged with faint
nebulous dark bordering ; those in the anterior portion of the fore wing (with the
exception of those in the extremity of the pterostigmatic space) are edged more or less
broadly with piceous — most broadly so in the marginal, submarginal, and the next
adjoining areas, — and their bordering in the basal halves of the first two areas is confluent
to a variable extent ; between the great cross vein and the last-mentioned cross veinlets
the membrane is pale, contrasting conspicuously with the adjacent parts ; aud in proximity
to the wing-roots the base of the fore wing from the radius (3) to the inner margin is
somewhat pale, both membrane and nervures ; and so again to a small extent is the mem-
brane in proximity to the bifurcation of the praebrachial (6) nervure. Setse dull pale
yellowish.

Imago {dried). — $ . Notum dark pitch-brown. Abdomen of a duller colour than the
notum on the dorsum, but nearly as dark, probably discoloured considerably in drying ;
in segments 2-G the trachese appear to be pale and the joinings of the segments dark;
the sides of every segment in proximity to the pleurae are more or less dark ; segments
6-9 are traversed lengthwise l>y a fine median black line, and are marked eacli by a pair
of elongated dark spots or short streaks, one on each side of the line, at the l)ase ; the
pleural expansions of these segments, and in 9 and 8 a forked longitudinal streak just
above them on each side, are also dark. Venter light yellowish brown, with black or
piceous markings : the markings comprise in each of segments 2-7 a large l)lotcli on
each side, gradually rounded off towards the base of the segment, intersected by the pale
descending tracheoe near its anterior termination, and leaving only the joining pale ; also
a transverse streak at the joining, taiiering to a point from the middle in both directions,
whence is produced a short pointed streak or triangular citsp pointing forwards in the
middle of the hind border of the segment ; also a pair of small dots or oval spots, one on
each side of the middle of the segment aud in proximity to the point of the cusp ; also
the ventral ganglion nearer the base of the segment in the median line ; and, lastly,
another pair of larger oval spots set obliquely, and rather wider apart than the smaller
spots, one on each side of the middle near the base of the segment ; in segment 8 the
smaller pair of dots is extremely small, and in 9 they appear to be totally absent, the
larger pair alone remaining. Sette whitisii yellow, sometimes discoloured at the base.
Wings vitreous, faintly tinted with light brownish [excepting sometimes towards the tips
of the fore wings, perhaps in consequence of their having been seized between finger and
thumb at the time of capture] ; neuration piceous ; cross veinlets dark-edged, nearly in
correspondence with their edging in the subimago. Legs in 02)aque view dull light
brown-ochreous, all with the base of the femur, a broad baud before its extremity, one at
the base of the tibia, one embracing the tip of the tibia and the basal half of the first

SECOND SERIES. — ZOOLOGY, VOL. III. - 30

226 REV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES.

tarsal joint, and all with the extreme tips of the joints of the tarsus and with the ungues
hlack ; in transmitted light the ochre changes to dull aniher.

d . Very similar to the ? , but perhaps rather lighter in colour. Setae pale dull yel-
lowish. Forceps pale yellowish brown. Length of body lG-21 ; wing, d 16, 2 19-21;
setse, d im. 17 & 5, ? subim. 13 & 7 mm.

HaO. New Zealand; Christchurch (Wakefield, in M''Lach. Mus. and Brit. Mus.).

Section 11 of the Genera. — Tyjie of Bcetisca. Adult. — In the fore wing the second
axillary nervure (9-) meets the terminal margin close to the anal angle, simulating the
usual appearance of the anal nervure and usurping its usual functions : the first axillary
(9') and anal (8) nervures simulate complete intercalar nervures of the anal-pobrachial
interspace, and are immediately adjacent to each other ; the third and fourth axillary
nervures meet the inner margin before the middle, occupying the usual places of the
first and second. Pronotum of minimum proportions ; mesonotum excessively developed.
Xyniph. — Pal2:)us of maxilla i. shorter than tlie lacinia. Pronotum and the mcsonotal
sutures undefined in adolescence, the wings being immersed in a large notal hood or
shield, which obtects the tracheal brauchise and a large portion -of the abdomen,

B.ETISCA, Walsh, 18G2,

Illustrations. Adult (details), PL XXI. 37 ; (whole figure) subim. see unpublished
drawing by Abbot, Brit. Mus. Cat. MSS. 460 c, vol. xii. pi. 42 bis. No. 662 (1792).
Nymph, PI. LII. ; see also citations under B. ohesa of Walsh [with circumspection]
(1864) and Vayssiere (1882).

Adult. — Pore leg of 6 little longer than the body [as 8'5 is to 7 or 8] ; tarsus scarcely

2| as long as the tibia, and this little more than f as long as the femur ; the tarsal

joints in order of sliortening rank 1, 2, 3, 4, 5, and the first is very nearly If as long as

the second joint. Fore leg of $ about |- as long as the body : tarsus barely longer than

the tibia, and this about f as long as the femur ; the tarsal joints in decreasing length

rank 1, 5, 2, 3, 4, and the first is nearly Ih as long as the second joint. Hind tarsus of

$ about ly as long as the tibia, and this | as long as the femur ; the proportions of the

tarsal joints approximate to those of the joints of the fore tarsus, but the first is

scarcely If as long as the second joint. Ungues each unlike the other in every tarsus.

Hind wdngs ample, subrotund ; dilatation of the marginal area obtusely rounded off in

front; axillar region of moderate dimensions, but with plentiful neuration ; intercalar

neuration unusually long and plentiful ; cross veinlets remote from the terminal margin.

In both wings cross veinlets are very numerous, and many of them are delicate ; in the

fore wing they are not restricted from the vicinage of the terminal margin, where many

of the longitudinal nervures are provided with short branchlets. Prosternal projection

bifid ; mcsothorax remarkably stout ; abdomen relatively short. In the ? abdomen the

proportional lengths of the 3rd-10th segments may be formulated thus : — 6, 6, 7, 14, 7,

7, 7, 6 ; of the remaining two segments, the first is thoracoid, and the second was not

sufficiently traceable for measurement in the dried specimen examined ; the pleurae of

segments 7 and 8 are obtuse, those of segment 9 acutely truncate behind ; the ventral

KEV. A. E. EATON ON RECENT EPHEMERID.^ OE MAYFLIES. 227

lobe of segment 9 is subtriangulav, with tlie apex shortly and acutely excised. Forceps-
basis of d entire, slightly retuse in the middle ; forceps-limbs 3-jointed, with the first
joint nearly thrice as long as broad, the second (the longest joint) somewhat gil)bons at
its inner base and slightly incurved, and the third joint short. Penis-lobes unarmed,
apparently combined into a single acute ovate lamellar iutromittcnt organ, concave above
and terminating with a single seminal pore. Median caudal seta atrophied ; outer setae
in both sexes f to | as long as the body ; those of the ? suhimago, from | to f as long as
the body. Oculi of 6 undivided, nearly contiguous above. Vertex of $ head somewhat
transverse ; the occipital margin raised slightly above the level of the posterior orbits
of the oculi. Median ocellus of ? isolated, a little smaller than the others. Pronotum
of ? of minimum proportions, reflexed only in the least degree upon the mesopleurae.
Nymph. — [PI. LII. was prepared from a cast slough, and consequently a small but
appreciable amount of distortion must be allowed for in some of the figures.] Body
stout, tapering in its posterior half ; integument extensively but very minutely granu-
lated or scabrid. Abdominal tracheal branchiae, in specimens of advanced grade,
completely obtected by the convex mesouotal shield (referred to above in the Sectional
description) and \_fide Walsh] decumbent upon the dorsum in the cavity enclosed
thereby; their insertions in segments 2-G are successively aj)proximated to one another
by small degrees. The said shield (in which the fore wings are immersed) dilFers merely
in its larger development from those of the nymphs of OligoneuHa and Ephemerellu
(already described), occupying, as it does, not onXj the interspace between the terminal
margins of the wings, but also surrounding their extremities and extending laterally
beyond their costal margins to the borders of the dorsum, in which respects it is doubt-
less in agreement with that of Prosopistoma. The lateral margins of the shield are
flanged, in continuity Avith the narrowly dilated pleural margin of the mesothorax, to fit
closely those of the subjacent segments ; its posterior edge, somewhat cordately sinuate,
is received into a slot or furrow in the front of a correspondingly undulated ridge
traversing the anterior part of the dorsum of the sixth segment, which is the longest by
far of the segments. [In figure 1, owing to displacement in the moulted integument,
this is overlapped by the shield, which nearly attains the posterior border of that seg-
ment.] In moulting the shield splits longitudinally in the middle ; on each side of it
two large slightly compressed straight prickles arise, one in the midst and the other at
the lateral border a little anterior to it, sloped in front but steep behind, their bases
being prolonged forwards ; of these the intermediate are the smaller. Above each of
the fore wing-roots is a small triangular tubercle. Head shortly bicornute in front ;
the spikes, horizontally prorect, slightly divergent, and either smooth or (one or both of
them) unidentate on tlie inside near the point, arise from above the anterior border of
the upper part of the head, which, viewed from below, forms a prominent transverse
ledge emargiuate in the middle and receding at the sides. Gcnoe acutely prominent
below the orbits. Antenna) 7-joiuted; the last three joints and the second joint are
longer than the others. During life {fide Walsh) the antenna; ai^e deflexcd and lie back
in grooves below the oculi. Lobes of the mandibles strong and fang-like ; endopodite
well developed ; outer edge of the stipes minutely eroded. Palpus of maxilla i. shorter

228 EEV. A. E. EATON ON EECENT EPHEMEEID,^ OR MAYFLIES.

than the lacinia; the third joint subulate, as long as the second and longer than the
tirst ; lacinia nude on the crown, its terminal border beset with numerous curved
spines, its inner edge with a small isolated tuft of short hair in the middle. Lacinise of
maxillfB II. narrower than the lobes of the labium, which nearly resemble quadrants of
the longer segments of a short ellij)se ; pali^us chelate, the second joint being produced
distally on the inner side into a slender conical projection shorter than the terminal
joint. Median lobe of the tongue subquadrate, with the terminal corners rounded off,
and with the margin slightly mucronate iu the middle between them ; paraglossse
narrow, distally dilated and rounded off. Hind leg longer than the fore leg ; tarsus
(claw excluded) about 1| as long as the tibia. Pleurae of segments 6-9 of the abdomen
narrowly dilated oniscoidally ; their outer edges for some distance from the points
straight and oblique, and then rounded off. Setse all of one length, about ^ as long as
the body and plumosely pilose. Resident in swiftly flowing rivers on the underside of
stones, creeping slowly, but swimmiug with celerity.

Type. B. obesa (in "^ Baelis), Say.

Distribution. N. America.

Etymology. Diminutive of Baitis, the classical name of the Guadalquivir, grecised.

B.^TiscA OBESA, Say. Plate XXI. 37 (wings, legs, genitalia).

Baelis obesa, Say, Journ. Acad. Nat. Sc. Pliilad. viii. 1.'3 (1839) ; Pict., Hist. Nat. Nevropt. ii. Epliem.
195 (1843-5) ; Walk., List of Ncuropt. Ins. iu Brit. Mus. part iii. 563 (1853) ; Lc Conte, Reprint of
Say's Works, ii. 412 (1859) ; Hag., Smitlison. Miscell. Coll. (1861) 45.

Btetisca obesa, ! Walsh, Proc. Acad. Nat. Sc. Pliilad. (1862) 378 ; ! id., Proc. Ent. Soc. Philad. ii.
187 (1863); \id., ditto, iii. 200-G, fig. [uymph] (1864); ! Etu., Eut. Mo. Mag. v. 81) (1868); Packard,
(Juide to Study of Ins. ed. i. 595, fig. 576 [after Walsh] (1870) ; Etn., Trans. Ent. Soc. London
(1871), 101, pis. ii. 6 [wing; misdrawn] & v. 9 [details] ; Joly [translation of Walsh 1864], Bull. Soc.
d'Etud. Sc. Angers 1878-1879, pp. 157-173, figs. 1-3 [after Walsh] (1880); Vayssicre, Ann. d. Sc.
Nat. (6) Zool. xi. 4, 5, pi. i. 2 (1881) & xiii. 72-77, pis. vi. 56, is. 98-99 bis, & x. 99-103 (1882).

Subimarfo (dried). — Wings dark sepia-grey with a narrow transparent colourless space
on each side of every cross vcinlet in the greater part of the disk, and with broader
coloitrless spaces elsewhere in the parts deticient in cross veinlets, viz. : — in the fore
wing a large clear band, ]}roadest in the hinder half of the wing, describing a curve from
the anal angle outwards to nearly the middle of the costa, and almost interrupted at the
fork of the prtebrachial (6) nervure ; also a large ii-regular blotch extending transversely
from the costa half across the sectorial intercalarv nervures : iu the hind wing the base
is pale, and the dark ground-coloiir, very sjmrsely varied with pellucid spots, extends to
.some depth along the terminal margin. Seta? light warm sepia-brown. — A sjiecimen
from Detroit, JVIich., has light yellowish-grey wings varied with dusky ; and in the fore
wing the lighter colour occupies almost the whole of the space posterior to the anal (8)
nervure ; also a broad patch, in continuity with that space, extending in proximity to
the wing-roots, and near the conjunction of the sector (4) and cubitus (5), to the radius
(3) ; also a band, likewise in continuity with the first-mentioned space, passing straight
across to the costa by the fork constituted by the union of the sector (4) with the

EEV. A. E. EATON ON EECENT EPHEMERID.E OE MATELIES. 229

second intercalary in advance of the cubitus (5). Setae, forceps, and legs dull light
yellowish ; the ungues burnt-umber brown.

Imago {dried), ? . — Notuni rather dark burnt-umber-, or intense warm sepia-brown.
Abdomen above dark burnt-umber, varied with lighter, and modified at the sides near
the base with blue-purplish grey ; venter reddish white, with a longitudinal fuscous
line in the middle of the penultimate segment. Setye pubescent, yellowish white, with
rufescent joinings. " Intermediate setae ferruginous " [Walsh]. Forceps yellowish white.
Tore femur light amber-yellow, modified with brown-ochre towards the tip ; tibia and
tarsus brown-ochreous, with pitch-brown ungues ; in transmitted light the light amber
predominates. Hinder legs lighter than the fore legs; the tibia and tarsi yellowish
white. Wings vitreous ; longitudinal neuration of the fore wing translucent light
brownish, excepting the bases of the costa, radius, and axillary nervvires, which ai-e
pitch-brown ; the marginal area of this wing contains about 10 very faint cross
veinlets before the bulla, and 17 beyond it.

$ . Very similar. Length of body 6-8; wing 9-12 ; setse, 6 2 im. 6-7, subim. 6 3-5,
? 4-5 mm.

Hab. North America ; Illinois (Walsh) ; Indiana (Say) ; Detroit, Mich. (Mus. Comp.
Zool. Cambridge, Mass.) ; California (M'Lach. Mus.).

The Michigan subimago above described probably agrees with the precocious 6
referred to by A^'alsh at tlie end of his description in 1862.

Provisional Second Series of Group III. of the Genera of the EphemeridcB.

Adult nriknown. Nymph. — Palpi of both pairs of the maxillse multiarticulate ; that
of maxilla i. far shorter than tlie lacinia ; that of maxilla ii. much longer than the
lacinia, flagelliform and geniculated. Abdominal tracheal branchiae diversiform, borne
by segments 1-7 ; the foremost formed each of a narrow membranous lamina with long
fringes ; those of the second segment are composed of a rounded pergamentose lamina
with a fascicle of fibrils annexe:! to its base ; those of the remaining segments have been
lost in the unique specimen.

Section 12 of the Genera. — Tj^q nameless. Separated provisionally from Section 13
[see page 22].

Genus and Species undetermined.

Illustrations. Nymph, PI. LIII. (slough and details).

I^ ymph-slough. — Antennae shorter than the head, multiarticulate and subulate, with
the first two joints longer and much stouter than the remainder. Labrum transverse
and emarginate. Mandibles virtually symmetrical, each with two fang-like lobes pro-
jecting inwards nearly at right angles with it almost in the middle ; of these the lowest,
representing the molar portion of the crown, ends in a short sharp tooth dominating a
small excision; the intermediate fang is bifid, with acute unequal points; the extremity
of the mandible, narrowed cuneately from the lobes to the points, is slightly incurved
and trifid, with the median tooth the longest. Maxilla i. broad ; lacinia short, termi-

SECOND SERIES. — ZOOLOGY, VOL. III. 31

230 EEV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES.

natiug in several (about 5) curved subulate teeth ; palpus minute, setaceous, 11-joiufced,
with the second joint the longest, and the third, nearly equalled in length by the penul-
timate, longer than any of the remaining joints. Laciniaj of maxillaj ii. broadly falcate,
almost as broad as the subquadrangular lobes of the labium ; palpus 13-li-jointed ; the
first joint much tlie stoutest and longest, about half as long as the flagellum; the second
joint (the first of tlie flagellum) longer than any of the others. Terminal margins of the
fore wings free. Hind leg little longer than the fore leg ; tarsus about ^ as long as the
tibia, and this about § as long as the femur ; all the legs are fringed with hair along
their upper edges, and have strongly incurved ungues. Seta3 defective ; the median
plumose, the others ciliated within. Length of body 21 mm.
Hab. Chili (Reed, in M°Lach. Mus.).

Tart lY. Read December 17th, 1885.

Third Series of Group III. of the Genera of the Ephemeridce.

AdulL — Anal-axillar interspace of tlie fore wing curvilinear-trilateral, subtended by
the anal angle and a part of the terminal margin. Porccps-basis of d well developed — its
form and that of the penis (especially the latter) facilitate distinctions of genera ; forceps-
limbs either 4 -jointed, with the second joint proportionally very long, or 3-jointed (through
coalescence of the first with the second joint), with an enlargement at tlie base of the
proximal joint. Njmph [those of section 13 unknown] : palpi of maxillai i. and ii.
2-jointed and geniculated ; terminal joint of the palpus of maxilla ii. peculiarly
pouched. Abdominal tracheal branchiiie [excepting the hindermost in some genera]
foliaceous and fringeless, furnished at the base each with a fascicle of fibrils or an annexed
lamella filiformly dissected at the edges.

Section 13 of the Genera. — Type of Atopopus. Adult. — In the fore wing the first
axillary-nervure (9^) meets the inner margin at or near the very obtusely rounded anal
angle ; the second axillary (9-), subparallel with and adjacent to the first, receives several
branchlets [or curved cross veinlets] from the distal portion of the inner margin which
comes between its own termination and that of the third axillary nervure (9-'); the
almost straight anal nervure (8) meets the terminal margin rather far in advance of
the anal angle ; the trilateral, somewhat leg-of-mutton-shaped space [the " anal-axillar
interspace"], bounded by the anal and first axillary nervures together with the terminal
margin, and attenuated towards the wing-roots, contains a variable numlier of inter-
calary nervures, incursive from the terminal margin and commonly grouped together
in two couples of unequal length, of which the longer [usually the nearest to the first
axillar (9^)] extends about halfway to the wing-roots. Tarsi of the hinder legs as long
as the tibiic or longer. Nymph unknown ; perhaps that ranked in section 12.

Absence of requisite materials precludes description of the genera of this section in
full detail.

EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES. 231

AMETROFUS, Albania, 1878.

Illitstrations. AduU (details), PL XXII. 38.

Adult. — Pore tarsus of 6 nearly 5 (about 4f) times as long as the tibia, wliicli is f as
long as the femur ; the tarsal joints in diminishing sequence rank, 1, 3, 2 equal to 4, 5
[the intermediate joints probably vary slightly iu their mutual proportions], the first joint
about 1^ as long as the second and almost twice as long as the tibia. Pore leg of 2
about y as long as the body ; tarsus about 2f as long as the tibia, and this f as long as
the femur ; the joints in the order of their shortening rank 1, 2, 3 equal to 4, 5, and the
first joint is about IJ as long as the second, and little shorter than the tibia. Ungues
mutually dissimilar in every tarsus. In the anal-axillar interspace of the fore wing
figured the two intercalary nervui-es next to the anal nervure are the longest. Hind
wings well developed ; the dilatation of the marginal area angular in front ; the axillar
region ample and supplied with abundant neuration, to which tlie hindermost nervvire
contributes numerous branchlets. Porceps basis of 6 deeply and roundly excised, with
acute points ; forceps-limbs 4-jointed ; the proximal joint stout, nearly § as long as tlie
second, which is the longest; the other joints short. Ventral segment 9 of $ formerly
(as was that of Siphlurus, erroneously) described as lobeless ; but it is just possible that
(as in the genus alluded to) a very short obtuse lobe may have been overlooked. Median
caudal seta about as long as the others ; those in ? imago about If as long as the body ;
in ? subimago about as long as the body. 6 Oculi evenly contoured.

Ti/])e. A.fragiiis, Albarda.

DistribntioH. Holland.

Etymology . ai.ieTpoc. and ttovc, from the excessive length of the d fore tarsus compared
with the tibia.

The proportion of the total length of the 6 fore leg to the body is perhaps only as
11 to 14 approximately ; but this estimate rests upon the assumption that the original
drawings of the 6 and $ legs were uniform in scale of enlargement, which, though very
probable, is not absolutely certain.

AMETROPrs FRAGiLis, Albarda. Plate XXII. 38 (wings, legs, and genitalia).
Ametropus [type] fragiUs, ! Albarda, Ent. Mo. Mag. xv. 129 (1878) ; ! Etii. op. cit. xviii. 22 (1881).

Sttbimago (dried). — Wings uniformly light smoky grey, with light yellowish or
testaceous longitudinal nervures. Setse testaceous.

Imago {dried), 6 . — Notum pitch-brown. Abdomen bistre-brown above, testaceous
at the joinings and towards the sides ; venter in segments 2-7 yellowish, in 8 and 9
fuscescent ; forceps testaceous ; sette whitish. Pore leg testaceous, with the tibia, and
the femur distally, dull piceous. Hinder legs somewhat of a light brownish ochre.
Wings vitreous ; longitudinal neuration light amber-colour ; cross veinlets colourless,
those in the pterostigmatic portion of the marginal area of the fore wing numerous,
mostly simple, and gently curved.

2 . Very similar. I'ore leg rufo-piceous, with the base of the femur, the joinings, and
the terminal joint of the tarsus testaceous. Setie very light warm-sepia or cologne-earth

31*

232 EEV. A. E. EATOX ON EECENT EPHEMERID.E OR MAYFLIES,

grey, rubigiuose at the roots. Length of body 13-15 ; wing, 6 14-15, 2 10-17 ; setse,
$ im. 22, subim. 12 mm.

Hab. Holland ; near Rotterdam (Fransen) and near Arnhem (Van Medenbach de
Rooy) in Albarda's Mus. A single Ametropus withont locality, in Dr. Hagen's collection,
was sent to me amongst Uphemeridcs collected chiefly in southern Russia, Caucasus, and
Armenia.

ATOPOPUS, Etn., 1881.

Illustrations. Adult (details), PL XXII. 32.

Adult, cJ . — Pore leg about as long as the body ; tarsus about If as long as the tibia,
and this nearly 1^ as long as the femur ; the tarsal joints in order of shortening rank 1,
2, 3, 4, 5, and the first is about 1^ as long as the second, and nearly | as long as the
tibia. Hind tarsus twice as long as the tibia, and this about -^^ ^^ long as the femur ;
the joints in order of shortening rank 1, 2, 3, 5, 4, and the first is about 3-g as long as the
second, and upwards of 1^ as long as the tibia, — the excess is larger in the intermediate
leg. Ungues each unlike the other in every tarsus. In the anal-axillar interspace of the
fore wing the two intercalary nervures nearest to the anal (8) are shorter than the other
couple. Costal dilatation of the hind Aving angular in front ; axillar region of minimum
l^roportions. Porceps-basis transverse, widely excised behind, with the sides of the
excision convergent towards a narrow low prominence at the bottom. Porceps-limbs
virtually 3-jointed. Setae about twice as long as the body; the median aborted.

T//pe. A. tarsalis, Etn.

Distribution. Borneo.

Etymology . utottoc and -kdvc, from the strange proportions of the hinder tai'si.

Atopopus tarsalis, Etn. Plate XXII. 39 (wings, legs, genitalia d ).
Atopopus [type] tarsalis, ! Etu., Ent. Mo. Mag. xviii. 22 (1881).

Imago [dried), d . — Body pitch-black above, with the abdominal pleurfc and terminal
segment flavescent ; venter and forceps pitch-brou n ; setfc pitch-black. Pore leg pitch-
black ; the femur pitch-brown from the base to about the middle ; the tarsal joinings
whitish beneath. Hinder femora in opaque view pitch-brown ; tibiae flavescent ; tarsi
brownish : in transmitted light the femora become translucent brownish, the tibiae
yellow-amber, and the tarsi yellowish with a suifusion of rather deep smoky grey. Wings
vitreous, with pitch-l)rown markings and black neuration ; the markings comprise the
marginal area of the fore wing beyond the middle and, in part, nearer the base, the
submargiual area almost to the base, and a narrow patch on the terminal margin near
the anal angle ; in the hind wing the apex and terminal margin are likewise narrowly
bordered with the same colour. Length" of body, d , 9-10, wing 11, seta3 20 mm.

Hah. Labuan (M'^Lach. Mus.).

THALEROSPHYRUS, Etu. 1881.
Ilhfstrations. Adult (details), PI. XXII. 40.
Adult, d . — Pore legs defective in the specimens examined. Hind tarsus as long as the

EEV. A. E. EATON ON RECENT EPHEMEEID.E OR MAYFLIES. 233

tibia, and this about f as long as the femur ; the tarsal joints in order of shortening rank
1, 2, 3, 5, 1 — the first is about IJ as long as the second joint, and not quite ^ as long as
the tibia ; ungues each unlike the other. In the anal-axillar interspace of the fore wing
the two iutercalar nervures nearest to the anal (8) nervure are shorter than the next two.
Hind wing well developed [defective in the illustrations] ; the dilatation of the marginal
area angular in front. Eorceps-basis transverse, with a small subobtuse projection on
each side of its distal margin in proximity to the insertions of the limbs. Eorceps-
limbs 3-jointed, with the terminal joint minute. Median seta aborted ; the outer setse
defective in the specimens examined. ? unknow^n.

Type. Th. detenniiiatus (in XBaetis), Walker.

Distribution. Java and the Philippines.

Etymology. OaXepoc. and acpvpov, from the size of the ankle or proximal joint of the tarsus.

Thalerosphyrus determinattis. Walker. Plate XXII. 40 (wings, legs [part], forceps).

XBaetis determinata, ! Walk., List, of Neuropt. lus. iu Brit. Miis. part iii. 567 (1853).
Heptagenia determinata, !Etn., Trans. Ent. Soc. London (1871), 157.
Thaler osphyrus [type] determinattis, ! Etu., Ent. Mo. Mag. sviii. 22 (1881).

Imago {dried), S . — •Piceous with a yellowish stripe down the back, including (Jide
Walker) some piceous marks in the abdominal segments. Setae in 2 intense warm sepia-
brown. Legs flavescent, the femora broadly banded in the middle and distally with
fuscous ; both extremities of the tibiae, and the tarsi also fuscous. Wings vitreous, with
the neuratiou mostly fuscous ; the costa of the fore wing towards the base bright
yellow-ochreous, but in the marginal and submarginal areas somewhat thickened and
pitch-brown. Length of body, <5 (shrunken) 11 ; wing 12 ; setse, ? im. 27 mm.

Mab. Java (Brit. Mus. and Leyden Mus.).

Thai.erosphyrus torribus. Walker.

XBaetis torrida, ! Walk. List of Neuropt. Ins. in. Brit. Mus. part iii. 571 (1853).
Heptagenia torrida, ! Etu., Trans. Ent. Soc. London (1871), 157.

Imago (dried), $ . — Thorax dark rufo-piceous above. Abdomen discoloured, dark at
the hinder borders of tlie segments. Setse lost. Eore legs very dark rufo-piceous, darker
than tlie notum ; hinder legs with femur and tiliia translucent light raw-sienna brown,
and witli tarsus and the tip of the femur light pitch-brown or rufo-piceous. Wings of a
light raw-umbre grey tint, the marginal and submarginal areas of the fore wings darker ;
neuration pitch-brown. Length of body (shrunken) S, wing 9 5 mm.

Sab. The Philij)pine Islands.

Section 14 of the Genera. — Type of Ecdyurns. Adult. — Wiug-neuration conformable
in plan to that predominant in Section 13 of the genera, described at p. 230. Hinder
tarsi obviously shorter than tlie tibia. Nymph. — Palpus of maxilla i. longer than the
lacinia. Terminal margins of the fore wings free. Pronotum distinct.

The hind wings of the adult flies are well developed, as a rule, and have the costa
iharply elbowed at about the first |th of the wing's length ; the marginal area, moderately

234 EEV. A. E. EATON ON RECENT EPIIEMERID.E OR MAYFLIES.

Li'oacl at the base of the wing, becomes linear beyond the elbow, and the axillar region is
narrow. In Ble])tHs (PI. LXV. 1) the hind wing is abnormal. The 6 oculi are almost
contiguous with one another above ; and, in ? , the median ocellus is rather smaller tlian
the hinder ocelli.

The items chiefly relied upon for generical classification in this Section are differences
noticeable in the relative leugtlis of joints of the tarsi, and in the forms of the penis-lobes
of adult specimens ; and also peculiarities of the nymphs. The style of coloration of
the wings of subimagines, and the femoral markings (if any) of the flies are likewise of
some critical value. But to arrive at a true decision respecting the genus of an individual
representative of this type upon these bases, caution and extreme circumspection are
often demanded, in view of the following circumstances.

The relative lengths of the tarsal joints of corresponding legs are not strictly invariable
in every species of a genus, nor in all specimens of the same sex of a species. The
variations noticeable in the fore tarsi of a large series of examples of one species, like the
differences between the tarsi of some species and of other species of one genvis, may
reasonably be suspected to be due either to circumstances attending the last moult, or
(in some instances) to marked diversity in the nature of the habitats of the individual
nymphs. But apart from such variations, it sliould always be remembered that tarsi are
very subject to deformity. The deformity of a leg in course of reproduction is conspicuous,
and familiar to physiologists ; no entomologist w^ould be likely to mistake such a leg for
a well-proportioned limb. But it does not appear to have been noticed hitherto, that
when a nymph has chanced to sustain the loss of a limb in early life, the remaining leg
of that pair, although uninjured, is apt to deviate from its proper projiortions in the
adult fly, through some of its component parts becoming hypertroj)hied. In this way
one or more of tlio first two or three joints of either of the hinder tarsi may acquire
abnormal extension in so slight a degree as to be appreciable only by specialists, and
yet quite sufficient in amount to occasion perplexity should unblemished specimens be
unobtainable.

When Plate XXIV. was published, this characteristic defect in adult flies grown up
from maimed nymphs had not been discovered. Some of the legs there figured were
undoubtedly the fellows of limbs in course of reproduction. I have therefore re-drawn
and re-measured the legs of representative species of all the genera of this Section
(excepting Pcegniocles and Cumpsoneuria), and quote the results thus obtained both in
the tabulated admeasurements subjoined, and in the descrijitive lettei'press, in lieu of the
older data.

The aspect of the petiis in dead specimens is sometimes much altered from that
normally presented by it during life by convulsive movements made by the moribund
insect. Sometimes these lead to extreme extrusion of the lobes accompanied by excessive
lateral divergence ; but sometimes the contrary action is set up, and the lobes are
withdrawn by a process of intussusception either partially or completely, leaving in the
latter case nothing but the stimuli visible.

In the nymphs generical distinctions reside chiefly in the abdominal tracheal-branchiye,
in some of the mouth-parts, and in the structure of the pronotum. In re^^ose their

EEV, A. E. EATON ON EECENT EPHEMEEID.^ OR MAIFLIES. 235

compressed femora protect the tracheal-brancliiaj ; but in swimming progression is aided
by scrambling movements of the legs.

In the " Aid to the Gcnerical Identificatiou " of adult IMayflies of the Ecdyunis type,
Roman numerals designating tlie five joints of each tarsus stand at the head of the
columns of Arabic numerals which set fortli the proportionate lengths of the corresponding
tarsal joints of the species named in the left-hand column. The Aral)ic numerals, in fact,
state the millimetric admeasaremcnts of drawings diverse in scale of enlargement, made
with the aid of the camera lucida. The figures of the intermediate and hind tarsi are of
uniform scale with one another in the same species, but the scale is varied arbitrarily in
the different species inversely with the size of the specimens, so as to reduce the
dimensions of the longest joints approximately to a common standard of absolute length.
Similarly the figures of the fore tarsi are diversified in scale of enlargement with the size
and sex of the specimens, irrespectively of tlie figures of the hinder tarsi of the same
species, so as to facilitate the comparison of the proportions of the tarsal joints of the
fore leg in all specimens of either sex.

Short Tabulation' of Nymphs of Section 1 i of the Genera. — Type of Ecdyurus.

LaminjE of the foremost abdominal tracheal braiichia3 convergent, coming •

into contact beneath the metasternnm ; brancliial fibrils
fasciculated.

Median caudal seta present in specimens of advanced age Rhithrogena. PI. LIV.

Median caudal seta entirely absent in aged specimens Iron. PI. LV.

Laminse of the foremost abdominal tracheal branchiic widely remote from
each other.
Median caudal seta entirely absent in aged specimens. Branchial fibrils

fasciculated Epeorns. PI. L VI.

Median caudal seta present.

LaminiK of the hindermost tracheal branchite conspicuously differ-
ent from the others, being liiiear-lanceolate instead of broad ;
branchial fibrils connate for some distance, thus forming a
single filiformly multifid membranous appendage to each of
the broader laminse, which are oblique at the base.

Broader branchial laminae obovate-oblong and cuspidate Nameless Gen. PI. LVIl.

Broader branchial lamina3 snb-quadrilatcral, mostly aurieled

below at the base and rounded off at the other corners Nameless Gen. PI. LVIII.

Laminje of the hindermost tracheal branchiaj very similar in form
to the others ; branchial fibrils fasciculated.
Branchial lamiufe of the intermediate pairs of tracheal

branchiae mostly ovate-triangular and broad Nameless Gen. PI. LIX.

Branchial laminie narrowly lanceolate Heptac/enia. PI. LX.

Branchial lamiiue of the anterior pairs of the series ellipsoidal ;
those of hinder pairs pass gradually from oblong-oval to
obovate. In Junior specimens the laminaj are narrower
and trilateral Ecdyurus. Pis. LXT., LXII.

236

EEV. A. E. EATON ON EECENT EPHEMEEIDiE OR MAYFLIES.

Tabulation showing the proportionate lengths of the joints of the tarsi ; the joints of each tarsus are indicated by
Roman numerals, their relative lengths by Arabic,— explained at p. 235.

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EEV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES. 237

EPEORUS, Etii., 1881 ; restricted [in PI. XXIY.] 1883.

Illustrations. Adult (details), PL XXIV. 44 A. Nymph, PI. LVI.

Adult. — First joint of the liiud tarsus rather longer than the second; first joint of the
fore tarsus commensurate with tlie second joint; ungues of the 6 fore tarsus alike and
obtuse ; penis lol^es of moderate breadth, joroduced outwards a little at their extremities.
Fore leg of 6 about as long as the body : tarsus about l,y as long as the tibia, and this
about IJ as long as the femur ; the tarsal' joints in order of shortening rankl equal to 2,
3, 4, 5. Pore leg of 2 about yo as long as the body ; tarsus about | as long as the tibia,
and this about x| ^^ long as the femur ; the tarsal joints rank as in tlie other sex. Hind
tarsus of 6 about f as long as the tibia, and this about i as long as the femur ; joints
1-4 of the tarsus diminish successively in length by small gradations. Ungues of the 6
fore tarsus alike, broad and obtuse; those of the hinder tarsi and also of the ? fore
tarsus each unlike the other. Hind wings of ordinary form ; the axillar region narrow^
but Avith sutficient neuratiou. In the 2 abdomen the relative lengths of the dorsal
segments 2-10 may be formulated thus : — 7, 9, 12, 12, 12, 10, 10, 5, 5 ; ventral lobe of
the ninth segment refuse. Porceps-basis of the S produced behind into short divergent
lobes for the support of the forceps-limbs ; the short proximal joints of the limbs
combine with the second joints so as to constitute a gibbous enlargement at the base of
each limb. The seminal ducts terminate near the extremities of the penis-lobes ; stimuli
not obvious. Outer caudal setae of 6 about thrice, of ? 2.^-3 times, the length of the
body. Vertex of ? head transverse; the edge of the occiput ascends from the middle
towards the posterior orbits of the oculi in even curves ; median ocellus somewhat
isolated, moderately prominent, in dried examples, below the front border of the upper
surface of the head. Pronotum of 2 excised, or sometimes cordately excised in the middle-
behind ; the reflexed lateral lobes rounded below and somewhat straightened beliind.

Subimafjo. — "Wings tinted wath greyish ; the neuration opaque ; the bordering of the
cross veinlets (when developed) inconspicuous. During repose the insect prorects its
fore legs a little apart, and the seta? are only separated to a small extent.

Nymph. — Abdominal tracheal branchiae obliquely rcclinate or decuiubent at the sides,
with short scanty suberect fasciculate fibrils ; lamina; of the foremost pair far apart, each
a little longer than broad and obliquely ovate ; hinder lamin;^ nearly uniformly oval,,
with the outer or inferior margins thickened and ciliate ; the fourth lamina on each
side is the longest, and those anterior to it diminish successively in size less than the
three that follow : branchial trachege well defined, laxly and delicately arborescent,
distributed chiefly towards the thinner parts of the lamina?. Median caudal seta totally
absent; the two little longer than the body, and glabrous. Pronotum well defined,
truncate posteriorly ; its lateral ])orders undilated, rounded off at the front corners, but
subparallel behind. Pangs of the maudiljles unequal, compressed, denticulated at the
tips ; the exterior fang broad and only moderately acute ; the interior fang much shorter
and smaller; endopodite absent, represented only on the left mandible by an incon-
spicuous tuft of hairs. Lacinia of maxilla i. nude externally, and terminated Ijy three
subequal subulate fangs ; first joint of the palpus stout, enlarged only slightly towards

SECOND SEEIES. — ZOOLOGY, VOL. III. 32

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

the base ; second joint clavate, obliquely truncate and densely velutinous at the end, and
acute at the tip. Median lobe of the tongue subquadrangular, longer than broad;
paraglossse obliquely truncate, broadest at about the middle. The dark markings of the
femora on the coloui'ed side comprise a pair of short opposite longitudinal streaks near
the base, separated by a narrow interval from three other longitudinal streaks, of which
the two longer extend to the tip, and the shorter is contiguous with the lower edge ;
these three combine partially to form an irregular submedian fascia ; a dot in the inter,
space between the basal and distal groups of streaks is coalescent with the lower streak
of the former group.

Type. E. torrentium, Etn.

Distribution. Europe, Armenia, and North America. A Himalayan insect also is
ranked provisionally in this genus.

Etymology . eVrjojOoc, soaring on high.

The Armenian and American species, communicated by Dr. Hagen, are undescribed.
A single pinned specimen from the former province is in his own cabinet ; and from the
latter continent three nymphs in alcohol, exhibiting the normal structure, are in Mus.
Comp. Zool. Cambridge, Mass., registered 22(?, Wenas V., W. T., Taylor's 6, vii. 1882.
Before Iron and Cinygma were recognized as genera, other specimens than those above
referred to were returned as species of Epeorus, Etn. MS.

The generical identification of the nymph was established by an exhaustive examination
of the'fauna of sites in a mill-stream frequented by the imago of E. torrentium at Tarascon
(Ariege). The subimago was observed to take flight at places where the water rippled
strongly over submerged stones ; the stream was nearly waist-deep, and the strength of
the current rendered the employment of a water-net indispeusable to the capture of the
nymphs lurking beneath the stones. This mill-stream is close to the highway above the
town.

In insects of this genus the coloration of the body is often difficult to define, owing
to the superficial tissues differing in hue from more deeply situated pigmentary matter
visible through them. The pattern of the ventral markings affords an easy means of
distinguishing the species of adult specimens.

Epeorus geminus, sp. nov.

Imago, s . — {dried.) Notum brown-ochreous, darker behind. In each of the ventral
segments 3-7 a single narrowly obcuneate, or obovate-lanceolate, dark spot contains before
the tip of the segment a pair of pale dots. In dorsal segments 2-8 the terminal margin
is dark, excepting at the pleurte, the hinder angles of which are of a light colour ; and
the dark colouring is continued from the said margin on each side, descending forwards
obliquely in a gentle curve to the main trachea, and, running onwards along it, terminates
at the place of the branching-off of the dorsal trachea. — [Living.) Eyes warm sepia-brown.
Notum bistre-brown, darker laterally and posteriorly. Dorsal abdominal segments 2-8,
light brownish yellow at the base and sides, bordered broadly with pitch-brown along
the greater part of the terminal margin, and striped obhquely with the same colour on
each side, the stripes descending from the bordering nearly to the middle of the lateral

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 239

margin ; the remaining segments darker. Venter traversed lengthwise by a median
very light burnt-umber stripe, which in segments 1-7 is dilated more or less broadly,
posteriorly, so as to form a series of obovate or obovate-lanceolate spots. Setse piceous,
with the joinings of the more attenuated portions opaque. Fore leg piceous, with the
basal f of the femur above (like the trochanter) either yellowish brown or rufo-pieeous.
Hinder femora {dried) light raw umber or yellowish brown, with a fine very indistinct
dark longitudinal streak in the midst ; tibiae yellower than the femora ; tarsi light bistre-
brown ; in transmitted light the femur becomes brownish amber, and tlie tibias yellowish
amber. Wings vitreous, tinged in the pterostigmatic region of the fore wing with bistre-
grey ; neuration piceous, excepting the proximal extremities of the longitudinal uervures
posterior to the radius, the costa of the fore wing at the roots, and that of the hind wing
in the vicinage of the salient angle. Length of body 14-15 ; wing 16 ; setae, 6 im. 40 mm.
Hal). Portugal ; common by a stream from the Estrella, S. of Sabugeiro (4200 ft.,
10'30 A.M., 7th June, 1880, water 56° F.). In the living insect the tips and median
streaks of the hinder femora are blackish.

Epeorus assimilis, sp. nov.

Subimago ? [dried). — Wings light bistre-grey, with bistre-brown neuration ; the wing-
roots lighter and pale yellowish.

Imago s [dried). — Notum pitch-black, or pitch-brown in front and pitch-black behind.
In each of the ventral segments 3-7 a single broadly obcuneate dark spot contains a pair
of ill-defined pale and mostly elongate dots. In dorsal segments 2-8 the terminal
margin is dark excepting at the pleurae, the hinder angles of which are of a light colour ;
and the dark colouring is produced forwards from the said margin in a curve through
the scar of the nymphal tracheal branchia on each side of the segment, terminating
thereabouts and not extending to the place of the branching-off of the dorsal segmental
trachea. Fore leg piceous, in some lights somewhat rufo-piceous along the upper edge of
the femur, but less distinctly so than in E. gemiuus. Hinder femora light bistre-brown,
very indistinctly banded with darker in the middle ; tibiae and tarsi in opaque view
rather lighter than the femora, but only in a slight degree, with the tarsal joinings
brownish and the ungues piceous ; in transmitted light the hinder tibiae are of a yellower
amber-colour than the femora. Wings vitreous, tinted slightly, or sometimes strongly,
towards the base with light yellov\dsh-green, and tinged with sepia-grey in the pterostig-
matic region of the fore wing ; neuration pitch-black, with the same exceptions as in
E.geminm. Length of body 14 ; wing, 6 15-16, $ subim. 17 ; setae, S im. 35-45 mm.

Sal). France and Belgium ; near Pau, in the Neez, al)ove the Pont d'Oly (600 ft.,
June 4, 1878). Also the Schwarzwald, Baden (M^Lach., end of July 1835), where it
occurs at altitudes of 2200-2700 ft.

Epeorus alpicola, Etn. (restricted).

Heptaffenia alpicola, ! Etn., Trans. Eut. Soc. London (1871), 148 [excl. Carinthian examples & pL vi.
19, detail oi Ecdyurus Zelleri].
Imago [dried). — Notum varying from reddish umlier or Vandyke-brown to rufo-

32*

240 EEV. A. E. EATON ON EECENT EPHEMERID.I: OR MAYFLIES.

piceous or almost to brown-ochre, and commonly traversed by a darker longitudinal
median stripe in front. The ventral markings in segments 1-8 compose a continuous
median dark stripe dilated in the middle of each of the segments (although not always
distinctly so in some of the hinder segments) : the usual pale dots are indistinct or
absent. In dorsal segments 1-8 the terminal border is very distinctly edged with dark
colouring, which extends almost to the lower margin of the hinder lateral angle, and
which, in lieu of running forwards in a curve at the side of the segment, exhibits at most
only a short acute projection barely reaching the edge of the scar of the nymphal
tracheal branchia. (Livinff.) — d . Eyes roman sepia-brown. Notum either fusco-luteous,
or pitch-brown varied with pitch-black. Superficies of the dorsum light bistre, or
greenish grey ; the underlying tissues especially in segments 8-10 are often tinged in some
measure with orange or yellowish : at the terminal margin segments 1-8 are bordered
narrowly and somewhat evenly with piceous, and the bordering almost extends to the
lateral margins of the hinder angles of the pleuree in segments 1-7 ; but in segment 8 it
ceases at the pleurae so as to leave the hinder angles of the segment wholly of the
lighter colour ; in segment 9 a triangular streak of a similarly dark colour extends on
each side in proximity to the pleura from the terminal margin to the base of the segment.
Moreover in every abdominal segment the dorsal vessel is bordered on both sides with
light brownish, this colouring forming in segments 4-6 twin triangles, acuminate behind,
having the track of the vessel as their common base adjacent to their acute angles.
Venter light yellowish olive-grey, tinged in the penultimate segment with brown-ochre,
and traversed lengtliwise by an extremely light jecinoreous or burnt-umber stripe in
segments 1-7, which is dilated angulaidy in the middle of each segment so as to be
resolvable into a continuous series of hexagonal spots, broad in the anterior segments
and elongated in the hinder segments ; in each of these spots are the usual pair of pale
dots beyond the middle, and three longitudinal dark lines (the dark borders of the nerve-
trunks visible through the integument) in front. Forceps olivaceous or w^arm sepia-
brown, with the last two joints dusky inside. Setse warm sepia-brown, becoming more
intense towards the roots. Fore femur pitch-lu'own or rufo-piceous, the tibia and tarsus
darker, with the distal edges of the intermediate tarsal joints whitish : when dried the
femiir in opaque view becomes bistre-brown, with the lower edge dark for some distance
from the base, and with faint indications of a dark broadly diffused streak a little before
the middle ; the tibia and tarsus become pitch-brown or pitch-black ; in transmitted light
the femur becomes brownish amber-colour, the tibia more opaque tlian it, and the tarsus
subequal in translucency to the femur. Hinder femora pitch-brown, dark at the tips ;
tibia? dull reddish pitcli-brown ; tarsi black or pitch-black : when dried the femora in
opaque vieio become light bistre-brown, each dark at the tip and with a dark longitudinal
streak almost from the base nearly to the middle, tapering at both ends ; and the tibiae
and tarsi become pitch-brown. Wings vitreous, tinged with bistre-brown or sometimes
bistre-grey in the pterostigmatic region of the fore wing : neuration in opaque view
black, in transmitted light pitch-brown, excepting at the bases of the wings, where
the colouring of the main nervures becomes deficient or at most light raw-umber
brown.

EEV. A. E. EATON ON EECENT EPHExMERID.E OE MAYFLIES. 241

? (dried). — Notum more of a brown-oclire than in the other sex, whence an approach
in general appearance is made to E. torrej/tiiiM 2 ; but the ventral markings of
K alpkola S conform to those of the 6 and suffice to distinguish the species. The
pterostigmatic region of the fore wing is only slightly tinted with bistre-grey. Length
of body, 6 12-14, ? 13-14 ; wing, s 11-16, ? 15 ; setge, 6 im. 36-44, 2 im. about
33 mm.

Rab. The Bernese Oberland, and from the Pennine to the Ehaetian Alps, at altitudes
of about 3000-6000 ft. Switzerland : Meyringen, near the Alpbach (M°Lach.) ; a torrent
between Champery and Tervin, Valais (4500 ft. 14 August, 6 p.m., water 50- E.) ; the
St. Gothard (jVPLach.). Savoie : les Contamines (about 4000 ft) ; Chamounix (M^Lach.).
Italy : Macugnaga, Val Anzasca (about 5000 ft., M'Lach.) ; the Oglio, in Val Mazza, near
Ponte di Legno (5800 ft. 29 July, 5 p.m., water 49 P.).

Epeoetjs toruentium, Etu. Plate XXIV. 44 a (legs & penis) & LVI. (nymph).
Epeorus [type] toirenfhcm, ! Etn. Eut. Mo. Mag. xviii. 26 (1881).

Subimago [licing). — Wings cinereous with olivaceous or bistre-brown longitudinal
nervures and dark-edged black cross veinlets. Fore legs piceous ; hinder legs olive- or
bistre-brown with black tarsi. Eyes blackish green. Setee blackish with opaque joinings.
(Dried.) — Wings light bistre-grey in opaque view, with raw-umber longitudinal
nervures, and black cross veinlets narrowly margined with light grey ; the wing-roots
lighter.

Imago (dried). — d . Notum light brown-ochre, sometimes modified posteriorly with
faint traces of light bistre. The ventral markings form a continuous series of spots
diminishing in breadth inversely with the lengthening of the segments : in d the spot
in segment 5 is narrowly spathulate, those in segments 7 and 8 are sublineai-, that in
segment 3 broadly pyriform, and that in segment 2 almost semicircular ; the usual pairs
of pale dots or spots are distinct as well as the three or four tine dark lines alongside of
the nerve-trunks. In dorsal segments 2-8 the terminal margin is dark excepting at the
pleurge and in close proximity to them ; the dark colouring, leaving the hinder angles of
the segment pale, is suddenly produced forwards in a curve from the said margin to the
scar of the nymphal tracheal brauchia, and, distinctly skirting the upper and the front
edges of the scar, either terminates in the pleura at about the middle of the segment,
short of the actual edge, or (in some examples) is very faintly traceable beyond that up
to the place of the branching-off of the dorsal segmental trachea ; in 2 the edges of the
said branchial scars are dark all round. Eore leg in opaque view : — femur pitch-black
lengthwise below and either light bistre or dvill rufo-piceous above ; tibia and tarsus
aitch-black or pitch-brown : in transmitted light the femur becomes translucent piceous,
:he tibia and tarsus or sometimes only the tarsus bistre-brown. Hinder legs in opaque
new dull yellowish brown, with the tarsi in some lights dull reddish brown, and with an
U-defined blackish band nearly in the middle of each femur ; in transmitted light the
irevaihng colour is an impure pale brownish amber, the ungues and the distal edges of
he tarsal joints, however, remaining opaque and brownish. Wings vitreous; the
)terostigmatic region of the fore wing almost imperceptibly tinted with greenish grey :

242 EEV. A. E. EATON OIN EECENT EPHEMERID.E OR MAYFLIES.

neuration in some lights pitcli-black, in others pitch-brown, the cross veinlets in some
positions remaining of the darker colour while the longitudinal nervures become pitch-
brown ; in both pairs of wings the subcosta is dark throughout, but the other main
nervures become more or less deficient in colouring near the wing-roots. Setae sepia- or
warm sepia-brown at the roots, lighter distally, with dark joinings. The living d is
described in the publication cited above.

? {living). — ^Eyes greenish, intersected by a fusco-piceous line, and exhibiting a
moveable black spot. Very similar in colour and markings to 6 . Dorsum of abdomen
in segments 2-7 either fusco-luteovis or light bistre-brown, with a rounded pale space on
each side extending some distance from the base of each ; segments 8-10 brown-ochreous :
in each of the intermediate segments the recurved stripes from the dark terminal
bordering are piceous, and there is a dark median longitudinal streak from which the
colouring spreads outwards for a short distance along the basal margin of the segment ;
the median streak disappears in the process of drying. Length of body, d 11, ? 13 ;
wing, 6 12, $ 15 ; setaj, d im. 28-29, subim. 17, S im. 22-26, subim. 19 mm.

Hab. Southern France, and perhaps Northern Italy : August and September.
Common at Tarascon (Ariege), inhabiting the conduit above the town as well as the
main stream (1560 ft., August 25th, afternoon and evening, water 64° P., and Sept. 1st).
A ? subimago doubtfully referred here was captured between Lovere and Breno in the
Val Camonica (770 ft., August 3rd, 3.30 p.m., water 66° F.). This specimen (cMed) has
very light sepia-grey wings, with pitch-black neuration and pale yellowish wing-roots.
The Oglio and Ariege in the places specified have apparently a similar water-climate,
and are inhabited by Oligoneuria rhcnana ; therefore it is not improbable that the same
species of Epeorus is common to both. My hesitation as to the identification of the
Italian insect proceeds from the slight colour-differences noticeable between the single
examples of subimago available for comparison ; but these may be due solely to disparity
of age.

Care must be taken to distinguish this species from Ecdyurus fiuminum 2 .

Epeoktjs psi, sp. nov.

Imago [in spirits). — 6 . Body discoloured. The abdomen exhibits black markings
upon a lighter ground-colour, viz. : — on the dorsum, in segment 2 a small round median
spot ; in segments 3 and 4 corresponding single trilobate spots ; in segments 5-9 corre-
sponding single tridents or ^-oid markings, each formed of a median longitudinal line in
combination with oblique stripes ascending the sides of the dorsum. The ventral
markings in each of segments 2-7 comprise a very fine longitudinal median line produced
forwards from the hinder part of the segment, sometimes partially effaced anteriorly,
and a pair of fine tapering streaks, one on each side of the median line, mutually
convergent towards the base of the segment. Each femur has a neatly defined black spot
nearly in the middle, and is darkened towards the knee ; ungues each unlike the other.

? . Ventral lobe of segment 9 very slightly emarginate in the middle. Length of
body, 6 16, S 18 ; wing, 6 16, ? 22-24 ; setae, d and ? im. 40 mm.

Hah. Kooloo, Himalaya (Rev. M. Carleton, Mus. Comp. Zool. Cambridge, Mass.).

EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 243

BLEPTUS, gen. nov.

Illustrations. Achilt (detail) PI. LXV. 1.

Adult. — Eirst joint of the hind tarsus rather longer than the second ; first joint of
the 6 fore tarsus also longer than the second ; ungues each unlike the other ; penis
lobes when dried conformable to those of normal species of Bliithrogena ; hind wings
unusually small, destitute of axillar neuration. — Fore leg of <s about li as long as the
body ; tarsus nearly 1\ as long as the tibia, and this about 1-^^ as long as the femur ;
the tarsal joints in the order of their shortening rank 1, 2, 3, 4, 5. Hind tarsus of
6 about f as long as the tibia, and this l^f as long as the femur ; the tarsal joints in
order of shortening rank 1 equal to 5, 2 subequal to 3, 4. Ungues in every tarsus
each unlike the other. Forceps-basis of d bifid, but only slightly emarginate in
the middle of its posterior border, and not produced into projecting lobes at the
bases of the limbs ; the short proximal joint of each limb is well defined. Penis lobes
tubular, curved very slightly outwards, but contiguous at the roots ; orifices of the
seminal ducts terminal. Outer caudal setae of d 3i as long as the body. Only the
adult 6 is known.

Type. JB.fasc'mttis, sp. nov.

Distribution. Japan.

Etymology. /SAeTrroc, worth seeing.

Bleptus fasciatus, sp. nov. Plate LXV. 1 (hind wing).

Imago {dried) 6 . — Notum dark brown-ochre. Dorsum of abdomen light brown-ochre,

with the joinings of the segments and a fine longitudinal median line pitch-brown or

intense warm sepia ; segments 8-10 rather darker than the others : venter spotless.

Setae warm sepia-brown, dark at the roots. Porceps-limbs slightly brownish ; the basis

concolorous with the venter. Femora and tibiae in opaque vieiv light raw-umber brown,

dark just at the knee, and piceous at the extreme tip of the fore tibia : tarsi dull light

yellowish, the fore tarsus approaching the lightest tints of Roman ochre or raw sienna,

and having the terminal joint and ungues light raw-umber brown ; but the hinder tarsi

are lighter and more uniform in tint. In transmitted light the general colouring of the

femora and tibise becomes a rich yellow amber, and that of the tarsi whitish amber, with

the joinings of the hinder tarsi slightly opaque. Wings vitreous, with brownish or

greyish markings : in oimque vieto of the fore wing the marginal and submarginal areas

are of a light raw-umber bro^vn tint, which in the pterostigmatic region acquires a slight

iegree of opacity ; a narrow, irregular fascia, curved outwards a little, and of rather a

greyer brown (approaching light bistre) than the said areas, crosses the wing almost

lirectly from the radius to the vicinage of the extremity of the anal nervure, and there-

ibouts becomes slightly dilated, running inwards a little along the margin of the anal-

ixillar interspace ; a cloud of the same colour as the fascia, concave inwards, occupies

he extremity of the wing posterior to the radius, and the same colouring borders more

•r less narrowly the remainder of the terminal and inner margins : in transmitted light

ery little difference is perceptible between the tint of the marginal and submarginal

reas, and that of the markings of the remainder of the fore wing. A broad intense

244 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MATELIES.

sepia or brown-black border surrounds the tip of the hind wing, and, narrowing gradually,
terminates anteriorly where the costa first comes into proximity to the subcosta, while
posteriorly its extremity is nearly coincident with that of the anal (8) nervure. Wing-
nem-ation, in opaque view, for the most part pitch-black ; but that of the colourless
portion of the hind wing is pale ; and in the fore wing the subcosta and radius outside
the pterostigmatic region, together with the interjacent cross veinlets and parts near the
subcosta of the cross veinlets in the adjoining portion of the marginal area, and also the
near extremities of the main nervures posterior to the radius, are light raw-umber.
Length of body 10 ; wing 13 ; setae, 6 im. about 35 mm.

Jlab. Japan ; Yagohara, 29th July (G. Lewis, in M'Lach. Mus.).

IROX, Etn., 1883 [in Plate XXIV.].

Illustrations. Adult (details), PL XXIII. 44 [Epeoriis] and PI. XXIV. 44
[/row]. Nymph, PI. LV.

Adult. — First joint of the hind tarsus equal to the second and third joints respectively ;
the corresponding joints of the intermediate tarsus similai'ly proportioned ; first joint of
the c? fore tarsus longer than the second, which is equal in length to the third joint ;
first joint of the ? fore tarsus shorter than the second, and this equal to the tliird joint ;
ungues mutually dissimilar. Penis lobes apparently liable to be deformed through
desiccation ; in the typical species they are comparable to those of Thalei'osphjrus
(PI. XXIII. 40), but are not so broad ; but in the other species they seem to be tubular
and contiguous, somewhat as in Bleptus or species of BhUhrogena. — Fore leg of d about
as long as the body ; tarsus about 1^ the length of the tibia, and this about twice as long
as the femur; the joints in the order of their shortening rank 1, 2 equal to 3, 4, 5.
Fore leg of $ about as long as the body ; tarsus about | the length of the tibia, and
this about l-^-o as long as the femur; the joints in the order of their shortening rank 2
equal to 3, 1 equal to 5, 4. Hind tarsus of 6 about f as long as the tibia, and this very
nearly as long as the femur ; its joints in order of their shortening rank 5, 1-3, 4, and
the first three joints mutually equal in length are each about half as long as the fifth
joint. Ungues in every tarsus each unlike the other. Hind wings of ordinary form;
the axillar region narrow, but with sufficient neuration. In tlie ? al)domen the relative
lengths of the dorsal segments in dried examples maybe formulated thus : — 7, 9, 10, 10,
10, 10, 8, 6'5, 6 ; ventral lobe of the ninth segment slightly emarginate. Forceps-basis
of 6 seldom conformable to that of Mhithrogena, but usually tridentate, or saliently
curved behind between the insertions of the limbs. Penis lobes either as in Rhithrogena,
or else narrow and split lengthwise along their inner sides ; stimuli well developed in the
type, but not obvious in the other species, perhaps retractile. Outer caudal setge of 6
about 4 times, those of $ about twice, as long as the body. Vertex of the dried 2 head
transverse, convex from side to side : the occipital border when not refuse is scarcely
prominent in the middle, and almost even with the posterior orbits of the oculi ; median
ocellus somewhat isolated, prominent, but rather below the anterior border of the upper

EEY. A. E. EATON OX EECEXT EPHEMEEID^ OE :NL\TFLIES. 245

surface of the head. Pronotaui of 2 somewhat eordately excised behind; the reflexed
lobes rounded.

Sv.bimago. — Wings yellowish or gi-eyish in tint ; neuration opaque, not edged with
greyish.

Nymph intermediate in character between Epeorus and Wiithrogenn. — Abdominal
tracheal branchiae disposed as in the latter genus, with short sparse fasciculate fibrils ;
laminae of the ^foremost pair very large, transverse, narrowly subreniform with the sinus
eccentric, in mutual contact at their inner extremities beneath the metasternum ; laminae
of the intermediate pairs obliquely reclinate at the sides, lessening successively in breadth
from the foremost, and also in length (but in both directions) from the third and fourth
pairs, each of them oblique, more or less broadly ovate and subacute, with the outer
or inferior margin thickened and ciliate ; laminae of the hindermost pair obliquely
conduplicate and incurved so as to meet at the tips when deflected beneath the pen-
ultimate segment : branchial tracheae distinct, pinnately branched, but largely deficient
towards the thickened portion of the lamina (which part is broader in Iron than in
Epeorus), and both coarser and sparser than in the preceding genus. Pronotum
transverse, short : the hind margin uneven ; the lateral margins undilated and mutually
subparallel. The markings on the coloured side of the femora comprise two groups of
longitudinal streaks with a rounded spot interposed between them, somewhat as in
Epeorus ; but in Iron this spot is isolated. Caudal setse and mouth-parts similar to those-
of Epeorus.

Type. T. longimanus, sp. nov.

Distribution. Xorth America, and (undescribed species in M^'Lach. Mus.) on Irazu in
Costa Rica.

Etymology, e'lpw, a dissembler.

The identification of the nymph rests upon specimens from "Washington Territory in
Mus. Comp. Zool. Cambridge, !Mass., communicated by Dr. Hagen, representing subimago
and nymph, viz. : — 1 d and 1 $ subim. registered " Wenas V., W. T., Pressy's 7. vii.
1882," and 3 nymphs registered " Klikitat V., W. T., Thorpe's 10. vii. 1882, S. Henshaw."

Irox LOXGiMA>'rs, sp. nov. Plates XXIII. & XXIV. 44 (wings and legs), LXY. 2
(genitalia).

Epeorus (Colorado sp.), ! Etn., Ent. IMo. Mag. xviii. 26 (1881). — E. longimanus, ! id., in the writing
of PI. XXIII. of this monograph (1883) .

Iron longimanus, lEtn., in the writing of PL XXIV. of this monograph (1883).

Imago {dried) 6 . — Notum either light yellowish ochre, or a light reddish-brown ochre.
Dorsum of abdominal segments 2-9 tinged extensively with Kght brownish [sometimes
light bistre, sometimes Vandyke], and in segments 2-7 exhibiting slightly depressed
spaces translucent and deficient in colouring, viz. : — on each side of the segment an
elongate ellipsoidal spot near the plem-ae, and a narrow space extending from spot to
spot across the base ; there is also, as frequently in EphemeridcB, a small obovate or
elongate pale spot on each side of the dark tract of the dorsal vessel ; segments 9 and 10
ire sometimes light-brown ochre, with a dark line down the middle : the pleurae are of a

SECOND SERIES. — ZOOLOGY, VOL. III. 33

246 REV. A. E. EATOX ON RECENT EPHEMERID^ OR MAYFLIES.

light colour, and the dark colouring of the terminal margin of each of the intermediate
segments does not enter their hinder lateral angles, but a short bistre-brown streak runs
in a curve from the said margin to the scar of the nymphal tracheal branchia on each
side of every such segment very near the said angles. Venter of a light colour, trans-
lucent, apparently showing the light brownish ganglionic cords, and perhaps a small
whitish spot on each side of them in each of the 2nd to 7th segments. Porceps-basis very
salient in the middle behind. Setae light warm sepia-brown. Femora and anterior
tibia in opaque vieio translucent raw umber [in some lights rather yellower], the former
each with a rounded black spot in the middle, and the latter bistre-brown at the insertion
of the tarsus ; fore tarsus dull light yellowish brown ; hinder tibiae and tarsi light
yellowish brown or brownish yellow, with [in some positions of the specimens only] the
terminal joint and the distal edges of the other tarsal joints light brownish. Wings
vitreous ; neuration of the fore-wing in opaque view light pitch-brown, but the great
cross vein, the baseward extremity of the subcosta, and those of the nervures posterior to
it are somewhat deficient in colour ; the neuration of the hind wing also, as a whole, is of
a similarly pale colour ; in transmitted light the stronger nervures of the fore wing
become light brownish amber ; pterostigmatic cross veinlets simple. Length of body
9-10 ; wing 11 ; setse, 6 im. about 26-33 mm.

Hab. Colorado (M'Lach. Mus.) ; Manitou, Col. (Morrison, in Mus. Comp. Zool.
Cambridge, Mass.).

Iron nitidus, sp. nov. Plate LXV. 3 (genitalia).

Imago {dried). — s . Notum light brown-ochre. Abdomen above and beneath in
segments 2-7 very light bistre-brown (or in small examples very light yellowish
ochre) somewhat translucent, with the joinings opaque, the dark colouring filling the
hinder lateral angles of the segments ; segments 8-10 light brown ochre, sometimes with
the dorsal joinings light brown. Porceps-Hmbs light bistre. Setse in some lights
whitish yellow, tinged towards the roots with brownish ; in other lights their predominant
colour is light yellowish brown. Pore femur and tibia in opaque view light raw-umber
brown, the latter bistre-brown at the insertion of the tarsus ; foi'e tarsus whitish brown-
ochre, with the joinings, the terminal joint and ungues slightly brownish ; in transmitted
light their predominant colours change to brownish amber and whitish amber respec-
tively. Hinder legs in opaque view very pale yellowish, approaching whitish yeUow-
ochre, with the extreme bases of the tibiae, the tarsal joinings, terminal joints, and
ungues warm sepia-brown. Wings vitreous, strongly iridescent; the pterostigmatic
region of the fore wing tinted with extremely light raw-umber ; the remainder of the
marginal and submarginal areas more faintly so tinted, and the other part of the wing
almost imperceptibly so ; neuration raw-u.mber brown ; pterostigmatic cross veinlets,
almost without exception, simple.

Variation. — In opaque view the 6 fore tibia is lighter than the femur, and the tarsus
is uniformly light bistre-brown : in transmitted light the tibia and tarsus are almost
concolorous.

EEV. A. E. EATON ON RECENT EPHEIMEEID.E OR aiATELIES. 247

S . Wing-membrane transparent, tinged universally with a light brownish yellow
approaching tlie lightest shades of raw-umber. Eore tarsus lighter than the tibia, and
with narrow brownish joinings. Notum in one specimen as dark as in the d ; in
another specimen it is of a much lighter brown-ochre. Length of body, c? 9-12, 2
(shrunken) 9 ; wing, c? 11-14, ? 15 ; setae, s im. 28-36, 2 im. 22 mm.
ITab. Mt. Hood, Oregon, and (Edwards) California (M'^Lach. Mus.).

CINYGMA, geu. nov.

Illustrations. — Achilt (details), PI. LXV. 4, 5.

Adult. — Very closely related to Iron, the proportions of the tarsal joints of the inter-
mediate legs being similar ; but in the hind tarsus, joints 1-4 diminish successively in
length, and there are differences in the proportions of the joints of the fore tarsus.
First joint of the 6 fore tarsus shorter than the second, and this a very little shorter
than the third joint ; first joint of the ? fore tarsus shorter than the second, but as long
as the third joint ; ungues each unlike the other. Penis-lobes similar to those of Rhi-
throgena. Fore leg of d t% as long as the body; tarsus about 1| the length of the
tibia, which is barely longer than the femur ; the tarsal joints in the order of their
shortening rank 3, 2, 4, 1, 5, and the first is about f as long as the second joint. Pore
leg of ? about -^ as long as the body ; tarsus about f the length of the tibia, and this
about as long as the femur ; the tarsal joints in the order of their shortening rank 2, 1
equal to 3 and to 5, 4, and the first f as long as the second. Hind tarsus oi 6 \ the length
of the tibia, and this about f that of the femur ; its joints in the order of their
shortening rank 5, 1, 2, 3, 4, the proximal three joints differing (if at all) successively in
length by only small gradations. Ungues in every tarsus, each unlike the other. Hind
wings of the usual form ; the axiliar region narrow. In the dried 2 abdomen the
relative lengths of the dorsal segments 2-10 may be formulated thus : — 5, 6, 8, 10, 10,
10, 9, 7, 5 ; ventral lobe of the ninth segment refuse. Porceps-basis either produced
into short lobes (as in Epeorus) for the support of the limbs, or else saliently toothed
near the insertions of the liml)s on each side of its posterior border ; penis-lobes similar
to those of BhUhrogena. Outer caudal setae of d thrice, of 5 about twice, the length
of the body. Median ocellus of 2 somewhat isolated, and (though prominent) lower
than the anterior border of the upper surface of the L ead ; occipital margin almost even
nith the posterior orbits of the oculi. Pronotum of 2 emarginate in the middle behind ;
:he refiexed lateral lobes angular.

SuUmago. Wings uniformly greyish or yellowish ; their neuration opaque, but not
)ordered.

Type. C. integrum, sp. nov.

Distribution. North America.

Etymology. Kivvjfxa, from the hovering habits of the flies.

33*

248 EEV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES.

CiNYGMA INTEGRUM, sp. iiov. Plate LXV. 4 (genitalia).

Subiniago {dried). — Wings transparent brownish grey, approaching light Cologne-
earth ; the hind wings lighter than the others, approacliing whitish Cologne-earth grey :
neuration inconspicuous, suhopaque ; the costa pale at the roots. Abdomen bistre-brown
above, varied in segments 2-7 with very light brown-ochre ; the darker colour borders
the terminal margins of these segments broadly, excepting at the pleuraj, and in each of
them is produced forwards to the base of the segment, both as a narrow strij)e along the
track of tlie dorsal vessel, and also as a broad longitudinal stripe through the midst of
each side of the back; and conversely an oblong spot of the lighter colour extends from
the base some distance along the pleurae on each side of the back, and a narrower spot
saliently curved externally reaches from the base some distance along each side of the
dorsal vessel ; venter unicolorous, very light brownish ochi'e.

Imago {dried), d . — Notum light pitch-, or Vandyke-brown. Abdomen in segments
2-7 translucent, light Vandyke-brown, opaque at the joinings above the pleura?, and with
three slightly darker longitudinal stripes from the hinder border of each of these
segments, viz. : — one coincident with the track of the dorsal vessel, which is intersected
lengtliAvise by a fine pale median line, and is sometimes only very faintly indicated, and
another rather broader and darker stripe on each side of that, falling short of the base of
the segment and vaguely delimited along its upper side ; moreover the trachea? are dark :
in segments 8-10 the prevailing colour Ijecomes modified either with light burnt-umber
or with opaque burnt- sienna or brown -ochre, while the median stripe is posteriorly
obliterated more or less in every segment, and iu segments 8 and 9 the lateral stripes
attain the base. Venter spotless, in segments 1-G light Vandyke-brown, in the hinder
segments light burnt-umber, approaching opaque Inirnt-sienna. Setae very light bistre
or whitish bistre-grey. Pore femur and tibia in ojxique view light bistre-brown, witli the
insertion of the tarsus black, and with two broad indistinct obscure bands on the femur
(one just before, and the other just beyond the middle) ; tarsus in some lights whitish
brown-oclire, in other lights bistre-grey, or nearly concolorous with the tibia ; in trans-
mitted light the femur and tibia acquire a light brownish amber tint. Hinder legs
lighter than the fore leg, the femora each with a single brown indistinct dark band
beyond the middle, the tibiae in opaque view whitish brown-ochre, and the tarsi either
concolorous with the tibiae or in some lights greyish or light brownish : in transmitted
light the femora become light yellowish amber, and the tibia? whitish amber-coloured.
Wings vitreous ; the pterostigmatic region of the fore wing (tinged, like the mem-
brane just at the roots, with extremely light bistre-grey) contains evenly anastomosing
cross veinlets : neuration pitch-brown.

? . Very similar to 6 ; but the notum is of a light yellowish browu approaching light
brown-ochre, the setae whitish brown-ochre, the femora of some examples more strongly
coloured than in 6 , and the tibiae in opaque view dull light brown-ochre. Length of
body, 6 11, $ shrunken ; wing, d 12, ? 10-13 ; setae, 6 im. upwards of 25, S im.
16-20 mm.

Kah. Washington Territory, and Mt. Hood, Oregon (M'Lach. Mus.).

REV. A. E. EATON ON EECENT EPHEMERID,^ OR MAYFLIES. 249

CiNYGMA PAR, sp. iiov. Plate LXV. 5 (genitalia).

Imago '{dried), 6 . — Notum light pitcli-brown, sometimes approaching light luteo-
piceous anteriorly at the sides. Dorsum of the abdomen Vandyke-brown and opaque in
segments 8-10 ; the other segments for the most part are lighter and somewhat trans-
lucent, the dark colouring at their tips being shaded off anteriorly and encroached upon
by dirty-whitish subtransparent spaces, viz. : — a large space on each side of the back in
front, a narrow strip extending across from the one space to the other along the anterior
margin of the segment, and three longitudinal linear streaks proceeding from the base
nearly to the terminal border of the segment, of which the intermediate (coincident
with the course of the dorsal vessel) and the others are narrowly edged with dark
colouring : in the large subtransparent spaces referred to the trachea? are visible, and in
some lights appear slightly brownish ; the hinder angles of the pleurae are pale. Venter
in segments 3-7 translucent, Avith conspicuous nervous ganglia of a light warm sepia-
brown ; the hinder segments opaque, and of a very light brownish ochre. Setge light
warm sepia-brown. Legs in opaque view bistre-brown, the base of the fore femur and
the fore trochanter rather lighter, the insertion of the fore tarsus slightly darker : in
transmitted light their predominant colour is brown-amber or golden brown. AVings
vitreous, tinted with light bistre-grey throughout, but with a stronger tint than else-
where in the j^terostigmatic region of the fore Aving and at the wing-roots : neuration
in opaque view bistre-brown, changing in transmitted light to raw-umber brown : the cross
veinlets of the pterostigmatic space in the fore wing are mostly simple and seldom
anastomo seat all, and then only irregularly and very sjiarsely. Length of body, <S 8 ;
wing 9-10 ; sette, 6 im. 18-20 mm.

Hah. Arizona (M'^Lach. Mus.).

CiNYGMA MIMUS, sp. UOV.

Imago {dried), 6 . — Very similar in aspect to the European Rhithrogena semicoloruta.
Notum either liglit raw-umber or light chestnut-brown. Abdomen discoloured : in
opaque view segments 7-10 are in some specimens of a light broAvnish colour approaching
broAvn-ochre, and the remaining segments of a light purplish broAvn ; but in other
specimens the prevailing colour is more nearly madder-brown : segments 2-7 are each of
them colourless and transparent at the extreme base, and the colourless spaces, narroAV
in the middle, are enlarged a little by the pleurae, presenting thereabouts a small rounded
expansion on each side bounded posteriorly by the anterior trachea? of the segment : the
arrangement of the ventral colouring resembles that of the dorsum. Seta? light raw-
umber brown. Legs light yellowish brown, approaching raAV-umber or dull bronze-
broAvn in some lights, with the insertion of the fore tarsus and the ungues of that foot
light pitch-brown, and the hinder tibia? and tarsi rather lighter and yellower than the
femora ; in transmitted light the femora and fore tibiae become light brownish amber,
and the remainder yelloAvish amber. Wings vitreous with raw-umber brown neuration
varying in intensity Avith change of light : but the subcosta and radius to the middle,
md the basal extremities of the hinder longitudinal nervm-es of the fore wing, and the

250 EEV. A. E. EATON ON EECENT EPHEMERIDiE OR MAYFLIES.

costa and the bases of the remaining nervures of the hind wing appear in most positions
of a light raw-umber or yellowish brown, and the rest of the neuration intense raw-
iimber approaching pitch-brown : the wing-membrane is faintly tinted with light raw-
umber throughout ; but the tint is chiefly noticeable in the hind wing and the basal half
of the fore wing, as in the Rhithrogena referred to above. Length of body 9 ; wing 10 ;
setae, s im. about 20 mm.
Hah. Colorado (M'Lach. Mus.) ; Manitou, Col. (Mus. Comp. Zool, Cambridge, Mass.).

CiNTGMA GEMINATTJM, Sp. nOV.

Suhimago (dried). — Very similar in aspect to Heptageiiia stilplmrea. Wings and
neuration in ? light yellowish ochre throughout ; in s the membrane is rather of a
yellowish grey, but the neuration is light yellowish ochre, though less strongly coloured
than in the other sex. Setae concolorous with the wings. Notum yellow-oclu*e varied
with lighter. Abdomen faded. Fore femur in 6 light brownish ochre, in ? Mars
yellow : tibiae and tarsi all whitish yellow-ochre, with the tarsal joinings and the
joining of the tibia with the tarsus light brownish ; in transmitted light the fore femur
becomes brownish amljer, the hinder femora and fore tibia light yellowish amber, and
the tarsi and hinder tibioe whitish amber.

Imago [dried), $ . — Almost indistinguishable without inspection from Septagenia
sulphured, S im., and even when closely compared together the differences in colour
between the two species are trivial and few. C. geminativm has the vertex of the head
suffused with light reddish brown, no black spots near the eyes either on the vertex or
on the face, nor any at the bases of the coxae ; setoe uniformly whitish ; wing-neuration
for the most part piceous or bistre-brown instead of black, the stronger longitudinal
nervures amber-coloured towards the base ; wing-membrane vitreous, miiformly tinted
in the faintest degree with pale yellowish. Length of wing, d 8-9'5, ? 9-12 ; setae, ?
im. [the smallest specimen] about 18 mm.

Hal). Washington Territory and (Lord Walsingham) California (in M'Lacb. Mus.);
Arkansas Canon, Col. (P. R. Uhler, in Mus. Comp. Zool. Cambridge, Mass.). This
species and Rhithrogena eleyantula are almost exactly alike in colour.

RHITHROGENA, Etn., 1881

Illustrations. Adult (details) Pis. XXIII. and XXIV. 43, see also citation of
Palmen (1884) under Rh. semlcolorata ; (whole figures) refer to citations of Stephens
(1835) and Pictet (1843-5) under the same, and of the latter under Rh. seinit'mcta.
Nymph, PI. LIV. ; see also citation of Pictet (1843-5) % Ba'etis % lateralis under Rh.
aurantiaca.

Adult. — First joint of the hind tarsus equal to the second and a little longer than the
third joint; first joint of the intermediate tarsus a little shorter than the second, but
equal to the third joint ; first joint of the d fore tarsus much shorter than the second,
and this equal or subequal to the third joint ; first joint of the ? fore tarsus much
(about ^) shorter than the second, which is longer than the thu'd joint ; ungues mutually

EEV. A. E. EATOX ON KECEXT EPIIEMEEID^ OR MAYFLIES. 251

dissimilar. Penis-lobes narrow, often extremely so when dried and apt to shrink to mere

peg-like projections (compare PI. XXIV. 43^). — Fore leg of c? l^-li the length of the

body : tarsus about 1| as long as the tibia, and this ly the length of the femur ; the

joints in order of their shortening rank 3 subeqnal to 2, 4, 5, 1, and the first is about ^ as

long as the second joint. Fore leg of ? about as long as the body : tarsus little more than

J the length of the tibia, and this nearly 1^ that of the femur : the joints, in the order of

their shortening, rank variously in diiferent species, the second or the fifth being the

longest and sometimes of the same length, the third usually shorter (rarely as long as

the fifth), the first usually equal in length to the fourth (rarely a little longer) and about

^ as long as the second joint. Hind tarsus S about f the length of the tibia, which

is little shorter than the femur ; its joints, in order of their shortening, rank 5, 1 equal to

2, 3, 4 : those of the intermediate tarsus rank 5, 2, 1 equal to 3, 4. Ungues each unlike

the other in every tarsus. Hind wings of the usual form; axillary region narrow. The

relative lengths of the dorsal segments of the dried $ abdomen may be formulated

thus : — 5, 9, 12, 14, 13, 10, 9, 5, 4 ; ventral lobe of the ninth segment either obtusely

rounded or slightly retuse at the tip. Forceps-basis of the d usually concave in the

middle behind, rarely saHently curved. Penis-lobes divergent from each other during

life, often contiguous when dried: inferior stimuli weU developed, usually closely

appressed to the lobes : apertures of the seminal ducts terminal. Outer caudal setae of

d usually 2-2|, seldom 3 times, the length of the body, those of ? about twice its length.

Median ocellus of 2 prominent, contiguous with the anterior border of the upper surface

of the head : the occipital border very slightly (if at all) convex in the middle, almost

even with the posterior orbits of the oculi. Pronotum of ? somewhat cordately excised

behind ; the lateral lobes not extensively reflexed.

SiMmago. — Wings tinted with grey [yellowish in a single species from Arizona]:
neuration not conspicuously darker than the membrane, nor bordered with pigment
especially. The ordinary length of this period is 24-36 hours : the insect dm-ing repose
stands upon all its feet with wings erect and setae divergent.

Nymph. — In the pose of the laminae of the abdominal tracheal brancliiae — the foremost

pair attaining mutual contact at the tips of the laminae beneath the metasternum, the

intermediate pairs reclining outwards (figs. 1, 2) when not deflected out of sight (fig. 3),

and the hindermost pair transversed lengthwise by an eccentric open fold and brought

together beneath the penultimate segment — this nymph resembles that of Iron. But the

iaminse are slightly different in form from those of that nymph : the foremost are very

arge, transverse, oblong, and curved : the other laminae exhibit successive gradations in

brm from subrotund-oblong, through oblong-obovate and obovate to oval : again,

dthough their inferior margins are ciliate thev are not thickened. Moreover the

asciculated fibrils are longer in proportion to the laminae and more lax than in Iron ;

md the branchial tracheae are invisible, or become obliterated after death. Median

■audal setce subeqnal to the others, nearly as long as the body, minutely plumose for

ome distance beyond its basal ^ : the other setae ciliated correspondingly on then- inner

ides. Pronotum transverse, very short, undilated, and either curved or nearly straight

t the sides : its posterior margin well defined, saliently rounded off on each side of a

252 REV. A. E. EATON ON RECENT EPHEMERID^ OR MAYFLIES.

median sinus. Fangs of the mandibles very unequal and of peculiar construction :
viewed from beneath (PL LIV. 8 and 9) without compression, the exterior and much the
larger fang, which is set obliquely in relation to the stipes, appears falcate, sharply
truncate at its outer base, just opposite the very rudimentary interior fang, and serrulate
for some distance before the tip along its outer edge : viewed from above under pressure
(PL LXV. 6) each fang opens out into a concave expansion ; the exterior becomes acutely
subovate triangular, truncate at the inner basal angl , where it joins the crown of the
mandible, and displays fine serrulations along both its lateral margins, while its base is
pectinate or ciliated and inflexed ; the interior fang [or ? endopodite] partly contained in
the concavity of the outer fang, is oblong-cochleariform or like an oblong scoop, slenderly
serrulate at its terminal border, finely and densely pectinate along the upturned edge
subtended by the concavity of the outer fang, and sparsely ciliate aloug the opposite edge.
The hairs comj)Osing the tuft near the inner bases of the fangs appear unilaterally plumose
when highly magnified in a favourable light. Lacinia of maxilla i. beset along the edge
of the crown with appressed pectinate teeth : proximal joint of the palpus broadly dilated
behind : terminal joint stoutly clavate, oblique at the extremity, and densely scahrid
externally from near the base to the acute point. Median lobe of the tongue (as in
Epeorus) quadrilateral, broader than the paraglossae, which are narrow and dilated in the
middle. Eemora marked on the coloured side each with a conspicuous isolated dark
spot, in or about the middle, and sometimes clouded with grey between that and the tip.

NORTH AMERICAN SPECIES.

Rhithrogbna jejuna (renamed).

X Baef'ts W/usca, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 568 (1353) ; Hag., Smitlison.
Miscell. Coll. (1861) Synop. Neuropt. N. Am. 45.

Heptagenia fusca, ! Etn., Trans. Eut. Soc. London (1871) 138, pi. vi. 13-13 6 [detail].

Imago {dried). — s . Thorax dull rufo-piceous above. Abdomen in segments 2-5
translucent burnt-umber brown, with the apical borders of tlie dorsal segments darker.
Porceps bistre-brown. Legs bistre-brown ; the femora each with a black longitudinal
streak tajjeriug at both ends and commencing at a short distance from the base ; the
apical lobe of the fore tibia pitch-black. Wings vitreous, the membrane tinted with very
light bistre-grey, scarcely darker or greyish-tinted in the pterostigmatic space ; neuration
pitch-brown ; the marginal area of the fore wing contains about 3 cross veinlets before
and 19 beyond the bulla ; many of these in the pterostigmatic region divide irregularly
and anastomose with one another.

S . Abdomen bistre-brown, the distal borders of segments 3-8 rather broadly margined
with pitch-black. In the marginal area of the fore wing are about 6 ci-oss veinlets
before, and 21 beyond the bulla. Length of body 6-7, wing 9-10 mm., in both sexes.

Hab. St. Martin's Palls, Albany Eiver, Hudson's Bay (Brit. Mus.). The specific
name of this species should be rendered " uninteresting".

EEY. A. E. EAIOX OX EZCZXT EPHEMEEIDJ: OE ilATTLIES. 253

Rhitheogeva MAXirESTA (renamed).

; Baitis \\ debilis, ! Walsh, Proc. Acad. Nat. Sc. Philad. (186.2) 371 ; Hag., Proc. Ent. Soc. Philad. ii.
170 (1863) [nee. ; B. debilis ! Walk. 1853; neque B. \\ debilis ! Walk. JCI. debilis) I860].
X Siphlwrus debilis, Etn., Trans. Ent. Soc. London 1,1871) 130.

Subimago. — "Wings fumose, with fuscous neuration. Setae cloudy at tlie tips. Fore
tarsi fuscous.

Imago {living), 6 . — Eyes broTm above, fuscous in their loivest ^. "N'otiim generally
piceous. Dorsum of abdomen ferruginous, with the distal f-4 of each segment more or
less piceous. Setfe uniformly whitish ; forceps pale. Legs pale greenish ; the femora
with a narrow median band [r thia longitudinal streak" and generally the knee fuscous ;
the tip of the fore tibia, the tips of the tarsi, and the incisures of the fore tarsus fuscous.
"Wings hyaline ; neuration pale greenish hyaline, excepting the basal | of the costa, sub-
costa, and radius, and occasionally their tips, which are fuscous in the fore win».

2 . Paler than d ; thorax almost yellow. Abdomen ferrusinous, usually darker
at the tip of every joint. "Wing-veins dusky along the costa and at the tip of the
fore wing, jradually becoming hyaline as they approach the anal angle. Length of
body 4-7 ; wing 5-7 ; setae, <s im. IS-li, subim. about 5, 5 im. 8-ll"5 mm.

Sab. Eock Island, 111. [after "Walsh]. "Why "Walsh should have supposed this insect
to be m.ore nearly related to Siphlunis than to Septagenia is inexplicable.

Ehitheogexa hagexi (renamed). Plate XXIT. 43 c (penis dried).

Heptagenia |1 brunnea, ! Hag., Ann. Rep. U. S. Geolog. &: Geograph. Snrvey of the Terr. 1873,
part iii. Zool. 581 (1875) [ J im. only].

Imago [dried), d . — Thorax abo^e bright-brown ochreous, the peak of the mesonotum
flavescent, a line adjacent to the tegulse and a streak below it in front of these in a
depression broAvn-black. Abdomen above pitch-bro-mi, the tips of the segments darker ;
venter rufescenti-lutescent, spotless ; setae sepia-brown, with most of the joinings opaque.
Porceps pitch-brown. "Wings ritreous, the fore wings almost imperceptibly tinted with
li^ht sepia-grey in the pterostigmatic space ; their marginal area contains 4 or 5 cross
veinlets before the bulla, then 5-7 simple, followed by 11-14 irregular cross
veinlets anastomosing with one another nearer the costa than the subcosta ; neuration
pitch-brown, paler just at the wing-roots. Fore legs fuscous, the tibiae and tarsi piceo-
fuscous; hinder less luteo-fuscescent, their tarsi slightly browner or warm sepia; every
femur in its proximal half is marked with a longitudinal brown-black streak tapering at
both ends. Length of body 10, wing 13 mm.

Sab. Nevada, Truckee in the Sierra Nevada, June 10 (G. E. Crotch).

EhITHROGEXA EliEGASTTLA, sp. nov.

Subimago {dried). — "Wings as in Heptagenia snlphiirea, extremely pale yellowish ochre,
with concolorous neuration. Setae dull whitish, with the joinings narrowly reddish.
Tarsi slishtly tinged with brownish, approaching bistre-brown; the joinings seem opaque
only in transmitted li^ht. The femoral bands ai-e faintlv defined.

SECOND SERIES. — ZOOLOGT, VOL. HI. 34

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

Imago {dried), d . — Similar in general aspect to Heptagenia sulplmrea. Notum very
pale yellowish ochre, traversed lengthwise by a median reddish brown-ochre stripe
approaching raw-umber. Dorsum of the abdomen in segments 2-5 and the base of
segment 6 transparent whitish shaded with greenish bistre-grey, with the joinings of the
segments narrowly subopaqvie and of a darker shade of the same grey ; the remainder
of segment 6 and the hinder dorsal segments nearly concolorous with the notum.
Venter uniformly pale yellowish ochre. Tore femur in opaque view light bronze-brown
approaching raw-umber, darker and light red dish -brown just at the knee, and very
indistinctly banded in the middle with the same colour; tibia in some positions
concolorous with the femur, but in other positions both it and the tarsus appear lighter,
and the tip of the tibia, the last joint and joinings of the tarsus, and the ungues are
rufo-piceous or of a dull reddish tint : in transmitted light the prevailing colour of the
leg is light yellowish amber, and the markings are reddish amber. Hinder legs rather
similar in colour and markings to the fore leg, but lighter, and without any trace of the
median femoral baud or any spot at the tip of the tibia. Wings vitreous ; the fore wdng
tinted slightly with light greenish- or bistre-grey in the pterostigmatic region, and more
faintly still in the remainder of the marginal and submarginal areas : neuration in
opaque view piceous or black, excepting the subcosta and radius in the basal half of the
fore wing, which are yellow-amber ; in some positions the longitudinal neuration appears
pitch-brown, and the cross veinlets black : in transmitted light the greater part of the
neuration appears brown-amber : the great cross vein of the fore wing is thickened
posteriorly and piceous.

$ . Light yellowish ochreous like Ileptagcnia stdjihurea. Head marked on each side
with a small triangular black spot at the anterior low^er angle of the ocidi, and with a
reddish brown mark close to the orbit in the midst of the vertex. The rugie at the sides
of the thorax between the wing-roots and the legs are edged with black, as in the 6 .
Legs rather stronger in colour than iu the other sex, the femora being transparent
greenish grey and having the median band, though faint, better defined. Length of
body (shrunken) 6 ; wing, j 9, ? 10 mm. Seta) defective.

Hab. Arkansas Canon, Colorado (P. 11. Uhler, in Mus. Comp. Zool. Cambridge,
Mass.) ; Arizona (M°Lach. Mus.).

E-HiTHKOGENA viTREA, Walker.

t Palingenia vitrea, ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 555 (1853).
Heptagenia vitrea, ! Etn., Ti-ans. Ent. Soc. Loudon (1871) 143, note.

Stibimago {dried), ? . — Wing-membrane very light smoky grey, the neuration extremely
light brown-ochraceous. Body light brown-ochreous ; the legs nearly of the same
colour, each femur banded in the middle with black-grey, and light brownish at the
knee ; fore tarsus light w^arm scpia-brow^n. In the marginal area of the fore wing are
6-7 cross veinlets before the bulla, and 15-17, simple and straight, beyond it. Length
of body 6 ; wing 6 mm.

Sab. St, Martin's Falls, Albany River, Hudson's Bay (Brit. Mus.).

EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES. 255

EUROPEAN SPECIES.

Rhithrogena borealis, Etn.

Heptagenia borealis, ! Etu., Trans. Ent. Soc. London (1871) 137, pi. vi. 11 [detail] ; Palmen, Paar.
Ausf.-Giinge d. Geschl. Org. b. Insect. 852 (1884) [anatom.].

Imago {dried), 6 . — Notum piceous. Abdomen ochraceous, translucent, witli the tips
of the anterior segments, in addition to the last three or four segments, light fuscous
above. Setse fawn-grey with fuscous joinings. Legs light fuscous. Wings vitreous ;
the longitudinal nervures light fuscous. Length of body or wing, d 10 mm.

Hab. Finmark, between Koutokseino and Karesuando (Walker MS., in Dale Mus.).

RhITHROGENA NIVATA, Etn.

Heptagenia nivata, ! Etn., Trans. Ent. Soc. London (1871) 137, pi. vi. 10 [genitalia].

Suhimago {living). — Eore wings dark cinereous ; hind wings lighter. Hinder legs
olivaceous, with dusky tarsi ; fore legs darker. Setae dull black.

Imago {lioing), <s . — Eyes sooty black above, tinged slightly with olivaceous below.
Notum jet-black. Dorsum of the abdomen fuscous, rather paler by the joinings ; venter
olivaceous. Seta? dusky, with the joinings narrowly dark. Fore femur olive-black, the
tibia and tarsus black ; hinder femora olivaceous, the tibise dull whitish-olive-grey or
cretaceous, the tarsi tinted with olive. Wings uniformly vitreous ; neuration olive-grey.

5 . Fore tibia and tarsus dusky, very dark ; hinder tibite cretaceous, the tarsi dusky,
with pale ungues. Venter olivaceous, with rather darker spots under the ganglia : lobe
of the 9th segment slightly emarginate. Length of body 11 ; wing, 6 12, ? 17 ; setse,
6 im. 27, subim. 8, S im. 12-15 mm.

Rab. The Barberine in the Val de Trient (about 3700 ft.) and Lac de Combal (5774 ft.).

RniTHROGENA ALPESTRis, sp. uov. Plate XXIV. 43 a [genitalia, 6 ].

Ehithrogena | semUincta, Etn. MS. in the writing of PI. xxiv.

Subimago {dried). — Wings very light brownish grey (Cologne Earth grey) with opaque
longitudinal neuration ; nearly concolorous with dried examples of Hh. semicolotYda.

Imago {liclng), 6 . — Eyes fuscescent, or greenish bistre-brown above, traversed by a
broad black band, and bluish grey below that band. Notum fusco-piceous. Abdomen
above suffusco-piceous, pale by the joinings at the extreme bases of the intermediate
segments ; venter fuligineo-fuscous, with pale joinings, tinged in the penultimate segment
with burnt-sienna (rubigineous) ; forceps dusky. Sette slightly dusky, with subpiceous
joinings towards the roots. Eore leg blackish, with the end of the femur and tibia
black ; hinder legs very light greenish grey, with the tip of the femur fuscous above,
and the tarsi dusky, with the terminal margins of the short joints black ; trochanters
terminated each by a black point; coxa? suffuscous ; mesosternum piceous. Wings
uniformly vitreous, with subpiceous neuration : tegulse light yellowish.

? . Eyes fusco-olivaceous traversed by a moveable black band. Epistoma greyish ;
vertex of head piceous, varied with yellowish fuscous. Abdomen lighter than in the s ;
segments 2-7, each with a pale dot on each side of the median dorsal line nearly in the

34*

256 KEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES.

middle : egg-valve darker than the neighbouring parts ; lobe of the 9th ventral segment
entire. Legs of a greener tint than in the d ; a dark longitudinal streak nearly in the
middle of the inner side of the fore femur ; the hinder tibite whitish basewards, but
distally, like the tarsi, dusky. Pterostigmatic region very faintly tinted with dusky ;
tegulse more or less yellowish. Length of body 8-5 ; wing, d 10, 9 11 ; setse, d im.
20-25, ? im. 17 mm.

Mab. Switzerland, Savoy, and North Italy ; July to September. Alpbach, Meyringen
(1 subim. 15th August, M'Lach.); common near the Chalets de Pas, Champery (57GOft.,
5 P.M., 20th August, water 51° F.) ; very common in the vicinage of Charbonni^re, about
the head-waters of the Dranse de Biot (4300-1800 ft., 1-5 p.m., 2nd Sept., water 62° to
48" F.) ; also singly by the Oglio in the Val Mazza above Ponte di Legno (5800 ft.,
4.46 P.M., 29th July, water 49° to 56° F.).

RniTnKOGENA HYBUIDA, Sp. nOV.

Imago (dried), 6 . — Notum black. Dorsum of the abdomen pitch-brown. Setse light
warm sepia-brown with slightly opaque joinings. Fore leg pitch-brown or intense bistre-
brown : hinder femora in opaque view uniformly of a reddish brown, the tibiae lighter and
of a rather yellower brown in some postures, and the tarsi slightly greyish ; no femoral
markings. The colouring of the wings in its distribution conforms to that of Variation 1,
of Eh. semicolorata, but is of a duller hue, being light bistre-brown instead of raw-umber.
Wing-neuration, in opaque view, entirely pitch-brown, excepting that the sector (4),
cubitus, brachial, and anal (8) nervures of the fore wing are deficient in colour at the
extreme roots where they meet the raised fold in the membrane. Length of wing 9-10 mm.

Sab. Savoy, in the neighbourhood of Samoens ; common about the head-waters of
the Dranse de Biot, near Charbonniere (4780 ft., 10 a.m., 12th August) ; also near the
Chalets do Jouplane (5100 ft., 9.30 a.m., 29th August, water 52° F.). Easily mistaken
for the following species ; but the absence of femoral markings, and the uniformly
dark colour of the subcosta and radius of the fore wing seem to necessitate their
separation.

RniTnuoGENA semicolorata, Curtis. Plates XXIII. 43 [& virtually 44] (wings), XXIV.
43 (legs), & 43 '"' (penis). Nymph Plate LIV. 3, 4.

? {Ephemera] or E. sticjma [Zsch. Mas. Lesk. i. 150, no. 20 (1789) ] ; Gmel. Liim. Syst. Nat. ed.
xiii. i. pars v. 2G30 (1790) ; 01., Eucyc. Metli. vi. 423 (1791).—? E. fuscula, Schrank, ¥n. Boica, ii.
199 (1708).

t Baetis semicolorata, Curt., Lend. & Edinb. Philos. Mag. scr. 3 (1831) 131; ! Steph., 111. Brit. Eot.
vi. 61, pi. xxix. 2 (183.5) ; Pict. Hist. Nat. Nevropt. ii. Eplie'm. 178, pi. xxii. 4-9 (1843-5) ; Walk., List
of Neuropt. Ins. in Brit. Mus. part iii. 577 (1853) ; Hag., Ent. Anu. (1863) 36.— J B. semitinda, Pict.,
Hist. Nat. Nevropt. ii. Ephem. 180, pi. xxii. 1-3 (1843-5) ; Walk., List &c. part iii. 558 (1853); Brauer,
Neuropt. Austr. 26 (1857) ; Ausser., Ann. d. Soc. Natur. Modena, An. iv. 133 (1869) ; Etn., Trans.
Ent. Soc. London (1871) 36, note.

Heptayenia semicolorata, ! Etn. Trans. But. Soc. London (1871) 136, pi. vi. 9 [detail] ; Hag. & Etn.,
op. cit. (1873) 403; Mcyer-Dur, Bull. Soc. Ent. Suisse iv. 311 (1874) ; Rostock, Jahresb. d. Ver. f.

EEV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES. 257

Naturk. Zwickau, 1877, p. 89 (1878) ; Palmuu, Paar. Ausf.-Gaiige d. Gcschl. Org. b. Insect. S. 44 & 52,
taf. ii. 30 (1884) [detail & anatom.] .— /f. semiiiticta, Mcyer-Diir, Bull. Soc. Eut. Suisse, iv. 312
(1874).

Rhithrogtma [type] semicolorata, ! Etn., Ent. Mo. Mag. xviii. 23 (1881); nee Rh. semithida, ! id., in
the writing of PI. xxiv. 43 a of this work.

Subimago {living).— Fovc wings very light grey ; hind wings paler. Legs greenish-, or
brownish-grey, with a small elongated spot in the middle of the femur, and with the
tarsus brown-Llack or grecnish-hlack. Setae very pale grey, s . Oculi dark olivaceous,
crossed by a transverse black line. {Dried.)— Fovg wings very light brownish-grey;
hind wings dull greyish white : femoral spots often indistinct or lost.

Imago {living), J .—Genital stimuli narrowly ligulate, closely appressed to the lobes
of the penis, and acutely bi- or tri-deuticulate at the tips. Eyes intense raw-umber or
olive-brown above, and either black or pitch-brown below, and sometimes with a
bluish grey or greenish grey edging to this darker surface , ocelli piceous. Notum light
bistre-brown or pale fuscous, varied on the metanotum with pitch-brown, and sometimes
with a small yellowish spot near the peak. Dorsum of the abdomen light bistre-brown
or greenish grey, sometimes tinted in segments 8-10 with brown-ochre or raw-umber,
and with the joinings of the intermediate segments whitish: venter dull light sepia- or
olive-grey in segments 2-7 or 8, and either somewhat dull rubiginose (medium burnt-
sienna) or ochreous in the last two or three segments. Setae light sepia-brown, or dusky,
or brown-black. Eorceps-basis dull, either rubiginose or greenish grey : the limbs
blackish, with the last two joints sepia- grey. Femora light greenish grey, each with a
submedian triangular longitudinal black streak, which is acute inwards and acuminate
outwards in the hinder legs, but more rounded in the fore leg : fore tibia and tarsus
either sepia-grey or dark olive-grey ; hinder tibiae and tarsi sometimes of a lighter sepia-,
or greenish-grey than the fore legs, and sometimes of a yellower tint, with the extreme
distal edges of the short tarsal joints black, and with the ungues slightly rufescent or
greyish. When dried the femora in opaque view approach raw-umber brown in their
general hue ; in transmitted liglit the femora become strongly yellowish amber, and the
hinder tibia? pale yellowisli amber : the femoral streaks sometimes disappear. Wings
vitreous, varying considerably in the tint and extent of their coloration.

In the typical semicolorata, Curt, [the semifmcta of Pictet] the membrane in the basal
half of the fore wing, and throughout the hind wing, is only faintly tinted witli dull
rusty yellow : in opaque view the neuration of both wings ajipears pitch-black, exceptino-
the extreme roots of the costa, sector (4), cubitus, prajbrachial, pobrachial, and anal (8),
the great cross vein, and the part between the roots and the bulla of the subcosta and
radius (3) of the fore wing, which are subtestaceous or rusty yellow ; in transmitted
light the whole of the neuration becomes in some positions light brownish, but in most
positions light brownish amber.

Variation 1 [the semicolorata of Pictet, not of Curt.]. — The coloration of the fore
wing extends to the tip in tlie marginal and submargiual areas, and in the disk reaches
from the wing-roots to a little beyond the junction of the sector (1) and the fourth
sectorial intercalar nervure, the fork of the pi-aibrachial (G), and the anal angle, formin"

258 EEY. A. E. EATOX ON EECEXT EPIIEMEEID^ OE MAYFLIES.

a distinctly defined cloud of deeper tint than tlie colouring of the typical specimens — in
fact, sometimes a medium raw-umber brown cloud. Legs darker than in the typical race :
vjhen dried the fore femur becomes raw-umber brown, and the tibia and tarsus light
pitch-brown, with the insertion of the latter dark ; femoral streak distinct.

Variation 2. — The whole of the membrane of the fore wing is tinted with dull rusty
yellow, and the colouring in the basal half is scarcely, if at all, darker than in the
remainder, although, when the wings are erect, it may apparently be so where the hind
^viIlgs underlie the others. Notum brown-ochreous. Legs lighter than in the typical
race ; femoral streaks distinct but rather small.

9 {licing). — Eyes olive-black. Dorsum of the abdomen intermediate in tint between
yellow-ochre and raw-sienna, very pale by the joinings ; venter very light Mars-yellow ;
lobe of the ninth ventral segment emarginate. Legs golden-brown or brown-amber ; the
fore tibia and tarsus, the hinder tarsi, and the bases of the hinder tibise tinged Avith
olive-grey ; the femoral spots or streaks, the femoral tracheae, and the points of the
trochanters black. Wings vitreous, colourless or almost colourless : in opaqtte view the
stronger of the longitudinal nervures appear to be subtestaceous or rusty yellow, the
finer nervures piceous, and the cross veinlcts black ; in transmitted light all of the
neuration appears subtestaceous.

Variation [the semicolorata of Pict., not of Curt.]. — The colour of the wings resembles
that of Variation 2 of the other sex.

Length of body 7-11 ; wing 7-12 [usually 10-12] ; setae [of the larger specimens],
6 im. 23-28, subim. 8-9, ? im. 14, subim. 10 mm.

Eab. Europe, from Js'orway (WaUengren) southwards to the Alps and Pyrenees.
The typical race is common in Great Britain from June to September, frequenting trout-
streams and the swift parts of rivers ranging in temperature during the summer from
about 51° to 58° E. In Cumberland, on Cross Eell, it ascends to about 1500 feet. The
same race occurs on the continent in Belgium, Erance, Saxony, Switzerland, Bavaria,
northern Italy, and (Zeller, in M^Lach. Mus.) Cariuthia, e. g. at the following localities : —
the stream at Yersoix in June (Pict.) [uj)wards of 1250 ft., water 58° F. in the afternoon
of August 24th] ; Morillon near Samoens [2200 ft., water 50° E., 4-6 p.m. August 30th];
between Partenkirchen and Mitten wald in Bavaria ; in the Ortler district, both in the
Val Eurva above S'" Caterina [6300 ft., water 59° E., July 28th], and in the Val Mazza
near Ponte di Legno [5800 ft., water in the Oglio 49° E., but 56° E. in a tributary torrent
at the same place, July 29th, in the afternoon] ; along the Neez, above the Pont d'Oly,
near Jurancon, Pau [about 600 ft.] ; on the road to the Col des Tontes from Eaux Bonnes
[3220 ft.] ; and at the outlet of the Lac d'Aious [5945 ft.].

Variation 1 is represented in M'^Lach. Mus. by specimens from Autun, Gex (Ain), and
Neuchatel. According to Pictet it is common in the neighbourhood of Geneva, at
streams, and is wont to appear in large numbers before rain or thunder-storms in sum-
mer. Variation 2, in the same collection, is ticketed Carintbia, May 27th (ZeUerj.
Pictet makes no mention of the femoral markings.

EET. A. E. EATOX OX EECEXT EPHEilEEIDj: OE MAYFLIES. 259

PlHIThkogexa ArEAS'TiACA, Burmeister.

X Bae'tis aurantiaca, Bunn., Haudb. d. Ent. Bd. ii. Abth. ii. 801 (1839) ; Pict., Hist. Xat. X'erropt.
ii. Ephem. 191 (1843-5) ; Walk., List of X'europt. Ins. in Brit. Mus. part iii. 560 (1853) ; Etn., Trans.
Ent. Soc. London (1871), 148 [note to Sraon. of Heptagenia iridana].—? B. j lateralis, Pict., op. cit.,
pi. xsi. i. [nymph] (1843-5).

Heptagenia aurantiaca, Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 315 (1874) ; ! Eostoek, Jahresb. d. Ver.
f. Xaturk. Zwickau, 1877, p. 91 (1878).

BJiithrogena [nympli], ! Etn., Ent. Mo. Mag. xviii. 24 (1881).

Subimago {Uving), 2 . — "Wings usually griseous, seldom light sepia-grey, the hind
"vrings scai'cely, if at all, lighter than the fore wings ; wing-roots dull pale brownish-
yellow marked with a brown spot, the great cross vein similarly brownish ; neuration a
little darker. Setse griseous. Oculi subolivaceous or coesious, with a black transverse
line and a black moveable spot ; orbits of ocelli black ; a black line or triangular spot
extends from the base of the antenna almost to the orbit of the ocellus, and the facial
carina has sometimes a small black spot upon it. Pronotum pale, sometimes edged with
black ; a faint fuscous blotch at the front border of the mesonotum ; tegulae, a stripe in
continuation with them, the two longitudinal sutures of the mesonotum nearest to the
tegulae, and one or two lines on the pleurae in advance of the intermediate coxse, sub-
piceous or nigro-piceous ; a black spot on the foremost stigma ; a dark or black dot or
dash upon the outer proximal joining of the intermediate coxa, or in front of it, and a
spot upon the meso-pectus behind the coxa (or else a fine subpiceous line between the
coxa and the mesopectus in its stead) ; a black spot at the base of the hind coxa in front,
and another beneath at its tip ; trochanters black-pointed. Fore femiu: greenish grey,
black at the extreme edge of the knee above, and marked nearly in the middle with a
small black Y-shaped or triangular spot ; fore tibia blackish grey, black at the knee ;
fore tarsus and ungues black. Hinder legs lighter, but correspondingly marked.

Imago {living), 6 . — Oculi commonly intense burnt-umber brown above and greenish

grey beneath, divided either by a black transverse line or by a pale space edged with

black ; sometimes the upper portion is fusco-olivaceous, and the lower csesious or cferu-

lescenti-griseous ; in twilight, or by candle-light, the upper part appears greenish black.

Occiput black ; face pale, marked, as in subimago, with fuscous or piceous. Thorax

above varying from brownish yellow-green (pistazinous), or fuscous, or pitch-brown, or

luteo-piceous, to pitch-black [changing to lutcous or luteo-piceous in dried examples] ;

the metanotum black or piceous ; sternum concolorous with the mesonotum. Markings

of the pleurtc and pectus, coxte, and femora very similar to the same in subimago ;

ground-colour of the legs : — fore femur at first pistazinous changing to piceous ; tibia and

■arsus in some lights darker, in others the tarsus is paler than the tibia, and its insertion

s black : hinder femora at first almost greenish white, changing to light olivaceous ;

ibiae paler, sometimes piceous at the tip ; tarsi smoky, or blackish grey, darker than the

ore tarsus, with the incisures very narrowly black. Wings vitreous ; neuration either

uscesceut or colourless, but the subcostal bulla piceous ; cross veinlets in the marginal

jea of the fore wing usually quite simple, 2-6 (3 commonly) before the bulla very

260 EEV. A. E. EATON OX RECENT EPIIEJIERTDiE OE MAYFLIES.

faint, 1 (rarely 2) at or near the bulla, and 10-19 (usually about 16) beyond it better
developed. Abdomen above fuscous or pistazinous, the segments narrowly darker
immediately before their pale extreme apical edges, their sides paler and eoncolorous with
the venter ; in segments 2-7 from the lateral line near the base of the segment on each
side of the dorsum a dark fuscous stripe (sometimes black towards its origin) ascends
obliquely, growing gradually lighter and less defined, and blends with the dark colouring
along the midst of the posterior border of the segment ; these stripes are most strongly
marked in the binder segments. Venter in the anterior segments spotless, pale or
cinereous, in 7-10 more or less lutescent or orange-tinted ; forceps black or greenish
black, paler inside distally ; penis testaceous. Sctic sepia-grey, becoming whitish
distally, sometimes black close to their origin ; a few of the joinings near tbe base
black.

$ (living). — Mai'kings similar to those of the subimago. . Oculi subglaucous, with
Iheir orbits and the line across subpiceous. Ground-colour of thorax light fusco-
olivaceous ; the oblique abdominal stripes are sometimes abbreviated, the stigmata
marked with a dark dot. Wings and neuration colourless. Fore tarsus eoncolorous
with the tibia, its joints narrowly edged above at the tips with blackish like those of tbe
binder tarsi, whose ungues are sometimes slightly rubiginose. Venter pale ochraceous ;
setae sometimes greyish white, sometimes greyish ; ventral lobe slightly excised. In
other respects similar to the j .

Dried specimens have the main nervures of the wings pale amber-colour, tbe great
cross vein of the fore wing blackish or piceous, the costa beyond it greyish, and the
bulla black ; the cross veinlets remain pellucid as a rule. In some specimens the hinder
tarsi are a shade darker tban the tibia;. The lateral stripes of the abdomen sometimes
are reduced to spots, and sometimes are almost obliterated. Length of body 6-5-9 ;
wing 7-10 ; setsD, d im. 11-15, subim. 0-5, $ im. 9-10, subim. 6-5 mm.

Hab Common on the continent, in rivers and streams, from Holland and Germany
southwards to Switzerland, the Pyrenees, and Portugal, c. g. at the following places : —
Aruhem, Ilalle, Dresden; Basle, Berne, Versoix ; Brive, near Le Puy (Haute Loire),
Toulouse, Tarascon (Ariegc), Orthcz ; and Ponte de MarccUos (Beira Baixa).

Herr Eostock's identification of this species with Burmcister's %B. aurantiaca appears
compatible with the latitude of interpretation allowed to the descriptions of more than
forty years' standing. Burmeistcr omits to mention the conspicuous dark spots on the
femora ; but Pictet did just the same thing with respect to those of the preceding species ;
and therefore no stress need be laid upon the omission.

IIhithrogena gekwanica, sp. nov. Plate XXIV. 43 h (penis dried).

Imago [dried), d . — Notum pitch-brown anteriorly, pitch-black posteriorly. Abdomen
fusco-piceous or piceo-fuscous, paler by the dorsal joinings. Seta3 fuligiueo-piceous.
Pore femur piceous ; tibia fuligineo-piceous. Uindcr femora piceo-lutescent, each with
a dark median band, the trochanters rather lighter; tibite light yellowish amber; tarsi
fuscescent, with piceous ungues. Wings vitreous, tinged slightly with light olive-grey

EEV. A. E. EATON OX EECENT EPHE:\IEEIDJJ OE MAYFLIES. 261

in tlie marginal and submargiual areas ; costa, subcosta, aud radius piceous ; the re-
maining neuration either pitch-black or black Length of body or wing 14- ; setae, j im.
about 28, subim. about 16 mm.
Sab. The Ehine, near Laiiflenburg (Berne Mus.).

P^GNIODES, Etn. 1881.

Illustrations. Adult (details), Pis. XXIII. & XXIV. 41.

Adnlt. — First joint of the hind tarsus shorter than the second, which equals the third
joint in length ; the corresponding joints of the intermediate tarsus similarly propor-
tioned ; first joint of the 2 fore tarsus much (about ^) shorter than the second, and this
rather longer than the third joint ; ungues mutually dissimilar. Penis-lobes rather
narrow and subcylindrical, with suddenly enlarged patulous tips, in the typical species.
— Fore leg of d defective in the specimens examined ; but the first tarsal joint is
shorter than the second. Fore tarsus of ? about f the length of the tibia, and this
about as long as the femur; the tarsal joints in the order of their shortening rank
2, 3, 5, 1, i, aud the first is nearly ^ as long as the second. Hind tarsus of $ nearly
y the length of the tibia, aud this about f as long as the femur ; its joints in the order of
their shortening rank 3 subequal to 5, 2, 1, 4. Ungues each unlike the other in every
tarsus. Hind wings of usual form ; the axillar region narrow. Penis-lobes at the base
subcylindrical, but distally enlarged suddenly to a moderate extent in the typical
species ; the seminal ducts apparently open into the capacious cavities of the hollow
lobes ; inferior stimuli well developed. Forceps basis saliently curved to a moderate
extent in the middle behind. Ventral lobe of the ninth $ abdominal segment entire.
Outer caudal setre in both the sexes about thrice the length of the bodv.

O ft

Ti/2>e. P. ciipuhdiis (in Heptageiiia), Etn.
Distribution. China and Tibet.
Etymology. Trai'/viwhnc, sportive.

P^GXiODES CUPTTXATUS, Etn. Plate XXIII. 41 (part of fore wing, hind wing), XXIV.

41 (legs $ & J genitalia).

Heptagenia ciipulata, ! Etn., Trans. Ent. Soc. London (1871) 138, pi. vi. 1-1, 1-la [detail] ; Palmen,
Paar. Ausf.-Gange d. Geschl. Org. b. Insect. S. 74 [anatom.] (1884).

Pagniocles [type] aqndatus, ! Etn., Ent. Mo. Mag. xviii, 23 (1881).

Snhimacjo [dried). — Wings light raw-umber grey, the bind wings very narrowly edged
with black-grey along the terminal margin ; longitudinal neuration raw-umber brown ;
cross veinlets mostly pitch-brown or pitch-black.

Imago [dried], d . — Thorax deep brown-ochreous above, the pronotum with a double
black spot in the middle, the metapleura with a descending brown-pm"ple stripe.
Abdomen light brown-ochreous above, with a median longitudinal streak, the apical
borders of the secrments, and in each of the scsmenls 2-8 on each side, with a broad

SECOND SERIES. — ZOOLOGY, YOL. III. 35

262 EEV. A. E. EATON ON EECENT EPHEMERIDiE OE MATFLIES,

oblique lateral stripe from the hinder border to the spiracular line, and a fine abbreviated
streak from the hinder angle of the dorsum along the same line, intense purple-madder-
brown, or purple-black; venter unicolorous. Setae light burnt-umber brown. Legs
dull translucent rufo-lutescent, almost rufous, the fore leg with the apical projection of
the tibia pitch-brown, and the tarsus light brown-ochreous. Wings vitreous ; the fore
wing from the base to tlie pterostigmatic space in the marginal and submarginal areas
faintly tinted with light yellowish-green, and from thence to the apex coloured with
raw-umber brown ; the hind wing in the larger portion of the marginal area tinted with
light yellowish-green, and along the terminal margin narrowly bordered with black-
grey or brown-black ; longitudinal neviration mostly pitch-brown, the costa of the fore
wing in some lights seeming darker, and the nervures near the wing-roots, the svibcosta
and radius for some little distance farther, and the great cross vein, light raw-amber ;
cross vcinlets pitch-black.

? . Neviration of wings pitch-black, excepting the bases of the costa and subcosta, the
great cross vein, and the proximal extremities of the longitudinal nervures posterior to
the radius, Avhich are very light raw-umber brown. Legs rufo-lutescent, with the
terminal joint of every tarsus intense warm sepia-brown. Egg-valve acute ; ventral lobe
of the penultimate segment entire, and traversed by a median longitudinal fold. Length
of body, c? (large example) 18, 2 16 ; wing, d 11-15, S 21 ; set£E, 6 im. 48 (or more),
2 54 mm.
Hub. China, Hong Kong (Brit. Mas.).

Thkee Nymphs, generis incerii, of the Ecdyurus type.

Nymph No. I. — PI. LVII. (whole figure and details).

Six anterior pairs of the abdominal tracheal branchiae provided with broad, pointed
laminae recumbent upon the sides of the dorsum ; seventh pair spreading, the laminae
linear-lanceolate and minute. Each of the anterior laminae is oblique, somewhat obovate
and cuspidate, but is asymmetrical, the lower margin being either truncate obliquely or
sinuate, and the opposite side slightly dilated, between the base and the widest part of
the lamina, while the cusp is nearer the upper than the lower edge ; each contains a
strongly defined fruticosely branched trachea, and partially overlies the branchial
filaments, which are not fascicled in the usual manner, but explauate, and connected
together by their membrane for some distance from the roots, thus constituting a single
subrotund lamella, fringed deeply with long branching filaments, annexed to the base
of the lamina. The hindermost laminae each contain a ji innately branched trachea, and
are pilose at the edges, but apparently lack fibrils. Median caudal seta subequal in
length to the others and to the body ; their joinings beset with minute spreading hairs.
Pronotum transverse, very short, well defined behind ; its lateral margins slightly
dilated ; its posterior margin rounded off obtusely towards the sides, and sinuate in the
middle. Ventral segments 2-5, short, the hinder ones successively longer ; the lobe of
the ninih segment of 2 elliptical at the tip, and sinuate on each side thereof ; pleurse

EEY. A. E. EATON OX EECEXT EPHEilEEID-E OE MATELTES. 263

shortly and acuminately produced into teeth at the hinder angles of segments 7-9.
Fangs of the mandihles slim, compressed and subeqal in length ; the exterior tridenti-
culate at the summit, and serrulate along the superior edge ; the interior fangs diversi-
form, terminated each by a tooth and two denticulations ; in the right mandible the tooth
is intermediate between the denticulations, is subulate, elongate, and slightly twisted,
and the inferior denticulation is preceded by a few short hairs placed in a row along the
edge of the fang ; in the left mandible the tooth is somewhat conical and is above the
denticulations. Lacinia of maxilla i. beset at the edge of the crown with short appressed
triangular pectinate teeth, and terminated by two simple pungent spinules ; proximal
joint of the palpus stout; terminal joint comparatively slender, its inner side nearly
straight, the outer side gently curved, pungent at the point and somewhat pilose in
proximity to its termination externally. Median lobe of the tongue inflated, subovate,
grooved lengthwise in the middle nearly as far as the tip, and then transversely tumes-
cent ; paraglossae broadly dUated, slightly recurved at the tips, and much larger than
the median lobe. Femora, on the coloured side, banded with grey in two or three
places ; the bands confluent below. Length of body 7 ; setae about 7 mm.

Sab. Xiagara and Trenton Falls, X. T. (G. H. Hubbard, 20 & 22, v. 1874) ; Dakota
(Cones, 1872 & 1873), common; also X. Illinois (Prof. T^'. A. Forbes, vi. 1883).
Figured and described from sj^ecimens communicated by Dr. Hagen (in Mus. Comp.
Zool. Cambridge, Mass.).

It is possible that the Swedish insect figured by De Geer, Mem. pour servir a I'Hist.
des Ins. ii. part ii. pi. xviii. 1—4, may be congeneric with Xymph Xo. I. The nymph
was found by him in May in a ditch by the gardens of Leufsta, near Dannemora, in
which grew many species of aquatic plants. Towards the end of May the imago appears,
of which the oculi are sea-green. The nymphs climb uj) the plants to undergo the
penultimate moult.

XriiPH Xo. II. — PI. LVIII. (whole figure and details).

Six anterior pairs of the abdominal tracheal branchiaj provided with broad, obtuse or
refuse laminfe recumbent upon the sides of the dorsum; laminae of the seventh pair
linear-lanceolate and spreading. The anterior laminae are quadrilateral, longer than
broad, oblique at ths base, pilose at their exposed edges, and pergamentose ; all but the
foremost are auricled at the base on the lower side, and all are slightly sinuate at the
base on the upper side, the foremost being merely dilated instead of auricled corre-
spondingly ; distally the first three are truncate and slighly refuse, but the next three
are obtusely rounded at the extremities ; the hindermost lamina;, linear-lanceolate,
acuminate and ciliated, lie outwards and obliquely backwards from the sides, and
seemingly are destitute of branchial fibrils. Each of the anterior laminae contains a
strongly defined fruticosely branched trachea, and partially overlies the explanate
branchial fibrils which are connected together by membrane as in Xymph Xo. I., but
more extensively and so as to resemble an oval membranous lamella, deeply fringed
*vith branched filaments, and produced into a laciniated auricle at the base on the

35*

264 EEV. A. E. EATON ON EECENT EPHEMEEID.^ OR MAYFLIES.

upper side {i. e. the side farthest from the auricle of the pergamentose lamina). Median
caudal seta about If as long as the others, and twice as long as the body ; their joinings
beset with minute spreading hair. Pronotura transverse, imperfectly delimited, being
confluent with the mesonotum at the lateral margins (although well defined elsewhere)
and there slightly dilated anteriorly. Ventral segments short, the lobe of the 9th in
the ? triangular ; pleurae in segments G-9 produced posteriorly into short acuminate
triangular teeth. Fangs of the mandibles slender, compressed, subequal in length ; the
exterior 2-3 denticulate at the tip, and serrulate at the upper border ; the inferior fang
bidendate in the right mandible, tridentate in the left, without remarkable differences in
the teeth. Maxilla i. and tongue very similar to those of Nymph No. I. ; the former
more sparsely beset with spinules and cilia?, in the place of pectinate teeth, at the edge
of the crown, and with stronger fangs at the point ; its palpus furnished with a com-
pressed acute spine below its pimgent point. Femora marked on the coloured side with
two broad dark bands, each containing a pale blotcli upon the upper margin ; the bands
are confluent below. Length of body 7"2, setae 13 mm.

Sab. The Falls of Niagara, N. Y., 3 examples by Mr. H. Hubbard, 22, v. 1874 (Mus.
Comp. Zool. Cambridge, Mass.) ; also 3 or 13 probably from Ithaca, Fall Creek, N. Y.,
and G from Crystal Lake by Prof. S. A. Forbes. Figured and described from specimens
communicated by Dr. Hagen.

Nymph, No. III.— PI. LIX. (whole figure and details).

Abdominal tracheal branchioB all reclinate at the sides of the body, with moderately
long fascicled fibrils ; laminae oblique, the foremost and the hindei*most two obtuse and
almost semi-obovate, the others subovate, triangular, and broad ; branchial trachea3 well
developed, arborescently branched, excentric, with their longer branches ascending or
directed towards the broader sides of the laminas. Caudal setae defective in the specimens
examined ; the median seta Avell develojjcd. Pronotum transverse, very short, well
defined behind ; the lateral margins dilated and rounded off. Ventral segments subequal
in length ; the lobe of the ninth segment of the ? narrowly elliptical at the tip ; pleurae
in segments G-8 produced into minute acuminate teeth. Fangs of the mandibles slender,
unequal, stronger in the left than in the right mandible ; the exterior fang, bifid, and
denticulate along its upper side in the latter, is in the former more compressed, acumi-
nately lanceolate, and serrulate along both edges; tbe interior fang, slightly bifid, or
slenderly bidentate in both of them, is in the right mandible obviously stunted, and in
place of an endopodite has three short unilaterally plumose setulse, Avhile the other
mandible has only a single smooth setala in that place. Lacinia of maxilla i. beset at
the edge of the crown with numerous flattened pectinate teeth, and with a few bristles
at the point instead of spines ; proximal joint of the palpus stout ; terminal joint slen-
derly clavate, obliquely trimcate, densely puljesceut at the end and acute at the tip.
Tongue very similar in form to those of the preceding two nymphs. Femora marked on
the coloured side with three irregular zigzag grey fasciae, narrowly confluent in the
n\iddle, preceded by a solitary oval spot near the base. Length of body 7 mm.

EEY. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 265

Hab. Dakota, 1872 ; 20 examples captured by Mr. Coues (Mus. Comp. Zool. Cambridge,
Mass.) communicated by Dr. Hagen.

HEPTAGENIA, Walsh, 1863; restricted, Etn. 1881.

Illustrations. Adult (details), Pis. XXIII. & XXIV. 45 ; see also [anatom.] citations
of Palmen (1884) under II. Jlavipennis and sulplinrea; (whole figures) see citations,
under the same species of Sulzer (1776), Panzer (1805), and Pictet (1813-5). Nijmph,
PL LX.

Adult. — First joint of the hind tarsus shorter than the second, which is either equal
to or a little longer than tlie third joint ; the corresponding joints of the intermediate
tarsus of like proportions ; first joint of the 6 fore tarsus much shorter than the second,
and this equal or subequal in length to the thu'd joint ; first joint of the S fore tarsus
much shorter tlian the second, which slightly exceeds the third in length ; ungues each
imlike the other. Penis-lobes somewhat explanate, oblong, and svibtruncate at their
divergent extremities. — Fore leg of 6 about 1^ the length of the body ; tarsus about
If as long as the tibia, Avhicli is very little longer than the femur ; the tarsal joints in
the order of their shortening rank 2 equal to 3, 4, 5, 1, and the first is about j as long as
the second joint. Fore leg of ? about equal in length to the body; tarsus about f as
long as the tibia, which is about y| as long as tlie femur ; the tarsal joints in the order
of their shortening rank 2, 3, 5, 4, 1, and the first is J-| as long as the second joint.
Hind tarsus of d about | as long as the tibia, which is less thaji | as long as the femur;
its joints in the order of their shortening rank in d 5, 2 equal to 3, 1, 4, in $ 5, 2, 3, 1, 4.
Ungues each unlike the other in every tarsus. Hind wings of ordinary form ; the axillar
region narrow. In the dried ? abdomen tJie relative lengths of the dorsal segments
2-10 may be formulated thus: — 5, 7, 8, 8, 10, 10, 8, 6, 7 ; ventral lobe of the ninth
segment obtusely rounded or refuse. Forceps-basis of 6 seldom truncate behind, usually
slightly prominent between the insertions of the limbs, and refuse in the middle. Penis
lobes rather broad, flattened beneath, subtruncate at the tips, and curved outwards to a
moderate extent divergently ; stimuli well developed, adjacent to the median line. Outer
caudal sette of 6 l^-^^ (but usually twice) tlie length of the body ; those of $ l4-2i its
length. Vertex of ? head transverse ; tlie edge of the occiput, transverse in the midst,
ascends at the posterior orbits of the oculi usually only in a slight degree ; median ocellus
prominent, contiguous with the anterior margin of the upper surface of the head.
Pronotum of ? subcordately excised behind ; the reflexed lateral lobes only slightly
rounded posteriorly.

Subhnago. — AVings tinted with yellowish, very rarely with greyish ; neuration opaque,
the cross veinlets acquiring a black tint and narrow dark grey borders, the membrane

ikewise becoming transversely striped in the disk, and the terminal margins bordered

^ith greyish, shortly before the final moult.
Nymph. — Abdominal tracheal branchiae spreading at the sides ; branchial fibrils

'ascicled and about as long as the narrowly lanceolate lamina?, of which the fifth is the

ongest, the others shortening successively in a slight degree in both directions therefrom ;

>ranchial trachese indistinct in the laminae after death, through the absence of pigment.

SECOND SERIES. — ZOOLOGY, VOL. III. 36

2G6 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

Median caudal seta subequal to the others, about If as long as the body, and beset at the
joinings on both sides nearly throughout with minute spreading pubescence, while they
are similarly beset on the inner side only. Pronotum well defined, sinuate in the middle
posteriorly ; its lateral borders scarcely at all dilated, nearly straight, but rounded off
slightly in front. Fangs of the mandibles strongly dcA^eloped, subequal, inflected and
compressed; the exterior somewhat triangular, acute, serrulate along the upper edge;
the interior fang bifid; endopodite absent, represented perhaps by a minute tuft of hair
in the left mandible, and a single short hair in the right. Lacinia of maxilla i. beset at
the outer edge of the crown with flattened pectinate teeth, and terminated by two con-
tiguous flattened spines at the point ; fii'st joint of the palpus stout ; terminal joint
slender, slightly clavate, oblique and velutinous at the end, and pungent at the point.
Median lobe of the tongue obtuse and somewhat hexagonal ; paraglossiB broadly
expanded, almost oval, not recurved at the tips. Femora marked on the coloured side
with a pair of large opposite confluent spots, forming an irregular distal band, and a
pair of separate longitudinal opposite streaks near the base, sometimes connected with
the band bv dark colourini? alons: the edijes of the femur.

NORTH AMERICAN SPECIES.

Heptagenia flavescens, Walsh.

t Palingenia flavescens, ! Walsh, Proc. Acad. Nat. Sc. Philad. (18G2) 373 ; Hag., Proc. Ent. Soc. Philad.
ii. 177 (18G3).

Heptagenia [type] flavescens, ! Etn., Ent. Mo. Mag. v. 90 (1808) ; id.. Trans. Ent. Soc. London (1871)
112, pi. vi. IG [detail ill drawn] ; Hag., op. cit. (1873) 404; ! Etn., Ent. Mo. Mag. xviii. 24 (1881).

Subimago. — Wings slightly tinged with fuscous in s ; in ? subflavescent, subopaque,
with yellowish neuration, " except on the disk and tip," [where doubtless they are
fuscous]. SetfG of 6 dull greenish ; of ? pale, a little fuscous at the tips.

Imago, d. — Yellowish. Eyes bright greenish yellow during life. Notum ferruginous,
sometimes verging upon piceous. Dorsum of abdomen ferruginous, darker at the tips
of segments 2-7, and with a pair of subobsolete pale vittse at the base of each of them;
venter pale greenish in segments 2-7 or -8. Setae whitish ; the joinings fuscous, and
sometimes towards the roots alternately "white" [wide?] and narrow. Forceps pale,
at the tips fuscous. Fore leg pale ferruginous, with a median and a terminal baud on
the femur, the tip of the tibia, and the tarsal joinings and tips fuscous. Hinder legs
yellowish, Avith the tips of the femora fuscoiis, and the tarsal joinings and tips a little
cloudy. Fore wdng hyaline, with a pale ferruginous cloud iu the pterostigmatic region ;
neuration fuscous, excepting the basal § of the costa, subcosta, and radius, which are
yellowish ; the thickening at the bulla of the subcosta, about 0'5 mm. long, is more or
less obfuscated. $ paler than 6; vertex and notum rather luteous than ferruginous;
dorsum of the abdomen pale fuscous or pale ferruginous, without any pale vittie. Setae
in one specimen uniformly whitish. " The costal cross veins are hyaline on their basal
|." Length of body 9-13; wing 11-15; setne, d im. 27-38, subim. 17, 2 im. 27-28,
subim. 13 mm.

Hab. Rock Island, 111. [After Walsh.]

REV. A. E. EATON ON IIECENT EPHEMEEID.E OR MAYFLIES. 267

Heptagenia interpunctata, Say.

\Baetis inter punctata, Say, Journ. Acad. Nat. Sc. Pbilad. viii. 11 (1839) ; Pict., Hist. Nat. Nevropt.
ii., Epliem. 19J, (18i3-5) ; Walk., List of Neuropt. in Brit. ^Mus. part iii. 5(52 (1853); Le Coute, Com-
plete Writiug.s of T. Say, ii. 411 (1859); Hag., Smitlison. Miseell. Coll. (18G1) Syuop. Neuropt. N.
Am. 44.

\Palingenia interpundata, Walsh, Proc. Acad. Nat. Sc. Pliilad. (18G2) 374; Hag., Proc. Ent. Soc.
Philad. ii. 177 (1863) ; Walsh, op. cit. ii. 190 (18G3).

Heptagenia inter punctata, Etn., Trans. Ent. Soc. London (1871) 112.

Suhimago. — Wiugs at first opaque aud tinged -with yellowish, afterwards becoming
fuscous; neuratiou fuscous, excepting the basal f of the costa, subcosta, and radius,
which are yellowish, aud the neuration of the axillar region of the fore wing, which
(like the whole neuration of the hind wing, except at the tip) is light amber-coloured.

Imago, 6 . — Yellowish. Eyes during life pale greenish yellow, bisected horizontally
by a black line ; near their uj^per orbits is a black spot on eacli side, sometimes obscured
by the vertex being obfuscated, aud again below each of tlie antennoo is anotlier black
spot a little elongated transversely, which appears angular only when viewed obliquely.
Prothorax marked with a black triangle at the base and a black line on each side ; notum
piceous. Abdomen in segments 2-7 or -8 " pale obscure greenish hyaline " [?=traus-
parent and tinged faintly with greenish], with the terminal ^ of each of them, and a
median longitudinal Hue or stripe on the dorsum piceous, which stripe is usually broad,
and when broad contains a pale spot on each side : the remaining dorsal segments almost
entirely piceous: venter ]}a\e, obscure greenish, with the tips of the segments darker;
forceps pale, sometimes cloudy at the tips. Setre pale greenish, narrowly fuscous at the
joinings, except in one immature specimen. F5re leg pale greenish yellow, with a
median and a terminal band on the femur, the tip of the tibia, aud tlie joinings and tip
of the tarsus fuscous. Hinder legs somewhat paler, but similarly marked on the femur
and at the extremity of the tibia, excepting in one instance where the median femoral
bands were wanting. Wings hyaline ; the fore wing clouded with yellowish brown
along the costa, especially in the pterostigmatic space, and the hind wing tipped
distinctly with brown ; behind the bulla, in the midst of the inters])ace between the
radius (3) and the sector (4) of the fore wing is a very coarse black longitudinal streak
about O'o mm. long : neuration for the most part fuscous ; but in their basal two thirds
the costa, subcosta, and radius are yellowish ; the cross veinlets in the marginal and
submarginal areas of the fore wing are very coarse.

2 . Differs from the d in having the black triangle at the base of the prothorax
reduced to a dot ; meso- and metanotum luteous. Al}domen in segments 2-9 egg-yellow
above and beneath, with the piceous markings much narrower than those of the d , and
with the ventral joinings pale instead of dark ; segment 10 whitish. In the fore wing
the costal border is uniformly clouded with yellowish, not darker in the pterostigmatic
space, and the neuration in proximity to the inner margin, like that of all but the tip of
the hind wing, is yellowish hyaline. Length of body G-10 ; Aving, d 8-11-5, ? 8-14 ;
setae, d im. 20-25, subim. 9-15, 2 im. 14-24, subim. 7-14 mm,

Bab. Eock Island, 111. [after Walsh]. Also Indiana (Say) ; Alleghany Mts., Va.,

Washington, D.C., Trenton Falls and Chicago (Osten Sacken, teste Ilag.).

30*

268 EEV. A. E. EATON ON EECENT EPHEMEKID.E OK MAYFLIES.

EUROPEAN AND ASIATIC SPECIES.

In Herr Rostock's analysis of the Saxon species of Jleptayenia, some of the
characteristics relied upon are in some degree variable with the individual specimen
{e. g. the coloration or tlie partial deficiency in colour of the marginal area of the
fore wing).

Heptagenia sulphueba, Miiller. Plate XXIV. 45 (legs).

Ephemera sulphirea, Miill., Zool. Dan. Prodr. 142 {\77€>). — E. hehola, Stihz., Abgek. Gesch. d. Ins.
171, pi. xxiv. 7 (1776). — E. leucophthalma, StriJm, N. Saml. Kougl. Dausk. Vidcnsk. Selsk. Skrift. ii.
90 (1783) ; Wallengrcn, Christ. Videtisk. Forhandl. No. ii. 21 (1880).— JS. \bioculata, Romer, Gen. Ins.
Lin. & Fahr. icon, illust. 23, pi. xxiv. 7 [after Subz.] (1789). — [Ephemera] or E. ferruginea [Zsch.
Mns. Lesk. i. 150. no. 18 (1789)]; Gmcl., Linn. Syst. Nat. ed. xiii. i. pars v. 2630 (1790); 01., Encycl.
Meth. vi. 422 (1791). — E.\bioculata, var.. Panzer, in Explic. Scliief. Ic. ccxxix. (1804); id., Fn. Ins.
Germ. init. Heft xciv. no. 17 (1805). — E. citrina, Humrael, Essais Entom. no. iv. 71 (1825). — E. \lutea,
IStepli., 111. Brit. Eut. vi. 55 (1835).

Bactis e/ei/aiis, Curt., Lond. & Edinb. Philos. Mag. ser. 3 (1834) 120; ! Steph., 111. Brit. Ent. vi. 64
(1835) ; Pict., Hist. Nat. Nevropt. ii. Epliem. 193 (1843-5); Walk., List of Neuropt. in Brit. Mas.
part iii. 560 (1853) ; Hag., Ent. Ann. (1863) 25.— jS. costaUs, Curt., Lend. & Ediub. Phil. Mag. ser. 3
(1831) 120; ! Steph., 111. Brit. Ent. vi. 64 (1835) ; Pict. Hist. Nat. Nevropt. ii. Ephe'm. 194 (1843-5) ;
Walk., List of Neuropt. in Brit. Mus. part iii. 561 (1853). — B. straminea, Curt., Lond. & Edinb. Philos.
Mag. ser. 3 (1831) 121.— ? 5. marf/inalis, Burm., Handb. d. Ent. ]5d. ii. Abth. ii. 801 [excl. citations]
(1839).—^. ci/anojjs, Pict., Hist. Nat. Nevropt. ii. Ephein. 171, pi. xx. 2 (1843-5); Walk., List of
Neuropt. Ins. in Brit. Mus. part iii. 556 (1853). — B. sulphurea, Pict., Hist. Nat. Nevropt. ii. Ephem.
185, pi. xxiii. 8 (1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 558 (1853) ; Brau.,Neur.
Austr. 74 bis (1857) ; Ausser., Ann. d. Soc.'Natur. Modcna, An. iv. 134 (1869) ; Joly, Rev. d. Sc. Nat.
Montpellier, v. 323, pis. viii., ix. figs. 36-38 bis & 51, 52 [anatomical details] (1876). — B. % lutea, Hag.,
Ent. Ann. (1863) 23.

Heptagenia elegans, !Etn., Trans. Ent. Soc. London (1871) 145, pi. iii. 5 [wing] & vi. 18-18 b [details];
Hag., op. cit. (1873) 404 ; Meycr-Diir, Bull. Soc. Ent. Suisse, iv. 312 (1874) ; Rostock, Jahresb. d. Ver.
f. Naturk. Zwickau, 1877, p. 90 (1878) ; Pahncn, Paar. Ausf.-Gauge d. geschl. Org. b. Insect. S. 44,
64, 65, 74, 75, 77, 78, 83, 92, taf. ii. 28, 29, iii. 39-41, & iv. 58 [anatom.] (1884).

Suhimago (living). — Eyes pale blue-verditer, or else pale yellow-green with a movable
round sjoot surrounded by about half a dozen little circular specks of less intense grey ;
orbits of ocelli olivaceous ; a small triangular black speck on each side of the face at the
lower part of the inner orbit, and sometimes a rhomboid black spot close to the eyes on
the vertex ; a linear dash on the pleura just behind the fore coxa, and from 1 to 3 dots,
also black, near and above the intermediate coxa. On each side of the mesonotum is a
pitch-brown streak tapering forwards from the hinder part of the segment and angu-
lated close to the Aviug-roots. Wings at first unicolorous sulphur-, or lemon-yellow; the
membrane afterwards becomes dull greenish yelloAV, or even yellow- green (like fumes of
chlorine) ; a tapering grey streak is developed transversely from near the inner-terminal
angle of the fore wing, and another nearer the tip of the wing from the vicinage of the
pterostigmatic space, while simultaneously a grey band of moderate breadth appears
along the terminal margin and the cross veinlets together with a dot at the bulla turn

EEV. A. E. EATON OX RECENT EPHEMERID.E OR MAYFLIES. 2G9

black. Fore femur and base of tibia light yellowish greeu ; the remainder of the tibia
lighter in tint ; kinder femora and the bases of the tibiae whitish, with a yellowish green
tint ; the remainder of the tibite smoky white. Tarsi smoky white, or greyish, with
])]ack joinings and ungues. Setae smoky white with rufescent joinings. IFheii dried the
wings are transparent dull light yellowish, and it depends upon what was the period at
which the specimen Avas killed whether the cross veinlets are also yellowish or else
brownish or black.

Imago {dried). — Femora not dark-banded. Dorsum of the abdomen devoid of a longi-
tudinal median dark stripe, but with the terminal margins of the segments narrowly
dark-bordered nearly from side to side. Metathorax as pale at the sides as elsewhere. —

d {living). Eyes at first ctesious, with a transverse dark line and movable markings
like those of the subimago : sometimes they are tinged with pale yellowish green above,
and more deeply so below. At a later period, and when viewed under artificial light,
their colour changes to black or greenish black ; but later still it is apt to become cajsious
again. Head and sides of the thorax marked as in subimago with either black, piceous,
or fuscous. Pronotum light greenish bistre, or olive-brown ; the remainder of the notum
either light pitch-browu or somewhat brown-ochreous : tegulse, pleurse, and sternum
much paler, and variously coloured with pale greenish yellow, pale greenish brown, &c.
Dorsum of abdomen in segments 1-7 or -8 (excepting at the sides) translucent light
greenish brown, or olivaceous grey, narrowly darker (often pitch-black) at the terminal
margins of the segments ; segments 8 or 9-10 opaque, and more or less brown-ochreous
varied with yellow ochre. Venter in segments 1-7 or -8, and the sides of the corre-
spending dorsal segments, very pale transparent olivaceous green ; the remaining ventral
segments opaque and somewhat yellow-ochreous. Seta3 smoke-grey, or greyish white,
with black, pitch-brown, or rufescent joinings. Fore legs subolivaceous, sometimes
tinged with yellowish brown : tarsus smoky grey ; the tip of the femur, both extremities
of the tibia, and the tarsal joinings, blackened. Hinder legs yellowish -green or whitish
amber-colour, with the tarsus and tij) of the tibia smoke-grey, and often with the tarsal
joinings blackened. "Wings vitreous, with pitch-black neuration, excepting that, towards
the roots, the principal nerviu-es arc often tinged with greenish- or amber-yellow : in the
fore wing the whole of the submarginal area and at least the pterostigmatic portion of
the marginal area are of a greenisli- or yellowish-amber tint, the pterostigmatic parts
being subopaque and often tinged with grey ; but frequently the remaining portion of
the marginal area is likewise amber-tinted. In dried specimens the greater portion of
the wing-neuration becomes pitch-brown ; the axillar fold of the fore wang is bordered
externally with a slight brownish cloud ; the legs to a large extent become strongly
amber-coloured, and the notum raw-umber brown ; while the thoracic pleurai often lose
the dark markings and become almost uniformly pale brownish yellow.

2 {living). — Eyes either light yellowish green, glaucous, coisious, or black ; on each
side of the face and vertex at the orbit of the eye is respectively a triangular black spot
md a triangular fuscous spot. Notum laterally of the very lightest shade of brown-ochre,

out along the middle fuscous, with the peaks of the meso- and metanota yellow-ochreous ;

n front of the upper part of the base of the intermediate coxa is usually a fuscescent or

270 REV. A. E. EATON ON RECENT EPHEMElilD.E OR MAYFLIES.

black spot or streak. Dorsum of abdomen in segments 2-7 either very light olive-green
or light gamboge-yellow, but in segments 8-10 light yellow or yellow-ochre ; the terminal
borders of the segments narrowly fuscous ; venter spotless. Setce white or greyish white,
with dark or rufescent joinings. Legs gamboge- or amber-yellow ; the tarsi greyish white>
with black joinings. Wings vitreous ; the fore wing usually tinged only in the marginal
and submarginal areas with lemon-yellow, but sometimes a fainter tint of the same colour
suffuses the remainder of the membrane universally ; neuration mostly black, but the
stronger portions of the longitudinal nervures, the great cross vein, and the axillar fold
are gamboge- or amber-yellow. In dried specimens the notum becomes light brownish
ochre, instead of fuscous, along the middle, and in many positions the longitudinal
neuration of the wings becomes amber-yellow, while the cross veinlets remain pitch-
black or black ; the colouring of the wing-membrane in the marginal and submargiual
areas of the fore wing of ordinary specimens becomes brownish amber, and is most
apparent only in the sul)marginal area and in the pterostigmatic portion of the marginal
area, though not entirely deficient in the remainder of the former area.

Variation, <S im. [dried). — The abdomen is almost uniformly light pitch-brown
(excepting, as usual, tbe terminal edges of the dorsal segments), and the tract of tlie
dorsal vessel is subopaque, but not so dark as to be reckoned as a dark dorsal stripe.
Hah. Ponte de Morcellos (Beira Baixa), Portugal.

Length of body, 6 7-10, 2 9-11 ; wing, d 8-5-12, ? 11-13 ; seta?, cJ im. 16-23,
2 im. 14-19, subim. d & ? 12-15 mm.

Hah. Generally distributed in Eui'ojje in streams and the swift parts of rivers from at
least Hammerfest to the south of Prance and northern Portugal, and from Great Britain
to southern Russia. May to September. In Brauer's description of the 6 fore tarsus
" dritte " is written for " vierte."

Heptagenia cJiiRULANS, Rostock.

Heptagenia C(erulans, ! Rostock, Jahresb. d. Vcr. f. Naturk. Zwickau, 1877, p. 89 (1878).

Imago. — " Thorax yellow-brown, darker behind. Abdomen brown above, darker at the
tips of the segments, ochreous at the sides and beneath, and tinged with orange in the
last three segments. Forceps brownish. Setse smutty-white, annulated with darker
towards the tips. Pore leg of <3 testaceous-brown, with darker joinings. Pore wings
with bluish iridescence, the marginal area eitlier colourless or, at the most, tinged with
yellowish at the apex. Expanse of wing 21 ; length of setiE, 6 im. 25 mm." [After
Eostock.]

Hah. TVeisseritz, near Dretschen, Saxony (Rostock). I have had no recent opportunity
of comparing this species with H. gallica. As nothing is said by Herr Rostock of any
spot at the side of the metanotum, or of any dorsal abdominal stripe in H. ccsrulans, I
Lave supposed them to be distinct species.

Heptagenia flava, Rostock.

Heptagenia flava, ! Rostock, Jahresb. d. Vcr. f. Naturk. Zwickau, 1877, p. 90 (1878).

EEV. A. E. EATON ON RECENT EPHEMERID^ OR MAYFLIES. 271

Suhimago (dried). — Wings dull light yellowish, less transparent than in S. sulphurea ;
the hind wings broadly l)ordered with a liglit greyish cloud along the terminal margin ;
the fore wing faintly tinged at the pterostigma with very light red-purple, or purple-
madder. Neuratiou at first lutescent, the cross veinlets turning black as in H. sulphurea.
Setae lutescent with dark joinings.

Imago [dried). — Femora not dark-banded. Dorsal segments 1-7 2 or 1-10 6 of the
abdomen traversed lengthwise by a dark median stripe, and dai"k-edged halfway across
the terminal border on each side of the stripe. A dark stripe on each side descends
obliquely from the first dorsal segment, running close behind the hind Aving-roots and the
spiracle, and just in front of tlie insertion of the hind leg. — <S . Thorax brown-ochreous or
piceo-luteous above, " with a dark violet-brown spot on each side of the prothorax.''
Abdomen bright yellow, with a broad stripe along the middle of the back strongly tinged
with purple-madder, darkest above the dorsal vessel and at the joinings for a short distance
on each side of that ; in some examples the ordinary curved pale translucent line is
visible on each side of the dorsal vessel in segments 2-5, and the other markings comprise
a median linear black-purple stri2ie extending from segment 1 to segment 7 or 8, and a
purple-madder band extending halfway across the back along the distal margin of each
of these segments, and then produced foi-Avards almost at right angles with the margin in
a linear stripe to the basal joining of the segment, so as to enclose a light-coloured blotch
on each side of the median stripe at the base of the segment. Set;je white or pinkish
white, with reddisli joinings. Eore femur brown, tinged with madder-pnrple, chiefly so
where in other species the two dark bauds are placed ; fore tibia and tarsus testaceous,
or in transmitted light pale amber-yellow, the extremity of the tibia, the tarsal joinings,
and the imgues burnt-umber brown ; hinder legs very light testaceous, or else amber-
yellow, with an ill-defined jiurplc-brown mark at the end of the fumur, best seen in the
intermediate leg and at the lower edge of the limb; their tarsal joinings and ungues
purple-brown. Wings vitreous ; the fore wing tinged with light amber-yellow in the
I base and pterostigmatic portion of the marginal area, and in the whole of the submarginal
area; in the pterostigmatic part of both areas, about halfway between the bulla and
the apex, is a faint red-purple cloud ; neuration for the most part pitch-black, the costa,
subcosta, and the radius to beyond the middle light pitch-brown or yello\iish brown, the
ibulla pitch-black ; the axillary nervures and the proximal extremities of the others very
light yellowish brown.

2 ■ Very similar ; the inner orbit of each eye with a black line below running inwards
towards the carina, and a black triangular streak above tapering backwards obliquely.
Pronotum with a curved tapering pnrple-black strealc on each side directed obliquely
lownwards from the upper posterior angles. The indistinct markings of the legs are
Similar to those of the male, but the fore femur is less tinged sometimes with madder-
ourple, and the burnt-umber broAvn at the tip of the fore tibia is restricted to the joining.
Length of body 9-12; wing, 6 10-12, 2 11-15; seta:', 6 im. 24, subim. 13, ? im. 15-
J5, subim. (large example) 19 mm.

Bub. Middle Europe; Arnhem in Holland, near the railway bridge, 27th July; near
Oretschen, Saxony (Rostock). In IVPLach. Mus. are two examples from Herr Rostock,

272 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

and eight (probably from Poseu), captured during the second fortnight in June, from Prof.
Zeller. The red-purple tint in the pterostigmatic region of the fore wing, the black-purple
dorsal stripe, and the faint traces of the almost obliterated purple-brown femoral bands
serve to mark off this species from its very similar neiglibours.

Heptagenia gallica, sp. nov. Plate XXIII. 45 (fore wing), XXIV. 45 a ( $ tarsi 1 & 2,
penis dried). Nijmph, Plate LX.

Heptayenia [nymph], ! Etn., Ent. Mo. Mag. xviii. 25 (1881). — H. gallku, ! id., in the writing of the
plates cited above (1883).

Imago {dried). — Femora, each more or less faintly marked with a dark median band,
which bands in some [possibly newly moulted] specimens are incomplete, the colouring
matter extending only part way across from the under edge of the femur. On each side
of the metanotum above the insertion of the hind coxa is a dark spot, which is relatively
large and rounded in 6 , but quadrangular and smaller in $ . Tract of the dorsal vessel
narrowly bordered with brownish ; the terminal edges of the intermediate dorsal
segments are entirely dark. — d {living). Eyes at first black, changing to csesious with
a black transverse line. Thorax raw-sienna above, Avith the peak of tlie mesonotum
and a large round spot just behind and below the hind wing-roots black. Dorsum of
abdomen in the middle of the intermediate segments, and right across their terminal
borders, fuscous ; segment 10 raw-sienna ; the sides of the dorsum in segments 2-7 trans-
lucent whitish, with the main trunk of tlie tracheae in a large measure black. Setae
whitish, distally with every joining, but near the base with only the alternate joinings
piceous. Hinder legs whitish amber or cretaceous, with greyish tarsi and black tarsal
joinings : the spine of the trochanter and tlie median spot at the lower border of the femur
blackish, the tip of the femur fuscescent. The fore femur, tinged with raw-sienna, is
similarly marked w ith blackish, and the tip of the fore tibia and the terminal joint of the
tarsus are also black ; but the other joints of the fore tarsus are concolorous with the tibia
with black joinings, excepting the first joint, which is greyish. In front of the basal
joining of the hind coxa is a dark dash ; the mesosternal ganglion shows as a cordate
fuscous blotch. Wings vitreous, with piceous neuration ; the great cross vein, towards
the costa, and the proximal extremities of the longitudinal ncrvurcs of the fore wing are
deficient in colour ; in some positions the costa, subcosta, and radius of this wing become
bistre-brown, and in trcms?nitted light the neuration, as a whole, appears brownish amber-
colour. The pterostigmatic region is sometimes very faintly tinged with brownish. —
When dried the notum is brown ochreous, varied behind with pitch-brown ; the fore tibia
and tarsus become very light brown-ochreous with blackish markings. Hinder legs very
pale yellowish amber, with greyish markings ; the bands at the tips of the femora become
obsolete.

? {dried). — Before oviposition the insect closely resembles JT./«t'a in its colouring;
but afterwards it is as follows : — Thorax above pale yellowish ochre, approaching Naples
yellow, varied behind, and also below the tegulse in front, with a whiter ochre. Abdomen
in segments 2-7 translucent dull whitish ochre, with the terminal margins of the segments
narrowly dark grey across the back, and with a brownish streak from in front, tapering

EEV. A. E. EATON OX EECENT EPHEMEfilD.E OE MAYFLIES. 273:

posteriorly, on each side of the tract of the dorsal vessel, and another very faint triana-urar-
cloud of a similar tint from the hind margin of the segment, on the outer side of the streak,
tapering forwards, tending to enclose between them a small curved pale sjiace ; the maiu
tracheal trunks are greyish in segments 6-8, hut liardly perceptil)ly so in the anterior
segments ; segments 8-10 opaque, liglit yellow-ochre, with the vulva brown-ochreous.
Setae white, Avith dark joinings. AYings vitreous throughout, with the greater part of the
neuration piceous, but with the stronger parts of the longitudinal nervures and the great
cross vein of the fore wing in opaque view light dull yellowisli or yellowish grey ; in-
transmitted light the longitudinal neuration acquires amber-tints, while in most positions
the cross veinlets remain black. The markings of the hinder femoi'a are more distinct
than in the other sex ; and just before the extremity of tlie femur the loAver edge of the
limb is for a little distance black. Length of body, 6 10 ; wing, 6 11, 2 12 ; setae, S im.
24<, 2 im. 22 mm.

Hub. Netherlands, near Arnhera, end of July. France, at Toulouse, July-September -
common near the Pont d'Empalot, and by St. Michel ojiposite the island. The newly-
moulted nymph is entirely light yellowish ; but on immersion in a solution of alcohol the
greyish-black markings become developed after death.

Heptagexia flavipenxis, Dufour.

XEphemera jlavqjennis, Dufour, Mem. par divers sav.aus, Instit. de France, viii. 580 note (1841).

XBaetls longicauda, Stepli. 111. Brit. Eut. vi. 63 (ISSo) [numen iiieptiim] ; Pict., Hist. Nat. Nevropt.
ii. Ephem. 193 (1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part. iii. 560 (1853) ; Hag., Eut.
Ann. (1863) 24.— JB. cerea, Piet., Hist. &c. 183, pi. xsiii. 2 (1843-5) ; Walk., List. &c. iii. 558 (1853).

Heptagenia flavijiennis, ! Etn., Trans. Ent. Soc. London (1871) 144, pi. vi. 17-17 c [details] ; !Mever-
Diir, Bull. Soc. Ent. Suisse, iv. 312 (1874) ; Rostock, Jahresb. d. Xer. f. Xatnrk. Zwickau, 1877, p. 90
(1878) ; Palmen, Paar. Ausf.-Gange d. geschl. Org. b. Insect. SS. 68, 74, 77, 78, taf. iv. 55 [anatom.]
(1884).— D«r. ? H. voUtans, ! Etn., Trans. Ent. Soc. London (1870) 7 ; ! id., op. cit. (1871) 147, pi. vi. 20
[detail] ; Rostock, Jabresb. d. Ver. f. Naturk. Zwickau 1877, p. 89 (1878) ; Palmen, Paar. Ausf.-Gange
d. geschl. Org. b. lusect. S. 52 [anatom.] (1884).

Subimago {living). — Eyes and wings very similar in colour and in their developed
markings to those of H. snip //urea; the bullae of the costa and subcosta, and the cross
veinlets of the pterostigmatic region black. Femora of a light dull warm brown-ochre,
banded in the middle and at the tip with light reddish; tarsi and tips of tibite greyish
jlack. Sette concolorous with the femora, scarcely opaque at the joinings. When
Iried the wing-membraue is brighter than in //. sulphitrea, approaching in tint a very
ight shade of Mars-yellow or Italian ochre.

Imago {dried). — Femora (or at least the fore femur) more or less faintly dark-banded
u the middle ; but the bauds often disappear from the hinder femoi-a of dried specimens.
)n each side of the metanotum, behind the upper part of the insertion of the hind coxa,
s a rounded black spot, which is small in both sexes. The ti-act of the dorsal vessel is
lot bordered ; but the extreme terminal edges of the intermediate dorsal segments are
ark almost from side to side. — ■ 6 {living), eyes bright or very light olive-green. Notum
aw-sienna or furfurosus. Dorsum of abdomen in segments 2-7 either greenish grey or
ght yellowish green, or light sulphureous, with the terminal margins of the segments

SECO>D SERIES. — ZOOLOGY, VOL. III. 37

274 EEV. A. E. EATON ON RECENT EPHEMEIIID.E OE MAYFLIES.

greyish black nearly fi-om side to side ; segments 8-10 raw-sienna. Setae light brownish
ochre with dark joinings. Legs as in subimago, but with the fore tarsus sepia-brown,
dark at the tips of the joints. Wings vitreous, tinged with greenish yellow, esj)ecially
towards the fore costa ; longitudinal neuration blackish green ; cross veinlets, and the
bullae of tlie subcosta and radius, black. When dried the notum becomes light brownish
ochre; a small dark spot is visible on each side just above the hinder part of the insertion
of the hind coxa. Segments 2-7 of the abdomen are translucent whitish, with a
slight yellowish tint posteriorly and in the middle of the back, and are edged with light
bistre-brown nearly across their terminal margins ; their trachea? are white. Segments
8-10 arc bright brown-ochre. The fore wings are tinged with yellowish amber distinctly
tlu'oughout the submarginal area, and also in the uttermost extremities of the two
following areas ; in the marginal area the tint is mucli fainter. In, opaque vieio the finer
longitudinal neuration and the cross veinlets appear black or piceous, while the great
cross vein and the thicker nervures of the fore wing appear yellowish brown ; in tram-
mitted light the longitudinal neuration becomes yellowish amber, and the cross veinlets
remain black. The bulla of the subcosta is thickened for some distance, and black.

Variation 1. 6 {dried). The wing-membrane is faintly tinged with yellowish through-
out the disk, and the stronger tint in the marginal area is as distinct as that of the
submarginal area. The ground-colour of segments 2-7 and 10 of the abdomen is
subopaque light yellowish approaching Roman ochre ; that of segments 8 and 9 light
reddish. Hub. Orthez.

"^Variation 2 [yolitans]. Eyes of 6 blackisb brown. Notum atro-fuscous. Dorsum
of abdomen light bistre-brown, with the tips of the segments darker. Setae pale greenish
grey, with darker joinings. Hah. Kear Heading, Berks.

$ [dried). Very similar to //. (jallica \ but the dark edging docs not extend the whole
way across the back along the terminal margins of segments 2-7, and the course of the
dorsal vessel is not marked out ; the main tracheae also are whitish or pale. Setae whitish,
with reddish joinings. Wings vitreous, tinged throughout the submarginal area of the
fore wing distinctly, and more faintly so in the marginal area flith yellowish amber;
neuration coloured as in the other sex ; the bulla of the subcosta is thickened, and
brownish or piceous. The median markings of the hinder femora are hardly perceptible ;
but close to the knee, very near the under edge of the femur, is a very small black
spot or dot. On the head is a black dot on each side of the vertex close to the eyes, and
another on each side below the eyes. Length of body 12-14 ; wing, 6 11j-15, ? 17;
setae, i im. 20-33, subim. 2i, ? im. 21 mm.

Hah. England, near lieadiug, on the Kennet and Ilolybrook. Switzerland, at Basle
(M'Lacli.) and by the Lake of Geneva (Pict.). Erance, at Orthez (Basses Pyreuecfi).
June and July. The subimago emerges chiefly after sunset.

I refer here as a variation the insect described in 1870 as a distinct species, — //. volitans,
— with some hesitation. The difference in the colour of the eyes is immaterial; the
coloration of the legs is favourable to their identity. The colouring of the body,
however, is a more serious obstacle to their union ; but it may not be insurmountable.

EEY. A. E. EATON ON RECENT EPHEMER1D.E OR MAYFLIES. 275

COMPSONEURIA, Etn. 1881.
Illustrations. Adult (details), Pis. XXIII. & XXIY. 42.

Adult. — Joints 1-4 of the hind tarsus diminish successively in lensth ; first joint of
the $ fore tarsus rather shorter than the second, hut longer than the third joint ; ungues
each unlike the other. Penis lohes subsimilar to those of Ileptagenia. Cross vcinlets
conspicuously few in number in the fore wing. — [Proportions in length of the legs and
liody not recorded.] Fore tarsus of 2 almost as long as the tibia, which is f the length
of the femur; the joints in the order of their shortening rank 2, 1, 3, 5, 4, and the first
is about -|- as long as the second. Hind tarsus of ? little more than ^ as long as the
tibia, which is about -f as long as the femur; its joints in the order of their shortening
rank 5 equal to 1, 2, 3, 4, and the first is about ly as long as the second joint. Ungues
each unlike the other in every tarsiis. Hind wings of the ordinary form ; the axillar
region narrow. In the disk of the fore wing, posterior to the radius, are four someAvhat
dislocated transverse series of cross veinlets : of these the innermost, commencing near
the junction of the sector (4) and cubitus (5), becomes irregularly dislocated inwards at
the anal (8) nervure ; the second (the nearest to the bulla), dislocated outwards in the
sectorial region, becomes posteriorly, between the cubitus (5) and the hinder branch of
the pobrachial (7), more nearly aligned with its commencement, running as a whole sub-
parallel Avith the first series ; the third, receding from a point nearly opposite the
commencement of the pterostigmatic region, is interrupted between the fourth sectorial
intercalary nervure and the cubitus, and its elements are diverted towards tlie fourth
series between the cubitus and the anterior branch of the pobrachial ; the fourth series,
intermediate between the third and the extremity of the wing, meets the terminal
margin between the culjitus and the prsebrachial (6) nervures. Penis-lobes and other
genitalia very similar to those of Heptagenia. Caudal sette defective in the specimens
.examined.
I Type. C. spectahilis, Etn.

Distribution. Malay Region.

Etymologij. ko^c^oc and vevp'iov, from the elegance of the cross veinlets in the fore wings
of the typical species. Possibly (as in CaUiho'tis) they may vary in number aad
arrangement with the species.

I!oMPSOXErRiA SPECTABiLis, Etn. Pis. XXIII. 42 (wings $ ), XXIY. 42 ( ? fore and hind
legs, 6 genitalia).
Compsoneuria spectahilis, ! Etn., Ent. Mo. Mag. xviii. 23 (1881).

Imago (dried), 6 . — Yellowish ochre approaching light straw-colour. Xotum varied
vith pitch-brown. Segments 2-8 of the abdomen bordered narrowly in the midst of
heir posterior dorsal margin with black, and marked on each side with a black line
ecurreut obliquely from that bordering towards the spiracle ; segments 3-7 have also
ach a lanceolate black streak produced from the same bordering along the line of the
orsal vessel ; segments 9 and 10 pale. Yeuter and forceps light yellow-ochreous. Hind

276 EEV. A. E. EATON 02s EECENT EPHEMEEID.E OK MAYFLIES.

teg Tpale straw- or amber-yellow ; the troehauter, a baud in the middle aud another at
the tip of the femur, the base of the tibia, and the extreme edges of the tarsal joinings
pitch-black; the other legs wanting. "Wings vitreous; longitudinal neuration pellucid,
-excepting that the costa, subcosta, and radius are piceous towards the tip of the fore
wing ; cross veinlets jiiceous, and narrowly bordered with piceous.

2 . Very similar; but the general colouring of the body is brown-ochre instead of
yellow-ochre. In the hind wing there are rather more cross veinlets than in the other
sex. Length of body 6 ; wing, d 7, ? 8 mm.

Sab. Lahat (in Leydeu Mus.) ; received from Mr. C. Hitsema.

ECDYURUS, Etn. 18G8; revived 1881.

Illustrations. Adult (details). Pis. XXIII. & XXIV. 46, see also [anatom.] citations
of Palmen (1884) under U. angustipenu'ts and venosus ; (whole figures) see citations of
Pictet (18i3-5) under U. helvetlcus, purjinrascens, angustipeiinis, obscurus, lateralis, &
moiitaniis, and of Curtis (1834) under venosus. Nynqjh, Pis. LXI. [junior] & LXII.
(senior) ; see also Pictet, o/j. cit. (1843-5) pi. 10.

Adult. — In the hind tarsus joints 1-4 usually diminish successively in length, but
the first is sometimes equal or subequal in length to the second joint ; in the inter-
mediate tarsus the first joint is moi'C commonly as long as the second joint ; first joint
of the 6 fore tarsus usually about h as long as the second (in E. helveticus scarcely ^ as
long as the second joint), which is nearly of the same lengtli as the third joint ; first
joint of the ? fore tarsus shorter tliau the second, which exceeds the third joint in
length. Penis-lobes stout, usually broadly trilateral, but sometimes obovate ; stimuli
well developed, adjacent to the median line. Fore leg of 6 l-lj as long as the body;
tarsus about twice as long as the tibia, which is almost as long as the femur; tlie tai'sal
joints in the order of their shortening usually rank 2, 3, 4, 1, 5 [in E. heloeticus 2, 3, 4,
5, 1] and the first is usually about ^ [in E. heloeticus about ^ or j] as long as the second
joint. Fore leg of $ subequal in length to the body or about f as long as it ; tarsus
^-\\ as long as the tibia, which is about f as long as the femur ; tJie tarsal joints in
the order of their shortening rank usually 2, 5, 3, 1, 4 [in E. helveticus 2, 5, 3, 1 equal
to 4] and the first varies in proportion to the second joint from about f— n: as long.
Hind tarsus of <s about y as long as the tibia, wliicli is about Ij as long as the femur;
the joints in the order of their shortening usually rank 5, 1 equal to 2, 3, 4, but in the
$ tarsus and in that of E. helveticus <s they rank 5, 1, 2, 3, 4. Ungues each unlike
the other in every tarsus. Hind wings of the usual form ; the axilhu' region narrow.
In the dried ? abdomen the relative lengths of the dorsal segments 2-10 may be
formulated thus : — 5, 8, 9, 9, 9, 9, 7, G, 6 ; ventral lobe of the ninth segment entire.
Forceps-basis of s usually slightly or moderately curved saliently behind betw^een the
insertions of the limbs, and sometimes with a small blunt projection or tooth on each
side of the curve adjacent to their insertions. Penis-lobes stout, usually expanded
broadly outwards at the tips, but sometimes obovate ; stimuli well developed, adjacent
to the median line. Caudal seta? of 6 2A-3 times the length of the body, those of 2

EEV. A. E. EATON OX EECENT EPHEMERID.E Oil MAYFLIES. 277

about 1^ its length. Vertex of 2 head transverse; posterior orbits of the oculi higher
than the interjacent portion of the edge of the occiput ; median ocellus prominent,
contiguous with the anterior margin of the upper surface of the head. Pronotum of 2
either refuse only or subcordately excised behind ; the reflexed lobes somewhat rounded
behind.

Nymph {setiior). — Alulominal tracheal branchiae, when not spread, obliquely reclinate
at the sides, with Avell-developed suberect or ascending fascicled fibrils ; the laminae
successively increase in size from the first to the fifth pair, and then diminish gradually
to the seventh ; the fibrils attain their maximum develoj^ment at the third pair, and
decreasing successively from tliat point in opposite directions, both in density and
length, are lacking in the seventh pair ; the foremost lamina?, narrowly ovate-oblong in
form, are (like the next two) small in proportion to the fibrils ; those of the second
pair are ovate, of the fifth pair ovate-oblong, of the seventh obliquely obovate, and the
others exhibit intermediate gradations of form : branchial tracheae well defined, com-
monly alternate-pinnately branched, but occasionally (as in PL LXII. 20) arborescent.
Median caudal seta subequal to the others, minutely plumose, while they are unilaterally
so, and about as long as the body. Pronotum completely defined ; the lateral borders
broadly dilated, rounded ofi" in front, and produced behind into acute angles flanking the
anterior portion of the mesonotum. Ventral segments subequal in length ; the lobe of
9th segment of $ subtriangular ; pleurae narrowly dilated, saliently curved at the outer
edge anteriorly, and shortly acuminate behind, so as to form minute teeth. Pangs of
the mandibles narrowly subfalcate ; the exterior, and stronger, serrulate at the edges;
the interior, more sleudi?r and shorter, is in the left mandible or tridendate at the
point ; in the place of the endopodite, in both mandibles, is a short tuft of plumose
hair. Lacinia of maxilla i. beset with flattened pectinate teetli along the edge of the
crown, and terminated by a pair of contiguous flattened subulate si:)ines at tlie point :
first joint of the palpus moderately stout ; terminal joint slender, clavate, obliquely
truncate and densely velutinous at the end, pungent at the tip, and pubescent externally.
Median lolje of the tongue truncate-subcordate, with the au.ricles excised ; paraglossae
broadly unciform, Avith the points recurved. Pemora marked on the coloured side with
two irregular zigzag grey bands composed of confiueut sjiots, and apt to be respectively
connected with a spot near the base, and another, or two, near the tip.

The nymphs figured respectively in PL LXI. and PL LXII. 24, probably are merely
junior grades of species of Ecch/io-tis; and the latter is the younger, judging from the
completeness of the delimitation of the pronotum at the hinder lateral angles. The
somewhat older N. American nymph (PL LXI.) ditl'ers from that of U. venosus of
senior grade in the following particulars. The lateral borders of the pronotum are not
produced posteriorly, but are intimately blended with the mesonotum ; and hence the
pronotum wants definition at the hinder lateral angles. The mandibles lack the tufts
of hair adjacent to the bases of the interior fangs ; and the left mandible has a single
slender bristle in their place, like that of those figured in Pis. LVIIL, LIX. The
median lobe of the tongue resembles somewhat that of the nymph last referred to; jjut
the paraglossae differ both from those of that nymph and from those of the senior

278 REV. A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES.

Ecdyurits, being broader at the base, less recurved and more pointed at the tips : and
the tongue as a whole bears some resemblance in outline to an Eagle Ray {Myliohatis
aquila). Resident in rivers and streams.

Type. E. venostts (in Ephemera), Pab.

Dlslrihution. Europe eastwards to Siberia, the Caucasus and the river Euphrates ; the
Himalaya ; Nortli America from Texas northwards.

Etymology. tKlixD and ovpa, in allusion to the abortion of the median caudal seta.

NORTH AMERICAN SPECIES.

EcDYURUS CANADENSIS, Walker.

XBa'etis canadensis, ! Walk., List of Neuropt. Ins. in Brit. Mas. part iii. 5G9 (1853) ; Hag., Smithson.
ifiscell. Coll. (18(51), Syuop. Neuropt. N. Am. 47.

Heptagenia canadensis, ! Etn., Trans. Ent. Soc. London (1871), 138, pi. vi. 12, Via.

Imago (dried), 6 . — Head and thorax above rufo-piceous or rufo-lutescent, with a large
Idackspot on each side of the face below the antennse adjacent to the orbits of the eyes:
the pleurae streaked with piceous above the interspaces in advance of the hinder coxae.
Abdomen in segments 2-9, translucent, subochraceous, or very light bistre-grey, the
10th segment rufesceut, tlie apical borders of the previous segments across the middle
of the back, and the lateral spots or oblique stripes prolonged forwards from tliem pitch-
black ; venter very light wliitish ochreous. Setae pale, with fuscous joinings. Fore
femur (as an opaque ol)ject) rufo-lutescent or (with transmitted light) translucent bistre-
brown, with a broad black band at the base, another in the middle, and with a rufo-
piceous knee ; fore tibia rufo-lutescent tipped with black ; fore tarsus light brown-ochre,
with black joinings. Hinder femora (as opaque objects) light olive grey, or (with
transmitted light) very light greenish-yellow amber-colour, l)anded with black-grey in
the middle and near their terminations : hinder tibiae and tarsi light brown-ochreous,
their joinings rather dark, and the distal tarsal joint Ijrown. Wings vitreous, with
pitch-brown or bistre-brown neuration, excepting the cross veinlets between the costa
and sector in the fore wing, which are pitch-black. Tlie fore wing at the roots and in
the portion of the submarginal area subtending the pterostigmatic space very light raw-
umber, this colour extending further along the margin to just beyond the extremity of
the wing ; the remainder of the same area of a very much fainter tint : in the area
between the radius and the sector, in the vicinage of the bulla, 2 or 3 cross veinlets
approximated to one another are intersected by a short intense sepia-brown dash
rounded at both its extremities, and 3 or 4 of those nearer the base of the wing are
marked each with a rounded spot of the same colotu*. Terminal margin of the hind
wing narrowly bordered with sepia-grey. Length of body, ? 7"5, wing 8 mm.

Hub. Canada (Brit. Mus.).

ECDYURUS VERTICIS, Say.

J Baetis vertlcis, Say, Journ. Acad. Nat. Sc. Pliilad. viii. 42 (1839) ; Walk., List of Neuropt. Ins. in
Brit. Mus. part iii. 502 (1853); Le Conte, Complete Writings of T. Say, ii. 412 (1859) ; Hag., Smith-

EEV. A. E. EATON ON RECENT EPIIEMERID.E OR MAYFLIES. 279

son. Miseell. Coll. (1861) Synop. Neuropt. N. Am. 4G; Walsb, Proc. Ent. See. Pliilad. ii. 204 (1863) ;
Etn., Trans. Ent. Soc. Loudon (1871), 121.— B. flaveula, Vict., Hist. Nat. Nevropt. ii. Epliem. 186,
pi. xxiii. 4 (18J3-0) ; ! Walk., List of Neuropt. Iiis. iu Brit. Mus. part iii. 559 (1853) ; Hag., Smithsou.
MisceU. Coll. (1861) Synop. Neuropt. N. Am. 44.

Heptageniajldveola, ! Etu., Trans. Eut. Soc. Loudon (1871) 119, pi. vi. 2.2, 22 « [detail].

Subimago {dried). — Wings very light grey ; the longitudinal neuratiou of the fore
wing is, in some lights, concolorous with the membrane, in others pitch-brown ; the cross
veinlets in the ? , at first dark grey, afterwards become pitch-black ; those before the
bulla in the marginal and submarginal areas also become bordered with deep warm sepia-
brown ; the neuration of the hind Aving is concolorous with the membrane. Eemora
banded in the middle, and again distally more narrowly with dark grey. The whole of
the body and legs in the female are chiefly very light yellow-ochreous approaching Naples
yellow ; the abdominal segments 1-9 bordered distally in the midst of the back with
black grey, and in segments 1-6 marked with a small black s2)ot on each side of the
back just before the distal liorder, in place perhaps of the usual oblique stripes.

Imago [dried). — 6 . Thorax rufo-lutcous above. Abdomen in segments 2-7 trans-
lucent ochraceous, white with the joinings above bistre-brown; segments 8-10 ruf'o-
luteous above ; venter spotless. Setae whitish-grey, with the joinings scarcely at all
darker. Legs sub-stramineous, ■\\'ith dark joinings ; everj" femur with a bistre-brown baud
in the middle and another distally ; the fore tarsus whitish, with dark joinings. Wings
vitreous ; the fore wing with the neuration mostly black, the costa, subcosta, and radius
however, being light translucent testaceous ; neuration of the hind wings pellucid.

2 . Head and thorax very light ochraceous ; a greyish ii\)oi at the lower end of the
facial carina, a dark oblique streak at the base of the fore coxa, a black dash in the
suture in front of the hind coxa, and another on the hinder surface of the pleura above
the coxa. Abdomen (discoloured) of a redder yellow; the segments above narrowly
edged with black-grey at the joinings. Sette whitish-grey, Avith pitch-brown joinings.
Legs extremely light yellow-ochreous ; the median and distal l)auds of the femora dark
sepia-brown ; the extreme edge of the tibia at its distal termination above, and the
terminal joint of the tarsus, and also the ungues, light brown. Wings vitreous ; the
fore wing tinged very faintly with light dull greenish yellow in the submarginal area as
far as the vicinage of the pterostigma from the base of the wing; longitudinal neuration
translucent and of a light colour ; cross veinlets light bistre-brown, the great cross vein
coloured more strongly near the subcosta. The marginal area of tlie fore wing contains
about 4 cross veinlets before, and 11 beyond the bulla; these last are simple. Length
of body, c? 9, 2 8-10; wing, 6 10, 2 11-13; setoc, 6 im. 20, ? subim. 10 mm.

Rab. St. Martin's Falls, Albany River, Hudson's Bay (Barnston, in Brit. Mus.) ;
West Farms, N.Y. (Angus, in M'Lach. Mus.) ; Tennessee (Poepig), Dalton, Ga. (Osten-
Sacken) and Washington {id., iu Hag. Mus.).

EcDYURTJS LUBiDiPENNis, Burmcister.

Ephemera noveboracana, Lichteusteiu, Cat. INIus. Holtliusien, iii. 193 (1796) ?

XBaetis luridipennis, Burm., Handb. d. Eut. Bd. ii. Abth. ii. 801 (1839) ; Pict., Hist. Nat. Nevropt.

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

ii. Ephem. 192 (1843-5;; ! Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 563 (1853); Hag.,
Smithson. Misccll. Coll. (1861) Synop. Neuropt. N. Am. 49.— B. noveboracana. id., op. cit. 50 (1861) ?
Heptagenia luridipennis , ! Etn., Trans. Eut. Soc. London (1871) 149, jjI. vi. 21, 21 a [detail].

Suhimayo {dried). — Wings transpareut, very liylit bistre - 2;rey ; the longitudinal
nervures bistre-brown, the cross veinlets piteh-black. Seta3 light bistre-brown, with
dark joinings.

Imago {dried). — <3 . Thorax above rufo-testaceous or (in other lights) fusco-lutescent;
abdomen in segments 2-7 translucent light burnt-umber brown, opaque at the joinings,
and formerly with dark oljlique lateral stripes ; the hinder segments rather dark bistre-
brown. Setaj bistre-grey, witli dark joinings. Fore femora and tibitt; subtestaceous,
with two dark bands on the femur and the end of the tibia fuscous ; fore tarsus light
bistre-grey. Hinder legs dull light yellow-oclire, the coxaj, trochanters, and femoral
bauds, light w-arm sepia-brown, the apical edges of the tarsal joints, and the ungues
brownish. Wings vitreous, sliglitly discoloured in the pterostigmatic portion of the
marginal and submarginal areas ; tlie neuration pitch-brown, excepting the thicker
longitudinal nervures near the base, wliicli are there bistre-brown.

? . Very similar to the 6 . Thorax raw-umber brown above. Legs dull light-
yellowish green horn-colour ; a band in the middle and at the extremity of the femur,
the joinings and the terminal joints of the tarsus, ungues included, warm sepia-brown.
The portion of the submarginal area of the fore wing adjacent to the pterostigmatic
space is faintly tinted with pale greenish. Length of body 10-11 ; wing, 6 13, ? 15 ;
seta?, d 25 (?), ? 15 (?) mm.

Hah. St. Martin's Falls, Albany River, Hudson's Bay (Brit. Mus.) ; the St. Lawrence,
Canada (De Selys-Longchamps).

EcDYURUS viCARiTJS, Walker.

X Ba'elis vicaria, ! Walk., List of Neuropt. Ins. in Brit. !Mus. part iii. 565 (1853) ; Hag., Smitlison.
Miscell. Coll. (1861) Synop. Neuropt. N. Am. 48. — B. lessellatu, .'Walk., List of Neuropt. Ins. in Brit.
Mus. part iii. 566 ?

X Ephemera pudica, ! Hag., Smithson. Miscell. Col., Synop. Neuropt. N. Am. 39 (1861).

Hepiaffenia vicaria, ! Etn., Trans. Ent. Soc. London (1871) 150, pi. vi. 23, 23 « [details]: — nee H.
Xpudica, ! Ilag., Ann. Rep. U. S. Geolog. & Geograpli. Survey of the Terr, for 1873, part iii. Zool. 581
(1865).

Subimago ? {dried). — Wings warm sepia-grey ; longitudinal neuration yellowisli brown ;
ci'oss veinlets in some parts black-brown, in other parts light sepia-brown, edged narrowly
with liglit sepia-grey, the black-l)rown or intense sepia colouriiig spreading along the
longitudinal nervures at tlieir junctions with cross veinlets, and causing the nervures to
be banded. Setae bistre-grey, with darker joinings.

Imago {dried), 6 . — Notum brown-ochreous, modified with law-umber brown ; an
intense black-lirowu stripe from tlie fore wing roots on each side of tlie mesothorax.
Dorsum of the abdomen in segments 2-9 liglit jjitch-brown, in segment 10 brown-
ochreous ; on the dorsum and venter, by the spiracles, are translucent flgure-of-6-shaped
marks, and at the base of evei'y intermediate dorsal segment is a pair of short pale lougi
tudinal lines. Seta; bistre-brown with dark joinings. Fore femur, in opaque view, light
bistre-brown, banded broadly in tlie middle and narrowly at the tip w'ith jntch-brown;
tibia rather a redder raw-umber than the femur, brown-black at the tip; tarsus light

EEV. A. E. EATON OX EECENT EPHEMKEID.E OE MAYFLIES. 281

warm sepia-brown. Hinder femora, in opaque view, testaceous or very light browu-
ochreous, banded broadly in the middle and rather broadly at the tip with brown-black ;
tibise brown-ochreous ; tarsi brown-black. Wings vitreous, tinged in the pterostigmatic
region of the fore wing with liglit bistre-grey ; neuration either pitch-brown or very
dark rufo-piceous ; the cross veinlets interjacent between the fore costa and the pobra-
chial (7) are most of them slightly thickened, and those of the pterostigmatic space are
simple and straight.

? . Similar to 6 . Length of body, 6 12 ; wing, j 13, ? 14-5-18 ; seta?, d 35 mm.

Sab. The St. Lawrence (Walker) ; Chicago and Washington (Hagen) ; Savannah
(Ostcn-Sacken). I did not compare the subimagines described respectively by Hagen and
Walker ; and have only quite lately come to consider them to be of one species.

EUROPEAN AND ASIATIC SPECIES.

* Penis-lobes broudhj expanded outwards at the tips.

EcDTTjRUS Krtjeperi, Stein.

X Putamantfiiis Krueperi, Stein, Berlin, ent. Zeit. vii. 411 (1.S63).
? Lcptnphlebia Krueperi, Etn., Trans. Ent. Soc. London (1871) 86.
I Baetis Krueperi, Stein MS., Etn., op. cH. (1873) 395.

Imago (dried), d . — Notum dark pitch-brown, approacliing intense burnt-umber.
Dorsum of abdomen bright brown-ochre, approaching in some lights Mars-yellow ; the
joinings of the segments appear slightly opaque, and oblique dark lateral stripes of the
ordinary description are faintly indicated in segments 2-7 or -8 [tlie specimens described
are aged and doul)tless faded] ; the ventral nerve-ganglia are visil)le. Setae whitish
brown-ochre, browner towards the roots ; their joinings light pitch-brown and, in the
lighter portion, alternately narrow and broad. Fore leg, in opaque view, pitch-brown.
Hinder femora, in opaque view, light raw-umber brown, thetibiEB rather lighter, the tarsi,
in some lights, nearly concolorous with the femora. Fore wings vitreous, tinted faintlv
throughout the disk with whitish raw-umber, but more distinctly tinged with light
raw-umber at the roots and in the marginal and submarginal areas, and especially so at
the commencement of the pterostigmatic space ; the cross veinlets of this space are
branched, and anastomose evenly with one another. Hind wing conspicuously tinged with
light raw-umber brown, darkest towards the terminal margin. Wiug-neuration, in
opaque view, for the most part pitch-brown ; but the near extremities of the longitudinal
nervures jiosterior to the radius (3) in both wings, the whole of the costa of the hind
wing, and the extreme base of the costa in the fore wing are light raw-umber.

2 . Notum dark brown-ochre. Abdomen discoloured ; the oblique stripes at the sides
jf the segments are piceous, and the spaces below them are of a light colour. Setfe
lefective, piceous at the base, with opaque joinings. Legs similar to those of d in
colour, but with the hinder tibiae darker. Fore wing very similar to that of the d , but
ess distinctly discoloured along the costa. Hind wing as nearly colourless as the fore

SECOND SERIES. — ZOOLOGY, VOL. III. 38

282 REV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES.

wiug throughout, excepting only the neuration. Ventral lobe of segment 9 ellipsoidally
rounded off. Length of body 10-11 ; wing, j 12-14, $ 14 mm. ; seta) defective.

Hab. Greece (Stein, in Berlin Mus.) ; Albania (Sir S. Saunders), 2 cJ , 1 ? im. (in
M'^Lach. Mus.).

Part V. Road November ISth, 1886.

I FIND myself unable to decide, from dried specimens, whether E. lielveticus, venosus,
and forcipula are entitled to rank as species only or as races. It is possible, if speci-
mens were grouped in accordance with their style of coloration, that JE. forcipula might
justly be held to bear the same kind of relationship towards H. lielveticus, as the var.
qucpsitor to E. venosus, and that the peculiar shortness of the first joint of the d fore
tarsus of E. helceticiis may be found to be something less than a specific distinction.
On the 3rd of June, 1885, I captured two 6 imagines of E. venosus by the river at Eden
Lacy in Cumberland, having the tai'sal joint in question percejjtibly shorter pro-
portionally than that joint is in any other specimens caught elsewhere, or at other times
in the same place, during that year. Specimens of E. venosus that have been relaxed
and set out for the cabinet after they have become dry in the first instance are very apt
to lose their markings and to be rendered unserviceable for study ; and I liave conse-
quently found it difficult to institute comparisons between the unset specimens in my
own collection, and a large proportion of those from other collections submitted to me
for identification.

EcDYUBTJS HELVETicus, sp. nov. Plate XXIV. 46 a ( d fore tarsus).

XBaJdtis Xvenosus, Pict., Hist. Nat. Nevropt. ii. Epliem. 1G7, pi. .\x. [part.] (1813-5).

Subimago {living). — Wing-membrane either fumatose or dusky, tinged at the base of
the fore costa and again beyond the middle with bright or sulphur-yellow, but elsewhere
in the basal half of the same with dull greenish, approaching olive-green ; fore wing
marked with the usual dark stripes ; terminal margin of the hind wing broadly bordered
with dark grey. Eyes of 6 dull yellowish green, traversed l>y a reddish-brown line, and
displaying a movable black spot ; those of 2 dark and dull olivaceous. Eore femur of
6 pitch-brown ; tibia rather lighter ; hinder femora dull greenish grey or olivaceous ;
tarsi black ; setae pitch-black ; forceps black.

Imago [dried), 6 . — Notum light brownish or pitch-brown. Eore leg of d uniformly
piceous, with the first tarsal joint short for an Ecdyurus. Pterostigmatic S2)ace of the
fore wing darkened. Abdomen nearly ixniformly brownish above, with the following
exceptions : — in transmitted light on each side of the base in segments 2-7 a smal
colourless translucent narrow space or spot, rounded below, extends nearly to the anterioi
dorsal trachea of the segment ; and between the two dorsal tracheae of the segment, the
shallow, oval depression (covered in the nymph by the tracheal branchia) is rather palei
than its borders. — {Living). Eyes sometimes intense- bistre or pitch-brown above, some
times rich rufo-fuscous, and traversed below by a dark or rusty line edged with ligh

EEV. A. E. EATON ON KECENT EPHEMEEID^ OR MAYFLIES. 283

greenish or yellowish ; they also exhibit a movable black spot. Notum either testaceo-
piceous or pitch-black. Dorsum of abdomen either dark l)istrc-bro\vn or rufo-piceous,
with the terminal borders of the segments opaque, having, however, their extreme edges
sometimes pale, and with small translucent markings at the bases of some of the segments,
similar to those already described in dried specimens. Venter sometimes uniformly dark
warm-sepia, sometimes a rather yellower brown with paler joinings; segment 9 tinged
with dull orange, and edged at the extreme base and at the sides with pitch-black ; a
pair of abbreviated divergent black lines is apparent at the base of the segment in
segments 2-8, and the nerve-ganglia are visibly darkened in segments 4-7. Forceps-
basis olive-black ; the limbs black, each with a whitish spot inside at the base of the
penultimate joint, and with the terminal joint wdiite inside. Seta3 pitch-black at the
base, becoming distally light dusky grey with darker joinings. Pore legs pitch-black,
Avith the femora lighter towards the base, and with the tarsal incisures whitish beneath.
Hinder femora light olivaceous, tinged with bistre towards the knee ; tibia3 light oliva-
ceous, tinged with smoke-grey distally, [with change of light a yellowish tint predom-
inates over the olive] ; tarsi pitch-black, with the joinings pale beneath. Wings vitreous ;
the fore wing often tinted conspicuously towards the roots and in the marginal and sul>
marginal areas with dull gi'eenish yellow, or with yellowish green, and blackened or dark
grey in the pterostigmatic region ; neuration for the most part pitch-black, excepting
that the stronger nervures in the disk are tinged with fuscous, and become near the roots
olivaceous or flavo-piccous.

2 (dried). — Very similar to E. venosus 2 . Length of body 10-13-5 ; wing, 6 12-13,
$ 13-15: seta?, 6 im. 25-35, subim. 15, ? im. 21, subim. 14 mm.

Hab. Alpine Switzerland, N. Italy and Savoy, chiefly at altitudes of over 2000 ft.
Common in July and August at the following localities : — the head-waters of the Dranse
de Biot near the Charbonniere at 4800 ft., and (in the same neighbourhood) both near the
Chalets de Jouplane, Samoens, at 5100 ft., and near Bonavaux, Champery, at 5400 ft. ;
also in Val Furva near Bormio at 6300 ft., and in tlie neiuhbouriug Mt. Adamello district.
Streams and torrents ranging in temperature at the stated season from 50° to 02° F.
seem to be the most suitable for the species, although it may sometimes be met with
where the temperature of the water in the morning is as low as 46° F., or as high in the
afternoon as 68° F. Mr. M''Lachlan captured several specimens of this species near
Interlaken in the Habkern Thai, on the 21st of August ; and I am disposed to identify
with it a specimen captured by me in the Apennino Pistojese, at 4200-5200 ft., in the
Valle Sestajoue.

[ECDTTOUS VENOSUS, Fabricius. Adult, PI. XXIII. 40 (liind wing) ; PL XXIV. 46
(legs and genitalia). Nijmph, PI. LXII.
Ephemera venosa, Fabr., Syst. Ent. .304 (1775); if/., Sp. Iiis. i.3Sl (1782); jrf., Maiit. Ins. i. 2^13
(1787) ; Gmel., Linn. Syst. Nat. cd. 13, i. pars v. 2G29 (1790) ; Ol., Encycl. Meth. vi. 418 (1791); Fabr.,
Eut. Syst. iii. pars i. 70 (1793) ; Lat., Hist. Nat. d. Crust, et lus. xiii. 97 (1805). — E. berolinensis,
MiilL, Zool. Dan. Prodr. 143 note (1776) ?—E. fusco-grisea, Retz., C. de G. Gen. et Sp. Ins. no. 183
(1783) ? — E. nervosa, YilL, C. Linn. Eut. iii. 22 (1789). — E. nigrhnana, Dufour, Mem. par divers sav.,
Instit. de France, %-iii. 580 footnote (1811) ?— £. rufa, Ramb., Hist. Nat. d. Ins. Nevropt. 269 (1842).

38*

284 REV. A. B. EATON ON EECENT EFIIEMEEID^ OE MAYFLIES.

XBaetls dispar, Curt., Load. & Edinb. Phil. Mag. ser. 3 (1831) 120; id., Brit. Ent. xi. 484 (1834) ;
! Steph., 111. Brit. Eut. vi. 63 (1835).— 5. venosa, id., op. cit., I. c. ; Burm., Handb. d. Eut., Bd. ii. Abth.
ii. 801 (1839) ; Walk., List of Neuropt. Ins. in Brit. Mus. part iii. 556 (1853) ; Pictet, Hist. Nat. d.
Ins. Nevropt. ii. Epheui. 167 [part.] (184.3-5) ; Brauer, Neuropt. Austr. 26 (1857) ; Hag., Eut. Ann.
(1863) 22; Karsch, Die Insectenwelt, v. 400-2 (1863).— 5. .wS/MSca, 1 Steph., 111. Brit. Ent. vi. 64
(1835); Pict., Hist. Nat. Nevropt. ii. Epliem. 194 (1843-45) ; Walk., List &c. part iii. 561 (1853).—
B. purpitt-ascens, Pict., Hist. Nat. Nevropt. ii. Ephem. 174, pi. xx. 4 (1843-5) ; Walk., List &c. part iii.
557 (1853); Brauer, Neuropt. Austr. 26 (1857); Ausser., Ann. d. Soc. Natur. Modena, An. iv. 135
(1869) ; [??] Mocsary, Rev. d. Inhaltes der Termeszetrajze, Fuzetek ii. 124-5, or [German text] Naturh.
Hefte ii. Bd. ii. u. iii. 181-2 (1878) ?— 5. J longicauda, ! Ronalds, Fly-fisher's Ent. ed. 5, pi. ix. (1856).—
B. Xmontana, Hag., Ent. Ann. (1863) 26 [part]. — B. Picteti, Meyer-DUr, Mitth. schw. ent. Ges. i.
121 (1864).

Ecdym-m venosus, !Etn., Trans. Ent. Soc. London (1868) 142 note [misspelt Ecdyonurus] ; lid., Ent.
Mo. Mag. xviii. 25 [nymph] (1881). — E. quce.^itor, \ id. MS., in the writing of PI. XXIV. 466 [penis]
(1883).

Heptagenia venosa, ! Etn., Ent. Mo. Mag. v. 90 (1868) ; id.. Trans. Ent. Soc. Loud. (1871) 151 [part]
pl. vi. 24 [genitalia] ; Hag., op. cit. (1873) 404-5 ; ! Meyer-Dur, Bull. Soc. Ent. Suisse, iv. 314 (1874);
Rostock, Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 92 (1878) ; Palmen, Paar. Ausf.-Giinge d. Geschl.
Org. b. Insect. SS. 40, 44, 47-48, 51, 65-6, 69, 70, 74, 76-80 & 92, taf. iv. 57, 59, 68, & taf. v. 93 [anatom.]
(1884). — H. niyrimana, Etn., Trans. Ent. Soc. London (1871) 144? — H. % lomjicauda, ! id., op. cit. (1871)
152, pl. vi. 25 [genitalia].— iy. Picteti, id., op. cit. (1871) 153. — H.purpurascens, ! Meyer-DUr, Bull. Soc.
Ent. Suisse, iv. 135 (1874).

Subimago {living). — Wing-membrane either very light ivoi'y-black-grey, or very light
fawn or Cologne-earth grey, with the borders of the cross veiulets narrowly darker.
Before the moult, dark transverse stripes and bands appear ia the wings, similar to
those described under Heptagenia sidphurea. A greenish-yellow tint usually pervades
the pterostigmatic space, and is sometimes diffused about tlie base of the fore wing.
Fore femur piceous or olive-grey ; hinder femora olivaceous ; tibisje grey or l)lack-grey ;
tarsi black. Setae pitch-black. [Dried.) — The wings vary in appearance according to
the period at which the specimen is killed, as follows : — 1st, wings uniformly light sepia-
grey, with the cross-veinlets and most of the longitudinal nervures {i. e. all but the
stronger nervures) rather a darker grey, and equal to each other in definition ; 2nd, the
cross-veinlets become bordered with grey, and hence the longitudinal neuration becomes
less obvious to the naked eye ; 3rd, the colouring-matter of the wing-membrane appears
to become concentrated in the immediate neighbourhood of the cross-veinlets, so as to
produce dark transverse bands, leaving the spaces where cross-veiulets are scarce paler
than the other parts. The wings of some specimens might be described as of a dark
colour with pale transverse stripes and bands, instead of vice versa, light with dark
markings.

Imago {dried). — Notum of d pitch-brown, sometimes approaching pitch-black; that
of $ lighter, sometimes brown-ochre or ferruginous brown. Fore leg of 6 uniformly
pitch-brown, excepting that sometimes the femur is lighter jvtst at the base ; 1st tarsal
joint of normal length. Pterostigmatic space usually more or less obscured, sometimes
clear. Terminal margins of the intermediate al)dominal segments dark, excepting at the
pleurae; dorsal segments 2-S marked, on both sides, either with a dark triangle, or

REV. A. E. EATON ON RECENT EPHEMERID.E OR MATTLIES. 285

(through the obtuse angle and lower edge of the triangle being deficient in dark pigment)
with a broad oblique dark stripe enclosing near The posterior angle of the segment a
small pale space. — • d {licbig). Eyes either intense sepia-brown, traversed below by a
dark line edged with light yellowish or greenish grey ; or pitch-brown traversed by a
dark line. Frons piceous ; epistoma olive-grey or black. Notum at first bistre-brown,
changing to intense pitch-brown, or even to pitch-black ; a stripe in advance of the wing-
roots is either dull orange varied with light greenish yellow, or else subochraceous or
Mars-yellow. Dorsum of abdomen either light raw-umbcr-brown, or greyish bistre-brown
in the middle, and dull light yellowish or greenish at the sides of segments 2-6 [in the
hinder segments more of the former tint], with the apical borders of the segments dark
or piceous (excepting at the pleura?), and marked on both sides of each segment with
either a triangle or an oblique stripe of a reddish-brown or burnt-umber colour. When
there are stripes, each stripe tapers forward from a rather l)road base at the hind margin
to the spiracle : the stripes in segments 7 and 8 are broader than in the anterior segments,
and each subtends a dull light yellowish triangular spot in the hinder angle of the dorsum ;
this spot is almost effaced by the stripe in segment 9. The pleurae throughout the
abdomen and the sides of the dorsum of segment 10 in front of the insertions of the setae
are of a similar pale colour. Venter in segments 1-6 either light bistre-brown, olive-
brown, or olive-grey, becoming posteriorly more and more of a light brownish ochre or
dull orange ; the impressed dots and dashes are not usually dark-coloured like those of
E. insi(jn'is. Setae and forceps-limbs piceous. Fore femur dark bistre-brown, paler at
the base ; tibia and tarsus in some lights pitch-black. Hinder femora either light
brownish olive, light bistre, or fusco-luteovis, but pitch-brown just at the knee; tibiae in some
positions lighter than the femora, or even testaceous ; tarsi in some lights blackish grey
some or greyish black, in others pitch-black or intense sepia-brown. Wings vitreous, some-
times colourless, but often tinged faintly « itli greenish or yellowish green in the basal
half of the disk and in the greater portion of the marginal and submarginal areas of the
fore wing, and usually blackened or obscured with intense sepia-brown in the pterostig-
matic space. Neuration pitch-black, the basal extremities of the stronger nervures
lighter in some positions ; in living specimens the bullae are pale.

$ (living). — Very similar to the cT but lighter. Notum bistre or light pitch-brown ;
tvheu dried brown-ochre or ferruginous brown. The dorsal tracheae outside the abdom-
inal stripes are dark. The pterostigmatic space of the fore wing is usually very slightly,
ifat all, discoloured, and is seldom so dark as it commonly is in the other sex; neuration
often pitch-brown in small specimens. Head often dull orange, with the surroundings
of the ocelli and a spot on the occipital margin pitch-brown, and with the epistoma
olive-grey ; eyes intense sepia-brown. Length of body, d 10-15, ? 10-18 ; wing, d
11-15, ? 11-18; seta-, d im. 22-18, ? im. 11-25, subim. 12-17 mm.

Sab. Generally distributed from Lapland and Finmark southwards. Common in
Great Britain from June to September. Specimens of medium size are found in Switzer-
land and the adjoining districts at moderate altitudes, e. g., at Gex and Berne (M°Lach.) ;
also near Samoens at 2200 ft., and near Bannio, Val Anzasca, at 3000 ft., and near
Fontana, Val Bavona, not far from Bignasco, at about 2000 ft. Similar specimens have

286 REV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES.

been also taken in France at Autun, by M''Lacblan ; some captured by bim near St. Moritz
(Grisons) on tbe 12th August, and in Val Bedretta, 17tb August, are unusually large.
In tbe Basses- Pyrenees it occurs near Laruns and Eaux Cbaudes at about 1800-2000 ft.
I am inclined now to consider E. qucesitor, Etn., MS., to be only a local form of this
species; but for fear of possible error I subjoin a description of tbe living insect.

Variation ? 'iqnccs'dor]. Imago {living), d . — Eyes dark pitch-brown or intense sepia,
traversed by a deep umber-brown line edged with light yellowish. Notum rufo-piceous ;
tchen dried light pitch-brown. Dorsum of abdomen rich reddish purple-brown, bordered
with pitch-brown at the hind margins of the segments 2-9, between the ends of the
oblique lateral stripes, which themselves are of a red-purple tint and cut off triangular
spaces of a lighter red-purplish tint; pleune light yellow; spiracular spots black;
segment 10 is of the pale ground-colour. Venter anteriorly light burnt-umber brown ;
segments 8 and 9 rubiginose with dark joinings. Setae light sepia-brown v^ith dark join-
ings, becoming pitch-black at the roots. Eore femur dark pitch-brown ; tibia and tarsus
pitch-black. Hinder femora greenish grey or light olivaceous, brownish at the tips,
their trachese finely irrorated with black ; tibice tinged with light yellow-ochre ; tarsi
black. Wings vitreous, tinged faintly with greenish in the marginal and submarginal
areas before the middle, and also in the pterostigmatic space ; neuration pitch-black,
lighter at the wing-roots.

$ (living). — Eyes dull olivaceous, mottled outside with pitch-brown or burnt-sienna,
and traversed by a line of the same colour. Notum pitch-brown. The triangular lateral
markings of the dorsal segments of the abdomen are dark burnt-carmine, and the lighter
parts are more rosy than in the other sex. Setie towards the roots deep warm sepia-
brown, becoming distally light warm sepia-grey with dark joinings. Length of body 11 ;
Aving, d 12-13, 2 15 ; setre, d im. 31-10, ? im. 25 mm.

Hab. The Apennino Pistojese at the Limestre near Villa Margherita, San Marcello,
at the end of July, at an altitude of 2100 ft. The males, after 0 p.m., were caught on the
wing whilst flying in a very peculiar manner about the tops of alder trees {Almis), about
20 ft. from the ground. Their movements resembled somewhat those of Rhizotrogtis d
in quest of a female — whence tbe name qucesitor. Earlier in the day specimens were
obtained by beating.

EcDYURTJS FOKCiPTJLA, Kollar, MS. Plate XXIV. 4G c (penis).

X BaMs fordpula , Kollar, ]MS., Pict., Hist. Nat. Nevropt. ii. Ephem. 169-170 note (18i3-5).

Hejdayenia Xulpicola, ! Etn., Trans. Ent. Soc. London (1871) 148, pi. vi. 19 [penis dried; Carintbian
specimens only]. — H. fordpula, id., op. cit. (1871) 152 [undescribed] ; Meyer-Dijr, Mittb. scbw. ent.
Gcs. iv. 314 (1874) ; ! Rostock, Jabresb. d. Ver. f. Naturk. Zwickau, 1877, p. 91 (1878).

Ecdijurvs italicus, ! Etn., MS., in tbe writing oi' PI. XXIV. 6 of tbe present work (1883).— £. Zelleri,
! id. MS., p. 239 supra in bibliograpby of Epeorm alpicola (1885).

SiiUmago [living). — Wings uniformly black-grey, slightly tinged with greenish in the
marginal area towards the base and at the tegulse. Eyes olive-green above, and rather
a light )-eddish brown by their lower orbits, with a red-brown line intervening between
these two colovu's. Eore leg pitch-brown ; hinder femora and tibia? brownish olive with
dull black tarsi. SetsE pitch-black.

EEV. A. E. EATOX ON EECEXT EPHEMEEID.^ OE MAYFLIES. 287

Imago [dried], 6 . — Notum brownish ochre or reddish brown, sometimes darker behind.
Fore leg in opaque view uniformly piceous ; 1st tarsal joint of normal length. Ptero-
stigmatic portion of the marginal area of the fore wing dai'kened more or less. Abdomen,
in opaque view, usually marked at the sides with dark triangular spots, each occupying
the lower half of the flank of the dorsum, but leaving the pleurae pale ; in transmitted
light the spiracles become translucent, and a pale obovate space appears inside each of
the dark triangles above the pleuras. In diseased specimens, such as are infested with
internal parasites, the dorsum is commonly of a uniformly dark colour, with opaque
joinings, excepting that in segments 4-7 the extreme bases of the segments on each side
may be nari'owly translucent. {Living.) — Upper portion of the eyes either greenish
bistre-brown, or olive-green ; a burnt-umber-brown line, edged above with bright yellow
separates this portion from a narrow greenish fuscous stripe along the lower orbit. Thorax
pitch-brown above, darker behind. Abdomen red -purple-brown above, with the joinings
of the segments opaque in the midst, and pale at the pleura3, and sometimes with scarcely
any indications of the usual dorso-lateral triangular markings ; venter spotless, paler than
the dorsum, and tinged in segment 9 with orange. Forceps black. Setee dull black at
the base, but sepia-grey with dark joinings nearer their extremities. Fore leg pitch-
black, with the trochanter rufo-piceous. Hinder femora dull light olive-grey, slightly
tinged at the edges and about the knee with rufo-piceous ; tibiae darker olive-grey ; tarsi
dull brownish black. Wings vitreous ; marginal area of the fore wing tinged slightly for
some distance from the roots with greenish yellow, and in the pterostigmatic region
with light blackish grey ; neuration piceous, pale at the roots ; tegulaj bright yellowish.

S very similar. Length of body 9-12 ; wing 10-13 ; setae 6 im. 22-31, subim.
16, 2 im. 21 mm.

Kah. Continental Europe from Saxony southwards to Central Italy. Common in
Val Anzasca near Ponte Grande at 1350 ft., 19th July ; also in the Apennino Pistojese,
both near San Marcello by the Limestre and its tributaries in the chestnut-wood below
Gavanina at 2150-2750 ft., and also in the Valle Sestajone at -1230 ft. [2nd August, 11
A.M., water 50° F.]. Specimens captured by Prof. Zeller in Carinthia during June 1867
are in ]\l''Lach. Mus., and being faded through damp and age, were until recently mis-
taken by me for a distinct species. I had (prior to inspecting specimens named by
Rostock in Albarda Mus.) always supposed the species named forcipula by the Swiss
entomologists to be identical with Ecdyurus flmninum — a view that might be contended
for ; but, adopting Herr Rostock's application of the name, I now give precedence to
forcipula over italicus.

EcDYURUs BELLiEr.i, Ilageu.

X Baetis Bellkri, ! Hag., Aim. Soc. Ent. Fr. (1860) 746.
Heptayenia BeUicri, ! Etn., Traus. Ent. Soc. London (1871) 15 1.

Imago {dried), ? . — Wings vitreous, with piceous neuration, and with the pterostig-
matic region of the fore wing darkened. Fore legs piceous ; hinder legs testaceous with
fuscous tarsi. Setae piceous. Ventral lobe of the 9th abdominal segment entire. Length
of wing 14 mm.

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

Hah. Sicily. Somewhat similar in colour to S. montana, according to Hagen. The
lacteous tint of the wing-membrane might be clue to camphor. The type was examined
bv me in 1869 ; but I have uo recollection of the insect.

EcDTUBTJS iNsiGNis, Etn. Plate XSIV. 46 d (penis).

Ephemera, ! Ronalds, Fly-fisher's Ent. ed. 1, pi. xi. 2.2 (1836).

Hcptaffcmia insiffnis, \ Etn., Trans. Ent. Soc. London (1870) 7; Mil., op. cit. (1871) 153, pi. vi. 26,
266 [detail] ; Palmen, Paar. Ausf.-Giinge d. geschl.-Org. b. Insect. S. 74, 77, 78 [anatom.] (188-t).

SuhlnuKjo {living). — Wings liglit sepia-grey, the cross-veinlets narrowly edged with
darker grey ; longitudinal nervures subolivaceous or dark greenish grey in the greater
portion of the wing, the wing-roots, and sometimes the adjoining parts of the said nervures,
light olive-green or greenish yellow ; cross-veinlets black. Settc and hinder tarsi black.

Imago {living), 6 . — Eyes either dark olive-green intersected by an olive-brown line and
exhibiting a large dark round movable spot, or else greenish black or black, their pre-
dominant colour changing with age or the time of day. Notum in front either very dark
bottle-green or bistre-brown, posteriorly black varied with yellowish brown, or with
brown-ochre or dull orange ; teguloe light greenish yellow. Abdomen whitish green,
[the " green " approaching green oxide of chromium] modified in segments 8 and 9 with
brown-ochre above, with yellow-ochre in segment 10, and marked with black in segments
1-8 above and beneath ; the dorsal markings in each of these segments are an oblique
streak descending from the hind margin to the pleuron, in close proximity to the anterior
lateral angle of the dorsum on each side, tapering downwards and narrowly cuneiform,
and these two streaks are connected together by a very narrow black edging along the
interjacent portion of the terminal margin of the segment ; in $ the tract of the dorsal
vessel is likewise blackish : the ventral markings in segments 1-7 comprise, severally, a
short acute longitudinal streak <3 (or triangular spot ? ) from the base in the middle, a
pair of short isolated lines parallel with the dorsal streaks of the same segment, com-
mencing at a short distance from the median streak a little before its point, and divergent
from each otlier backwards, a pair of dots placed transversely adjacent to the ganglionic
tract, a little to the rear of the ends of the divergent lines, and, lastly, a fine line on
each side closely skirting the pleuron, terminating some distance from the tip of the
segment, and interrupted a little before the middle ; in segments 8 and 9, the ohve-
green ground-colour is suffused more or less with reddish brown in 6 , and is varied in
2 with pitch-brown. Seta; pitch-brown at the base, passing into intense sepia-brown and
distally into warm sepia. Eore femur and tibia pitch-brown, the tarsus rather lighter in
some positions ; in immature specimens the femur is dark olive- brown approaching bistre,
and is blackish at the knee ; hinder femora light olive-green modified with bistre, the
latter colour predominating at the knee and along the upper and lower edges ; tibiae
paler than the femora ; tarsi blackish or ivory-black. Wings vitreous ; in the fore wing
the longitudinal neuration and sometimes most of the cross-veinlets in the pterostigmatic
space are dull olivaceous (excepting the bases of the nervures posterior to the subcosta,
which are whitish), and the remaining, cross-veinlets are black; a small blackish cloud is

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 289

also noticeable in the pterostigmatic region of that wing, situated at about f of the
distance from the bullte towards the apex of the marginal area, between the costa and
the radius : in the hind wing the neuration appears whitish in some lights, in others the
cross-veinlets towards the extremity of the wing become greyish.

2 {living). — Eyes brownish olive. Pronotum greenish olive ; mesonotum light olive-
brown ; metanotum blackish, varied with light and brownish ochre. Abdomen light
greenish olive, with a dark narrow median stripe along the back in segments 2-7, which
is dilated anteriorly in every segment, in addition to the other blackish markings de-
scribed in the 6 . Seta; intense sepia-brown at the base, becoming lighter with dark
joinings distally. In other respects very similar to the 6 . Length of body 10-1 i ;
wing, 6 10-12, 2 12-15 ; setiB S iui. 32-34, subim. 14-20, 2 im. 22-25, subim. 15 mm.

Rab. England, in rapid parts of rivers, such as the Dart, the Kennet, and the Eden ;
May to August ; France, in the Garonne, close to St. Michel, Toulouse.

EcDYUUUS FLUMiNUM, Pictet. Ni/mijli, Plate LXII. (part).

^ Ephemera speciosa, Toia, lus. ]\Ius. Graic. 98 (17G1) ; Sclir., Enumer. Ins. Austr. indig. no. 604
(1781); Vill., C. Linn. Ent. iii. 22 (1789) ; 01., Encycl. Meth. vi. 418 (1791) ; Lat., Hist. Nat.d. Crust,
et Ins. xiii. 97 (1805).- — E. I bioculata, Panzer, in Explic. Sclitef. Ic. ccxxix. [excl. var,] (1804). — I E.
angustipennis, ! Ramb., Hist. Nat. des Ins. Nevropt. 295 (1842) ; Walk., List of Neuropt. Ins. in Brit.
Mus., part iii. 571 (1853) [nomen ineptum] .

% Baetis fluminum, Pict., Hist. Nat. Nevropt. ii. Ephem. 164, pis. svi.-xix. (184.3-5) ; ImhofF, Insect,
d. Scliw. Bd. iv. [a pi. & fig., not numbered] (1845); Walk., List of Neuropt. Ins. in Brit. Mus.
part iii. 556 (1853) ; Brauer, Neuropt. Austr. 26 (1857) ; Karsch, Die Insectenwelt, v. 400-402 (1863) ;
Hag., Ann. Soc. Ent. Fr. (1864) 38; Meyer-Diir, Mitth. scliw. ent. Ges. i. 221 (1864); Ausser., Ann.
d. Soc. Natur. xModena, An. iv. 134 (1869).— B. angustipennis, Ed. Pict., Nevropt. d'Espagne 23 (1865).
— ?B speciosus, Etn., Trans. Ent. Soc. Loudon (1871) 120 note; id., op. cit. (1873) 402.

Heptagtnia fluminum, Etn., Trans. Ent. Soc. London (1871) 146; Meycr-DUr, Mitth. schw. ent. Ges.
iv. 315 (1874); Rostock, Jahresb. d. Ver. f. Naturk. Zwickau, 1877, p. 91 (1878) ; Palmeu, Paar. Ausf.-
Gange d. Geschl.-Org. b. Insect. SS. 40, 60, 63, 65, 74 and 77, taf. iii. 38, and taf. iv. 56 (1884)
[auatom.]. — H. angiistijjennis, ! Etn., Trans. Ent. Soc. London (1871) 152.

Sublmciffo {dried). — Wings fawn-colour or liglit brownish grey, approaching vandyke-
and Cologne-earth ; neuration for the most part pitch-black, but some of the thicker
nervures are yellowish ; cross-veinlets black, narrowly edged with grey, rather paler
towards the costa. Setae either light yellowish, or else dark sepia-brown with dark join-
ings ; in living specimens they are blackish grey or dusky. Pictet's tigure Avell represents
the wings of the living insect ; after death the dark bands and stripes across the fore
wing disappear. These markings are as follows : — a transverse cloud in the basal portion
of the disk, followed by a transverse abbreviated streak from the anal angle, and another
a little further on from the costa in the neighbourhood of the bullte, and lastly, between
this and the tip of the fore wing, three narrow transverse streaks from the pterostigmatic
region. {Living.) — Eyes of ? greenish, surrounded with pitch-brown, and exhibiting a
movable black dot. Wings fawn-colour or smoky grey with black, grey -margined cross-
veinlets, rather paler towards the costa. Body more or less greenish ochraceous ; the
abdominal segments very narrowly darker at the tips ; segments 1-S striped obliquely

' SECOND SERIES. — ZOOLOGY, VOL. IH. 39

290 REV. A. E. EATON ON EECENT EPHEMERID^ OE MAYFLIES.

with black at the sides ; the first and the last of the stripes are less distinct than the
others. Pore femur intense olive-brown, darker towards the tip and at the edges ; tibia
blackish grey ; tarsus black. Hinder legs light greenish or olive-grey, with black tarsi.

Imago {liclug), 6 . — Eyes at first either intense sepia-brown, intersected below by a
transverse sulphureous line ; or else warm sepia, divided by a light greenish line ; in
moribund aged specimens they often become csesious. {Dried) [dark specimens], —
Notum rufo-piceous or dark reddish brown ; a piceous or black stripe extends from the
tegulae to tlie fore coxa. Dorsum of abdomen broadly red-pvirple-brown along the middle,
with the tract of the dorsal vessel and a considerable portion of the hinder part of each
of the intermediate segments slightly darker ; in segments 2-8 the sides of the dorsum
are light yellowish ochre, intersected obliquely by reddish-purple stripes, extending in
each segment from the pale stigmata or s))iracles to the hind margin, and emitting a
short streak from the spiracle along the main trachea to the nymphal tracheal scar of
the jireceding segment; hence the sides of the abdomen may be described as striped
alternately with reddish purple and light yellowish ochre, the latter colour occupying
the hinder angles of the dorsum, and a sj)ace on each side of the base above the dark
stripes in each of the segments specified. The dark stripes referred to are gradually
dilated posteriorly from in front, and their width varies somewhat with the individual ;
whence the light spaces above the stripes at the bases of the segments vary also in
form, being in some specimens ovate or triangular spots, but in others very narrow
streaks. The hinder segments are more largely occupied by the dark colouring ; but the
tenth is almost wholly reddish purple. Venter spotless, either light yellowish ochre in
segments 1-G and in the forceps-basis, but tinged with reddish purple in the remaining
segments ; or else tinged more or less with reddish purple throughout. Setae whitish,
tinged with sepia near the roots ; the joinings piceous, and only for a short distance
near the base alternately narrow and broader. Eore femur and tibia pitch-brown ; tarsus
very light bistre-brow^u. Hinder legs light yellowish-amber, with the ungues and part of
the teriniual joint of the tarsus intense se2iia-l)rown, and with some brownish discoloration
close to the knee. Wings vitreous, almost imperceptibly tinged with bistre-grey in the
marginal and submarginal areas of the fore wing ; the pterostigmatic space is as clear as
the rest of the area ; neuration in most lights pitch-black or black, with the costa, sub-
costa, and radius of the fore wing pitch- or bistre-brown ; the great cross vein in most
positions remains black. Pterostigmatic cross-veinlets branched and anastomosing.

Variation [light specimens {dried)], 6 . — Notum rich brown-ochre. Dorsum of
abdomen to a large extent in segments 2-6 or 7 translucent pale bistre-brown, inclining
to olive-brow'n, with the joinings also to a large extent slightly opaque. The sides of
the dorsum are rather paler than tlie midst, but are not strongly contrasted in colour
with it ; the lateral stripes are black, and do not reach the hind margins of the segments
in all specimens, but only in some. Hence the sides of the dorsum do not appear to be
striped alternately with a light and a dark colour, but only display dark stripes on a light
ground. Pore femur bistre-brown, darker towards the knee.

$ {dried). — E-ather similar to 6 , but the notum is lighter. Fore leg bistre-brown,
dark at the tip of the femur : in many positions the tibia and tarsus appear as dark as the

&

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 291

femur. Hinder legs sometimes of a somewhat browner yellow amber-colour than in the
other sex ; the femora rather dark towards the tip ; tarsi in small specimens pale, with dark
joinings, but in large specimens usually intense sepia-brown or black ; basis of subcosta
and radius, and great cross vein of hind wing dark ; but the nervuros themselves light
yellowish ; ungues black. Setoe during life smoke-grey with rufescent joinings ; token
dried their prevailing colour is sometimes warm sepia-brown. The proportions of the
tarsal joints, the less obtuse apex of the ventral lobe of the 9th abdominal segment, and
the branched and anastomosing pterostigmatic cross-veinlets of the fore wing, serve to
distinguish tlie ? of H. angtistipenuis from Epeorus torrentium. Length of body, s 8-11,
S 9-12; wing, d 9-12, ? 9-11; sette, d im. 19-23, subim. 13, $ im. 15-22, subim.
11-13 mm.

Kab. Continental Europe from Norway (Wallengren) to Spain (Ramb.). Common
generally at rivers and lakes, from at least July to September, and doubtless earlier.
Amongst other localities it occurs in Holland at Arnheim ; in Switzerland in the
environs of Geneva and Lac Leman at Genthod, as well as at Basle and Berne ; in Savoy
at Annecy, Chambery, Aix-les-Bains, and Evian (M^Lach.) ; in Northern France at
Fontainebleau (zVZ.) ; in Southern France at Toulouse and Tarascon [Ariege] ; and at
Madrid (E,amb.). At the Berne Museum in 1879 Albert MiiUer showed me the original
drawings for Imhcff's plate (1845). The d oculi are rightly represented in the artist's
original drawing as warm sepia-brown, intersected horizontally l)y a ' gramineous ' line.
In the revised copy adopted as the original of the published figure the eyes were
coloured ' gramineous ' entirely. Pictet made them ' cyaneous ' — a very light shade of
ultramarine, or an intense ultra ash-blue. His specimens may have been moribund or
flaccid with age, or he may have coloured them after the eyes of a subimago.

ECDYUKUS VOLITANS, Etu.

Heptagema i-olHans, ! Etu., Trans. Eut. Soc. London (1870) 7; ! id., op. at. (1871) 147, jil. vi. 20
(genitalia) ; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, p. 89 (1878) ; Parfitt, Rep. & Trans.
Devon. Association, xi. 398 (1879) ; Palmeu, Paar. Ausf.-Gauge d. Geschl.-Org. b. Insect. S. 52
[anatom.] (1884). — % H. flavipennis, var. ?, Etn., supra at pp. 273 & 274 (1885).

Imago {dried). — Notum of d pitch-brown ; that of 2 light yellowish brown ap-
proaching brown-ochre, varied on the metanotum with pitch-brown. Fore leg of d
somewhat rufo-piceous in opaque view, with an indistinct darker median band on the
femur followed at a short interval by almost imperceptible traces of a preapical band ;
the extreme tips of the femur and tibia, and the tarsal joinings, piceous or blackish ; 1st
tarsal joint of normal length. Fore leg of 2 raw umber-brown, with the median and
preapical dark bands well defined ; tibia lighter than the femur ; tarsus partially or
wholly concolorous with the femur. Hinder legs light yellowish brown, with browner
femoral bands ; both bands are well defined in ? , but the proximal band is obsolete in
d ; tarsi more or less sepia- or w^arm sepia-brown, with dark incisures. Setae greyish
white, with piceous joinings ; in ? some of the alternate joinings near the base of the
setge are narrower than the others. Wings vitreous : neuration in d piceous. varying
with change of posture from pitch-black to pitch-brown, the cross-veinlets in some lights

39*

292 REV. A. E. EATOX OX EECEXT EPHEMERID.E OR MAYFLIES.

retciining the darker tint, while the longitudinal nervures assume the lighter ; neuratioa
in $ lighter than in d , especially towards the wing-roots, varying with change of
posture from light pitch- or light bistre-brown to raw umber-brown, the cross-veinlets,
as in the other sex, retaining the darker tint in some stand-points ; in the 6 the great
cross vein of tlie fore wing is dark from the radius almost to its junction with the costa,
but in the $ it is piceous only from the radius to about half across the marginal
area, and is in its dark part more strongly contrasted in colour with the neigh-
bouring nervures than in the <s . In the ptcrostigmatic region of the fore wing of
both sexes the reticulation formed by the branching and anastomosis of the cross-veinlets
varies considerably in extent with the individual, but in comparison with that of some of
tlie other species of this genus is unusually open in texture. 6 {living). — Eyes black-
brown. Notum atro-fuscous. Dorsum of abdomen light bistre-brown, with the tips of
the segments darker ; venter dark olive-grey, usually spotless. Setae liglit greenish
grey, with darker joinings. Legs somewhat as in dried specimens ; the tarsi and fore
tibia fuscous ; the bands of the hinder femora light reddish or carneous. Wings vitreous,
with blackish neuration, and with a slight discoloration in the ptcrostigmatic region of
the fore wing. Length of body 12-15 ; wing, 6 13-14, ? 11 ; seta? 6 im. 25-28 mm.

Hnh. England ; near Reading, on the Thames above Pangbourne, and on the Holy-
brook above Coley Park, towards the end of May. Holland, near Arnheim in Gelderland
(2 6 and 2 ? im., captured by Mr. j\Ieddenbach van Rooy, in Albarda Mus.) at the end
of May and beginning of June. Mr. Albarda has taken objection to the blunder
committed by me, at p. 274 supra, in referring this species (albeit with hesitation)
as a variation to Heptaxjcrdn flavipennis, and has lately forwarded to me for inspection
the four Dutch specimens mentioned above. My error arose from imperfect recollection
of the insect, which I had not seen since the time of its original descriiitiou.

ECDTURTJS ZEBEATA, HagCn.

X Bactis -ebrata, Hag., Ann. Soc. Ent. Fr. (1864) 38.

Heptagetiia zebrata, Etn., Trans. Ent. Soc. London (1871) 155 [part.]; vide Hag. & Etn., o/). ct/.
(1873) 40(].

Suhlma go {dried). — Wings dark grey; longitudinal neuration yellowish ; cross-veinlets
edged with black.

Imago, <3 . — Eyes blue or green during life. Notum livid, clouded with brown.
Abdomen yellow [jaune] with a broad median longitudinal l)lack dorsal stripe, and
oblique brown-black lateral stripes confluent with the bordering of the hind margins of
the segments. Seta; white, aunulated at the base, the middle, and the tip of each joint
with black. Legs pale yellow, with the knee and tarsus brown, and a broad black
median femoral band. Wings vitreous; the longitudinal nervures yellow; the cross-
veinlets brown; hence the fore wing has a spotted appearance, especially along the
anterior margin.

2 . — Similar, but larger than the <3 . The anterior margin of the fore wing is rather
more spotted. Length of wing, c7 10, ? 12 ; seta?, d im. 20, subim. 12, $ im. 15 mm.

Rah. Corsica (Hag.). [After Hagen.]

EEV. A. E. EATON OX RECENT EPIlEMERIDyE OR MAYFLIES. 293

EcDYURTJS FALLAx, Hagen.

t Baetisfallax, ! Hag., Ann. Soc. Ent. Fr. (1864) 38.— t B. seirdoa, ! Costa, Atti del. R. Accad. d. Sc.
fisic. e matemat. di Napoli, ix. 34 (1882).

Heptagenia % zebrata, ! Etu., Trans. Ent. Soc. London (1871) 155, j)l. vi. 28 [detail (part.)], vide Hag.
&Etn., op. clt. (1873) 406.

Imago {dried), <? . — Notum raw umber-brown, varied posteriorly with darker. " Ab-
domen lighter than in JH. angustipennis, brown ochreous, with the hinder borders of the
dorsal segments black. Setne dull yellowish, darker towards the roots." [After Hagen.]
Fore leg in opaque view dark raw umbcr-brown, with the tarsus, in some postures, the
tibia, the knee narrowly, and a darker broad band about the middle of the femur
pitch-brown. Hinder femora and tibise bi opaque vieio very light raw-umber, in other
positions yellower, and in transmitted light yellowish amber-colour, with a similar
pitch-brown or blackish band about the middle of the former, and with the knee
slightly brownish ; tarsi brownish, either dark raw umber or sepia, according to posture.
Wings vitreous, with pitch-brown ncuration ; the cross-veinlets in some postures appear
much darker tlian the longitudinal nervures, but in other postures the colouring is
uniform, although the cross-veinlets are strongly marked : in the only specimen examined
by me the pterostigmatic cross-veinlets of the fore wing are almost without exception
branchless, and somewhat evenly distributed. Length of wing 8-9 mm.

Eab. Corsica (Hag.) ; Gennargento, Sardinia (Costa). The specimen labelled E.
sordoa in Costa's handwriting, and kindly communicated to me by him, is a defective d
im., of « hich the abdomen is lacking. Judging from Hagen's description of fallax,
there need be little doubt as to the identity in species of the insects to which the above
names were applied : I have therefore relied largely upon Costa's specimen in this
description.

EcDYURUS ANNTJLiFER, Walker.

X Palingeriia annulifcra, ! Walk., Trans. Ent. Soc. Loudon, N.S. v. 199 (1860).
Heptagenia annulifera, ! Etu., ojo. «7. (1871) 148.

Imago (dried), 9 . — Thorax somewliat brown-ochreous above, darker in the middle
than at tlie sides of the pro- and mesonotum. Abdomen testaceous, witli a stripe down
the middle of the back, the hinder borders of the segments, and with the usual broad
oblique lateral stripes at the sides, black. Setae light-brownish white, with the alternate
joinings black. " Legs whitish, the femur banded with black " [teste Walker). Wings
vitreous with pellucid nervures, but with the cross-veinlets and the portions of the longi-
tudinal nervures in close proximity to them pitch-brown and narrowly edged with the
same colour. Length of body ? G ; wing 8 ; setae 10 mm., or more.

Hab. Hiudostan.

** Penis-lobes ohovate.

EcTDTJRUS AFFiNis, sp. nov. Plate XXIV. 4G(? (penis).

Imago {dried), 6 . — Notum bright reddish brown or ferrugineo-piceous in part, some-
times approaching pitch-brown behind ; tlie pleura are paler than in K lateralis, and

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

hence the yellowish streak in front of the fore wing-roots is not conspicuous. Setae
whitish. Fore leg, in opaque view, piceous, excepting the tarsus and the basal half of the
femur, which are lighter in colour. Wing-neuration in opaque view wliitish, excepting,
in the fore wing, the great cross vein and the roots of the subcosta and radius, which are
slightly brownish in certain postures. {Liviug.) — Eyes intense burnt uuiber-brown
alcove, black beneath, traversed by a chrome- or lemon-yellow line. Pronotum yellow-
ochreous, with a piceous streak on each side ; mesonotum bistre-brown ; tegulse yellowish
ochre; metanotum either j)itch- or jet-black ; pleura rufo-piceous, with black streaks
descending in front of the liases of the coxae ; sternum rufo-piceous. Abdomen either
rufo-badious [a colour approaching Mars orange] or reddish umber-brown : the dorsal
joinings and a short acute triangular streak from the base of each segment except the last
two, coincident with the tract of the dorsal vessel, darker than the ground-colour ; in
segments 2-6 above the pleura on each side of the back is a large triangular or quadri-
lateral ochraceous spot tapering anteriorly, Avliich contrasts to advantage with the
contiguous portions of the dark joining ; in segments 7 and 8 the corresponding pale
spaces are much smaller and less distinct. Venter in some specimens pale lurid, with a
continuous median series of obcordate blotches approaching Mars orange in colour.
Setffi white, with the first three or four joinings rufescent. Pore femur eitlier piceous
or rufo-piceous in its distal half, and paler or lurid towards the base, with traces of a
dark median band ; tibia and all but tlie last joint (which is either rufo-piceous or darker
than the other joints) of the tarsus either blackish grey or cerviuous. Hinder legs
lurid testaceous, with the median band and the tip of the femur, the base of the tibia,
and the joinings and terminal joint of the tarsus rufescent piceous, and the spiuule of
the trochanter piceous or black ; sometimes the tarsus is altogether reddish. Wings
vitreous, neuration colourless. Length of body, 6 12-13'5, wing 10-11, setae 6 im.
15-16 mm.

Sah. The Netherlands. This species was first communicated to me by Mr. Albarda,
who thought it might be identical with one of Hagen's Corsican species. I afterwards
met with it near Arnheim ; it is common in the neighbourhood of the raihvay -bridge at
the end of July, and doubtless earlier before the seasonal rise of the llhiue.

ECDYUEUS LATERALIS, Curtis.

X Baetis laleralis, Curt., Loiul. & Edinb. Pbilos. Mag. ser. 3 (1834) 121 ; ! Stepli., 111. Brit. Ent. vi. 65
(1833); Pict., Hist. Nat. Nevropt. ii. Ephem. 175, pi. xxi. 3-G (1843-5) ; Walk., List of Neuropt. Ins.
in Brit. Mus. part iii. 557 (1853) ; Hag, Ent. Ann. (18G3) 28.— jB. J ohscura, Pict., Hist. Nat. Nevropt.
ii. Ephem. 182, pi. xxiii. 1 (1843-5) ; Walk., List &c., part iii. 557 (1853) ; Hag., Ent. Ann. (18G3) 28
[nee IStcph. 1835].

J Clo'e brunnea, Ramb., Hist. Nat. tl. Ins. Nevropt. 298 (1842) ; Walk., List of Neuropt. Ins. in Brit.
Mus. part iii. 557 [as var. ? of C. % halteratci] (1853) ; Rosenbaucr, Tbier. Andalus. 3G6 (185G) ; Ed.
Piet., Synop. Nevropt. d'Espag. 26 (1865).

Heptayciiki lateralis, ! Etn., Trans. Ent. Soc. London (1871) 155, pi. vi. 27 [detail) ; Meyer-Diir, Bull.
Soe. Ent. Suisse, iv. 313 (1874). — H. ohscura, id., loc. cit. (1874) ; Rostock, Jabresb. d. Ver. f. Naturk.
Zwickau, 1877, p. 91 (1878).

SuUmago {dried). — Wings uniformly tinted either with brownish [vandyke] grey, or

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 295

(in some of the d Scotch examj)les) with blackish grey : the brown-grey tint matches
with that of the wings of Cloeon simile, subimago, and the black-grey with that of the
fore wings of Ephemerella igniia, subimago.

Imago {dried), d . — Notum dark pitch-brown. Setae light bistre-brown, sometimes
with the joinings opaque. Eore leg pitch-brown, lighter or bistre-brown towards the
base of the femur. Hinder legs light bistre-brown, with the knee and the tarsus pitch-
brown or blackish. [Living.) — Eyes very intense burnt umber-brown. Notum jet-black ;
a greenish-yellow or sulphur-coloured streak usually prolonged forwards from the fore
wing-roots strongly contrasts in colour with the dark pleura. Dorsum of abdomen
bistre-brown, modihed witli burut-umbcr ; segments 2-G are lighter than the remainder,
and have each of them the whole of the terminal margin narrowly bordered with pitch-
broAvn or a darker colour, a fuscous spot posteriorly on both sides, which disappears in
drying, and a pale space or cloud above tlie spiracular line on each side in the midst ;
the remaining segments likewise are paler near the same line. Venter sepia-brown,
tinged in the anterior segments with greenish ; the penultimate segment, tinged with
orange near the insertions of the forceps-limbs, has on each side a piceous lanceolate
wart resembling a spine. Forceps black, greyish inside distally. Setse sepia-brown.
Wings vitreous, with pitch-brown neuration. Pore femur fuscescent at the base, and
pitch-brown towards the tip ; tibia and tarsus pitch-black. Hinder legs subfuscous ; the
femur has a small sabrufesceut cloud nearly in the middle towards its upper edge, and
the tarsus is black-grey.

$ . — Very similar to the <S . {Living.) — Abdomen more uniformly opaque than in the
other sex, and marked on each side, in most of the segments, either with a dark trian-
gular spot or an oblique dark stripe from the terminal border. Venter fuscous, with
greenish-grey joinings ; the terminal ganglionic mass of the nervous tract is sometimes
tinged faintly with warm sepia-brown. Length of body 5-9 ; wing, 6 6-10, $ 7-10 ;
setae, c^ im. 19, subim. 10, 2 im. 15, subim. 8 mm.

Ilab. Locally common in the west and north of Great Britain, extending to Dorset in
the south. It chiefly inhabits trout-streams and the shores of lakes in hilly and moun
tainous districts ; and the fly appears from May to August. Nowhere have I found it
more abundant than it was along the shore of Ullswater, in Westmoreland, under Kail-
pot Crag, on 1st July. On the Continent it has an extensive range : — Styria (Brauer) ;
Carinthia (Zeller in M^Lacli. Mus.) ; Switzerland (Pictet and Meyer-Diir) ; Savoy, at the
Lac de Moutriond (3140 ft.) ; the stream below Preycinet-la-Tour (Haute-Loire) in the
direction of Les Estables, in company with Odontocerum (3770 ft.) ; Spain (Pwambur).
Small specimens of Rhithrogena semicolorcda, 2 im., are liable to be mistaken for tins
species, should their femoral spots happen to be indistinct ; but they are distinguishable
from it by their having simple, instead of branched and anastomosing cross-vciulets in
the pterostigmatic space of the fore wing, by the absence of the bright-yellowish streak
in front of the fore wing-roots, and by the ventral lobe of the 9th abdominal segment
being emarginate instead of seemingly subacute, or at least entire.

296 EEV. A. E. EATON ON EECENT EPHEMEEEDJi: OE MAYFLIES.

EPHEMERID^ OF UNCERTAIN GENERA.

The generic names here attributed to sjDecics placed in this category, when not of
very recent origin, are used in a lax and unrestricted sense, such as was accorded to them
hy Pictet (1843-5) or by myself in the year 1871.

AMERICAN SPECIES OP UNCERTAIN GENERA.
PoTAMANTHTJS VoGLERi, Weyenbergh.

Cloe (?) Voyleri, Weyenbergli, Tijdschr. v. Eut. xxvi. 1882-3, p. 171, pi. x. 5 (1883) [wings].

Imago [living), <2 . — Thorax jet-black ; abdomen black ; setae 3, greyish, with black
joinings ; legs somewhat pearl-grey, but darker. Wings vitreous, with black neuration,
excepting that the fore wings from the costa to the radius are dark-tinted. [In the
figure the proximal half of the marginal area is colourless.] Hind wing very small,
traversed liy a single longitudinal median nervure, which does not extend quite to the
margin.

$ . — Abdomen of lighter colour than that of the male. Length of body 3"5, setae 14-
15 nam.

Hah. ki Pasco Sobremonte, Cordova, Argentine Republic, flying in the sunshine at
about 8 A.M., on the 20th of Api'il.

From the figure of the fore A\ing and items detailed in the original description, it is
evident that tiiis species represents a genus of the Fifth Section, or Leptophlehia-iy^^.
What is stated of the hind wing should, perhaps, be received with caution, because, from
inspection of the figures, it appears that Prof. Weyenbergh was not accustomed to flatten
out the wings he delineated.

PoTAMANTUUS SiEWERTii, Weyenbergh.

Cloe Siewertii, Weyeubergh, Tijdschr. Ent. xxvi. 1882-3, p. 170 (1883).

Imago (living). — Upper portion of oculi dark red ; thorax sepia-brown ; abdomen dark
grey, darker at the joinings ; setse 3, pearl-grey, with darker joinings. Femora [sprieten]
blackish ; the remainder of the legs [pooten] light grey. Wings dull, spotless. Hind
wings very small. Length of body 3, sette 9 mm.

Ilab. Cordova, Argentine Republic ; sparingly in November.

POTAMANTHUSi?) INANIS, Pictet.

PotamanthuslW inanis, Pict., Hist. Nat. Nevropt. ii. Ephem. 232, pi. xxiv. 4 (1842-5); Walk., List of
Ncuropt. lus. in Brit. Mus. 517 (1853) ; Etn., Trans. Ent. Soc. London (1871) 91 [nee E. inanis, Gmel.

1790].

Imago {dried), d . — Thorax polished bright brown. Abdomen whitish for the most part,
but with the tip brown, and with a large brown dot on each side of every whitish
segment. Setae greyish, dotted with black. Legs brown. Wings vitreous, shghtly
greyish, rather darker along the costa, and tinged faintly with yellowish at the base;

EEY. A. E. EATON ON EECENT EPHEMEKID^ OE MATELIES. 297

neuration browu ; cross-veiulcts sparse. Hiud wings seemingly absent. Length of body
5, wing 6, setfe 6 mm.

Hub. Brazil ("Yienua Mns.). [After Pictet.] Pictet did not know exactly to which
of his genera this species should rightly be referred. His figure attributes to the meso-
thoracic wings a shape which would lead one to suspect that the absence of hind wings
in his two specimens was due to Psociclce or other cabinet pests. Otherwise, his state-
ment that cross-veinlets exist only in the anterior portion of the mesothoracic wing
wonld render it probable that the sjiecies might be related in some degree to one of the
genera illustrated in Plate XV. of the present volume, — supposing him to have used a
lens of low power in his examination of the specimens, and their setse to have exceeded
his estimate in length.

Thraltlus (?) viTRiPENNis, Elanchard.

Ephemera {doe) vitripennis, Blanch., Gay, Hist, fisic. y pcilitic. de Chile, vi. 107, Atl. Nevropt. ii. 3
(1851).

Cloeon vltrlpenne, Etu., Trans. Eut. Soc. Loudon (1871) 107.

Imago. — Body of a light brownish olive ; head flavo-rufous above. Mesothoracic
wings vitreous. Legs light testaceous; femora banded with fuscous in the middle and at
the tips. Setie Avhitish, annulated with In-own. Hind wings absent.

Hah. Chili. [After Blanchard.] Probably a Thruuhis, of which the hind wings had
been destroyed by Psociche.

SiPHLURUS QUEBECENSi.?, Provaucher.

I Ba'elisl canadensis, Provaucher, Natural. Canad. viii. 2G7 (187G) ; id. En. Ent. d. Canad. ii. fasc. i.
83 (1877).

Siphlurus quebecensis, Hag. MS., op.cit. ii. fasc. i. [corrections] 82- (1877).

Brune ; le vertex et le disque du prothorax ferrugineux. Abdomen avec la base des
segments testacee, surtout sur les cotes. Pattes pales, cuisses brunes, jointures
des articles des tarses noires. Ailes hyalines, le bord costale brun a I'extremite et
quelque peu ferrugineux a la base ; nervures transversales brunes. Soies tres tongues,
pales, a jointures brunes. 6 Sous-parfait : ailes un peu obscures, couleur du corps plus
sombre. Long. -40 pouce ; soies 1'20. [After Provanclier.]

Heptagenia quebecensis, Provaucher.

X Cloe quebecensis, Provaucher, Natural. Cauad. viii. 2G7 (187G) ; id.. En. Eut. d. Cauad. ii. fasc. i. 84
(1877).
Heptayenia quebecensis. Hag. 'Sl'&.,op. cit. ii. fasc. i. [corrections] 82' (1877).

Brun varie de roussatre. Thorax poli, d'un brun roussatre, les cotes avec les sutures
jaunatres. Ailes. . . . parfaitement hyalines, les nervures transversales interrompues,
peu apparentes. Pattes brun pale, les jointures des articles des tarses anterieurs noires.
Abdomen brun, blanchatre sous le ventre et a la base des segments sur les cotes. Soies
caudales. . . . blanchPitres, a jointures brunes. Long. "40 pouce, soies '05.

Hub. Quebec, common. [After Provaucher.]

SECOND SERIES. — ZOOLOGl', VOL. III. 40

298 EEY. A. E. EATOX ON EECENT EPHEMERID.E OR MAYFLIES.

Heptagenia I PUDiCA, Hageu.

Heptagenia Xpud'ica [ ? subim.l, ! Hag., Ann. Rep. U.S. Geol. & Geograph. Survey of the Terr. 1873,
part iii. Zool. 581 (1875) ; [uec % Ephemera pu die a, ! Hag. {\'6Q\) =Ecdijurits vicarius].

SuUmago (dried), ? . — The two specimens supposed in 1875 to be identical with the
species described in 1861 as Kjmdicn differ from this last specimen, but agree with each
other in the following particulars: — In the tarsus, joint 1 is tlie longest, joints 2-4
diminish successively in length, and joint 5 is as long as (if not longer than) joint 1 ;
ungues unlike each other in form. Wings talcose, grey-tinted in the disk, and slightly
yellowish along the costa ; longitudinal ncuration at first flavescent, and banded with
greyish black, but becoming in a large extent darker before the moult ; cross-veinlets
pitch-black, mostly bordered faintly with grey, this colour also spreading along the lon-
gitudinal nervures in the vicinage of their junctions with the former : near the anal angle
of the fore wing many of the cross-veinlets are at first pale and unbordered, but after a
time they become dark like the others. The wing-neuration is comparable to that repre-
sented in PL XXIII. fig. 41, the cross-veinlets being rather evenly distributed in the
disk ; the marginal area of tlie fore wing contains 9-11 cross-veinlets before the bulla, 1
or 2 at the bulla, and about 20 rarely forked beyond it. Notum lutesccnt. Abdomen
striped obliquely at the sides with black, and marked at the bases of most of the ventral
segments with two fine divergent black lines. The ventral lobe of segment 9 appears
to be obtuse behind, with a slight sinus in the middle closely flanked on either side by
a small acute tooth. The specimens w^ere ticketed 82 and 83 ; and the left hind leg of
82 was atrophied. Length of wing 20 mm.

IFab. Foot-hills, Colorado (W. L. Carpenter) in August. (Mus. Comp. Zool. Cam-
bridge, Mass.) This species may be related generically to Ej^eo^'us.

Heptagenia basalts, "Walker.

X Ba'ftis bcisfilis, ! Walk., List of Ncurnpt. Ins. in Brit. ]\Ins. part iii. 505 (18.J3) ; Hag., Smithson.
Misceli. Coll. (18G1) Synop. Ncuropt. N. Am. 50 ; [ncc B. bascdis, Stepli., Cat.].

Heptagenia hasalis, ! Etn., Trans. Ent. Soc. London (1871) 139, pi. vi. 15, 15 a [detail].

Imago (dried), <s . — Xotum piceous. Abdomen pitch-brown, pale at the joinings. Setae
very light reddish [Roman] sepia-grey, with pitch -brown joinings. Legs absent. Wings
vitreous, with pitch-black neuration : the fore \\ing towards the inner margin, and the
hind wing at the base, tinged with dark vandyke-grey ; the cross-veinlets in the disk of
the fore wing near the base of the wing, and between the costa and the pobrachial (7)
nervure, are narrowly edged with pitch-brown, or, in parts, with pitch-black ; their edging
in two places coalesces into pitch-black spots, situated one at the bulla of the subcosta,
and the other about midway between that and the extremity of the marginal area.
Length of body 13, wing 14, setre 25 mm.

Hab. Lake Winnipeg (Brit. Mus.).

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 299

Heptagenia pulchella, AValsb.

J PnUngenia puhhdla, Walsh, Proc. Acad. Nat. Sc. Philad. (18G2) 375 ; Hag., Proc. Eut. Soc. Pliilad.
ii. 177 (1863) ; Walsh, op. cit. ii. 203 (1863).

Heptagenia pulchella, Walsh, op. cit. ii. 204. (1863) ; Etn., Trans. Eut. Soc. London (1871) 141.

Suhimago. — Wings subopaque, clouded with fuscous ; cross-veiulets fuscous, bordered
with fuscous ; hind wings paler than the fore wings, and tipped with fuscous.

Imago [living), H' . — Fore tarsus \\ to 1^ as long as the tibia; joints 1-3 of the tarsus
subequal to each other. Ejes pearly Avhitish, changing to blackish. Notuiu ferrugineo-
pieeous, with the meso- and metathoracic scutella whitish. Abdomen, in segments 2-7,
and the base of segment 8, whitish hyaline, with the extreme terminal edges of the seg-
ments dark, and usually with a large fuscous dot at each of the spiracles ; the remainder
of the dorsum ferrugineo-piceous. Venter whitish. Setae whitish, with fuscous joinings
alternately narrow and broad in the basal half. Fore leg pale yellowish; the femur with
a median and a terminal baud, the tip of the tibia, and the joinings and tip of the tarsus
fuscous : hinder legs whitish, marked palely in correspondence, wanting sometimes the
median femoral band. Wings hyaline, clouded with pale brown in the pterostigmatic
space of the fore wing: neuration for the most part fuscous, but the " costal veins "
[? subcosta and radius] in their basal f are yellowish, and in the hind wing the " post-
costal veins" [? those posterior to the pobrachial (7)] and cross-veinlets are hyaline.

? . — Vertex whitish, varied with luteous or ferrugineous ; notum whitish, varied with
luteous ; sternum and pleura whitish. Dorsum and venter egg-yellow when full of
eggs; the dorsum marked in joints 1-G as in 6 , and slightly tinged sometimes in seg-
ments 7-9 with ferrugineous. The pterostigmatic cloud is lighter than in d ; and the
neuration of the hind wing is mostly hyaline. Length of body 5-8; setse, 6 im. 17-21,
subira. 10-13, £ im. 15-10, subim. 8-13 mm.

Hah. Rock Island, 111., and Maryland. In the fore wing the great cross-vein is very
strong, and the cross-veinlets, especially in the front of the wing, are coarser thau the
longitudinal neuration. [After Walsh.]

Heptagenia tekminata, Walsh.

X Palingeiiia terminata, Walsh, Proc. Acad. Nat. Sc. Philad. (1862) 376 ; Hag., Proc. Ent. Soc.
Philad. ii. 177 (1863) ; Walsh, op. cit. p. 203 (1863).

Heptagenia terminata [sp. ? or H. piilc/iella, var. ?],Etu., Trans. Ent. Soc. Loudon (1871) 141 note
[after II ag.] .

J Bu'etis X interpunctata, Provancher, Natural. Canad. viii. 26G (1876) ; id., En. Eut. d. Cauad. ii.
fasc. i. 83 (1877) [corrected at op. cit. p. 82' (Hag. MS.)].

Perhaps only a variation of H. i)ulcliella. The 6 imago has segments 2-7 of the
abdomen pale yellowish, without dots at the spiracles ; the hinder legs pale yellowish,
usually wanting the median femoral band. In the fore wing tlie cross-veiulets are
scarcely coarser than the longitudinal nervures (whence the wing seems paler than in
H. pulchella) and the " second costal vein" [? subcosta or ? radius] is generally thickened
and clouded for the length of 0-5 mm. at the bulla, which is rarely so in H. pulchella.

40*

300 EEV. A. E. EATOX OX EECEXT EPHEMEEID.li OR MAYFLIES.

Length of body 6-5-S-5 ; setae, d im. 19-22, subim. 12-13, $ im. 18-22, subim.
15-18 mm.

ITab. Eock Island, 111. [After AValsh.]

Heptagexia simplex, Walsh.

Heptagenia simplex, Walsh, Proc. Eut. Soc. Philad. ii. 204 (1863) ; Etti., Trans. Er.t. Soc. Loiulou
(1871) 111.

Suhimago. — Wings and neuration yellowish.

Ima(jo {iking), 6 . — Fore tarsus f as long as the tibia : joints 1-3 of the t;irsus sub-
equal to each other ; joint 4 a little shorter. Eyes bright greenish yellow. Notuui
flesh-colour. Abdomen in segments 2-7 hyaline; segments 8-10 whitish ; forceps white ;
setae white, tinged with dusky at the extreme tip. Pemora yellow or yellowish ; tibiae
and tarsi Avhite, with the extremities of the tarsi, the tip of the fore tibia, and sometimes
the joinings of the fore tarsus fuscous. Wings hyaline ; neuration colourless, excepting
in the distal \ or f of the fore wing, where it is fuscous, and sometimes the cross-veiulets
of the marginal area of the same wing are also fuscous ; in the pterostigmatic region the
cross-veinlets are coarse.

$ . — Fore tarsus h as long as the tibia ; joint 1 as long as joint 2. Abdomen egg-
yellow. Setae scarcely tinged with dusky at the tip. Only the extremities of the tarsi
are a little tinged with fuscous. Wing-nenration colourless, excepting that a few cross-
veinlets towards the extremity of the costa are dusky, and that the costa, subcosta,
cubitus, and radius are tinged with yellowish. Length of body, d 6-8, $ 7-8'5 ; setae,
d im. 14-18-5, subim. 10"5, $ im. 14-16, subim. 10-15 ; expanse of wings, d 16-20*5,
2 19-25-5 mm.

Mab. Eock Island, III., June. [After Walsh.]

Heptagenia critextata, Walsh.

Heptagenia cruentata, Walsh, Proc. Ent. Soc. Philad. ii. 205 (1863) ; Etn., Trans. Ent. Soc. London
(1871)140.

Sitbhnago. — Wings and their neuration dull opaque yellowish. Setae tinged with
dusky ; their joinings fuscous, less distinct than in the imago.

Imago {living), d . — Yellowish. Fore tarsus as long as the tibia; the first joint much
shorter than the second. In the hinder tarsi joint 1 is slightly shorter than joint 2.
Eyes jjale bluish grey, intersected by a black line. Notum and dorsum sanguineous.
Seta.^ whitish, with fuscous joinings, which towards the base are alternately broad and
narrow. Forceps i:)ale, fuscous towards the tips. In every leg the distal half of the
femur, the basal f and the terminal j of the tibia are pale sanguineous, that portion of
the femur presenting at each extremity a narrow dark sanguineous annulus, and the
tarsus has dusky joinings and ungues. Wings hyaline, tinged uniformly with yellowish
along the costa ; neuration close to the Aving-roots hyaline, but elsewhere fuscous,
excepting the costa, which is tinged with yellow in its basal § : the bulla of the " 2ud
costal vinn " [? subcosta] for about 0'5 mm. is thickened and obfuscated.

2 • — Fore tarsus shorter than the tibia ; joint 1 shorter than joint 2, and slightly so in

EEV. A. E. EATON OX EECEXT EPHEMEEID.E OE MAYFLIES. 301

the hinder tarsi. Occasionally paler than S , and sometimes with the venter sangui-
neons. The hyaline portion of the wing-nervures is more extensive than in 6 , especially
in the hind wings. Length of body 7-9; setai, d im. 25-27, snbim. 12-14, $ im.
17-20 mm.

Sab. Rock Island, 111. [After Walsh.]

HEPTAGEiSriA MACULIPEXNIS, Walsh.

Heptagenia macuUpennis, Walsh, Px-oc. Ent. Soc. Pliilad. ii. 20G (1863) ; ! Etn., Traus. Ent. Soc. Lon-
don (1871) 139.

Subimago. — Wings tinged with dusky ; cross-veinlets slightly bordered with dusky.
Setoe tinged with dusky towards the tips.

Imago, <s . — Fore tarsus longer than the tibia, \^ ith the tirst joint about f as long
as the second ; in the hinder tarsi the first joint is as long as the second. The
peculiarity of the cross-veinlets of the fore wing, described below, is noteworthy.
Notum ferrugineous. Dorsum of abdomen pale yellowisli to the basal ^ of segment
7, and then piceous up to the extreme base of segment 10 ; the remainder pale
yellowish. Seta3 and forceps whitish. Femora yellowish, usually with a short fine
fuscous vitta beneath at the tip ; tibiae and tarsi whitish, the tip of the fore tibia and the
ungues fuscous. Wings hyaline: in the fore wing most of the longitudinal nervures
are fine and dusky, and most of the cross-veinlets black ; but the neuration of the axillar
region, like that of the whole of the hind wing, is colourless : in the fore wing the black
cross-veinlets are comparatively coarse, and some of them are bordered with coal-black,
several of those in the margiiial and submarginal areas being immersed in small rounded
blots of that colour. The cross-veinlets of the marginal area are unevenly spaced ; 3
stand close together in a group at the bulla apart from the others in that area ; and again,
in the pterostigniatic portion of the same, midway betAveen the bulla and the ajjes, is
another similar group of 4 or 5 cross-veinlets, bordei*ed with black like those of the
former group : in all, the area contains, from the great cross-vein up to the bulla, 4-6
heavily bordered cross-veinlets, and beyond tlie bulla about 13, of which last only the 4
or 5 above mentioned are bordered. In the next two areas, 2-3 cross-veinlets are like-
wise grouped together in rear of the bulla apart from the others of those areas.

? . — Paler than the male ; dorsal segments 8-10 opaque whitish, tinged more or less
with ferrugineous. The bordering of the cross-veinlets is rather lighter than in <s
Pore tarsus longer than the tibia ; joint 1 about f as long as joint 2. Length of body
4'5-6 ; setfP, 6 im. 12-15, subim, 7'5, $ im. 9-12, subim. 8 mm.

Rab. Eock Island, 111. (Walsh) ; United States (M^Lach. ]\Ius.). [Chiefly after Walsh.]

ECDTURUS GUTTATUS, Pictct.

X BciLtis yuttata, Pict., Hist. Nat. Nevropt. ii. Epliem. 187, pi. xxiv. 3 (1843-15) ; Walk., List of
Neuropt. in Erit. Mus. part iii. 559 (1853).

Ephemera [Baetls) guttata, Blancliard, Gay, Hist, lisic. v politic, de Chile, vi. 106, Atl. Nevropt. ii. 2
(1851).

Heptagenia guttata, Etn., Traus. Ent. Soc. London (1871) 156.

Imago [dried), $ . — Head and thorax fuscous, varied with small spots of yellow and

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

brown. Abdomen yellow [fuscous in tbe figure cited], witli the apical borders and
oblique lateral stripes of the segments black, and with two longitudinal dorsal and ventral
series of black dashes or streaks besides. Setse yelloAv, with black annulations that are
narrow and broad alternately. Legs ochreous ; a spot on tlie femur and the extremities
of both femur and tibia piceous. Wings vitreous, with black neuration, and -with a
brownish tint in the costal region, where the cross-veinlets are coarser than elsewhere,
and irregular. Length of body, $ 12; wdng about 14; setae 18 mm.
Hab. Valdivia, Chili (Blan chard).

EUROPEAN SPECIES OF UNCERTAIN GENUS.

Eaetis fusctjs, Schneider.

Cloefusca, Sclm., Stctt. ent. Zcit. vi. 340 (1845).

Ba'etls? fuscus, Etn., Trans. Eut. Soc. London (1871) 120.

Imago ? . — " Tergum thoracis fuscuni ; alas vitriua?, nervis fuscis, antiea area costali
apicem versus fulvescente, et nervis transversalibus pluribus. Pedes saturate testacei.
Abdomen supra rufescens, apicibus segmentorum brunneis ; subtus testaceum. Setie
saturate testacea3, fusco annulatse." Long corp. ? 2'75, set. G-25 lin.

Hab. Messina, April. [After Schneider.]

Heptagenia iridana, Kolenati.

Baetis iridana, Kolcn., Wien. ent. Moiiatsclir. iv. 383.
Heptagmia indana, Etn., Trans. Ent. Soc. London (1871) 148.

Imago. — " Coi-porc rufo-brunueo, segmeutis abdominis dorsalibus postice late brunneo
marginatis ; alis iridinis, tribus nervorum anteriorum flavis, reliquis brunneis, i)tero-
stigmate [/. e., apice are* marginalis] infumato vei fiavescenti. Venter luteo-brnnneus,
setis obscurior." (Kolen.) Long. corp. 3'5; al. 5 ; set. 12 lin.

Hab. Altvater, in August and September, at an altitude of 4000 feet. The type is iu
the Hoyal Polytechnic, Brunn.

BAiiTis viTREATUS, Zettcrstcdt.

Ephemera v'ttrea, Zutt., Ins. Lap. col. 1045 (1840).
Baetis rttreatus, Wallengren.

" Nigra, nitida, pedibus sordide lutcis, alis byalinis, nervis valde tenuibus albidis crebre
reticulatis, setis caudalibus pallidis, articulatione fusca. Mas : abdominis medio forc-
ipeque sordide alba. Pcm. : abdomine toto nigro." Long. corp. fere 4 ; al. exp. 8 lin.

Hah. Western Finmark by standing water near Bozzekop, August 7th. Setoe 2,
dirty white, with fuscous joinings. (Zettcrstcdt.)

IIePTAGENIA MONTANA, Pictct.

X Baetis montana, Pict., Hist. Nat. Nevropt. ii. Ephcm. 172, pi. xx. 3 (1843-45); Walk., List of
Neuropt. Ins. iu Brit. ]Mus. part iii. 557 (1853) ; Braucr, Nenropt. Anstr. .'JG (1857) ; Ausser., Ann. d.
Soc. Natur. Modena, Ann. iv 434 (18G9).

Heptagenia montana, Etn., Trans. Ent. Soc. Loudon (1871) 154; Meyer-Diir, Bull. Soc. Ent. Suisse,
V. 313 (1874).

EEV. A. E. EATOX OX EECEXT EPHE:\IEEID.E OR MAYFLIES. 303

Imago [Uviug), 6 ■ — Head Ijlack ; eyes blue. Prouotum reddish, with a median black
spot ; meso- and metanotum black, the sides of the thorax lighter. Abdomen greyish
brown [in the figure light yellowish olive, witli the joinings of the segments and oblique
stripes at the sides dark]. Setne fuscous. Fore legs black ; hinder legs fulvous. Wings
vitreous, with a slight brownish tint in the pterostigmatic region of the fore wing ;
neuration fine and black. Length of body 13, wing 13, sette 30 mm.

Hub. Alpine Savoy, e.g. at a small stream descending from the Brevent above
Chamounix. [xlfter Pictet.]

Heptagenia gemmata, Scopoli.

Ephemera yemmata, Scop., Eut. Carn. 26i, pi. xxxviii. 683 [wretched fig.] (1763) ; Miill., Zool. Dan.
Prodr. 143 (1776) ; YiU., C. Linii. Ent. iii. 22 (1789) ; 01., Eueycl. Meth. vi. 431 (1791); Etn., Traus.
Eut. Soc. London (1871) 156 note; Hag., op. cit. (1873) 406.

Imago {dried), $ . — Corpus rufum. Incisurse abdominis marginibus flavicantibus.
Long. 17 mm.

Sab. Circa aquoDductum Fodinarum Idrensium. [After Scopoli.] According to
Dr. Hagcu (1873) this species is related to Ecdgunis veiiosus.

Species, some of which have been published elsewhere during the
progress of this work, axd others now first published.

The following species ought to follow Ciuiqjsnrus dorsalis, p. 42 : —

Campsubus Wapp.ei, Weyenbergh.

X Ephemera Wappcei, T\'e3'enb., Tijdsch. v. Ent. xxvi. 1882-3, p. 159, pi. x. 1 (1883) [wings].

Adidt. — Head light yellowish brown ; eyes small, black. Pronotum somewhat darker
than the head ; mesonotum [during life) yellow, changing {when dried) to yellow-brown ;
metanotum often somewhat darker. Abdomen above greyish yellow, becoming gradually
darker and sometimes approaching black posteriorly; venter yellowish grey throughout ;
the two appendices very pale, the "palpen" darker. Legs yellow or greyish yellow.
Wings transparent, but rather dull ; fore wings along the costal border brownish grey
through the colouring of the subcosta and radius.

In the S the abdomen posteriorly is rather darker above than it is in the c? . Length
of body 13 or under, wing 18, setae 6 40-43 mm.

Rob. Cordova, Argentine Republic. [After Weyenbergh ; condensed translation.]

Campsurus Holmbergii, Weyenbergh.

X Ephemera Holmbergii, Weyenb., Tijdsch. v. Eut. xxvi. 1882-3, p. 160 (1883).

Adult. — Vertex of head very dark between the black eyes. Thorax and abdomen very
largely overspread above by dark grey markings approaching sepia-brown, the remaining

304 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES.

surface being of a dirty yellow colour. The dark markings comprise, on the thorax, — an
almost circular stripe on the neck ; two very large subquadrate spots and the commence-
ment of a longitudinal median line on the pronotum ; two longitudinal stripes on the
mesonotum united by a transverse band before the metanotum ; and two somewhat
confluent and more or less raised [knobbclaehtig] black spots upon the hind border of
the metanotum preceded by four similar black dots soaiewhat coalescing into a more or
less curved line: — the markings on the abdomen comprise, — two small oblong spots on
the dorsum of the first segment situated one on eacli side of the middle line and some-
wliat near the lateral border ; in the next segment the correspondiug marks are widened,
and in the fourth and fifth segments the spots begin to be blended into one; in the
following segments the corresponding spots become gradually larger, so that towards the
extremity of the body the ^vliole of tlie dorsum is occupied by the grey-black colour,
excej)tiug the lateral borders of the segments and the whole of the tei-minal segment,
which remain of a yellowislx colour. Venter uniformly pale yellow. On each side
of the mesothorax a fine oblique dark line extends backwards and downwards from the
transverse band of colouring mentioned above, and sometimes unites with a very similar
line running downwards in the opposite direction upon the side of the metathorax so as
to form a single arcuate line. Seta3 shorter than in C. lFcq)p(Ei. Length of body
12 mm.

Hub. Buenos Ayres ; scarce. [After Weyenbergh ; abstract of translation.]

Campsurus Nappii, Weyenbergh.

PaUngcnia Nappii, Weycnb., Tijdscli. v. Eiit. xxvi. 1882-3, p. in2, pi. x. 2 (1883) [wings].

Adult. — Eyes brown-black. Underside of body yellowish. Pronotum greyish yellow,
with a darker longitudinal double median stripe, and with an extremely Jiarrow, dark,
nearly brown edging to its hind margin; the remainder of the notum grey-brown, with
three darker longitudinal stripes; the sides of the thorax lighter. Abdomen anteriorly
greyish above, with a darker transverse band in the hinder part of every segment ;
posteriorly these bands become successively broader, until in the seventh to the ninth
segments almost the whole surface of the dorsum is occupied by the darker colour ; the
tenth segment, however, remains yelloAV. Seta3 transparent white. Legs [pooteu en
sprieten] greyish, in some degree tinged with brownish. Wings transparent; fore wing
darker along tlie costal margin, owing to the colouring of the subcostaand radius, and
sometimes slightly lactescent in the remainder of the disk, as is usual in subimagines.
Length of body 13, wing about 12, sctse 6 about 33 millim.

Uab. Santiago d. E., Argentine E-epublic; January. [After Weyenbergh; abstract
translation.] Judging from the figures of the wings, I am disposed to rank this species
in Campsurus, as well as the two preceding, pending further observations. The wings
illustrated by Prof. Weyenbergh in the cited publication appear to have been drawn in
situ, without being flattened out ; and this should be borne in mind when reference is
made to the plate.

EEV. A. E. EATON ON EECENT EPHEMERIDiE OR MAYFLIES. 305

These Species should follow Epliemerella ignita, p. 127.

Ephemebella notata, sp. noY. Plate LXY. 9 (genitalia).

Siihimago (living). — Wings Avhitish grey, paler in proximity to the roots in. some lights ;
neuration in a large measure coucolorous with the membrane or whitish, but in the fore
wing the great cross-vein, the greater portion of the subcosta and radius, and in certain
lights the remaining longitudinal nervures, are light greenish yellow approaching yellow-
lake. Setse dark vandyke- or reddish-grey with reddish joinings. Hinder legs light
olive-grey with greyer tarsi : fore leg of d rather darker.

Imago, S {Uvlng). — Upper division of eyes light yellowish red (the "yellowish"
approaching Mars-yellow, the " red " medium burnt-sienna) ; lower division brownish
olive with a movable dark spot. Pronotum bistre-brown ; meso- and metanotum raw-
umber-brown ; pleura much lighter in colour. Abdomen above translucent bistre-grey
in segments 1-7, with the joinings more or less opaque; segments 8 and 9 raw-umber-
brown; segment 10 much lighter than these: venter in segments 1-7 light greenish
or ashy grey, marked with black lines and dots as in $ (see below) ; segments 8-10 some-
what brown-ochreous, paler along the middle and in segment 9 at the tip ; forceps light
greenish grey. Set;x! light warm-sepia grey with reddish joinings. Pore legs dark bistre-
grey ; hinder legs rather greener or yellower, and lighter, with the tarsal joinings grey,
and brownish ungues. Wings vitreous, with an evanescent yellowish stain in the
pterostigmatic region ; longitudinal neuration dull greenish grey ; cross-veinlets more
distinct than in E. igiiifa, and those in the pterostigmatic region less regularly forked or
connected together than the corresponding veinlets of that species.

2 {living). — Eyes light olive-green, ^\ ith a movable round black spot ; vertex of head
light yellow ; orbits of eyes and of the ocelli black, but the interspace between these
last, and two unequal dots on each side of the frontal carina, light brown-ochreous. Pro-
notum lighter than the mesonotum, and traversed in rear of the outer ocelli by two
longitudinal black stripes that are slightly divergent and dilated posteriorly. Meso- and
metanotum light brownish-ochre, ai)proacliing Mars-yellow ; the mesopleura in advance
of the wing-roots light yellow. Abdomen in segments 1-7 yellower than in d , the
prevailing tint approaching dull yellow-ochre ; the remaining segments rather browner
ochre than these ; venter rather lighter than the dorsum : the abdominal markino-s
comprise a fine, slightly irregular, transverse brownish line, close to the dorsal joiniu"",
at the base of the segment in segments 2-8 or 9, and some l)lackish marks in segments
1-8, viz. : — in segment 1 a streak at the side ascending the dorsal joining, a small spot
above and an isolated longitudinal line below the pleural projection, and a dot nearly
in the middle on each side of the ganglionic tract ; in segments 2-7 a short isolated
longitudinal linear streak met by a shorter erect or ascending streak and followed in
certain instances by a small dot at the scar of the nymphal tracheal branchia, above
the pleuron on each side, and a longer isolated linear longitudinal streak immediately
below the pleuron ; also in the same segments a pair of slender clavate streaks, half as
long as the segment, divergent posteriorly, produced from the base of each segment ; and

SECOND SERIES. — ZOOLOGY, VOL. III. 1-1

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

lastly, a pair of clots placed one on each side of the ganglionic tract nearly in the middle
of each of these segments : in segment 8 the corresponding markings are ill defined.
The pleura of segments 8 and 9 are acute behind. Femora yellowish instead of greenish,
their colour approaching dull yellowish ochre. Eggs light yellowish. Length of body
8-9; wing 9-11 ; setfe, d im. 15 & 14, subim. 7, ? im. 12 & 12-5, subim. 7 mm.

Hab. N. of England and S. of Scotland. Locally common by shallow and swift parts
of the river Eden in Cumloerland during June, near the villages of Langwathby and
Salkeld. Its occurrence in Scotland is vouched for by a single subimago in Mr. King's
collection. The 6 imago, while in the net, can be distinguished from E. Ignita by the
yellowish tint of the pterostigmatic portion of the fore wing.

Ephemerella hispanica, sp. nov.

Subimago {dried), $ . — AVings light blackish grey, w'ith opaque neuration. Abdomen
discoloured, but opaque : the terminal margins of dorsal segments 3-8 or 9 black in the
middle for some distance transversely, and then pale towards the sides ; the dorsum is
flanked on each side by a single series of longitudinal black stripes placed at the bases
of the pale pleura ; these stripes are visible ventrally, and together with a median
longitudinal black line, cause the venter (the joinings of which are pale) to a2)pear tri-
lineate. Seta3 dark grey, with black joinings. Sutures of the mesonotum black; on
each side of this segment, a little above the spiracle and in front of the tegulte, is a small
rounded black spot. Femur olive-grey ; hinder tibiae, in some lights, In-owner than the
femora ; tarsi and fore tibiye in opaque view blackish.

Imago (dried), d . — Notum bright raw-umber-brown : the rounded black spots in front
of the tegulse are each subjacent to a black longitudinal line along the margin of the
mesonotum : the thoracic pleura are raw-umber varied with dull light ochre, and their
sutures in the neighbourhood of the hinder coxte are black or pitch-black. Femora in
opaque view light yellowish umber or corneous, becoming translucent in transmitted
light; fore tibia dark j)itch-brown, excepting just at the knee, which is concolorous
with the femvir; fore tarsus bistre-grey; hinder tibiaj almost concolorous with the
femora, each with a blackish-grey stain externally just below the knee; hinder tarsi
bistre-brown. Wings vitreous ; neuration in souie postures colourless, but in other
postures the edge of the fore costa in its basal half appears blackish, and some of the
stronger of the longitudinal nervures assume an olive-grey or browuisJi-amber tint, the
bulla of the subcosta and the great cross-vein of the fore wing remaining colourless.
Lengtli of wing, d im. and $ subim. 9 mm.

Mab. Spain; San Ildefonso, Segovia; captured in July by Messrs. Ed. Pictet and
Meyer-Dur in the year 1859 (2 examples). By the courtesy of Mr. H. Albarda and
Prof. E. Frey-Gessuer, I have lately examined all that remains of the Spanish Uphe-
meridce collected by the deceased Swiss entomologists above mentioned. A single ?
subimago of this species is in Mr. Albarda's collection, and part of a d imago in Ed.
Pictet's Mus. ; but the ravages of Anthreniis preclude full description of the insect from
these materials.

From the same locality, in the same collection as the above species, are specimens of

EEY. A. E. EATOX OX EECEXT EPlIEilERID.E OE MAYFLIES. 307

Ephemerella ignita, and a fragmentary subimago of perhaps an undescribed species of
this genus, all captured Iw the same entomologists in July 1859.

This should folloio Ameletus exquisitus, p. 213.

Ameletus inopixatu.s, sp. nov. Plate LXV. 13 (genitalia).

Imago {dried), ? . — Head and I)ody pitch-brown, inclining to bui'nt-umber or rufo-
pieeous in the hinder alxlominal segments ; venter nearly concolorous with the dorsum.
Legs in opac[ue view light pitch-brown; in transmitted light rich brown-amber or trans-
lucent raw-umber-brown. Wings viti-eous, brilliantly iridescent, tinted uniformly and
very faintly indeed with rusty brown or ferruginous ; neuration in opaque view ferru-
ginous or rufo-piceous, in transmitted light ferruginous-amber ; cross-veinlets in opaque
view delicate, except in the pterostigmatic region of the fore wing, and there many or
some of those in the marginal area divide and anastomose so as to form an irregular and
ratlier open reticulation. Counted at the subcosta the number of cross-veinlets in the
marginal area of the fore wing is 13 before the bulla, and 27-29 beyond it. Length of
wing 10 mm.

Hah. Europe : the Schwarzwald and Vosges. Described from a single ? specimen, of
which the sette were lost, captured by M'^Lachlan at the end of July 1885 at the Eeld-
bergsee (1000-5000 ft.), and a single 6 'im. taken by him in 1883 at the Lac de Retourna,
both in M^Lach. Mus. The d' setae are light brown with opaque joinings.

The Geo&raphical Distribution of the Genera oe Recent Ephemerid^.

A brief summary of the geographical range of the genera and the number of known species by which
they are represented may here be given advantageously.

PaUngenia : Subgenus (typical) . Eastern N. Temperate region, in large rivers, 2 sp. — Subgenus Ana-

genesla : Indo-Mulay region and Irkutzk, 6 sp. — Subgenus , Brazil, 1 sp.

Oligonevna : Europe, iniddle and south, with Egypt, 1 sp. ; Brazil, 1 sp.

Elassoneuria : Natal, 1 sp.

SpaniophleUa : tropical S. America, 2 sp.

Lachlania : Central America and Cuba, 2 sp.

Homoeoneuria : Central America, 1 sp.

EiithypJociu : Tropical America, 2 sp.

Campsurus : America, from Texas to Brazil, 8 sp.

JoUa : Europe, S. of France ; N. America, Niagara 2 ; (?) sp.

Polymitarcijs : Middle Europe to N. Africa, 2 sp. ; Indo-Malay region, 1 sp. ; N. America, 1 or

(?) 2 sp.
Hexagenia : America N. and S., G sp. ; E. Siberia, 1 sp. (undescribed) ; Hindostan, 1 sp. (undescribed).
Ephemera: Northern temperate regions, 10 sp.; Hindostan, Ceylon, 3 sp. ; China, 1 sp. ; Japan, 2

sp. ; New Zealand, 1 sp. (undescribed) .
Pentagen'm : Illinois and Texas, 2 sp.

Potamanthus : Europe, middle and south, 2 sp. ; N. America, Virginia, 1 sp. (undescribed).
Rhoenanilms : Dutch East Indies, 1 sp.
Aialophkbia : Australia, 6 sp, ; New Zealand, 3 sp. ; Chili, 1 sp. ; Ceylon, 4 sj). ; Cape of Good Hope,

1 sp. ; Japan (undescriOed).

41*

308 IlEV. A. E. EATON OX EECENT EPHEMEEID^ OK MAYFLIES.

Leptophlebia : Europe, 5 sp. (one o£ them ranging into Turkestan) ; temperate N. America, 6 sp. and
others undescribed ; Chili, 1 sp. (undescribed).

Bhtsturus : temperate N. America, 1 sp. ; Scandinavia, perhaps 1 sp.

Choroterpes : continental Europe, 1 sp. ; Arizona, 1 sp. (undescribed).

Thraulus : southern Europe, 1 sp. ; Indo-Malayan region, 2 sp. ; tropical America, 4 sp. and others
undescribed. Probably uell represented in hot climates.

Adenophlehia : Cape Colony, 1 sp.

Hagenu/us : Cuba, 1 or 3 sp.

HabrujMebia : temperate and southern Europe, 6 sp. ; New Hampshire (undescribed).

CaUiarcys : southern Europe, 1 sp.

Ephenierdla : Europe, 3 sp. ; N. America, 6 sp. ; Japan, 1 sp.; China, 1 sp. (undescribed). Several
nameless genera related to this are found in N. America.

Tehganodes : Ceylon, 2 sp.

Tricorythus : Egypt, 1 sp. ; Malay Archipelago (undescribed) ; Cape Colony, 1 sp. ; perhaps south of
France, 1 sp.

Leptohtiphes : Argentine Republic, 1 sp.

Canis : Europe, 8 or 9 sp. ; Egypt, 1 sp. (undescribed) ; Morocco, 1 sp. (undescribed) ; LakeNyassa,
2 sp. ; Cape Colony, 1 sp. (undescribed) ; Ceylon, 1 sp. ; N. America, 2 sp. and several others
undescribed.

Prosopintoiua: middle and southern Europe, 1 sp. ; Madagascar, 1 sp. (Fly undescribed.)

Baetis : Europe, 14 sp., one of them ranging to Madeira and the Canaries, another to Canada, also one
undescribed ; Greenland, 1 sp. (?) ; Egypt, 1 sp. (undescribed) ; N. America, 6 sp. and up-
wards ; central and S. America, 2 sp. or perhaps 3 ; Indo-Malay I'egion, 3 or more sp. ; Aus-
tralia (undescribed). A kindred genus is known by the nymph from Peru.

Centroptilum : Europe, 8 sp., one of them ranging into Canada ; N. America, Arizona, 1 sp. (unde-
scribed) ; Cuba, 1 sp.

Cloeon : Europe, 5 sp., one of them ranging eastward to Armenia and Japan, and southwestwards to
Madeira and TenerifFe ; Indo-Malay region, 4 sp. (one undescribed) ; China, 1 sp., perhaps
a European ; Australia, 1 sp. (undescribed) ; Cape Colony, 1 sp. (undescribed) ; N. Ame-
rica, 3 sp. ; Argentine Republic, perhaps 1 sp. ; Chili, 1 sp. (undescribed).

Calliba'tis : throughout America ; N. America, 3 or 4 sp. and I undescribed (one of the former
ranging southwards to Central America) ; Cuba and Central America, 3 or 4 sp. (one un-
described); S. America, 2 sp. ; Australia, 1 sp. (undescribed).

Colobiiriscus : Australia, I sp.; New Zealand, 1 sp. ; N. America, 1 sp. (undescribed).

Chirotuiietes : Europe, 1 sp. ; N. America, 4 sp.

Metamonius : Chili, 1 sp.

Ameletus : Europe, 1 sp. ; N. America, 3 sp.

Dipteromimus : Japan, 1 sp.

Siphlurus : Europe, upwards of 4 sp. ; N. America, G sp. (the genus is probably represented by many
other species) ; E. Amurland, 1 sp. ; Japan, 1 sp. (undescribed) ; New Zealand, perhajw I sp.

Oniscigaster : New Zealand, 1 sp.

Bcetisca : N. America, 1 sp.

Gen. . A remarkable nymph from Chili [PI. LIIL] is worthy of mention here.

Ametropus : Europe, 1 sp., perhaps ranging to the Caucasus and Armenia.

Atopopus : Borneo, 1 sp.

Thahrosphyrus : Java and the Pliilipjnncs, 2 sp.

Epeorun : Em-ope, 4 sp. ; Armenia, 1 sp, (undescribed) ; Himalaya, 1 sp. (provisionally included) ;
N. America (undescribed).

EEV. A. E. EATOX ON EECENT EPHEMEEIDiE OE MAYELIES, 309

Bleptus : Japan, 1 sp.

Iron: Western N. America, 2 sp. ; Central America (uudcscribed).

Cinygma : Western N. America, 4 sp.

Rhithroyena : Europe, 7 sp. and npvvards; N. America, 5 sp.

Pagnludes: China, 1 sp. ; Tibet, 1 sp. (undescribcd).

Hepiageiiia : Europe, 4 sp., two of tlicm ranging to E. Amurland, and one undescribed from Segovia ;
N. America, 2 sp., and jjrobably many undescribed.

Compsoneuria : Malay region, 1 sp.

A kindred genus in N. America (undescribed) may here be enumerated.

Ecdyurus : N. America, 4 sp. ; Europe, 12 sp. ; the Caucasus, Mesopotamia, Himalaya, and Siberia
(undescribed).

The Ecdyurus type of genera is represented in Cape Colony. An undescribed ? specimen
of a species taken by Mr. R. Trimeu at Faarl, and now in M'Lach. Mus., has a superficial
likeness to species of Heptagenia, but differs therefrom in the proportions of its legs. Some
small undescribed species, not referable to Compsoneuria ^ and of undetermined genus, natives
of the Malay region, are represented in a Leyden Collection.

In tliis volume 55 genera and 270 species of recent Ephemerldce are characterized, in
addition to 11 nameless nymphs, and 19 species named by other authors, which cannot
now be classified exactly. Amongst them, 5 genera and 08 species were new to science,
and 13 of the older species had to be renamed.

A Conspectus of the Classification adopted in this volume prefaces at pp. 21-22 the
systematic description of the Ephemeridce. I now bring it to a close with an analysis of
the Grovips, &c., therein set forth. The tabulated characters apply solely to adult
insects, and are selected from fuller particulars given at the pages that are indicated, to
which reference should be made.

Analysis of the Group.s, Series, Sections, akd Genera.

Family EPHEMERID^ (p. 2).

1 . . . . Group I. (p. 22). At the roots of the mesothoracic wing the Anal (8)
nervure meets the Pobrachial (7) nervure; and, when axillar nervures are
developed, the 1st Axillar ('J') meets the Anal nervure. Ilinder tarsi usually
4-jointed ; when a fiftli joint is traceable, it is only very short, and is intimately
blended with the tibia 2

, Group II. (p. 77). At the roots of the mesothoracic wing [except in

Series 1 and 3] the Anal (3) nervure communicates only indirectly with the
Pobrachial (7) nervure, through an obsolete channel of circulation, discernible
in the wing-membrane. Legs all functional [except, perhaps, iu Frosopistoma].
Hinder tarsi usually 1-joiuted; a very short filth joint is sometimes intimately
blended with the tibia > . 3

310 EEV. A. E. EATON OX EECENT EPHEMEEID^ OE MAYFLIES.

Group III. (p- 199). At the roots of the mesothoracic wing the Anal

(8) nei'A'urc is sejiarate from the Pobrachial (7) nervure, but a channel of circu-
lation is traceable between them in the wing-membrane ; the 1st Axillar, de-
tached from its own group of nervurcs, either meets or approaches the Anal (8)
nervure. Hinder tarsi distinctly 5-jointed 4

2 . . . . Series 1 or Group I. (p. 22). Legs of ? short and feeble, when not
atrophied and functionless. Hind leg of ? longer than the fore leg. Eyes of

c? evenly contoured 5

Series 2 of Group I. (p. 47). Legs of ? all functional. Fore leg of

? at least as long as the hind leg, and usually rather longer. Eyes of d evenly
contoured 6

3 . . . . Series 1 or Group II. (p. 77). At the roots of the fore wing the Anal
(8) nervure approaches or meets the Pobrachial (7) and is met by the 1st Axil-
lar (9') which distally describes a bold curve. Eorceps-basis of J and lobe of
the 9th ventral segment of ? developed. Eyes of d evenly contoiu'ed ... 7

Series 2 op Group II. (p. 81). At the roots of the fore wing the Anal

(8) nervure is quite separate from the Pobrachial (7) : the 1st Axillar (9^) usually
describes a simple curve which is strongly arched distally ; but sometimes close
to the wing-roots, from certain points of view, it appears to be continued for-
wards along the crease in the wing-membrane so as to curve abruptly towards
the Anal (8) nervure, and then it may be termed ogee*-curved. Eorceps-basis
of 6 and lobe of the 9th ventral segment of ? developed. Eyes of d ascalaphoid 8

Series 3 of Group II. (p. 136). At the roots of the mesothoracic wing

the Anal (8) and Pobrachial (7) nervures lie close alongside of each other, or in
mutual contact, apart from the Axillar (9) nervures. Pra^brachial (G) nervure
forked. Eyes of <S evenly contoured aiul far asunder 9

Series 4 of Group II. (p. 153). At the roots of the mesothoracic wing

the Anal (8) nervure is quite separate both from the Pobrachial (7) and the
1st Axillar (9') nervure. The 1st Axillar nervure is gently curved, and the
Prsebrachial (6) nervure is essentially simple. Eorceps-basis of d and lobe of
the 9th ventral segment of $ undeveloped. Eyes of d divided into two unequal
segments ; the uj)per segment is large and turbinate, the lower small and oval . 10

4 . . . . Series 1 of Group III. (p. 199). The Anal-Axillar interspace [in
Bcetlsca the 2ud Axillar space] of the fore wing includes the anal angle and
the outer half of the inner margin. The Anal (8) nervure [in JBtstisca the 2nd
Axillar (9')] is less curved than the 1st Axillar (9*) [in Bcetisca the 3rd Axillar
(9'^)], and its numerous branchlets meet the outer Ijalf of the inner margin . . 11

Series 2 of Group III. (p. 229). Adult unknown 12

* Ogee or ogive, an architectural term, signifies the sinuate curve shown in vertical section of the side of a vase
or cup that is rounded at the base and everted at the rim.

EEV. A. E. EATON ON EECENT EPEMERID.E OR MAYFLIES, 311

.... Seiues 3 OF Group III. (p. 230). The Anal-Axill.ir interspace of the
fore Aving- includes the anal augie and part of the terminal margin, and it
contains a variable number of longitudinal intercalar nervures [usually four]
which are commonly disposed in two couples of unequal length : of these the
coujjle next to the 1st Axillar (9') nervure is the longest 13

5 . • . ■ Section 1 (p. 22). Subcosta of the fore wing, when developed, retired
somewhat in a fold of the membrane under the Radius (3). Palingenia Type 14

Section 2 (p. 26). Subcosta of the fore wing displayed (except in the

dried $ Campsurus) Polymitarcys Type. 19

6 • . . . Section 3 (p. 18). In the fore wing the Anal (8) and essentially simple
2nd Axillar (9") nervures bound a semi-sagittate space. [Compare Section 1,
infra.'\ Forceps-basis of s developed ; basal joints of the limbs shorter than
the next joints : lol)e of the 9th ventral segment of ? undeveloped.

Ephemera Type. 21

7 . . . . Section 4 (p. 78). In the fore wiug the Anal (8) and forked 2nd AxUlar
(9") nervures bound a semi-sagittate space. Basal joint of 6 forceps-limb the
longest of all. [Compare section 3 su2:)ra.~\ Potamanthtjs Type. 22

8 . . . . Section 5 (p. 82). In the fore wiug the Anal (8) and simple 2nd Axillar
(9') nervures bound a trilateral somewhat Icg-of-muttou-shaped space. The 1st
Axillar (9') at its proximal extremity, where it meets the transverse crease in
the wing-membrane, is nearer to the 2nd Axillar than to the Anal nervure. [In
Eageniiliis the 1st Axillar meets the 2nd Axillar nervure.]

Leftophlebia Type. 23

Section 6 (p. 122). In the fore wing the Anal (8) and simple 2nd Axillar

(9") nervures bound a curved trilateral space, truncate at its narrow end. The
Anal (8) and 1st xlxillar (9^) nervures converge, and at the base of the wing lie
close together, or in mutual contact, apart from the 2nd Axillar and from the
Pobrachial (7) nervure Ephemerella Type. 31

9 . . . . Section 7 (p. 137). In the mesothoracic wing the Anal (8) and 2nd
Axillar (9^) nervures bound a curved trilateral space, truncate, or abrupt at

its narrow end. Hind wings absent C^xis Type. 32

Section 8 (p. 149). AVing-neuration imperfectly elucidated. Hind

wings developed Prosofistoma Type. 34

0 . . . . Section 9 (p. 153). In the mesothoracic wing the Anal (8) and 2nd
Axillar nervixres bound a trilateral, somewhat leg-of-mutton-shaped space,
abrupt at its narrow end. Hind tarsus ^ to | the length of the tibia, 4-jointed,
with the proximal joint long Baetis TyjK^ 35

1 . . . . Section 10 (p. 200). In the fore wing the Anal (8) ncrvvire terminates
close by the anal angle ; the 1st Axillar (9') nervure terminates in or before the
middle of the inner margin. Pronotum well developed . . Siphlurus Type. 37

Section 11 (p. 226). In the fore wing the Anal (8) and the 1st x\.xillar

312 EEV. A. E. EATON ON EECENT EPHEMERID.^ OR MATFLIES.

(9^) nervures run almost parallel with one another to the terminal margin ; and
between these nervures and the anal angle, the 2nd Axillar (9") intervenes.
Pronotum of minimum proportions B^tisca Type. 42

12 .... Section 12 (p. 229). Adult unknown

13 .... Section 13 (p. 230). Hinder tarsi as long as the tibiae, or longer. In
the fore wing the 1st Axillar (9^) is almost parallel with, and is near the 2nd
Axillar (9') nervure, and it approaches the anal angle . . . Atopopus Type. 43

Section 14 (p. 233). Hinder tarsi shorter than the tibiai. In the fore

wing the 1st Axillar (9^) nervure seldom approaches the anal angle so nearly

as in Section 13 Ecdyurus Type. 45

Palingenia Type.

14 .... Axillar nervures well developed in the fore wing ;
wing-neuration plentiful ; wing-membrane translucent

but dull 15

Axillar nervures obsolescent or wanting in the

fore wing ; wing-neuration scanty 16

15 .... Prai'bracbial (C) nervure of the fore wing forked

beyond the middle ; two conspicuous couples of longi- [(p. 23).

tudinal nervures proceed to the terminal margin . . . Subgen. Palingenia

Prfebrachial nervure of the fore wing forked

before the middle; three conspicuous couples of longi- [(p. 25).

tudinal nervures proceed to tlie terminal margin . . . Subgen. Anagenesia

16 .... Wing-membrane dull or satin-like 17

Wing-membrane " shot " with blue or purple 18

17 .... Fore wing aiiparently 5-nerved, with the 5th

nervure forked Oligoneuria (p. 29).

Pore wing apparently 3-nerved, with the 2nd and

3rd nervures forked Elassoneuria (p, 32).

18 .... Pore wing apparently 5-nervcd, with the 4th and

5th nervures forked SpaiiioplileUa (p. 33).

Fore wing apparently 4-nerved, with 1st, 3rd,

and 4th nervures forked Lachlania (p. 34).

Pore wing apparently 4-nerved, with every ner-
vure simple Eomoeoneuria (p. 35).

Polymitarcys Type.

19 .... The Anal- Axillar interspace of the fore wing
contains numerous sinuate or ogee-curved branchlets
of the Anal (8) nervure which run transversely to the

inner margin. Setae 3 Euthyplocia (p. 36).

.. .... The aforesaid interspace contains two longitu-
dinal intercalar nervures or branches of the Anal (8)
nervure, and very few cross-veinlets. Setai 2 . . . , Campsuriis (p. 38).

EEV. A. E. EATON ON EECEXT EPHE.MEKID.E OR MAYFLIES. 313

A nameless insect differs from Campsiirus in

having an abundance of cross-veinlets Plate VI. 8 bis.

„ .... The aforesaid interspace contains 4 or 5 longitu-
dinal intercalar nervures, and an abundance of cross-
veinlets 20

20 Sette d 2 JoUa [?] (p. 42).

„ .... Set?e d 2, S 3 Fohjmitarcys (p. iS).

Ephemera Type.

21 .... Median caudal seta very short and rudimentary
in both sexes. Pronotum of ? longer than broad ; fore

tarsus of 2 subequal in length to the tibia Ilexagenia (p. 48).

Median seta subequal to the others in both sexes.

Pronotum of $ somewhat transverse ; fore tarsus of ?

about f as long as the tibia Ephemera (p. 58).

Median seta very short and rudimentary in the

d , but long and little shorter than the others in the 2 .

Pronotum of $ transverse ; fore tarsus of ? scarcely f

as long as the tibia Fentagenia (p. 75).

Potamautlius Type.

22 .... Median caudal seta long in both sexes .... Potamanthus (p. 78).
„ .... Median seta aborted in both sexes Bhoenanthns (p. 81).

Leptoplilebia Type.

23 .... Tarsal claws all narrow and uncinate 24

Of every tarsus one claw is broad and obtuse, the

other claw narrow and uncinate 25

24 .... Hind wing more or less obtusely subovate . . . Atalophlebia (p. 83).
, Hind wing oblong, oblique ; its marginal area

abbreviated and relatively very broad Adeiwphlehia (p. 111).

25 .... Hind wing obtusely ovate or oval; its marginal

ai"ea narrow throughout and far extended 26

Hind wing strongly angulated in front ; its mar-
ginal area broad and usually abbreviated 27

26 .... Median caudal seta equal to the others .... LeptopJilehia (p. 91).
Median seta much shorter than the others . . . Blastiirm (p. 100).

27 .... At the roots of the fore wing the 1st Axillar (U^)

meets the 2nd Axillar nervure Hagenulus (p. 113).

At the roots of the fore wing the 1st Axillar is

separate from the 2nd Axillar nervure 28

28 .... In the Anal- Axillar intersjmce of the fore wing

SECOND SERIES. — ZOOLOGY, VOL. III. 42

314 REV. A. E. EATON ON EECE^^T EPHE5IER1D.1; OR MAYFLIES.

if there are more tban two intercalar nervures, that
which is next to the Anal (8) nervure is long. Lobe of

the 9th ventral segment of $ obtuse 29

If there are more than two intercalar nervures

in the said interspace, that which is next to the Anal
(8) nervure is short or rudimentary. Lobe of the 9th
ventral segment of $ bifid and acutely excised 30

29 .... Basal joint of the cJ forceps-limb very short ; 2ud

joint by far the longest Churoterpes (p. lOi).

Basal joiiit of the 6 forceps-limb by far the

longest Thraulus (p. 106).

30 • • . . Basal joint of the s forceps-limb nearly as long

as the remainder of the limb Rabrophlehia (p. 114).

Basal joint of the 6 forceps-limb longer by far

than the remainder Calliarcys (p. 121).

Ephemerella Type.

31 .... Median caudal seta long. Hind wing well pro-
portioned, and with copious neviration : subcosta arched
and long. Basal joint of the <3 forccjis-limb shorter by

far than the 2nd joint Ephemerella {\y. 124).

Median seta aborted. Hind wing minute and

with scanty neuration : subcosta straight and abbrevi-
ated. Basal joint of the 6 forceps-limb rather longer
than the 2nd joint Teloganodcs {^.IM).

Csenis Type.

32 .... Cross-veiulets of the wing pluriserial 33

.. .... Cross-veinlets uniserial. Median caudal seta

long Ccenis (p. 141).

33 .... Median seta long Tricorythus (p. 138).

Median seta aborted Leptolujphes (p. 140).

Prosopistoma Type.

34 .... Median caudal seta developed Frosoinstoma {]).14Q).

Baetis Type.

35 .... Hind wings small or minute 36

Hind wings absent Cloeon (p. 179).

36 .... Hind wing oblique, elongate, narrow, and bi-

nerved, with usually a slender costal projection . . . Centroptllmn (p. 174).

EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 315

Hiud wiug oblique, usually rather broad aud

obtusely ovate, bi- or tri-uerved, with usually a small

aud acute costal projection Baetis (p. 156).

Hiud wing oblique, usually rather broad and

oblong, tri-nerved, with several cross-veinlets in at least
the marginal area, aud with a large aud very obtuse
costal protuberance CaUibcBtis (p, 191).

Siplilurus Type.

37 Hind tarsus shorter than the tibia 38

., Hind tarsus longer than the tibia 11

38 .... Proximal joint of the hiud tarsus distinctly

shorter than the next joint 39

Proximal joint of the hiud tarsus hardly per-
ceptibly shorter than the next joint. Of every tarsus
one claw is bluot and the other hooked Ameletus (p. 210).

Proximal joint of the hiud tarsus longer than the

next joint. Tarsal claws all narrow and hooked. Hind

wiugs minute Dijiteromimus (p. 213).

39 .... Of every tarsus one claw is blunt and the other

hooked Coloburus (p. 201).

Claws of the hinder tarsi, aud usually of the fore

tarsus also, all narrow and hooked •10

40 .... Axillar region of the hiud wing ample, containing
numerous lono- branchlets of the 2nd Axillar nervure.

Claws of the d fore tarsus peculiar in form .... Ch'wotojietes (p. 203).
Axillar region of the hind wing small aud nar-
row ; 2nd Axillar nervure of the same almost branch-
less Metamonius (p. 208).

41 .... Proximal joint of the hind tarsus longer than the

next joint. Tarsal claws all narrow aud hooked . . . SipJilurus {]}. 21-\>).

Proximal joint of the hind tarsus likewise longer

than the next joint. Of every tarsus one claw is blunt

and the other hooked Ouiscigaster (p. 223).

Bgetisca Type.

42 .... Hind tarsus longer tliau the tibia ; its proximal
joint longer than the next joint. Of every tarsus one

claw is blunt and the other hooked Bcstisca (p. 226).

■ Atopopus Type.

43 .... Axillar region of the hind wiug ample and with

42*

316 EEV. A. E. EATOX OX EECEXT EPHEMEMD.E OK MAYFLIES.

copious neuration. Hind tarsus probably rather longer

than the tibia. Median caudal seta long Ametropus (p. 231).

Axillar region of tlie hind Aving small, narrow,

and with sparse neuration. Median caudal seta aborted 44

44 . • • . Hind tarsus of J twice the length of the tibia . A tojwjnis {p. 232).
Hind tarsus of 6 equal in length to the tibia . Thalerosphyrus (p. 232).

Ecdyurus Type.

45 - ■ . • First joint of the hind tarsus longer than the

second; the second joint longer than the third 46

First joint of the hind tarsus equal to the second

joint 48

First joint of the hind tarsus shorter than the

second joint 50

46 .... First joint of the fore tarsus rather longer than

the second joint. Hind wings unusually small . . . Bleptus (p. 243).
First joint of the fore tarsus equal to the second

joint. Hind wings well developed Epeorus (p. 237).

First joint of the fore tarsus shorter than the

second joint. Hind wings well developed 47

47 .... Penis-Iolies (when dried) narrow and shrunk to
peg-like projections. Femora sometimes without mark-
ings, sometimes faintly banded Cinygma (p. 247).

Penis-lobes (when dried) stout, dilated at their

extremities. Cross-veinlets scarce in the fore wings.

Femora banded - Conipsoneuria (p. 275).

Penis-lobes stout, usually transversely and

broadly dilated at their extremities, but sometimes ob-

ovate. Cross-veinlets abundant in the fore wings.

Femora often banded, but sometimes without markings Ecdyurus [part] (p. 276).

48 • ■ . Second joint of the hind tarsus equal to the third
joint. Femora usually marked with a dark median spot,
but banded in one species and without markings in

another Iroii (p. 244).

Second joint of the hind tarsus longer than the

third joint 49

49 .... Penis-lobes (when dried) narrow and shrunk to
peg-like projections. Femora usually marked with a
dark median spot or streak, but sometimes without

markings Bhithrocjena (p. 250).

Penis-lobes stout and broadly dilated at their

extremities, or obovate. Femora often banded, but

sometimes without markings Ecdijurus [part] (p. 276).

EEV. A. E. EATOX ON EECEXT EPHEMEEID.E OE MAYFLIES. 317

50 .... Second joint of tlie hind tarsus equal to the third

joint 51

„ .... Second joint of the hind tarsus longer than the

third joint 52

51 .... Penis-lobes somewhat explanate and oblong, sub-
truncate at their divergent extremities. Femora usually

without markings, but sometimes faintly banded . . . Heptagenia [part] (p. 265).

,. .... Penis-lobes broad and short. Femora banded . Heptagenia [^iW^^^.^Ql).

Penis-lobes narrow and subcylindrical at their

bases, with suddenly enlarged patulous tij)s. Femora

without markings Fagnoides (p. 261).

52 . • - • Femora usually without markings, &c. [See 51

above.] iZ<'^;^*^e»/« [part] (2x265).

Femora usually marked with a dark median spot

or streak, &c. [See -19 above.] it///7/«'o<7e?2a[part](p.250).

Analytical Index to the Descriptions and Illustrations of Nymphs of
Ephemerkl(B contained in this Volume.

1. Palpi of maxilla II biarticulate 2

„ „ triarticulate 7

„ ,, phiriarticnlate, flagellate, cacli consisting of a long, stout basal joint and a
slender, multiarticulatc flagellnm. Seven pairs of abdominal tracheal brancliire : the foremost
different in shape from the others. A. iv-imeless S. American nymph p. 22'J, PI. LIII.

2. Basal joint of the palpus of maxilla ii shorter than the other joint. Palpus of maxilla i

also biarticulate 3

.. Basal joint of the palpus of maxilla ii subequal in length to the other joint. Palpus of maxilla

I triarticulate. Median lobe of tongue excised. Seven pairs of abdominal tracheal branehite ;

the foremost branchiae rudimentary, minute and fringeless ; the other branchiae ciliate or

fimbriate. Habits fossorial 6

.. Basal joint of the palpus of maxilla ii longer than the other joint, which is peculiarly pouched.

Palpus of maxilla i likewise biarticulate. Seven pairs of abdominal tracheal branchi;e. Lobes

of the labium more or less distant from one another. Type of Ecdi/urus.

See Tabulation at p. 23,-3, Pis. LIV.-LXII.

3. LaminfE of at least the hinder pairs of the abdominal tracheal branchite jugate, narrow, con-
duplicate lengthwise and fringed. Habits fossorial 4

.. Laminte of the abdominal tracheal branchife all single, broad, somewhat plane, fringeless, and
each provided at its base with a fascicle of fibrils. Habits prcdaceous 5

4. Six pairs of abdominal tracheal branchi:e all of uniform make. Median lobe of tongue acute.
Mandibles strong and short Palingenia, pp. 23 & 25, PI. XXV.

.. Seven pairs of abdominal tracheal branchire ; the foremost, unlike the others, is rudimentary,
minvite, single and spathulate. Median lobe of tongue obtuse. Crown of mandible prolonged
into a slender tusk in advance of the head Po///;/»7«rcys, p. 44, PL XXVIII.

Ji

318 EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES.

5. Seven uniform pairs of abdominal tracheal branchite, the foremost ventral : laminse small,
coriaceous, snbrotund. Median lobe of tongue acute. Maxilke ii coherent, enclosing and
intimately adherent to the labium. At maturity the space between the wings and the peak of
the mesonotum is spanned over by membrane sheathing the base of the dorsum.

Oligoneuria, p. 29, PI. XXVI.
.. Seven uniform latero-dorsal pairs of abdominal tracheal branchite ; the laminaj well developed,
foliaceous, and somewhat obovate. Labium and terminal margins of the fore wings free.
Median lobe of tongue obtuse. Caudal setae natatorial Jolia, p. 43, PI. XXYII.

6. Frons armed anteriorly with a single obtuse median protuberance. Tusks of mandibles con-
nivent when closed together i/e*Y/5^e?iJa, p. 48, Pis. XXIX. & LXIII. (part).

.. Frons armed anteriorly with two acutely conical projections. Tusks of mandibles overlapping
at the points when closed together Ephemera, p. 58, PL XXX.

7. Palpus of maxilla i quadriarticulate *. Maxillse ii concrete with the labium, which is undivided.
General form testudinate, broadly ovate, flattened beneath and highly convex dorsally. Caudal
setffl plumose, very short, retractile with the last segment. Tracheal brauchite concealed by a
large notal shield in which the anterior wings are immersed at maturity.

Prosopistoma, p. 149, PI. XLIII.

.. Palpus of maxilla i triarticulate 8

,, „ apparently f biarticulate [but if triarticulate, — Mandibles short. Lacinia

of maxilla i curved externally from the point to the insertion of the palpus, which is longer tlian
it. Seven pairs of abdominal tracheal branchiae. Lobes of the labium narrow &c., — cf. §18
below]. Tracheal branchiae all foliaceous and double, with unequal divisions.

Calllba'tis, p. 191, PL XLVIII.

8. Mandibles short 9

„ 2'1'olongcd beyond the head into slender incurved tusks. Six uniform pairs of abdo-

minal tracheal branchiae : the laminae jugate, narrowly lanceolate, conduplicatc lengthwise and
fringed. Median lobe of tongue excised. Frons unarmed anteriorly.

Euthyplocia, p. 37, PL XXIX. (part) .

9. Lacinia of maxilla i truncate for some distance outwards from the point ; consequently, between
the point and the insertion of the palpus, the exterior contour of the lacinia is angular : a
conspicuous dense patch of suberect hair occupies some part or the whole of the truncated edge :
palpus longer than the lacinia 10

.. Lacinia of maxilla i curved or irregularly rounded off from the point to the insertion of the
palpus 14

10. Six pairs of abdominal tracheal branchiae, all of uniform make ; each branchia consisting of
two jugate, elongate-oval, plumose or piunately parted laminae, with crowded subulate segments

Potamanthus, p. 78, PL XXXI.
.. Seven pairs of abdominal tracheal branchije 11

11. Tracheal branchiae uniform 12

.. Foremost tracheal branchiae quite different in form from the other pairs 13

12. Tracheal branchiie bipartite, with subulate or linear-lanceolate divisions.

Leptophh'hia, p. 92, PL XXX IL

* The biisis or place of insertion of the palpus might iu many iustauces be easily mistaken for a joint i^c.rj. in
SqMurus, PL L).

t The number of joints could not be positively ascertained from the specimens examined. Even the figure
published is suggestive of there being possibly a very short third joint at the tip of the palpus ; but no joining was
traceable thereabouts in the actual oljuct. — A. E. E.

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 319

'Hw.' Tracheal brancliire bifid, with filifornily dissected divisions . . Hahrophlebia, j). 115, PI. XXXVI.

13. Foremost tracheal brancliise bifid, with linear-lanceolate divisions : the others consist of
jugate, obliquely subovate, tail-pointed, fringeless, foliaceous lamiute. Blasturus, p. 100, PI. XXXIII.

., Foremost tracheal branchiae single, linear-lanceolate ; the others composed each of two jugate,
unequal, cuspidate, foliaceous lamiuic, oblique at the base, of which laminffi the smaller is
obliquely ovate, and the larger obliquely subcordatc-ovate, with unequal auricles : the cusps are
discontinuous with the blades of the laminte Choroterpes, p. 105, PI. XXXIV.

.. Foremost tracheal branchiae bipartite, with filiform divisions : the others composed each of
two jugate, oblong-ovate, fimbriate, foliaceous lamina; Thrauhis, p. 107, PI. XXXV.

14. Four or five pairs of abdominal tracheal branchiai. Palpus of maxilla i shorter than the lacinia 15
.. Six pairs of abdominal tracheal branchiae. Palpus of maxilla i longer than the lacinia . . 16
.. Seven pairs of abdominal tracheal branchia;. Palpus of maxilla i equal in length to, or

longer than, the lacinia 18

15. Pronotum well developed. Palpi of maxillae ii simply pointed. Hinder tracheal branchiae
each composed of a lamina, concave on the underside, sheltering a partly adherent forked
appendage beset with membranous lamellae. At maturity triangular membranes extend from
the terminal margins of the fore wings to the peak of the mesouotum. Type of Ephemerella.

See Tabulation, p. 123, Pis. XXXVII.-XL. & LXIV. (part).
.. Pronotum reduced to a minimum. Palpi of maxilhc ii forcipate. Tracheal branchiae at
maturity concealed by a large mesonotal shield, in which the fore wings are immersed.

Bcetisca, p. 226, PI. LII.

16. Foremost tracheal branchiae rudimentary, subulate ; the second pair elytroidal, sheltering the
hinder pairs, the laminae of which are fimbriate 17

.. Abdominal tracheal laminaj imbricate, all lamellar and pergamentosc : the foremost is
triangular-obovate in form ; each of the other laminae is somewhat oval, with a large rounded
foliated, eroded and laciniate lobe produced from its interior margin. Abdominal pleura
oniscoidally dilated Onisciff aster, p. 224, PI. LI.

17. Laminae of the hinder pairs of tracheal branchiaj each furnished on the underside with a

, „ filamentosely dissected appendage Trlconjthus (?), p. 138, PI. XLI.

I „ Hinder tracheal brauchife unprovided with any appendage Canis, p. 141, PI. XLII.

18. Lobes of the labium broad and obtuse. Pleura of the intermediate abdominal segments

I more or less narrowly dilated oniscoidally 19

I .. Lobes of the labium narrow and acute or falcate. Pleura of the intermediate abdominal

segments hardly at all produced. — Type of Baetis . . See Tabulation, p. 155, Pis. XLV.-XLVIII.

19. Abdominal tracheal branchiae all single and obovate. Palpus of maxilla i subequal in length
to the subquadrate lacinia, the crown of which is singularly beset with suberect pectinate spinules.

Chirotonetes (?), p. 204, PI. XLIX.
.. Abdominal tracheal branchite of the first two pairs, each formed of two foliaceous laminae
connate at the base : the laminae of the other pairs are single. Palpus of maxilla i longer
than the lacinia, which is longer than broad Siphlurus, p. 215, PI. L.

SECOND SERIES. — ZOOLOGY, VOL. III. 43

320 EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES.

ADDITIONS AND CORRRECTIONS.

Pa2:e 4, line 3 from top, after " forms " read also in Lei^tohyphes and in the sub imago
(not the adult) of Epliemerella, it is there, &c.

P. 20, 1. 17 from top, before " Bcetisca " insert Cloeon, JBaetis (with three sections).

P. 21, 1. 2 from bottom, /or " Serie" read Series.

P. 22, 1. 11 from bottom, dele " al " so as to read functionless.

P. 36, 1. 18 from bottom, for " Section 2 of the Genus " read Section 2 of the
Genera. —

P. 81, 1. 12 from bottom, for " Hagennbis " read Teloganodes.

P. 95, 1. 8 from bottom, add Mr. Albarda has lately sent me specimens representing
both sexes of the imago and the 6 subimago of L. Meyeri captured in the Netherlands
at Ginneken, N. Brabant, and at Arnhem, Guelderland, which I returned to him
undescribed a few years ago.

P. 101, 1. 15 from top, after " 172 (18C3) " add ; Walsh, op. cit. ii. 189 note 14, and
194 note 15 (1863).

P. 101, 1. 18, after [details] add; Packard, in 3rd Rep. U.S. Ent. Comm. chap. xi.
(part), pis. xlv.-xlvi. [morphology] (1883).

P. 106, 1. 10 from top, after Italy read Spain. Again, after " Portugal," add A speci-
men from San Ildefonso, Segovia (Ilei/er-Dur) is in Mr. Albarda's collection.

P. 109, 1. 4 from top, /or Palenburg read Palembang.

P. 114, 1. 9 from top, /or nodal point read bulla.

P. 122, 1. 1, before Algarve read Spain.

P. 122, 1. 14, after grey add ; neuration in opaque view concolorous with the
membrane.

P. 122, 1. 13 from bottom, add A single ? subimago, considerably damaged by An-
thremts, from San Ildefonso, Segovia {Meyer-Dilr), in Mr. Albarda's collection has the
wing 8'5 mm. long.

P. 124, 1. 2 from bottom, Ijefore GMdivA. insert The recurrent membrane of the fore wing-
roots extends in the form of short svibulate points beyond the peak of the scutellum in
the subimago ; but these mesonotal appendages are wanting in the imago.

P. 139, 1. 13 from bottom, add In translating the description of this species in 1871, I
carelessly wrote ventralibus for dorsalibus.

P. 141, 10. 2 from bottom, for " Homologue of the forceps-basis vindeveloped in ? ,"
read Ventral lobe of ? segment 9 obtusely rounded off and entire.

P. 143, 1. 2 from bottoms/or var. rivtjlorum read C^nis rivulorum, sp. nov.

P. 144, 1. 8, to the localities quoted, add Also the Eden in Cumberland ; profusely
abundant at Langwathby on certain evenings towards sunset so as to jjroduce an
appearance as of mist or dense haze hovering over the course of the river. A single
Scotch specimen is in Mr. King's collection.

P. 160, 1. 2 from bottom, after Brook ; add abundant in Briggle Beck and in the
Eden near Little Salkeld in Addingham, Cumberland ;

EEV. A. E. EATON ON EECENT EPHEMERID.E OE MAYFLIES. 321

P. 186, 1. 15 from top, for Teneriffe, common near the Jardin, read common in a
Fonda at Puerto de la Orotava, Tenerife, and near the Jardim.

This relates to Chirotonetes (?) obnatus, p. 208.

Stibimago (dried). — Wings whitish grey; fore wings less yellowish at the roots than in
Colobtirus Jmineralis, having a small yellowish spot at the roots of the snbcosta ; cross-
veinlets bordered with brown-black (corvinous), their bordering confluent here and there
into spots producing an irregular chequered appearance amongst the reticulation. Setae
warm sepia-brown, with dark joinings.

Imago {dried). — Notum of 6 black or pitch-brown ; that of 2 fusco-luteous or brown-
ochreous. Dorsum of abdomen rufo-fuscous, with a dark triangular spot behind on each
side of every intermediate segment, before the apex of which is an ochraceous sjraee
[ = ? a lateral series of oblique dark stripes each enclosing a pale space]. Setas fuliginous
or warm sepia-grey with darker joinings. Antepenultimate [? ventral] segment of $
usually conspicuously paler than the others, and traversed lengthwise by three black
lines. Eore legs brown-ochreous, the hinder legs flavescent, with black or dark-grey
markings, viz. : — a Ijand in the middle and another at the tip of the femur, the tip of the
tibia, the joinings and, to a large or small extent, the last three joints of the tarsus. Wings
vitreous ; fore wing faintly yellowish or amber-tinted in the first portions of the marginal
and submarginal areas, and tinged with brown-black in the pterostigmatic region, where
the cross-veinlets are dark-bordered, simple, and straight : neuration for the most part
pitch-black, but the subcosta and radius are yellowish towards the base. Length of body
11-1.5, wing 12-16 ; setae 6 and ? itn., 16 and 1, subim. <3 about 13, 2 11 mm.

Hah. Christchurch, New Zealand. Easily distinguished from Coloburus humeralis by
the dark-bordered cross-veinlets of the wings forming here and there irregular blots, by
the smaller extent of the yellowisli tint at the wing-roots, and by the banded femora.
Described and illustrated by me in 1876 after specimens at that time in the M'Lach. Mus.

P. 210, 1. 11 from bottom, add and Europe.

P. 216, 1. 1 from bottom, add I have lately seen, in Mr. Albarda's collection, a single
cJ subim. captured by Meyer-Diir at the same place. The Portuguese nymph figured in
PI. L. is probably of this species. These nymphs were plentiful in a streamlet near Sao
Barnabe in Algarve at an altitude of 700 ft. [water 61° E., 12th May, 1880, in the after-
noon], and there were sloughs relinquished by the subimago on some of the stones in the
stream ; but I failed to find the fly.

P. 232, 1. 6 from top add :—

A fragmentary d imago, probably of this species, forwarded to me, without record of
locality, by M. Erey-Gessner, differs from the s])ecimen described at p. 231 siijira and
figured in detail in PI. XXII. in the following particulars : — Many of the cross-veinlets
of the pterostigmatic portions of the marginal areas of the fore wdngs are forked near
the costa and some of them anastomose with one another ; the two short intercalary
nervures in the anal-axillar interspace of the fore wing, which are next to the 1st axillar
ncrvure, end inwards abruptly; the narrow linguiform penis is entire, not incised at the

43*

322 KEY. A. E. EATON ON EECENT EPHEMEEID.E OK MAYFLIES,

tip ; the forceps-basis is less deeply emarginate behind ; and in segments 8 and 9 the
venter is more of a light brown-ochre or " fuscous " in colour. Differences in the state
of preservation of the specimens may be held to account sufficiently for most of these
discrepancies, and individual idiosyncrasy for the remainder. From the coloration of
the abdomen of the adult fly, I am led to infer that the abdominal pairs of tracheal
branchife of the nymph are seven in number.

P. 233, 1. 4 from bottom, /or tibia read tibise.

P. 238, 1. 12 from bottom,/or Epeorus gbminus, sp. nov., read : —

Epeorus stlvicola, Ed. Pictet.

X Baetls sylvkola, ! Ed. Pict., Syuop. Nevropt. d'Espagne, 24, pi. iii. 7-12 (1865).
Heptagenia si/hicola, ! Etn., Trans. Ent. Soc. London (1871), 147.
Epeorus gemi litis, ! Etn., at p. 238, supra (1885).

SuLimago (dried), $. — Wing-membrane sepia-grey; neuration for the most part (in
opaque view) pitch-black, the subcosta being so entirely, in both wings, but the proximal
ends of the other main longitudinal nervures become light bistre-grey, and the tegulae
are light yellowish : cross-veinlets in both wings narrowly and very faintly bordered with
light grey. Setse intense warm sepia-brown, with black joinings. Length of body, d
12, 2 13 ; wing d 15, $ 16 mm.

P. 239, 1. 14 from top, after the parenthesis insert ; Spain, San Ildefonso, Segovia (Ed.
Pict.). M. E. Erey-Gessner lately transmitted to me for examination the type speci-
mens of this species ; and I have consequently been able to identify my Portuguese
Epeorus with Ed. Pictet's % B. sylvicola.

P. 239, 1. 6 from bottom, /or 1835 read 1885.

P. 239, 1. 7, add Also the Vosges (Puton, MS.).

P. 212, 1. 14 from bottom, add Plate LXV. 13 ( d genitalia).

P. 249, 1. 20 from bottom, for " anastomo seat all " read anastomose at all.

P. 252, after 1. 20 from top, add :—

Tgpe. Eh. semicolorata. Curt.

Disiribuiion. N. America and Europe.

Etfjinology . pelQpov, a stream, and ykvoc.

P. 266, after 1. 16 from toj^, add : —

Ti/2Je. H.fiavescens, "Walsh.

Distribution. Northern Hemisjohere from about 30° N. lat. within the Arctic Regions.

Etymology. eVra and yei'ea, in reference to the genus being seventh in a series.

The following descriptions refer to the North-American species of Heptagenia {antea,
p. 266).

Since tlie publication of the descriptions of IL. fiavescens and H. interpunctata, p. 266
and p, 267, a large series of the latter species and kindred forms has been added to
Mr. M'Lachlan's Collection. I have examined these, and I am led to suspect that the

EEV. A. E, EATON OX EECENT EPHEMEEID.E OE MAYELIES. 323

Nortli-Ainerican species differ generically from the European and Asiatic species hereto-
fore described, pp. 268-27 ±.

Tlie descrii^tions which here follow take cognizance only of the adult and subimago
conditions. It may, however, hereafter be found that when the nymph-stage of the
American form is fully worked out, the opinions here offered tentatively may require
modification.

The following characters of the American species of Heptagenia should be taken into
consideration Avith the characters of the genus already given at p. 265.

P. 265. Adult. — Eirst joint of the hind tarsus equal or subequal to the third joint;
first joint of the 6 fore tarsus about half as long as the second, and this rather shorter
than the third joint ; first joint of the ? fore tarsus little more than half as long as the
second, which is very little shorter than the third joint. Penis-lobes slightly flattened ;
their extremities roundly truncate. — Eore leg of d about 1^ as long as the body ; the tarsal
joints, in the order of their shortening, rank in the c? , 3, 2, 4, 1, 5, and the first is about
^ as long as the second joint ; and in the ? 3, 2 equal to 5, 1 equal to 4, and the first
is -—^ as long as the second, or \ as long as the third joint. The joints of the hind tarsus
in the order of their shortening rank in c? 2 equal to 3 equal to 5, 1, 4 ; in $ 5, 2 equal
to 3, 1, 4, or 1 equal to 4. Ventral lobe of ? segment 9 emarginate. Outer caudal setse
of 6 3-3^ the length of the body ; those of $ I5-2 its length.

Supplementary to Heptagenia interpuiictata, see p. 267-

XBaetis canadensis, var. (?), ! Walk., List of Neuropt. lus. in Brit. ]\Ius. part iii. 570 (1853) [?].

Subimago {dried). — Wings extremely light yellowish ochre, with neuration at first
nearly concolorous with the membrane, and with the extreme edge of the hind wing at
the apex and terminal margin blackish grey. The Aviug-neuratiou undergoes changes
of colour during the maturation of the insect similar in their nature to those described
under Heptagenia sulphurea, the greater part of it, in specimens very near the last moult,
becoming bistre- or raw-umber brown, and only the stronger uervures remaining
yellowish in opaque view. In the fore wing the cross-veinlets of the foremost three areas
(but not the great cross-vein) are black : the dark pigment in many of the specimens
spreads a little, anteriorly, on each side of nearly every cross-veinlet in the marginal
area ; and in the third of those areas, minute, more or less circular, dark-grey median
single spots are similarly apt to be formed upon some or all of the cross-veinlets in the
basal half of the area, and where the cross-veinlets are close together near the bulla of
the radius two or three of the spots often run together into a dark dash traversing the
middle of the cross-veinlets : some of the specimens have none of these spots. In the
remainder of the fore wing the cross-veinlets gradually become dark. Seta^ uniformly
light brownish.

Imago {dried), s . — Notum light yellowish approaching yellow-oclu-e, excepting the
pronotum, which in some lights approaches pale raw-umber brown ; the sides of the
thorax are varied vri.i\\ a much paler yellow. Abdomen in segments 1-8 semitrans-
parent greenish white, witli the terminal borders of the segments edged evenly and nar-

324 EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

rowlv with bistre-brown on tbe dorsum, and with a lighter brown on the venter ; seg-
ments 9-10 and sometimes part of the preceding segment opaque light-yellowish ochre,
mingled on the dorsum with a paler yeUow. Setae, in opaque view, uniformly warm sepia-
brown. Coxge eoncolorous with the thoracic pleura. Fore femur, in opaque view, light
brownish olive, banded narrowly with blackish in the middle and close to the tip ; tibia
and tarsus somewhat of a medium sepia-brown, the tibia in some postures, however,
assuming the colour of the femur, with the insertion of the tarsus sepia-brown, and the
tarsus becoming very light sepia-grey : in transmitted light the femur and tibia are a
rich translucent yellowish or greenish amber ; the tarsus remains dull. Hinder femora
and tibiiB paler and more transparent than those of the fore leg ; during life the pigment
forming the femoral markings may perhaps be arranged in bands ; but in dried spcclnLens
these markings consist of a small grey median spot, and another just before the tip,
which is small, elongated, and blackish, and is flanked on each side by a very fine abbre-
viated black line in the edge of the limb. In some lights the hinder tarsi, and even the
tibise also, appear light brownish, or brownish grey ; in other j)Ostures only the tarsal
incisures are very narrowly brownish ; in transmitted light the femora and tibias become
whitish amber, and the tarsi with (sometimes) the extreme tips of the tibiae remain dull
or blackish grey. Wings vitreous : in the fore wing the membrane of the marginal and
submarginal areas, from the base to the beginning of the pterostigmatic region, is, for
the most part, sometimes colourless like that of the disk, but usually has a very faint
amber tint ; the remainder of these areas is suffused distinctly with transparent colour-
ing that varies in tint with change of posture from dull light reddish or reddish brown,
to bistre-grey or raw umber-grey, and this colouring extends further along the margin
to the extremity of the wing ; in the marginal area the same colouring becomes rather
faint near the costa. The markings of cross-veinlets in the fore wing are the same in
the adult as in the subimago, when there are any at all. Where in the subimago the
edge of the hind wing is black, it is not only so in the imago also, but the wing is there
bordered narrowly with a bistre-grey cloud, which is shaded off inside and gradually
diminishes in width posteriorly. Neuration of the fore wing in opaque view pitch-black,
excepting the stronger portions of the costo, subcosta, and radius, and also the basal
extremities of the other longitudinal nervures, which in some postures appear palei% or
light bistre-brown : in other p)ositions the neuration altogether, or else only the longitu-
dinal nervures, becomes translucent rufo-piceous. The pterostigmatic nervures are
simple and not crowded together.

? . Very similar to the d , especially after oviposition : prior to this, the body is of a
richer yellow-ochi-e in its ground-colouring, and of course the abdomen is not translucent.
The marginal and submarginal areas are sometimes almost colourless ; sometimes only
the latter area, especially in the pterostigmatic region, is slightly amber-tinted, this tint
extending onwards along the margin to the extremity of the wing ; sometimes both
these areas and the colouring continued from them to the tip of the wing are light
amber-tinted, and a small reddish cloud lies between the costa and the radius at about
\ of the distance beyond the bulla towards the tip ; sometimes the reddish tint is as

EEV. A. E. EATON ON EECENT EPHEMEEID.^ OR JIATELIES.

325

extensively diffused in the pterostigmatic region as it is in most specimens of the other
sex. The hind wing is faintly amber- tinted to a considerable depth along the grey or
blackish apical or terminal margins. In the fore wing the lighter portions of the longi-
tudinal nervures are rather paler than in the c? , and the great cross- vein is paler than
the cross- veinlets ; the caudal setae are lighter in colour. Length of setae d im. 25-35,
? im. 25 mm.

Sab. North Carolina (M'Lach. Mus.). For comparison with the tabulation of propor-
tional lengths of tarsal joints of representatives of other genera given above at p. 230,
the corresponding admeasurements of the tarsi of adult specimens of this species are
here subjoined : —

Fore tarsus.

Intermediate tarsus.

Hind tarsus.

I.

II. III.

1

IV.

V.

I.

II.

III. IV.

V.

I.

II.

III.

IV.

V.

d ..

.i 10

20

24

16

8

5

7

7 1 4

i

5

6

6 3

1

6

$.-

1

., 6

11

12

G

11.

5

S

8 5

9

5

7

7

4

9

In the fore leg of the cT the tarsus is about If as long as the tibia ; in the ? the fore
tarsus is about # as long as the tibia.

P. 268, 1. 10 from top, /or Subz. read Sulz.

P. 270, lines 15 to 8 from bottom, note To H. cierulans belongs all that relates to H.
gallica, given below at pp. 272-273. I have lately examined specimens of H. ccerulans
in Mr. Albarda's collection named by Herr Eostock, and can now vouch for the identity
of S. gallica with ccerulans.

P. 272, 1. 5 from top, for gallica, sp. nov., read {cjallica, Etn. MS.=] c^rulans,
Rostock.

P. 272, 1. 7 from top, after '' Heptagenia" read ccerulans, ! Rostock, Jahresb. d. Ver.
f. Xaturk. Zwickaxi, 1877, p. 89 (1878). — Heptagenia.

P. 273, lines 14 from top, after " Hub.'' insert Weisseritz, near Dretschen, Saxony
(Rostock).

P. 273, lines 16-18 from top, omit all references relating to S. volitaus.

P. 274, dele lines 22-24 from top, and lines 1-4 from bottom. Note H. volitans
is an Ecdyurus described at p. 291.

P. 306, 1. 6 from bottom, /or Prof read M.

P. 307, 1. 18 from top, /or Retourna read Retourner.

P. 307, L 11 from bottom,/or 2; (?) sp., read ; (?) 2 sp.

P. 309, 1. 5 from bottom,/;/- (3) read (8).

P. 315, 1. 20, for Colohurus, read Coloburiscus.

326 EEV. E. A. EATON ON EECENT EPHEMEEID^ OE MAIFIJES.

DESCRIPTION OF THE PLATES.

The figures in Plates I.-XXIV. (witli two acknowledged exceptions) are mainly photo-litliographs of
drawings made with the camera liicida from the specimens by the Author. Being designed to illustrate the
genera, a distinctive numeral is appropriated to each genus ; and, when necessary, a special letter is affixed
to the generical numeral, to indicate what species are concerned in the illustrations appertaining to that
genus. Numerals written smaller than the generical numerals are used to designate particular legs and
wing-uervures. The fore leg, intermediate leg and hind leg are numbered respectively 1, 2, and 3.
The wing-nervures are numbered in accordance with the plan set forth in page 4 of this volume : —
1, the Costa, 2, the Siibcosta, 3, the Eadius, 4, the Sector, 4', the hindermost of the adventitious
branches of the Sector, 5, the Cubitus, 6 and 6', the Praibrachial and its hindermost branch, 7 and 7',
the Pobracbial and its hindermost branch, 8, the Anal, 9', 9", and 9^ Axillary nervures. The natural
lengths of the wings arc shown by hair-lines.

Plates XXV.-LXII. and part of LXIII. (with a single acknowledged exception) are from drawings by
HoUick, from the specimens, executed under the Author's supervision. The figures in each of these
Plates are numbered consecutively, and certain letters are uniformly used to designate particular parts of
the insects, viz. : — a, the antenna, Ibr, the labrura, r. md, the right mandible, I. nid, the left mandible, mx^,
the first maxilla, mx', the second maxilla, Ibm, the labium, /, the tongue, /', the fore leg, /', the inter-
mediate leg, r, the hind leg, tb, tracheal branchiie [those of the abdomen numbered pair by pair suc-
cessively from the foremost], c. s. caudal setse. In some of these Plates detached views of certain regions
of the body are uniformly lettered as follows : — A, dorsal view of the insect, B, ventral view of the same,
C, side view of the head, D, head from beneath, E, head from above, P, front view of head. The
natural lengths of the insects arc shown bj' hair-lines, and to the figure of each detail is annexed an
indication in numerals of the scale of enlargement.

Plates LXIV., LXV. and part of LXIII. are from drawings by the Author from the specimens, litho-
graphed by HoUick. They are essentially supplementary to earlier plates.

N.B. — The wings of dried specimens, in some of the genera, arc apt to be completely shrivelled up
{e.r/. those figured in Plate III.). "When such is the case, rccurse may be had to the following method
of preparing them for examination. The wing detached from the specimen is first of all floated upon
scalding water, and induced to expand as fully as possible whilst it is floating. It is next taken up
upon paper or a strip of glass and transferred to cold water, and then spread out to dry upon paper or
glass. If upon paper, the wing can presently be separated therefrom by bending the pajjer away from
it, and it can either be mounted permanently as an object for the microscope, or be placed temporarily
for examination within a compress-cell, care being taken to flatten it out by only vertical and gentle
pressure. If the result be then unsatisfactory, the whole process can be repeated.

Plate I.

Neuration, limbs, external $ genitalia, and J" head of 1. Palingenia (adult) : — all enlarged.

Figs. 1 a. P. longicavda : — wings, legs (1-3) of ^ , fore leg of ? with a larger view of the fore tarsus
and a much larger one of the ungues, a penis-lobe and forceps-limb (underside view), [the
two dots on the 4th joint of the limb are due to a flaw in the stone] , vertical view of the cJ
head, and side view of the same.

Fig. 1 b. P. lata : — fore wing.

Fig. 1 c. P. ampla : — fore wing.

Fig. 1 d. P.javardca : — xmdcrside view of c? genitalia.

EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 327

Plate II.

Neuration, limbs, extei'Dal fj genitalia, and parts of caudal sette of 1. PuHm/enia (adult)
aud 9. Jolia (reputed adult) : — all enlarged.

Figs. Id. P.javanica : — part of fore wing, legs (1-3) of J, with a larger view of the ungues of the

fore tarsiis, aud two portions of a caudal seta, taken respectively from before the middle and

towards the tip of the same, both highly magnified.
Figs. 1 e. P. tenera : — fore wing and two portions of a caudal seta corresponding with the above.
Figs. 1/. P. pajmana : — part of fore wiug, and underside view of genitalia.
Figs. 9. /. Rceseli : — parts of both wings, legs (1-3) of g , with enlarged views of the terminal joint of

the fore tarsus, and likewise of the intermediate aud the hind tarsi, and underside view of a

forceps-limb and penis.

Plate III.

Neuratiou, limbs, external J genitalia of 2. Oliyoiiciiria, 3. Elassoneuria, 4. Spaniojjhlebia,
5. Lachlaniaj 6. Homaoneuria, aud head of adult ^J Olii/oneuria : — all enlarged.

Figs. 2 «. O. rhenana : — wiugs of ^ and of $ , legs (1-3) of (J , much enlarged ; underside view of part of
the extremity of ^ abdomen, showing a 3-jointed forceps-limb, the penis, and (in stippled
outline) the retracted stimuli ; another underside view of the penis with sperm-ducts jjartlv
extruded and the stimuli retracted ; extremity of a forceps-limb 4-jointed instead of 3-jointed ;
head of adult ci viewed from above ; the same from in front ; the same from the side.

Figs. 2 b. 0. anomala : — wings, legs (1 and 3) of ,^ much enlarged and (1-3) of? ; side view of genitalia
(dried) with separate figures of a forcei)s-limb, aud of the jjcuis-lobes subtended by the forceps-
basis, or a laminar lobe of the 9th ventral segment.

Fig. 3. E. Trimeniana : — wings of ?.

Figs. 4. S. Trai/ue : — wiugs, legs (1-3) of (J , and underside view of genitalia.

Figs. 5. L. ahnormis : — wings of $ . -L. luc'ida : — partial underside view of genitalia.

Fig. 6. H. Salvinice : — wings of $ .

Plate IV.

Neuratiou, limbs, aud cj forceps of 7. Euthyplucia : — all enlarged.

Fig. 7 a. E. Hecuba : — wings of $ .

Fig. 7 b. Another species :• — hind wing of $ .

Figs. 7 c. E. anceps: — defective wiugs, legs (1-3), with enlarged views of the intermediate and posterior

tarsi; dorsal view of the extremity of the alxlomeu and forceps-limbs (seta; omitted), — all of the

cC aud dried.
Fig. 7 d. Another species : — underside view of forceps.

Plate V.

Neuration, limbs, external 6 genitalia, aud head of adult d of 8. Campsiiru.i : — all enlarged.

Figs. 8 a. C. albifiluni : — fore wing, fore leg of the adult ^ ; fore leg of cJ subimago ; underside view of
J genitalia, showing the penis-lobes in faint outline ; vertical view of the head and part of the
thorax.

Fig. 8 b. Another species : — hind wing of $ .

Figs. 8 c. C. latipmnis : — wings ; a partial underside view of (J genitalia, showing ou the right, at the base

of the figure, part of a filiform forceps-limb, with an unciform prickle adjacent thereto, also a

bifidly excised subgeuital plate, the penis-lobes slightly opened out but incurved, and either

stimuli or sperm-ducts protruded with divergent points ; another partial underside view of the

SECOND SEKIES. — ZOOLOGY, VOL. III. 4t4<

328 REV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

same from a different specimei), sliowing a forceps-limb, both of the spinules or prickles

adjacent to the forceps-limb, one half of the siibgenital plate, and the penis-lobes closed

togetlier (dried).
Fig. 8 d. C. cuspidatus : — underside view of J* genitalia (dried) .
Fig. 8 e. C. quadridentatus : — underside view of subgenital plate with the right forceps-limb entire ;

penis-lobes viewed from behind, points upwards; side view of a penis-lobe, point downwards,

much more enlarged (dried).
Figs. 8/. C. curtus : — partial underside view of ^J genitalia, showing the right forceps-limb and the base

of the left limb, and also the penis-lobes above the halves of the subgenital plate distorted in

drying. Also two detached figures, much more enlarged, of penis-lobes (dried).

Plate VI.

Neuration of 8", a nameless insect related to Campsurus. Also neuration, limbs, external J" genitalia,
and head of adult ^ of 10. Polymitarcijs : — all enlarged.

Fig. 8 bis. Nameless Brazilian insect (M'Lach. Mus.) : — wings.

Figs. 10 «. P. virgo : — wings; legs (1-3) of adult (^ , with enlarged views of the intermediate and pos-
terior tarsi ; fore leg of (^ subimago, on the same scale of enlargement as the adult fore leg ;
ventral view of (J genitalia, showing the penis and a forceps-limb ; vertical view of the adult
^ head with part of the pronotnm.

Fig. 10 6. A S. -African species: — fore wing.

Fig. 10 c. A N.W. -Indian species : — hind wing.

Plate VII.

Neuration, limbs, and external (J genitalia of 11. Hexagenia ; all enlarged.

Fig. 11 «. A N.W. -Indian species : — fore wing and part of hind wing.

Figs. 11 b,l\b' and l\h?. H. bilineata : — hind wing and part of a fore wing; three views of single forceps-
limbs, each with another view, on rather a larger scale, of the extremity of the limb, illustrating
variations in the number and relative size of the smaller joints [of these threCj the two on the
right side of the jilate are from dried specimens ; the underside view of the ^ genitalia, on
the left side of the plate, is from an alcoholic specimen, and shows the penis-lobes — one
shaded, the other in outline].

Figs. lie. H. Umbata : — wings; legs (1-3) of each sex;rr genitalia, showing a forceps-limb and a
penis-lobe (dried). The remarkable aberration displayed in the neuration of the fore wing
here figured is described at the bottom of p. 4.

Plate VIII.

Neuration, limbs, and external 6 genitalia of 12. Ephemera and 13. Pentagenia ; also head

of adult d Epjhemeru.
Figs. 12 a. E. danica : — wings ; legs (1-3) of d and (1) of ? , with an enlarged view of the terminal

joint and ungues of the c? fore tarsus ; forceps viewed from below.
Figs. 12 6. E. vulgata : — part of a fore wing; underside view of penis-lobes.
Figs. 12c. E. supposita: — underside view of d genitalia, showing forceps and penis; a slightly enlarged

side view of a penis-lobe (dried) .
Figs. 12 d. E. ghmcops; head of adult J, the upper figure being taken from in front of the specimen,

and the lower from the side. The latter view includes part of the prothorax and of the fore

leg.
Figs. 13. P. vittigera: — wings of both sexes ; legs (1-3) of both sexes; underside view of penis and a

forceps-limb (dried) .

EEV. A. E. EATON ON RECENT EPHEMERID^ OR MAYFLIES. 329

Plate IX.

Neuration, limbs, external d genitalia of 14. Polamanthus and 15. Rhoenanthus and head o£ adult

(5 Potamanthus : — all enlarged.

Figs. 14. P. luteus : — wings ; legs (1-3) of 6 and fore leg of J ; two underside views of forceps, one
in outline (dried) and the other shaded (freshly killed) ; two underside views of the penis, the
uppermost fresh, and the lower dried ; a vertical view of the adult ^J head, and a side view of
the same with part of the thorax and of the fore leg.

Figs. 15. Rh. speciosus : — both wings and part of a fore wing; underside view of forceps (dried) ; under-
side view of the penis (dried).

Plate X.

Neuration, limbs, external d genitalia, and adult ,;' head of IG. Atalophlebia : — all enlarged.

Figs. 16 a. A. annulata : — wings ; legs (1-3) of 6 with a more enlarged view of the hind tarsus ; forceps

(dried) ; underside view of penis (dried).
Fig. 16 6. A. taprobanes : — oblique side view of penis (dried).

Figs. 16c. A. australasica : — two fore wings and a hind wing; underside view of penis (dried).
Fig. 16 d. A. strigata : — hind wing and part of a fore wing ; fore leg of adult ? .
Figs. 16 e. A. nodularis: — fore wing; hind wing more enlarged; a side view and an underside view of

penis [rather inferior to the older figures of the same] (dried).
Figs. 16/". A. scita : — forceps and underside view of penis (dried).
Figs. 16 ff. A. chi/ensis : — hind wing; legs (1-3) of d; a forcej)s-limb and two views of the penis

(dried) .
Figs. 16 A. A. tabularis : — hind tarsus, intermediate tarsus, and the terminal joint of the fore tarsus of

the adult 6 ; underside view of the forceps-basis, and a forceps-limb ; underside view of penis ;

vertical view of adult 6 head ; side view of the same, showing the asealaphoid form of oculi

(from a specimen preserved in spirits and glycerine).
Figs. 16 i. A nameless species : — wings, and a more enlarged view of the hind wing.

Plate XI.

Neuration and limbs of 17. LeptoiMMa and 18. Blasiurus, and external g genitaHa

of Leptophhbia : — all enlarged.

Figs. 17 a. L. niarginata : — wings ; legs (1-3) of 6 and fore leg of $ , with a more enlarged view of the
intermediate (J tarsus; underside view of the forceps-basis and the right forceps-limb, illustrating
the occasional 4-jointed condition of the limb ; underside view of penis (freshly killed).

Figs. 17 6. L. mollis : — wings ; side view of forceps (dried).

Figs. 17 c. L. prtepedita: — {uppermost fyiin') side view of penis, subtended by an erect underside view of
the same ; {right and left figures at the bottom of the group) underside view of forceps, and side
view of the same (dried) .

Fig. 17 d. L. Meijeri: — underside view of penis (dried).

Figs. 18. B. concinnus l — ciipidus] : — wings and legs.

Plate XII.

Neuration, limbs, and external 6 genitalia of 19. Ckoroterpes, and 20. Thraulus : — all enlarged.
Figs. 19. Ch. Picteti : — wings, with a more enlarged view of the hind wing; legs (1-3) of d , with more
enlarged views of the intermediate and hind tarsi, and one, on much larger scale, of the
extremity of the fore tarsus ; underside view of forceps, and of penis (fiom specimens m
fluid).

4.i*

330 EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES.

Figs. 20. Th. bellus : — wings, with part of a fore wing, and a more enlarged view of the hind wing; legs
(1-3) of cj, with more enlarged views of the intermediate and hind tarsi; underside view of
forceps, and of penis (from specimens in fluid).

Plate XIII.

Neuration, limbs, and external ^ genitalia of 20*. Thravlus (provisional) [including 23*. CalUarcys
(provisional)], 21. AdenojMebia, and 22. Habrophkbia. — [For 23. Caliarcys (proper) see
Plate XIV.]

Figs. 20*^. Th. exigims : — wings, with a more enlarged view of the hind wing ; one of the hinder tarsi;
underside partial view of ^ genitalia, with another more enlarged view of the penis (dried).

Fig. 20*'. Th. colonibice : — hind wing, much enlarged.

Figs. 21. A. dislocans : — wings ; legs (1-3) of ^ , with a more enlarged view of the intermediate tarsus;
a forcejjs-limb and an underside view of the penis (dried).

Figs. 22 «. H.fusca : — wings; legs (1-3) of c?, with more enlarged views of the hinder tarsi; underside
view of the forceps, and of the penis (freshly killed) .

Figs. 22 b. H. modesta : — side view and underside view of penis (dried).

[Figs. 23*", 23*', and 23*', referred provisionally to Calliarcys in the writing on the Plate, are cited in
the descriptive letterpress at pp. 109-110 under Thraulus.']

Figs. 23*°. A nameless insect : — wings, with a more enlarged view of the hind wing.

Figs. 23*\ Th. Icetus : — part of a fore wing ; one of the hinder tarsi ; partial underside view of the
penis and a forceps-limb (dried).

Figs. 23*'. Th. mewicanus : — hind wing, much enlarged; underside view of the penis and a forceps-
limb (dried).

Plate XIV.

Neuration, limbs, and external $ genitalia of 23. Calliarcys, and 21. Ephemerella ; also adult

^ head of the latter : — all enlarged.

Figs. 23. C. humilis : — wings, with portions of two fore wings, illustrating differences in the inter-
calary nervures of the aual-axillar interspace, and a more enlarged view of the hind wing ; legs
(1-3) of cJ and the fore leg of ? , with more enlarged views of the 2 fore tarsus and the hinder
cJ tarsi ; underside view of forceps and penis (from a specimen in fluid) .

Figs. 24 a. E. ignita : — legs (1-3) of cJ and fore leg of $ ; underside view of forceps and penis ; head
of c? viewed from above, from the side, and from in front (freshly killed) .

Figs. 24 b. E. grandis, a N. -American species : — wings, with part of a fore wing showing an unusual
arrangement of the neuration, the longest of the adventitious nervures (7') included between
the pobrachial (7) and the anal (8) nervures, meeting this last instead of the pobrachial nervure;
a more enlarged view of the hind wing.

Fig. 24 c. E. invaria : — underside view of penis (dried).

Plate XV.

Neuration of 21 bis. Hagenulus, 24 bis. Teloganodes, 25. Tricorythus, 25 bis. Leptohyphes, 26. Canis, and
(after Vayssierc) 27. Prosopistoma, with limbs and genitalia of Hagenulus and Canis, and head
of adult (J of tills last.

Figs. 21bis. H. caltgatus : — wings, with a more enlarged view of the hind wing ; legs (1-3) of ? and
fore leg of ^J, with more enlarged \dews of the (J fore tarsus and $ hind tarsus; penis with a
slightly enlarged view of one of its divisions in a different posture ; one of the forceps-limbs
(dried). [This ^ im. should be ranked with the 4 $ imagines mentioned at p. 114, line 13
from top. j

BEV. A. E. EATOiV ON EECENT EPHEMERID^ OR MAYFLIES. 331

Figs. 24 bis. Tel. tristis : — wings, with a more enlarged view of the hind wing.

Fig. 25. Wing of a nameless Malay species of Tricorythus, received from Mr. Ritsema. [The ciliation
of the wing is rather too dense.]

Fig. 25 bis. L. exhn'ms : — wing.

Figs. 26 fl. C. haltcrata : — legs (1-3) of ? and fore legs of $ , with a more enlarged view of the ? hind
tarsus ; underside view of genitalia ; vertical view of adult J head, shaded, with the pi'onotum
in outline, showing the very great disproportion in size between the anterior ocellus [visible in
front], and the hinder ocelli [protuberant above the orbits of the eyes] (freshly killed).

Figs. 26 6. C. dinidiata : — wing; underside view of genitalia (freshly killed).

Figs. 27. P. ptmctifrons [foliacetini] : — wings of the reputed adult (preserved in fluid) after Vayssiere,
but not facsimile.

Plate XVI.

Neuration and (J forceps of 28. CaUibcetis and 29. Ba'etii; also femoral mai'kings of some species of
the former genus, and head of adult (^ Baiitis : — all enlarged.

Figs. 28 a. C. Hageni :— fore wing and a more enlarged view of the hind wing ; part of a femur.

Figs. 28 b. C. ferrugineus : — fore wing, and a more enlarged ^dew of the hind wing of ? im.

Figs. 28 c. C. pictus : — wings, with a more enlarged view of the hind wing ; two femora.

Figs. 28 d. C. montanus : — wings, with a more enlarged view of the hind wing; a femur.

Figs. 29 a. B. Salvini : — wings, with a more enlarged view of the hind wing : underside view of foi'ceps

(dried) .
Figs. 29 b. B. binoculatus : — wings, with a more enlarged \dew of the hind wing ; iinderside view of

forceps (freshly killed).
Figs. 29 c. B. rhodani : — hind wing, much enlarged ; head of cj viewed obliquely from above in front,

and the same viewed from the side, showing the form of the composite oculi, and the inequality

of the ocelli, described at p. 153 (freshly killed) .
Fig. 29 d. B. vermis : — underside view of forceps (freshly killed) .
Fig. 29 e. B. pwmilus : — hind wing, much enlarged (freshly killed) .
Fig. 29/. B. niger : — underside view of forcei^s (freshly killed).

I Plate XVII.

Limbs of 28. CalUbmtis, 29. Bai'tls, 30. Centroptilum, and 31. Clo'eon; wings and forceps of CV«//-o-
ptilum and Clo'eon, and adult (J head of the former : all enlarged.

Figs. 28. C. ferrugineus : — legs (1-3) of ^ , fore leg of ? (dried).

Figs. 29. jB. rhodani : — legs (1-3) of J" and fore leg of ? , with the hinder tarsi of the ? on a corre-
sponding scale of enlargement.

Figs. 30a. C. luteolum : — wings, with a more enlarged view of the hind wing; underside view of the
forceps ; head of adult <J from in front, and also from the side, showing the composite form
of tlie oculi and the disparity in size between the foremost and the hinder ocelli, described at
p. 153 (freshly killed) .

Figs. 30 6. C. p ennui alum : — hind wing, much enlarged ; legs (1-3) of J"; underside view of forceps ; side
view of (J head (freshly killed) .

b'ig. 30 c. C. tenellum : — underside view of forceps (preserved in fluid).

Figs. 31 a. C. diptertim : — fore leg and hinder tarsi of $ ; underside view of forceps (freshly killed).
Figs. 316. C. simile: — wing ; legs (1-3) of ^ ; underside view of forceps (freshly killed).
Fig. 31 c. C. rufulum: — underside view of forceps (freshly killed).

"'ig. 31 d. C. bimaculatum : — wing [in the pterostigraatic region, the front of tlie wing (through accident
on the part of the author) is slightly displaced] .

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

Plate XVIII.

Neuration, limbs, and external c? genitalia of 32. Coloburus {= Coloburiscus]; also external ^ genitalia
of 33. Chirotonetes, and limbs of 34. " Siphlurus?" [ — Ameletus] : — all enlarged.

Figs. 33 a. C. humeralis : — wings ; legs (1-3) of c? and fore leg of ? ; partial underside view of forceps;

underside of penis (dried) .
Figs. 32 b. A nameless N.-American CoJoburiscus : — hind wings and part of a fore wing ; legs (1-3) of ?

(dried).
Fig. 32 c. C. haleuticus : — underside view of penis (dried) .
Fig. 33 d. Ch. siccus : underside view of the forceps-basis, with parts of the limbs, with parts of the

penis-lobes in outline (dried) .
Figs. 33 e. Ch. aridus : — underside view of the forceps-basis, with parts of the limbs and a portion of the

9th segment ; also (above the number) underside view of the extremity of the penis in outline,

with dried exudation coarsely stippled (dried).
Figs. ?34a'. " S. ?femoratus" [ = A. subnotaius'] : — legs (1-3) of ^ and fore leg of ? (dried).

Plate XIX.

Neuration, limbs, external ^ genitalia, and ^ head of 33. Chirotonetes, and a
wing of 32. Coloburiscus : — all enlarged.

Fig. 32. C. " halenticus" [for haleuticus] : — fore wing.

Figs. 33 a. Ch. mancus : — wings only [the legs are wrongly lettered].

Figs. 33 b. Ch. ignotus : — both wings and part of a fore wing; legs [wrongly lettered 33 a for 33 i] (1-3)
of (J and fore leg of ? ; underside partial view of genitalia held aslant, showing a forceps-limb
and part of the forceps-basis with one and a portion of the other of the penis-lobes (dried) ;
vertical, front, and side views of adult ^ head (freshly killed).

Figs. 33 ? c. Ch. ? ornatus (page 208) :• — underside view of forceps and of penis (dried) .

Plate XX.

Neuration and limbs of 34. Siphlurus, ? 34. Metamonius, and 35. Dipteromimus, with external ^ genitalia
of the first and the last genus and head of adult ^ Siphlurus : — all enlarged.

Figs. ? 34 b. S. [^Metamonius'] anceps : — wings and legs (1-3) of ^ (dried) .

Figs. 34 c. S. typicus : — wings.

Figs. 34 f/. S. lacustris : — legs (1-3) of J' and fore leg of ? ; underside of forceps; vertical and side
views of adult ^ head (freshly killed) .

Fig. 34 e. S. armatus : — underside view of forceps and part of segment 9 (dried).

Figs. 35. D. tipuliformis : — fore wing and part of the hind wing; legs (1-2) of ^ , with a more enlarged
view of the intermediate tarsus ; side view and underside view of genitalia, showing the forceps
and the penis (dried). A complete figure of the hind wing is shown in PI. LXIV,

Plate XXI.

Neuration, limbs, and external ,^ genitalia of 36. Oniscigaster and 37. Bcetisca,
with head of adult ^ of the former : — all enlarged.

Figs. 36. 0. Wakefieldi : — wings ; legs (1-3) of ? and fore leg of (^ : underside view of the genitalia,
with the 9th and part of the 8th segment, showing the right and part of the left forceps-limb,
and the shrunken penis ; head viewed obliquely from in front and also from the side (dried).

Figs. 37. B. obesa : — wings; legs (1-3) of $ and fore leg of (J; underside view of the right forceps-
limb and the penis (dried) .

REV, A. E. EATON ON RECENT EPHEMERID.^ OR MAYFLIES. 333

Plate XXII.

Neuration, limbs, and external ^ genitalia of 38. Ametropus, 39. Atopojms, and
40. Thalerosphynis : — all enlarged.

Pigs. 38. Am. fragUis : — fore wing and most of the hind wing; fore leg of $ adult, and of ^ adult and
subimago, with a more enlarged view of d' intermediate leg ; underside view of force^Ds, with a
part of the left limb omitted ; underside view of penis placed in juxtaposition with the preceding
figure (dried).

Figs. 39. At. tarsaUs: — wings; legs (1-3) of ^ ; underside view of forceps aud penis (dried).

Figs. 40. Th. determinatus : — wings, slightly defective ; intermediate leg aud hind leg of ^ ; underside
view of genitalia, showing the forceps -basis, the left forceps-limb, and the penis (dried).

Plate XXIII.

Neuration of the Ecdyurus type, exhibiting differences, for the most part fortuitous, in the connections
established between the adventitious uervures aud the main nervures of wings, which are of no
generic significance. The fore wings were selected chieflj' for the purpose of demonstrating
diverse common combinations of the adventitious or intercalar nervures of the aual-axillar
interspace (defined at page 81) ; but fig. 43 has reference to those of the sectorial group,
and (like fig. 42) shows how a spurious " apical fork " may be originated. The figures are
all enlarged.

Figs. 41. Pcegniodes cupulatus: — hind wing and part of a fore wiug.

Fig. 42. Compsoneuria spectabilis : — wings. It may be doubted whether the remarkable paucity of
cross-veinlets in the fore wing is a constant generic characteristic.

Fig. 43. Rhithrogena semicolorata : — part of a fore wing, showing an occasional combination of sectorial
intercalary nervures.

Figs. 44. " Epeorus " [—Iron] longimanus : — wings and parts of fore wings of three different specimens.

Fig. 45. Heptagenia gaUica : — -fore wing.

Fig. 46. Ecdyurus i'eno.?u.i : — hind wiug, showing a denser condition of tlie adventitious neuration of the
terminal border than obtains in the other wings figured. This is not of generic import.

Plate XXIV.

Limbs and genitalia of 41. Ptegniodes, 42. Compsoneuria, 43. Rhithrogena, 44. Iron, 44 a. Epeorus,
45. Heptagenia, and 46. Ecdyurus : — all enlarged. — -N.B. Pages 234-236 of the letterpress
should be consulted on account of the possibility of some of the legs and tarsi represented iu
this Plate being deformed.

Figs. 41. P. cupulntus: — legs (1-3) of V [the intermediate is defective] ; underside view of penis aud
the left forceps-limb (dried).

Figs. 42. C. spectabilis: — fore and hind leg of ? ; underside partial view of genitalia (dried).

Figs. 43. Rli. semicolorata : — legs (1-3) of ^ and fore leg of § , with more enlarged views of the
corresponding tarsi ; underside views of penis (43^ and 43°) freshly killed and (43') dried.

Fig. 43 «. Rh. " seniiti?i,cta"[ = alpestris'] : — underside view of peuis (freshly killed).

Fig. 43 b. Rh. germanica : — underside view of penis (dried).

Fig. 43 c. Rh. Hageni : — underside view of penis (dried).

Fig. 43 d. Rh. aiirantiaca : — fore tarsus of $ (alcoholic) .

Pigs. 44. I. longimanus : — legs (1-3) of r? aud fore leg of ? , with more enlarged views of the corre-
sponding tarsi (dried).

334 EEV. A. E. EATON ON EECENT EPHEMEEIDiE OR MAYFLIES.

Figs. 44 A. Ep. torrentium : — legs (1-3) of ^ and fore leg of ? , with more enlarged views of the corre-
sponding tarsi ; underside view of penis (fresUj' killed) .

Figs. 45. H. sulphurea :■ — legs (1-3) of J' and fore leg of ? , with more enlarged views of the corre-
sponding tarsi ; underside view of penis (freshly killed).

Figs. 45 a. H. gallica : — fore tarsus and intermediate tarsus of ? ; underside view of penis (dried).

Figs. 46. Ec. venosus : — legs (1-3) of ^ and fore leg of ? , with more enlarged views of the corresponding
tarsi ; underside view of penis, with the lobes held somewhat apart (freshly killed) .

Fig. 46 a. Ec. helveticus : — fore tarsus of ^ (dried) for comparison with the corresponding figure of the
same tarsus of Ec. venosus.

Fig. 46 6. Ec." qucesitor" [ = j;cwo«/s, var.] : — underside view of penis (freshly killed) with the lobes
rather close together.

Fig. 46 c. Ec. italicus : — underside view of penis (freshly killed) with the lobes closed together.

Fig. 46 d. Ec. insignis : — corresponding view of penis (freshly killed) suffused with seminal fluid.

Plate XXV.

Figs. 1-19. Palingenia [Anar/enesia) , sp. — Nymph. Figures all enlarged. — 1. Dorsal view of insect
about §rds grown. 2. Ventral view of the thorax and abdomen of the same. 3. Side view of
the head and prothorax, x 11 diam. 4. Underside view of head, x 11 diam. 5. Antennae
and frons, x 13 diam. G. Antenna, x 45 diam. 7. Labrum, upper surface. 8. Left man-
dible, viewed from below, x 25 diam. 9. The same, viewed from above, x 25 diam. 10. Eight
1st maxilla and palpus, x 25 diam. 11. Eight 2nd maxilla and palpus, x 20 diam. 12. Dorsal
view of the tongue and its lateral lobes or paraglossre, x 25 diam. 13. Left fore leg, viewed
from liehind. 14. Front view of the same. 15. Tarsal claw of the same, more enlarged.
16. Intermediate leg. 17. Hind leg. 18. Eight tracheal branch ia of the 1st pair, or of the
2nd abdominal segment, spread out to show the arrangement of the fringes, x 10 diam.
19. Eight tracheal brauchia of the 2nd pair, x 13 diam. (From Ceylon, in alcohol.)

Figs. 20-24. Pulbiyema, sp. — Nymph. Figures all enlarged. 20. Dorsal view of the insect in an
advanced stage of growth, with the head and pi-othorax slightly dislocated. 21. Ventral view
of the head and body of the same. 22 and 23. Eight tracheal branchia of the 3rd pair or 4th
abdominal segment, with the divisions spread to show the fringes in 22, and closed together in
23, X 13 diam. 24. Dorsal view of two of the caudal set;c, x 12 diam. (From Brazil, in
alcohol.)

Plate XXVI.

Oliffoneuria rhenana. Nymph.

Figs. 1-20 all enlarged. — I. Dorsal view of insect, nearly approaching the last moult, in the attitude
of repose. 2. Ventral view of the head aud body of a rather younger, but also nearly adult
specimen, x 3 '5 diam. 3. Side view of the head, showing the tuft of fibrils of the tracheal branchia
annexed to the 1st maxilla, x 8 diam. 4. Vertical view of the head of the same ? , of advanced
age (A). 5. Vertical view of the thorax and a few of the anterior segments of the abdomen of
the younger specimen B, showing the hood formed by membrane uniting the terminal mai'gins of
the fore wings. 6. Diagrammatic side view of the thorax aud anterior abdominal segments of
specimen A, showing the position and relative sizes of the 1st aud 2nd abdominal tracheal
branchiae. 7. Antenna, x 30 diam. 8. Labrum, x 30 diam. 9 and 10. Left and right
mandibles, x 30 diam. II. Left 1st maxilla aud palpus, with the annexed fascicle of branchial
fibrils, X 30 diam. 12. The same, reversed, without the fibrils. 13. Interior view of labium,
lower maxillte, aud palpi, x 15 diam. 14. Tongue and paraglossa;, from above, x 30 diam.

BEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 385

15. Fore leg, 16. Intermediate leg, and 17. Hind leg, all x 8 diam. 18. Ventral view of the
right tracheal branchia of the foremost abdominal pair, with the lamina placed edgewise, so as
to display the fibrils, x 30 diam. 19. Vertical view of the right tracheal branchia of the 2ud
abdominal pair, with tlie lamina slightly dejDressed, so as to show the place of its insertion, x 30
diam. 20. Right and median caudal sette, x 8 diam. (From France, in fluid.)

Plate XXVII.

Joliu Hoeselii. Nymph.

Figs. 1-24, all enlarged. — 1. Dorsal view of insect shortly before the last moult, in the posture of
repose [the legs not quite in perspective]. 2. Ventral view of headless body of the same,
showing {t. b.) fibrillose tracheal biauchiic in the region of the neck beside the presternum.

3. Side view of head and part of the thorax, with fore leg and antenna cut off, x 12 diam.

4. Underside view of the same, showing [t. b.) branchial fibrils as before, x 12 diam.

5. Antenna, x 20 diam. 6. Exterior view of labrum, x 20 diam. 7 and 8. Right and left
mandibles, x 40 diam. 9. Left 1st maxilla and palpus, -ivith a tuft of [t. b.) branchial fibrils,
and pai't of a tendon annexed to the stipes, x 40 diam. 10. Underside, and 11. Upperside
views of the labium, 2nd maxilla3, and palpi, x 20 diam. 12. Tongue and paraglossse from
above, x 20 diam. 13. Fore leg, and 14. Interior view of the tibial armature, x 12 diam.

15. Intermediate, and IG. Hind legs, x 12 diam. 17-23. Right tracheal branchite of the seven
abdominal pairs numbered successively from the foremost, all x 30 diam. 24. Left tracheal
branchia of the third abdominal pair, x 10 diam. (From Toulouse, iu fluid.)

Plate XXVIII.

Polymitarcys viryo. Nymph.

Figs. 1-21, all enlarged. — 1. Dorsal view of $ insect in the attitude of repose, shortly before the last moult.
2. Ventral view of the headless body of another specimen. 3. Side view of J head and part of
prothorax, x 8 diam. [The " x 30 " belongs to fig. 15.] 4. Underside view and 5. Vertical view
of the same, x 8 diam. 6. Antenna, x 20 diam. 7. Labrum x 35 diam. 8. Underside of right
mandible, x 20 diam. ; some of the longer hairs were partially erased to make room for fig. 15.
9. Upperside of the same, x 20 diam. 10. Part of the left mandible, and 11. corresponding
part of the right mandible, placed for the display of the fangs and the molar surfaces, x 30
diam. 12. First maxilla and palpus, x 30 diam. 13. Labium, 2nd maxillie, and palpi viewed
from above [the lacinia; of the maxillae out of focus], x30 diam. 14. Side view of right 2ud
maxilla and palpus, x 30 diam. 15. Dorsal view of tongue and paraglossie, x 30 diam.

16. Left fore leg, x 12 diam. 17. The same, reversed. 18. Intermediate leg, and 19. Hind
leg, X 12 diam. 20. Tracheal branchia of the 1st abdominal pair, x 30 diam. 21. One of the
sixth pair, spread out for display of the fringes, x 30 diam. — This Plate underwent considerable
alterations at a late period before publication. Most of the figures were drawn from Toulouse
specimens; but after these were lithographed, better examples were obtained from Brive.

Plate XXIX.

Figs. 1-5. Hexagenia, sp. — Nymph. All enlarged. — 1. Dorsal view of insect about half-growTi.
2. Ventral view of head and body of the same. 3. Outside of a tracheal branchia of the 3rd
abdominal pair, x 13 diam. 4. The same, reversed ; the divisions of the lamina in both the
figures are spread out a little to display the fringes. 5. Right outer and median caudal setas,
X 12 diam. (From Mus. Comp. Zool. Cambridge, Mass., in alcohol.) For other details of
the nymph of Hexagenia see PI. LXIII.
SECOND SERIES. — ZOOLOGY, VOL. III. 45

336 EEV. A. E. EATON ON EECENT EPHEMEEIDiE OE MAYFLIES.

Figs. 6-17. Euthyplocia, sp. — Nymph-skin. All enlarged. — 6. Dorsal view of the slough of the insect,
shed perhaps at the last nymphal moult; scalded and posed in the attitude of Ephemera, PL XXX.
7. Underside of head of the same, x 4 diam. 8. Antenna and part of the right mandible, x 7
diam. 9. Exterior of labrum, x 20 diam. 10. Right mandible, from beneath, x 17 diam.
[The lacinia is doubtless out of shape in this as well as in the other figure.] 11. Corresponding
view of part of left mandible, x 17 diam. 12. First maxilla and palpus, x 25 diam. 13. Under-
side of labium, 2ud maxillae, and palpi, x 15 diam. 14. Dorsal view of tongue and para-
glossse, X 25 diam. 15. Fore leg, X 4 diam. 16. Intermediate leg, and 17. Hind leg, x 4
diam. After the figures were drawn, the skin was dried and re-carded (Mus. Roy. de Bruxelles) .
Pictet's figures of nymphs of this genus (cited in the text) are inaccurate in several particulars.

Plate XXX.

Ephemera vulgata. Nymph.

Figs. I-I9, all enlarged. — I. Dorsal view of $ insect of advanced grade in an attitude of repose.
2. Ventral view of the headless body of another specimen. 3. Side view (partly diagrammatic)
of the fore part of the body and head, with legs and antenna cut off, showing the arrangement
of the first three abdominal tracheal branchiae, and one of the two conical projections in front
of the head in profile, x 7 diam. 4. Underside of head, with antennae cut off, showing the
mandibles closed, and the tusks interlocked at their tips, X 7 diam. 5. Anteima, x 15 diam.
6. Exterior of labrum, x 25 diam. 7. Right mandible, viewed with the fangs pointing up-
wards, X 25 diam. 8. Left mandible, viewed with the fangs in profile, x 25 diam. 9. Part
of the right mandible with the fangs in profile, x 25 diam. 10. Exterior of left mandible,
X 25 diam. 11. First maxilla and palpus, x 25 diam. 12. Labium and 2nd maxillae, with parts
of palpi, viewed from above, x 25 diam. 13. Exterior of the same, with palpi. 14. Dorsum
of tongue and paraglossEe, x 25 diam. 15. Fore leg, 16. Intermediate leg, and 17. Hind leg,
all X 10 diam. 18. Tracheal branehia of the 1st abdominal pair, x 30 diam. 19. One of
the 4th abdominal pair, spread to display the fringes, x 15 diam. (In fluid.)

Plate XXXI.

Potamanthus luteus. Nymph.

Figs. 1-16, all enlarged • — 1. Dorsal view of $ insect of advanced grade, in a posture of repose.
2. Veiitral view of the head and body of the same. 3. Side view of the head and part of the
prothorax. 4. Underside of head. 5. Antenna, x 25 diam. 6. Exterior of labrum, x 35
diam. 7. Right mandible, with tendon attached, x 35 diam. 8. Left mandible, with tendon,
x 35 diam. 9. First maxilla and palpus, x 35 diam. 10. Exterior of labium, 2ud maxillse,
and palpi, x 35 diam. 11. The same, reversed. 12. Dorsal view of tongue and paraglossae,
X 35 diam. 13. Fore leg, 14. Intermediate leg, 15. Hind leg, all x 12 diam. 16. Tracheal
branehia of the 3rd abdominal pair. (From Brive, in fluid.)

Plate XXXII.

Leptophlebia cinda [fig. 2, L. submarffinata]. Nymph.

Figs. 1-13, all enlarged. — 1. Dorsal view of insect aboiit i grown, at rest, but with the legs disposed
somewhat conventionally. 2. Ventral view of the head and body of a specimen approaching the
last moult. 3. Antenna, x 70 diam. 4. Exterior of labrum, x 70 diam. 5. Right mandible,
with tendon attached, x 100 diam. 6. Left mandible, with tendon, x 100 diam. 7. First

EEV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 337

maxilla and palpus, with torn muscular tissue attached to the stipes, x 70 diam. 8. Labium,
2nd maxillfe, and palpi, x 50 diam. 9. Dorsal view of tongue and paraglossse, x 50 diam.

10. Fore leg, 11. Intermediate leg, 12. Hind leg, each x 50 diam. 13. Tracheal branchia of
the 3rd abdominal paii-, x 50 diam. (In fluid.)

Plate XXXIII.

Blastunts, sp. — Nymph.

Figs. 1-19, all enlarged. — 1. Dorsal view of insect with defective set;e, of advanced grade, in a con-
ventional attitude. 2. Ventral view of head and body of the same. 3. Antenna, x 25 diam.
4. Exterior of labriim, x 30 diam. 5. Right mandible, x 45 diam. 6. Left mandible, x 45
diam. 7. First maxilla and palpus, x 45 diam. 8. Underside of labium, 2nd maxillae, and
palpi, X 40 diam. 9. Dorsal view of tongue and paraglossiB, x 40 diam. 10. Fore leg,

11. Intermediate leg, 12. Hind leg, each x 13 diam. 13-19. Tracheal branchise of the abdo-
men (one of every pair) numbered successively from the foremost, all x 15 diam. (In alcohol.)

Plate XXXIV.

Choroterpes Picteti. Nymph.
Figs. 1-20, all enlarged. — 1. Dorsal view of insect of advanced grade. 2. Ventral view of head and
body of the same. 3. Antennae, x 25 diam. 4. Exterior of labrum, x 20 diam. 5. Right
mandible, with tendon attached, x 30 diam. 6. Left ditto. 7. First maxilla and palpus,
X 20 diam. 8. Point of the lacinia of the same maxilla reversed, x 60 diam. 9. Underside
of labium, 2nd maxillse, and palpi, x 20 diam. 10. Dorsal view of tongue and paraglossae,
X 20 diam. 11. Fore leg, 12. Intermediate leg, 13. Hind leg, all x 20 diam. 14-20.
Tracheal branchiae of the abdomen (one of every pair) numbered consecutively from the
foremost, all x 20 diam. (In fluid, from Portugal.)

Plate XXXV.

Tltraulus bellus. Nymph.
Figs. 1-22, all enlarged. — 1. Dorsal view of insect of very advanced grade, with the legs in a
conventional pose, but otherwise in a quiescent posture. 2. Ventral view of the head and
body of the same. 3. Autennee, x 30 diam. 4. Exterior of labrum, x 30 diam. 5. Right
mandible, with tendon attached, x 60 diam. 6. Left ditto. 7. First maxilla and palpus,
X 30 diam. 8. Point of the lacinia of the same maxilla reversed, x 60 diam. 9. One of the
pectinate spinules or bristles of the preceding, more enlarged. 10. Underside view of labium,
2nd maxillae, and palpi, x 30 diam. 11. Dorsal view of tongue and paraglossae, x 30 diam.
12. Fore leg, 13. Intermediate leg, 14. Hind leg, all x 20 diam. 15-21. Tracheal branchiae
of the abdomen (one of every pair) numbered consecutively from the foremost, all x 20 diam.
22. The foremost of these x 45 diam. (From Cintra, in fluid.)

Plate XXXVI.

Habrophlebia fusca. Nymph.
Figs. 1-24, all enlarged. — 1. Dorsal view of insect of advanced grade in repose. 2. Ventral view of
head and body of another specimen. 3. Antenna, x 25 diam 4. Exterior of labrum,
X 50 diam. 5 and 6. Right and left mandibles with tendon attached, x 65 diam. 7. First

45*

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

maxilla and palpus, x 65 diam. 8. Part of the laciuia of the same maxilla reversed, x 65
diam. 9. One of the pectinate spinules at the extreme point of the same, more enlarged.
10. Underside of hypopharynx, labium, 2nd maxillae, and palpi, x 65 diam. 11. Part of the
same reversed, x 65 diam. 12. Dorsal view of tongue and paraglossse [no record of
enlargement]. 13-15. Fore, intermediate, and hind legs numbered consecutively, X 20 diam.
16-22. Tracheal branchise of the abdomen (the right one of every pair) numbered consecutively
from the foremost, all x 20 diam. 23. The foremost of the same, x 35 diam. 24. The
outer and median caudal setae, x 20 diam. (In fluid.)

Plate XXXVII.

Ephemerdla igmta. Nymph.

Figs. 1-20, all enlarged. — 1. Dorsal view of $ insect, with legs in a conventional posture ; a light-
coloured specimen captured in the Holybrook above Reading, Berks, similar to that figured by
Pictet, op. cit. pi. xxix. 1, and of very advanced grade. 2. Ventral view of a dark ^ specimen
captured in a trout-stream, similar to that figured by Pictet, op. cit. pi. xxxiii. 1, and of very
advanced grade. 3. Head of <S , from in front. 4. Antenna, x 50 diam. 5. Exterior of
labrum, x 50 diam. 6 and 7. Right and left mandibles, with tendon attached, x 80 diam.
8. First maxilla and palpus, x 80 diam. 9. Underside view of labium, 2nd maxillae, and palpi,
X 85 diam. 10. Dorsal view of tongue and paraglossae, x 50 diam. 11-13. Legs numbered
consecutively, x 40 diam. 14-18. Tracheal branchiie of the abdomen (the left one of every
pair) numbered consecutively from the foremost, x 45 diam. 19. The third of the same
reversed to display the lamclligerous appendage, x 70 diam. 20. Outer and median caudal
setfe of J" , X 25 diam. (In fluid.) This Plate underwent considerable revision upon the stone
before publication.

Plate XXXVIII.

Figs. ]-10. Nymph No. I., allied to Ephemerella, described at p. 131. Figures all enlarged. —
1. Dorsal view of insect of advanced grade, with the legs disposed conventionally. 2. Ventral
view of head and body of the same. 3. Front view of head, x 12 diam. 4. First maxilla and
palpus, X 70 diam. 5. The same reversed. 6-8. Legs of the left side numbered in succession,
X 15 diam. 9. Spinules of the lower edge of the fore femur, x 60 diam. 10. A hair from
the upper edge of the hind femur, x 95 diam. (In alcohol.)

Figs. 11-15. Nymph No. II. (p. 131). Figures all enlarged. — 11. Dorsal view of insect of advanced
grade, in repose. 12. Ventral view of head and body of the same. 13. Side view of the
same. 14. Front view of head. 15. First maxilla and palpus, x 40 diam. (In alcohol.)

Plate XXXIX.

Nymph No. III., allied to Ephemerella, described at p. 132.
Figs. 1-22, all enlarged. — 1. Dorsal view of insect of very advanced grade. 2. Dorsal view of the
headless body of a younger specimen, with the tracheal branchiae removed from the right side
of the abdomen and depressed on the left side of the same. 3. Ventral view of head and
body of the same. 4. Front view of head, x 12 diam. 5. Antenna, x 30 diam. 6. Exterior
of labrum, x 40 diam. 7. Right mandible, x 65 diam. 8. Left mandible, with part of
the stipes omitted, x 65 diam. 9. Molar surface of the same, x 170 diam. 10. First
maxilla and palpus, x 65 diam. 11. Underside of labium, 2nd maxilla;, and jjalpi, x 40 diam.

EEV. A. E. EATON ON RECENT EPHEMERID.E OE MAYFLIES. 339

12. Upperside of labium and 2iid maxillfe, x 40 diam. 13. Doi'sal view o£ tongue and
paraglossse, x 40 diam. 14—16. Legs numbered in succession, x 13 diam. 17-22. Tracbeal
branchiae of the riglit side of the abdomeu, one of every pair, together with a second figure of
the third of them; figures 17, 18, and 20-22 represent the complete series numbered consecu-
tively from the foremost ; figure 19 is the reverse of the tliird in the series. (In alcohol.)

Plate XL.

Figs. 1-17. Nymph No. IV., allied to Ephemerella, described at p. 133. Figures aU enlarged. —
1. Dorsal view of a nymph-skin out of which the subimago had emerged. 2. Ventral view of
head and body of the same. 3. Vertical view of head, x 10 diam. 4. Exterior of labrum,
X 25 diam. 5 and 6. Right and left mandibles, x 40 diam. 7. First maxilla and palpus,
X 40 diam. 8. Underside of labium, 2nd maxilhe, and palpi, x 40 diam. 9. Dorsal view of
tongue and paraglossse, x 40 diam. 10-12. Legs, numbered successively from the foremost,
X 12 diam. 13-lG. Tracheal branchiffi of the abdomen, one of every pair, numbered consecu-
tively from the foremost, x 25 diam. 17. The third of them reversed, x 25 diam. (In
alcohol.)
Figs. 18-20. Nymph No. V., allied to Ephemerella, described at p. 133 [Supplemented by PI. LXIV.
figs. 3-8]. Figures all enlarged. — 18. Dorsal view of insect of advanced grade. 19. Ventral
view of head and body of the same. 20. Tracheal brauchia of the 3rd abdominal pair,
reversed. (In alcohol.)

Plate XLI.

Reputed Nymph of Tricorythus.
Pigs. 1-20, all enlarged. — 1. Dorsal view of insect of very advanced grade. 2. Ventral view of head
and body of the same. 3. Antenna, x 35 diam. 4. Exterior of labrum, x 35 diam.
5. Right mandible with tendon attached, x 65 diam. 6. Left ditto, x 65 diam. 7. First
maxilla and palpus, x 65 diam. 8. Tongue and paraglossse, x 35 diam. 9-11. Legs
numbered consecutively from the foremost, x 20 diam. 12. Foremost right abdominal
tracheal branchia [after Vayssi^re]. 13-17. Left tracheal branchiae of the remaining pairs
numbered consecutively, x 30 diam. 18. Left tracheal branchia of the 2nd abdominal pair
reversed, showing the marginal flange along the inner border, x 30 diam. 19. Part of the
exterior of the right tracheal branchia of the same pair, showing the row of hairs along the
inner border which hitch under the flange of the opposite one, x 30 diam. 20. Outer and
part of the median caudal setaj, x 15 diam. 21. Underside of labium, 2nd maxillae, and
palpi, X 65 diam. (In alcohol, from Dr. E. Joly ; captured at Toulouse.)

Plate XLII.

Canis halterata, figs. 1, 2, 7-17, and 22-25 ; a species from Portugal figs. 3, 4; and C luctuosa,
— Harrisella, figs. 5, G, 18-21, and 27-28. Nymphs. Figures all enlarged. — 1. Dorsal
view of insect of advanced grade, at rest, but with the intermediate legs disposed somewhat
conventionally. 2. Vertical view of head, showing the large rounded hinder ocelli prominent
above the oculi, x 30 diam. 3. Dorsal view of insect of very advanced grade, and of another
species, remarkable for the dilated lateral borders of the notum. 4. Ventral view of head and
body of the same. 5. Vertical view of head of C. Harrisella, remarkable for the conical
tubercles upon the sites of the ocelli, x 20 diam. 6. Antenna, x 50 diam. 7. Exterior of
labrum, x 65 diam. 8. Right mandible with tendon, x 100 diam. 9. Left ditto. 10. Part
of right mandible of another specimen placed to disjflay the fangs, x 50 diam. 11. The same

340 EEV. A. E. EATON ON RECENT EPHEMEEID^ OR MAYFLIES.

placed to display the molar surface, x 50 diam. 12. First maxilla and palpus, x 100 diatn.
13. Underside of labium, 2nd maxillae, and palpi, x 100 diam. 14. Dorsal view of tongue and
paraglossse, x 50 diam. 15-17. Legs numbered successively from in front, X 35 diam.
18-20. Legs of C Harrisella correspondingly numbered, x 20 diam. 21. Foremost right
tracheal branchia of the abdomen of the same, x 30 diam. 22-26. Left tracheal branchiiB of
the remaining abdominal pairs of C. halteraia numbered consecutively from the foremost (the
first of them, fig. 22, reversed), x 35 diam. 27. Exterior of the right tracheal branchia of the
2nd abdominal pair of C. Harrisella, x 30 diam. 28. Caudal setae of the same, x 20 diam.
[The terminal segment in this figure appears to be of questionable form.] (The named
nymphs were English specimens preserved in the glycerine water-and-spirits solution; the
Portuguese nymph was in an alcoholic solution.)

Plate XLIII.

Prosopistoina foliaceum. Nymph.

Figs. 1-12, all enlarged. — 1. Dorsal view of $ insect at rest, with setae partially retracted. 2. Ventral
view of the same, with the right legs cut off and the left legs slightly displaced to show the
depressions in which the femora are laid. 3. Antenna, x 100 diam. 4. Labrum and clypeus,
X 45 diam. 5. Eight mandible, furnished with an unusually long endopodite, x 90 diam.
6. First maxilla and palpus, x 90 diam. 7. Underside of labium and mentum, x 25 diam.
8. Underside of labium and 2nd maxillary palpi, x 65 diam. 9. Fore leg, x 40 diam.
10. Spinules of fore tibia, x 210 diam. 11. Intermediate leg, x 40 diam. 12. Hind leg,
x 40 diam. (From Dr. E. Joly, captured at Toulouse; in alcohol.)

Plate XLIV.

Baetis rhodani. Nymph.

Figs. 1-20, all enlarged. — 1. Dorsal view of ? insect of very advanced grade in repose (the legs not quite
in perspective). 2. Side view of head of the same. 3. Oblique under front view of the same,
x 35 diam. 4. Antenna, x 35 diam. 5. Exterior of labrum, x 35 diam. 6. First maxilla
and palpus, x 70 diam. 7. Right mandible and tendon, x 70 diam. 8. Left ditto.
9. Underside of labium, 2nd maxillae, and palpi, x 35 diam. 10. Dorsal view of tongue and
paraglossae, X 35 diam. 11-13. Legs numbered consecutively from the foremost, x 25 diam.
14^20. Right tracheal branchiae of every abdominal pair numbered consecutively from the
foremost, x 35 diam. (In alcohol.)

Plate XLV.

Nymph allied to Ce7i(roptilum, from Peru.
Figs. 1-19, all enlarged. — 1. Dorsal view of insect of advanced grade. 2. Ventral view of the same.
3. Part of antenna, x 40 diara. 4. Laln-um, x 50 diam. 5. Right mandible and tendon,
X 75 diam. 6. Left ditto. 7. First maxilla and palpus, x 50 diam. 8. Underside of
labium, 2nd maxillae, and palpi, x 40 diam. 9. Dorsal view of tongue and paraglossae, x 50
diam. 10-12. Left legs numbered consecutively, X 25 diam. 13-18. Right tracheal branchiae,
one of every abdominal pair, nvimbered consecutively from the foremost, x 40 diam. (In
alcohol.)

EEV. A. E. EATOX OX EECEXT EPHEMEEID^ OE MAYFLIES. 341

Plate XLVI.

CentroptUum luteolum. Nymph.
Figs. 1-19, all enlarged. — 1. Dorsal view o£ insect of advanced grade, in repose. 2. Ventral view of
head and body of the same. 3. Antenna, x 25 diam. 4. Exterior of labrum, x 65 diam.
5. Eight mandible with tendon attached, x 100 diam. 6. Left ditto. 7. First maxiUa
and palpus, x 100 diam. [The palpus is only 3-jointed. The artist has mistaken the prop
upon which the palpus is inserted for a 4th joint, and focussed the underlying edge of the
stipes. Compare the corresponding figures in Pis. XLVII. & L.] 8. Underside of labium,
2nd maxillae, and palpi, x 65 diam. 9. Dorsal view of tongue and paraglossas, x 65 diam.
10-12. Legs numbered consecutively from the foremost, x 30 diam. 13-19. Tracheal
branchiae of the abdomen, one of every pair, numbered consecutively from the foremost, x 60
diam. (In fluid.)

Plate XLVII.

Clo'eon riifulum, figs. 1 & 4, c. simile, figs. 2, 3, 5-21, and c. dipterum, fig. 22. Nymphs. Figures all
enlarged. — 1. Dorsal view of? insect of advanced grade, in repose [the legs not in perspective].

2. Side v-iew of prothorax and head, with the fore leg and antenna cut off, x 25 diam.

3. Front view of head, x 25 diam. 4. Antenna, x 18 diam. [The antennae of the other
species are much shorter and have fewer joints.] 5. Exterior of labrum, x 35 diam. 6. Right
mandible, x 70 diam. 7. Left ditto with part of the stipes omitted. 8. Lacinia and palpus
of the right 1st maxilla, x 70 diam. 9. Left 1st maxilla and palpus, x 70 diam. 10. Under-
side view of labium, 2nd maxillae, and palpi, x 35 diam. 11. Dorsal view of tongue and
paraglossfe, x 35 diam. 12-14. Legs numbered successively from the foremost, x 18 diam.
15-21. Right tracheal branchiae of the abdomen reversed, one of every pair, x 25 diam.
22. Right and median caudal seta^ x 10 diam. [The tail-points of most of the species are
short like these.] (In fluid.)

Plate XLVIII.

Callibtetis, sp. Nymph.
Figs. 1-19, all enlarged. — 1. Dorsal view of ? insect of very advanced grade. 2. Ventral view of
head and body of the same. 3. Antenna, x 23 diam. 4. Exterior of labrum, x 45 diam.
5. Right mandible with tendon attached, x 65 diam. 6. Left mandible, x 65 diam. 7. First
maxilla and palpus, x 65 diam. 8. Underside of labium, 2nd maxillae, and palpi, x 35 diam.
9. Dorsal view of tongue and paraglossae [enlargement unrecorded] . 10-12. Legs numbered
successively from the foremost, x 20 diam. 13-19. Right tracheal branchiae (in reverse) of
the abdomen, one of every pair, numbered consecutively from the foremost, x 30 diam. (In
alcohol, from Dr. Hagen.)

Plate XLIX.

? Chirotonetes, sp. Nymph.
Figs. 1-19, all enlarged. — 1. Dorsal view of insect of very advanced grade, in a conventional posture.
2. Ventral dew of head and body of the same. 3. Antenna, x 30 diam. 4. Labrum, x 30
diam. 5. Right mandible, with tendon attaclied and muscular tissue within the hollow of the
stipes, X 50 diam. 6. Left ditto. 7. First maxilla and palpus, x 50 diam. 8. Underside
of labium, 2nd maxillae, and palpi, x 50 diam. 9. Dorsal view of tongue and parao-lossie
X 30 diam. 10-12. Legs numbered successively from the foremost, x 15 diam. 13-19.
Right tracheal branchiic (in reverse) of the abdomen, one of every pair, x 50 diam. (lu
alcohol, from Dr. Hagen.)

342 EEV. A. E. EATON ON RECENT EPHEMERID.E OK MAYFLIES.

Plate L.

Siphlurus lacustris, figs. 1, 4-6, & 9-19; aud a nameless Portuguese species, figs. 2, 3, 7, 8, & 20-26.
Nymphs. Figures all enlarged. — 1. Dorsal view of ^ insect of very advanced grade at rest,
with tracheal branchiae spread; the legs not in pci'spective. 2. The same view of a ? of rather
younger grade of another species, with the tracheal branchiae depressed. 3. Ventral view of
head and body of the same. 4. Side view of head and part of thorax, x 8 diam. 5. Antenna,
X 30 diam. 6. Exterior of labrum, x 35 diam. 7. Right mandible with tendon attached,
X 35 diam. 8. Left mandible, x 35 diam. 9. The same, with the tendon, placed to display
the fangs, x 30 diam. 10. First maxilla and palpus, x 45 diam. [The joining above the
prop of the palpus is distended witli fluid accidentally.] 11. Underside or exterior view of
labium, 2nd maxillfe, and palpi. 12. Partial view of the same reversed. 13. Dorsal view of
tongue and paraglossa;, x 35 diam. 14-16. Legs numbered successively from the foremost,
X 16 diam. 17-19. Right tracheal branchise of the 1st, 3rd, and 7th abdominal pairs of
£(. lacustris, x 25 diam. 20-26. Right tracheal branchise of the abdomen, one of every pair,
of the other species, x 15 diam. [S. lacustris in fluid; the other species in alcohol.)

Plate LI.

Oniscigaster Wakefieldi. Nymph.

Figs. 1-23, all enlarged. — 1. Dorsal view of ^ insect about | grown, placed in a conventional
attitude. 2. Ventral view of head and body of the same. 3. Side view of head and part of
thorax, x 8 diam. 4. Front view of the head from above, x 8 diam. 5. The same from
below, x 8 diam. 6. Antenna, x 30 diam. 7. Exterior of labrum, x 30 diam. 8. Right
mandible with tendon attached, x 30 diara. 9. Left ditto. 10. First maxilla and palpus, x
30 diam. 11. Underside of labium, 2nd maxilhe, aud palpi, x 30 diam. 12. Dorsal view of
tongue and paraglosste, x 30 diam. 13-15. Legs numbered successively from the foremost,
X 11 diam. 10-21. Right tracheal branchiae of the abdomen, one of every pair, numbered
consecutively from the foremost, x 11 diam., in outline. 22 & 23. Finished di-awings of the
1st and 2nd of the same, x 20 diam., with the adjoining jjleura. (In alcohol.)

Plate LI I.

Ba-tisca obesa. Last slough cast by (J nymph.

Figs. 1-14, all enlarged. — 1. Dorsal view of slough. [The antennae were originally represented in
this figure ; but as they are out of sight when the insect is alive, they were erased in the proving,
and only a very faint indication of the left antenna was allowed to remain.] 2. Ventral
view of head and body of the same. 3. Side view of head and part of thorax, with the
antenna partly removed. 4. Antenna, x 75 diam. 5. Exterior of labrum, x 35 diam.
6. Right mandible Avith part of tendon, x 60 diam. 7. Left ditto. 8. First maxilla and
palpus, with membrane attached to the stipes, x 60 diam. 9. Underside of labium, 2nd
maxillae and palpi, mentum, and hypopharynx, x 35 diam. 10. Dorsal view of tongue and
paraglossffi, x 35 diam. 11-13. Right legs numbered successively from the foremost, X 19
diam. 14. Underside of the right and median caudal setae, with part of the extremity of the
abdomen, x 25 diam. (Slough scalded.)

EEV. A. E. EATON ON EECENT EPIIEMERID.E OR MAYFLIES. 343

Plate LIII.

Last slough cast by the nymph of a nameless insect, described at pp. 229-230.

Figs. 1-14, all enlarged. — 1. Dorsal view of slough, defective in flie sette and in the five hinder pairs
of abdominal tracheal branehiiB. 2. Antenna, x 35 diam. 3. Exterior of labrum [attached
to the frons, with antennae partly removed], x 10 diam. 4 & 5. Left mandible in two
jDOsitions, x 20 diam. G. First maxilla and palpus, with a portion of the tongue (paraglossa)
adhering, x 12 diam. 7. The same palpus, x 65 diam. 8. Underside of labium, 2ud
maxillae, palpi, &c., x 12 diam. 9. One of the same palpi, x 25 diam. 10-12. Legs
numbered successively from the foremost, x 10 diam. 13. One of the tracheal branchiae of
the foremost abdominal pair, x 12 diam. 14. Right tracheal branchia of the 2nd abdominal
pair, in reverse, x 12 diam. (Slough dried; scalded.)

Plate LIV.

Rhith'ogena aurantiaca and [figs. 3 & 4] Rh. semicolorata. Nymphs.

Figs. 1-24, all enlarged. — 1 Dorsal view of insect of very advanced grade, in repose, with tracheal
branchiae spread. 2. Ventral view of head and body of the same. 3. Dorsal view of another,
with the laminae of the tracheal branchiae deflected. 4. Side view of the same. 5. F'ace,
upside down, with antennae partly removed, x 12 diam. 6. Antenna, x 35 diam. 7. Labrum,
x 35 diam. 8. Right mandible, x 60 diam. 9. Left ditto, x 60 diam. [Point of mandible
more enlarged, PI. LXV. 6.] 10. First maxilla and palpus, x 35 diam. 11. Underside of
labium, 2ud maxillae, and palpi, x 35 diam. 12. Ditto, reversed. 13. Dorsal view of tongue
and paraglossae, x 35 diam. 14-16. Left legs, numbered successively from the foremost, x
15 diam. 17-23. Tracheal branchiae of the abdomen, one of every i^air, numbered consecutively
from the foremost, x 25 diam. 24. Left and median caudal setae, x 15 diam. [Rh. auran-
tiaca, in fluid, from Tarascon, Ariege ; Rh. semicolorata, in alcohol, from Dorset.)

Plate LV.

Iron, sp. Nymph.

Figs. 1-19, all enlarged.— 1. Dorsal view of insect of very advanced grade. 2. Ventral view of head
and l)ody of the same. 3. Face with antennae partly removed. 4. Antenna, x 30 diam.
5. Exterior of labrum, x 80 diam. 6. Right mandible, x 50 diam. 7. Left ditto. 8. First
maxilla and palpus, x 65 diam. 9. Underside or exterior of labium, 2nd maxilhe, and palpi,
x 30 diam. 10-12. Right legs [with the hairs of the tibiie accidentally thrown backwards,
and those of the tarsi out of sight] numbered successively from iu front, x 15 diam. 13-
19. Tracheal branchia; of the abdomen, one of eveiy pair, numbered consecutively from the
foremost, x 30 diam. [In alcohol, from Dr. Hagen.]

Plate LVI.

Epeorus torrentium. Nymph.
Figs. 1-22, all enlarged. — 1. Dorsal view of J insect of very advanced grade, in repose. 2. Ventral
view of head and body of the same. 3. Face, x 9 diam. 4. Antenna, x 30 diam.
5. Exterior of labrum, x 30 diam. 6. Right mandible, x 50 diam. 7. Left, ditto. 8. First
maxilla and palpus, x 30 diam. 9. Underside or exterior of labium, 2nd maxillae, and palpi,
X 25 diam. 10. Upperside or interior of ditto. 11. Tongue and paraglossae, x 30 diam.
12-14. Left legs, numbered successively from the foremost, x 10 diam. 15-21. Tracheal
branchiae of the abdomen, one of every pair, numbered consecutively fi-om in front, x 20 diam.
22. One caudal seta and part of the other, x 12 diam. [In alcohol, from Tarascon, Ariege.]
SECOND SERIES. — ZOOLOGY, VOL. III. 46

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

Plate LVII.
Nymph No. I., allied to Ecdyurus, described at p. 262.

Figs. 1-21, all enlarged. — 1. Dorsal view of insect of very advanced grade. 2. Ventral view of head
and body of the same. 3. Face, x 12 diam. 4. Part of antenna, x 40 diam. 5. Labrum,
X 35 diam. 6. Right mandible, x GO diam. 7. Left ditto. 8. First maxilla and palpus, x
40 diam. 9. Underside or exterior of labium, 2nd maxillae, and palpi, x 20 diam. 10. Dorsal
view of tongue and paraglossae, x 35 diam. 11-13. Right legs, numbered successively from
the foremost. 14-20. Tracheal branchiae of the abdomen, one of every pair, numbered
consecutively from the foremost, the 2nd reversed to display the arrangements of the fibrils,
X 35 diam. 21. Median and part of the left caudal sette, x 12 diam. (In alcohol.)

Plate LVIII.

Nymph No. II., allied to Ecdyurus, described at p. 263.

Figs. 1-21, all enlarged. — 1. Dorsal view of insect of advanced grade. 2. Ventral view of head and
body of the same. 3. Face, x 12 diam. 4. Antenna, x 40 diam. 5. Interior surface of
labrum, x 20 diam. 6. Part of the right mandible, x 35 diam. 7. Left mandible, x 35 diam.
8. Fii'st maxilla and palpus, x 35 diam. 9. Underside of labium, 2nd maxilhe, and palpi,
X 15 diam. 10. Dorsal \'iew of tongue and paraglossae, x 15 diam. 11. Right fore leg,
X 20 diam. 12 & 13. Left legs of the other pairs, numbered successively, x 20 diam.
14-20. Tracheal branchiae of the abdomen, one of every pair, numbered consecutively from
in front, x 30 diam. 21. The 3rd of them reversed to display the explanate webbed fibrils,
X 40 diam. (In alcohol.)

Plate LIX.

Nymph No. III., allied to Ecdyurus, described at p. 264.
Figs. 1-19, all enlarged. — 1. Dorsal view of ? insect of very advanced grade, lacking setae. 2. Ventral
view of head and body of the same. 3. Part of antenna, x 50 diam. 4. Inner side of labrum,
X 50 diam. 5. Right mandible, x 70 diam. 6. Left ditto. 7. First maxilla and palpus,
X 70 diam. 8. Underside or exterior of labium, 2nd maxillae, and palpi, x 25 diam. 9. Dorsal
view of tongue and paraglossia, x 50 diam. 10-12. Right legs of every pair, numbered
successively from the foremost. 13-19. Tracheal branchiae of the abdomen, one of every
pair, numbered consecutively from in front, x 50 diam. (In alcohol.)

Plate LX.

Heptagenia [ccerulans] gaUica. Nymph.
Figs. 1-23, all enlarged. — 1. Dorsal view of ? insect of very advanced grade, at rest. 2. Ventral
view of thorax and abdomen of another ? specimen. 3. Face. 4. Underside of head.
5. Antenna, x 35 diam. 6. Exterior of labrum, x 25 diam. 7. Right mandible, x 40 diam.
8. Left ditto. 9. First maxilla and palpus, x 40 diam. 10. Underside of labium, 2nd
maxillae, and palpi, x 25 diam. 11. Dorsal view of tongue and paraglossae, x 30 diam.
12. Left fore leg, x 12 diam. 13 & 14. Right legs of the other pairs, numbered successively
from the foremost, x 12 diam. 15-21. Tracheal branchiae of the abdomen, one of every pair,
numbered consecutively from in front, x 30 diam. 22. The 1st of them reversed, to display
the fibrils x 30 diam. 23. Right and median caudal setae, x 12 diam. (In alcohol, from
Toulouse.)

EEV. A. E. EATON OX EECENT EPHEMEEID-E OR MAYFLIES. 345

Plate LXI.

Nymph of junior grade, perhaps of an Ecdyurus allied to E. renosus, but possibly of one
related more nearly to E. lateralis : see p. 277.
Figs. 1-17, all enlarged. — 1. Dorsal view of insect about | grown. 2. Ventral view of head and body
of the same. 3. Part of antenna, x 30 diam. 4. Labrum, x 35 diam. 5. Right mandible,
X 70 diam. 6. Left ditto. 7. First maxilla and palpus, x 35 diam. 8. Underside of labium,
2nd maxillse, and palpi, x 17 diam. 9. Dorsal view of tongue and paraglossse, x 30 diam.
10. Right intermediate leg, x 13 diam. 11-17. Tracheal branchiae of the abdomen, one of
every pair, numbered consecutively from in front, x 35 diam. (In alcohol.)

Plate LXII.

Ecdyurus fluminum [ — angustlpennis, figs. 1 & 4—23], E. venosus [figs. 2 & 3], and another [perhaps
a junior grade of E. venosus, or perhaps of E. lateralis, figs. 24 & 251. Nymphs.

Figs. 1-25, all enlarged. — 1. Dorsal view of insect of moderately advanced grade. 2. Ventral view
of head and body of another of very advanced grade. 3. Face of the same. 4. Antenna,
X 30 diam. 5. Labrum, x 20 diam. 6. Right mandible, x 50 diam. 7. Part of the left
ditto. 8. First maxilla and palpus, x 20 diam. 9. Point of the lacinia of the same, x 170
diam. 10. Underside of labium, 2nd maxilUe, and palpi, x 20 diam. 11. The same reversed,
X 20 diam. 12. Dorsal view of tongue and paraglossje, x 20 diam. 13-15. Right legs, one
of each pair, numbered successively from the foremost, x 10 diam. [In the original drawings
the markings were not shown in any of these figures, the specimens being faded ; but
subsequently the markings of a newly killed specimen of E. renosus were introduced into
fig. 13.] 16-22. Tracheal branchiae of the abdomen, one of every pair, numbered consecutively
from in front, x 20 diam. 23. Median and right caudal setae, x 7 diam. 24. Dorsal view of
insect of junior grade. 25. Right tracheal branchiae of the 3rd pair of the same, x 40 diam.
[E. fluminum in fluid; the others in alcohol.)

Plate LXIII.

Figs. 1-13. Hexayenia, sp. Nymph. Supplementary to PI. XXIX. Figures all enlarged. —

1. Antenna, x 20 diam. 2. Exterior of labrum, x 25 diam. 3. Right mandible, x 20 diam.

4. Left ditto. 5. First maxilla and palpus, x 25 diam. 6. Underside of labium, 2nd

maxillae, and paljDi, x 25 diam. 7. The same reversed [showing only the bases of the palpi].

8. Dorsal view of tongue and paraglossae, x 20 diam. 9. Right fore leg, x 9 diam.

10. Ditto in reverse. 11 & 12. The other right legs, numbered consecutively, x 9 diam.

13. Tracheal brancliire of the 1st abdominal pair, x 25 diam. (In alcohol.)
Figs. 14-17. Ephemera; forceps of adult ,-J of four species. Supplementary to PI. VIII. Figures all

enlarged.^ — 14. E. compar (dried). 15. E. guttulata (dried). 16. E. simulans, with the

penis-lobes (in alcohol). 17. E. varia, with the penis-lobes (dried).

Plate LXIV.

Supplementary to earlier Plates. Figures 3-8 drawn by A. T. Hollick ; the other
figures by the Author. All enlarged.

Figs. 1, la. Atalophlebia fasciata [Supplemental to PI. X.]. — 1. Penis of adult 6 in profile; 1 a. Ditto,
supine.

46*

346 EEV. A. E. EATON ON RECENT EPHEMERID.E OR MAYFLIES.

Figs. 2,2 a. Habrophlebia fusca [Suppl. to PI. XIII. 22«].— 2. Fore leg of adult ? . 2 a. Tarsus of
ditto, more enlai-ged.

Fios. 3-8. Abdominal tracheal branehiaj of a nameless N. -American nymph, allied to Ephemerella
[Suppl. to PL XL. 18-20]. — 3-7. One of every pair, numbered consecutively from the fore-
mast, viewed prone. 8. One of the 2nd pair, supine. All enlarged 30 diam.

Figs. 9-20. Genitalia of adult ^ Ba'ctis [Suppl. to PI. XVI. 29]. — 9. B. scambus, forceps-limb.
10. B. vemistulus, ditto. 11. Penis of the same. 12. B. rhodani, forceps-limb. 13. B.
Bocaffii, ditto. 14. B. gemellus, ditto. 15. B. Atrebatinus, ditto. 16. B. tenax, ditto.
17. B. melanonyx, ditto. 18. B. alpinus, ditto. 19. B. buceratus, ditto. 20. B, pumilus,
ditto.

Fig. 21. Ctntroptilum Udeolum, fore leg of ? adult [Suppl. to PL XVII. 30].

Figs. 22-24-. Ameletus, tarsus and forceps-basis [Suppl. to PL XVIII. ? 34]. — 22. A. dissitus, forceps-
basis. 22 a. Hind tarsus. 23. A. subnotatus, {orce]^s-hasis. 24. A. exquisitus, ditto.

Fig. 25. Dipieromimns tipuliformis, hind wing [Suppl. to and corrective of PL XX. 35].

Fig. 26. Siphlurus occidentalis, forceps-basis [Suppl. to PL XX. 34].

Plate LXV.

Supplemeatary to earlier Plates. Figures of details, all enlarged, drawn by the Author.

Fig. 1. Bleptus fasciatus : — limbs, hinder tarsi, and liind wing of adult ^J [Suppl. to PL XXIV.].

Figs. 2 & 3. Iron : — ventral views of adult J* genitalia, dried [Suppl. to PL XXIV. 44] . — 2. /. longi-
mauus. 3. /. ii'itidus.

Figs. 4 & 5. Cinygma: — -veutj-al views of adult <^ genitalia, dried [Suppl. to PI. XXIV.]. — 4. C. inte-
grum. 5. C. par.

Fig. 6. Rhithrogena aiirantiaca. nymjih [Suppl. to PL LIV. 8] . Fangs of the right mandible, viewed
from above, under pressure, enlarged 173 diameters.

Fig. 7. Epeorus psi : — ventral view of adult ,^ genitalia, in alcohol [Suppl. to PL XXIV. 44 a].

Fig. 8. [Suppl. to Pis. XII. & XIII.]. — Hind wing of a nameless N. -American insect in Mus. Comp.
ZooL, Cambridge, Mass., ticketed No. 78, Kentucky, 7. iii. 1882.

Fig. 9. Ephemerella notata : — ventral view of adult ^ genitalia (living) [Suppl. to PL XIV.].

Figs. 10 & 11. Ba'etis: — hind wings [Suppl. to PL XVI.]. — 10. B. consuetus. 11. B. solidus. Enlarged
106 diameters.

Fig. 12. Ceniroptilum Putyi: — hind wing [Suppl. to PL XVII. 30]. Enlarged 137 diameters.

Fig. 13. Ameletus inopinatus : — ventral view of adult J" forceps, dried [Suppl. to Pis. XVIII. ? 34 and
LXIV. 22-24].

Additions and Corrections (coutinued from p. 325).

P. 282, 1. 18 from bottom, for venosus read venosa.
P. 302, 1. 12 from top, before fuscus insert ||.

P. 315, 1. 20, for Culuhiu-us [preoccupied in Entomology] read Coloburiscus.
P. 320, before 1. 7 from bottom iii3iTt : — P. 142, after 1. 10 from top read

Synonymy. Brachycercas, Curtis (1834), applicable only to 5 and subimago specimens. Jlacrocemts, Westwooii,
Partington's Brit. Cycloped. ii. 439 (1830), appropriate only to the (S im.

1 ND E X.

'Additions and CoiTcctious,320,346.
American sp. of Centroptilum, 179 ;

CloiJon, 190.
Analysis gen. Leptophlebia type,

82 ; of Groups, Genera, &c., 309.
Analytical index to descrip. and

illus. of Nymphs, 317.
Asiatic sp. of Ecdyurus, 2S1 ; Hep-

tagenia, 268.

Baetis, Central and S. Amer. sp.
of, 170 ; European sp. of, 158 ;
Indian and Cingalese sp. of, 171 ;
N.-Amer. sp. of, 168.

Central and S.-Amer. sp. of Baetis,

170.
I!entroptilum, American sp., 179.
Characters as basis of classification

not fundamental, 17.
^iugalese sp. of Cloeon, 181.
-loeon, Amer. sp., 190; Cingalese

sp., 181 : European sp., 182.
>08s-veiulets, 6.
'olour, definition shades and tints

of, 1.
Conspectus of classification, 21.

Icdyurus, N.-Amer. sp. of, 278 ;

European and Asiatic sp. of, 281.
igg and Oviposition, 11.
European sp. of Baetis, 158 ; Cloeon,

182 ; Ecdyurus, 281 ; Heptageuia,

268 ; Ehithrogena, 255 ; Siphlu-

lus, 216.

Forceps, of male, 8.
Fore wings, shape, 3; their nerv-
ures, 5.

Genera, group I., 22 ; group II.,

77 ; group III., 199.
Geographical distrib. of Ephemer-

idse, 307.

Habits of Mayflies, 8.
Hairs and hairy covering, 17.
Heptagenia, N.-Amer. sp. of, 266,

323 ; European and Asiatic sp.

of, 268.
Hind wings, shape, 3.
History classification of Ephemer-

idse, 18.

Indian and Cingalese sp. of Baetis,

171.
Introductory Eemarks, 1.

Legs, peculiarities of, 8, 234, 236,
325.

Nervures, fore w ing, groups of, 5 ;

hind wing, groups of, 6.
North-Amer. sp. of Baetis, 168 ;

Ecdyurus, 278 ; Heptagenia, 266 ;

Ehithrogena, 252; Siphlurus,218.
Nymph, habits of, 12 ; characters

and peculiarities of, 13.

Ocelli, size of, 3.
Oviposition and the Egg, 11.

Peculiarities, structural details,

sexes, 3.
Pseudimago, as a term, 17.

Ehithrogena, N.-Amer. sp. of, 252 ;
European sp. of, 255.

Siphlurus, European sp., 216; N.-
Amer. sp., 218.

Structure, Ephemerida in general,
o

Subimago, term now used, 17.
Systematic descrip. of genera and
species, 22.

Tabular classif. of genera, 21.

Tabulation, gen. Siphlurus type,
200; generic identification adults,
type of Ecdyurus, 236 ; Nymphs,
type of Baetis, 155 ; of Ecdyurus,
235 ; of Ephemerella, 123.

Term Nymph, how employed, 12.

Tracheal branchiae, 15 ; respiration,
other organs, 16.

Wing-membrane, structure of, 3.
Wing-neuration, 4.

Young of Ephemeridse, 12.

For the Alphabetical list of Genera and Species see pp. 3-18-352.

348

INDEX.

GENERA AND SPECIES.

Numbers in black type refer to the description of the genus or species. Synonyms are in italics.
Parallels || mark preoccupied names, the double dagger J names misapplied, and vincula [ ] paljeon-
tological names. These last are only inserted to record every name used in the Family.

Adenophlcbia, 82, 111.

colombiw, 110.

dislocans, 112.
Ameletus, 201, 210.

dissitus, 210.

exquisitus, 212.

inopinatus, 307.

subDotatus, 211.
Ametropus, 231.

fragilis, 231, 321.
Anagenesia (subgen.), 25.
Asthenopvs, 40.

curtus, 40.

dorsalis, 41.
Atalopblcbia, 82, 83.

annulata, 85.

australasica, 86.

australis, 86.

chilensis, 91.

costah's, 89.

dentatn, 88.

faseiata, 84.

femoralis, 85.

furcifera, 87.

inconspiciia, 87.

nodularis, 89.

scita, 90.

strigata, 88.

tabularis, 91.

Taprobanes, 85.
Atopopus, 232.

tarsalis, 232.

Baetis, 155, 156.
I B not is, 18.

albivittata, 49.

albus {alba), 47.

alpiuus, 166.

alternata, 219.

amnicus, 166.

angtdata, 50.

angiisfipennis, 2S9.

II annulata, 219.

lanomala, Pict. (1854)].

arida, 200.

atrebatinus. 164.

Baetis

aurantiaca, 259.
australasica, 86.
aictumnalis, 159.
basalis, 298.
BelUeri, 287.
bilineata, 50.
binoculatus, 158.
bioculata or -us, 158.
X bioculata, 168.
Bocagii, 162.
buceratus, 166.
canadensis, 278.

I canadensis, 297, 323.
cerea, 273.
cinguJata, 116.
consuetus, 172.
costalis, 268.

II costalis, 89.

X culiciformis, 161.

ci/anops, 268.

II debilis, 171, 253..

determinata, 233.

dispar, 284.

elegans, 268.
fallax, 293.
fasciatus, 197.

ferainalis, 171.
femorata, 220.

Xfemorata, 219.
ferrugineus, 193.
Jinitimus, 165.
flaveola, 279.
flavescens, 158.
flavida, 216.
fluctuans, 193.
fluminuni, 289.
forciptila, 286.
fusa, Walker for spq.
ftisca, 104.

Wfusca, 252.
fuscatn, 159.

Wfuscata, 129.

?||fuscus, 302.

gemellus, 163.

\_gigantea, Hag. & Pict.
(1S5G)].

Baetis

[grossa, Ilag. & Pict.

(1856)].
y«««/^, 301.
Hageni, 169.
ignava, 101.
ignota, 205.
interlincata, 220.
interpunctata, 2G7.
J interpunctata, 299.
invaria, 129.
iridana, 302.
Krueperi, 281.
lateralis, 294.
J lateralis, 259.
longicaiida, 273.
J longicaiida, 284.
[longipes. Hag. (1854)].
luridipennis, 279.
Zw/ra, 268.
luteoliis, 175.
marginalis, 79, 268.
melanonyx, 165.
mellea, 79.
montana, 302.
J ? montana, 284.
niger (nigra), 167
noccboracana, 280.
oira«, 22S.
obscura, 126.
J obscura, 294.
pJtceops {phceopa), 161.
P/e;e/», 284.
pictus, 195.
posticatus, 169.
propinquus, 169.
pumilus, 166.
jjurpurascens, 284.
pygmffius, 170.
reinota, 202.
reticulata, 94.
rhdJani, 161.
+ rJiodani, var., 163.
nibeseens, 169.
Salviui, 170.
sardoa, 293.
scambus, 160.

Baetis

scita, 90.

semicolorata, 256.

scmitincta, 256.

Siccrf, 208.

solidus, 172.

speciosus, 289.

Stelzneri, 171.

sframinea, 268.

striata, 161.

subfusca, 284.

sulphurea, 268.

sylvicola, 322.

Taprobanes, 85.

tenax, 164.

tessellata, 280.

II tessellata, 192.

torrida, 233.

tindatus, 193.

unicolor, 169.

venosa, 282, 284.

veuustubis, 160.

vernus (verna), 161.

verticis, 278.

vicaria, 280.

vitreatus, 302.

zebrata, 292.
Bffitisca, 226.

obesa, 228.
J Binocithis foUaceus,
1.50.

pennigerus, 150.

pisc.iforme, 150.
Blastunis, 82, 100.

concinnus, 101.

cupidus, 101.

gravastellus, 102.

uebulosus, 103.

? vespertinus, 103.
Bleptus, 243.

fasciatus, 236, 243.
Brachyccrcus, 18.

cliironomiformis, 144.

Harrisella, 146.

minima, 142.
Brachyplilebia, 19.

bioculata, 159.

rS'DEX.

349

C<£neus, Agassiz, Xomen-

clat., for seq.
Caenis, 141.

albida, 139.

arnica, 147.

argentata, 146.

irevicauda, li.3.

ehironomiformis, 14i.

cibaria, 148.

dimidiata, 142.

diminuta, 147.

discolor, 139.

grisea, 14-5.

halterata, 144.

X halterata, 146.

Harrisella, 146.

hilaris, 147.

internipta, 144.

kungu, 148.

lactea, 143.

Xlactea, 144.

lactella, 144.

luctuosa, 146.

macrura, 144.

maxima, 140.

nigra. Hag. MS.

oopbora, 146.

pennata, 143.

perpusilla, 147.

rivulorum, 143.

Tohusta, 145.

sinensis, 1S9.

taricauda, 139.
CaOiarcys, 83, 121.
t Calliarcgs (provisional).
109, 110, 122.

humilis, 122.

IcEtus, 110.

mexicanus, 109.
Callib»tis, 1.3.3, 191.

fasciatus, 197.

ferrugineus. 193.

Hageni, 192.

montanus, 196.

pictus, 195.

SeUacki, 198.

sp. — :, 195.

Tindatus, 196.
Campsurus, 38.

albicans, 39.

albifilum, 39.

curtus, 40.

cuspidatus. 40.

decoloratus, 41.

dorsalis, 41.

Holmbergii, 303.

Campsurus

latipennis, 39.

Xappii, 304.

? pusilla, 47.

quadridentatus, 40.

Wappsei, 303.
Centroptilum, 155,174.

lacustre, 176.

lituratum, 178.

luteolum, 175.

nemorale, 177.

pennulatuui, 176.

Poeyi, 179.

pulchrum, 177.

stenopterys, 178.

tenellum, 178.
Chelysentomon, 1.51.

pennigerum, 1.31.
Chirotonetes, 200, 203.

aridiis, 206.

ignotus, 205.

intermedius, 207.

maneus, 206.

r ornaius, 20S. -321.

siccus. 208.
CMoeon, 179.

dimidiatum, ISS.

dipterum, ls3.
Choroterpes, 83, 104.

lusitanica, 105.

Picteti, 105.
Cinygma, 247.

geminatuQi, 250.

integrum, 236, 248.

inLmus, 249.

par, 249.
Cloe, 19.

ajinis, 183.

albipennis, 175.

alpina. 166.

apicalis, 183.

aufumnalis, 159.

hioculata, 159, ISS.

hrunnea, 294.

cingulata, 116.

cognata, 183.

consueta, 172.

dimidiata, 188.

diptera, 183.

i diptera, 168.

duhia, 190.
fasciata, 197.
ferruginea, 193.
Jluctuans, 193.
fusca, 302.
fuscata, 96.

Cloe

halterata, 175.
horariu, 143.
hyalinata, 175.
litura, 178.
Lorentzii, 197.
maderensis, 161.
t marginalis, ISl.
melanonyx, 165.
mendax, 190.
mollis, 97.
1 obscura, 186.
ochracea, 175.
posticata, 169.
propinqua, 169.
puinila, 167.
tpumita, 159.
tpumila, ISS.
pygmaa, 170.
quebecensis, 297.
rhodani, 161.
rubescens, 196.
SeUacki, 19S.
Siewertii, 296.
signata, 108.
solida, 172.
Stelzneri, 171.
striata, 167.
subinfuscata, 188.
translucida, 175.
tristis, 135.
undata, 196.
i undata, 193.
Ii unicolor, 169 [bis].
cerna, 161.
ticina, 190.
i vicina, 169.
virgo, 1S3.
vitripennis, 297.
Togleri, 296.
Cloeon, 155, 179.
albipenne, 175.
alpina. 166.
autumnalis, 159.
bimaculatum, 182.
bioeulata, 159.
± bioculatum (bioeulata),

16S, 175.
cingulata, 116.
cognatum, 183.
concinnum, 187.
consobrinum, 183.
± culiciformis, 94.
debilis, 171.
dimidiatum, ISS.
J dimidiatum, 183.

Cloeon

dipterum, 182.

discolor, 139.

? dubium, 190.

fasciata, 197.

fuscata, 96.

halterata, 175, 188.

hyalinatum, 175.

/;Yura, 178.

marginale, 181.

marmoratum, 1S3.

melanonyx, 165.

mendas, 190.

obscurum, 183.
obscurum, 186.

ochraceum, 175.

? Oldendorfii, 191.

pallida, 183.

posticata, 169.

pumila, ISS.

Ipumilum, 159.

rhodani, 162.

rufulum, 188.

russulum, ISS, 1S9.

simile, 186.

sinense, 1S9.

sy. — , 182.

striata, 167.

subinfuscatum, 188.

translucida, 175.

u«(fff/<7, 196.

verna, 161.

ricinum, 190.

ci'ryo, 183.

vitripenne, 297.
Cloeopsis

diptera, 183.

+ diptera, rar., 188.
Coloburiscus [for sej.],

308.
II CoZo&ttras, 200, 201.

halenticus [for sej.J, PI.
XIX.

haleuticus, 203.

humeralis, 202.
Compsoneuria, 275.

spectabilis, 275.
[Cronicus, Etn. (1871)].

[anomalus, Pict.].

Dipteromimu5, 201 213.
tipulilormis, 213.

Ecdyonurus, 284.
Ecdyurus, 235, 276.
affinis, 293.

350

INDEX.

JEcAyurus

annulifer, 293.

Bellieri, 287.

canadensis, 278.

fallax, 293.

flumiuum, 236, 289.

forcipula, 280.

guttatus, 301.

helveticus, 236, 282.

insignis, 288.

italicus, 236, 286.

Krueperi, 281.

lateralis, 291.

luridipennis, 279.

quasitor, 284, 286.

venosus, 236, 283.

verticis, 278.

vicarius, 280.

volitans, 291, 325.

zebrata, 292.

Zelleri, 286.
Elassoneuria, 32.

Trimeniana, 32.
Epeorus, 235, 237.

alpicola, 236, 239.

assimilis, 236, 239.

geminus, 236, 238,
322.

longimnnus, 245.

psi, 236, 242.

sylvicola, 322.

torrentiuni, 236, 241.
Ephemera, 68.

albicans, 39.

ii alhipennis, 95.

II alhipennis, 142.

J alhipennis, 45.

X alhipennis, 104.

alhipes, 178.

angttstipennis, 289.

anindata, 183.

apicalis, 126.

atrostoma, 28.

atistralis, 86.

heroUnensis, 283.

hiocwlata, 158.

J hioculata, 161.

J hioculata, 188.

X hioculata, 268.

t hioculata, 2S9.

hrevicauda, 144.

+ hrevicauda, 146.

caudata, 175.

[cellulosa, Hag. (1861)].

clilorotica, 79.

Ephemera

cincta, 95.

cifrina, 268.

cognata, 61.

colomhiw, 110.

communis, 60.

compar, 65.

+ culiciformis, 158.

+ culiciformis, 178.

X culiciformis, 183.

+ culiciformis, 188.

cup>ida, 101.

danica, 61.

J danica, 60.

J danica, 63.

decora, 67.

J decora, 09.

diapliana, 158.

diluta, 126.

diptera, 182.

dislocans, 112.

dispar, 94.

duhia, 161.

erytliroplifhalma, 126.

espectans, 72.
fasciata, 72.
ferruginea, 268.
jlava, 158.

flaveola, 71.
flavicans, 79.
flavipennis, 273.
flos-aquce, 24.
fuliginosa, 25.
fusca, 116.

Xfusca, 126.
fuscata, 158.
fusco-grisea, 283.
fuscula, 256,
gemmata, 303.
gigantea, 303.

glauc-ops, 64,
guttata, 301.

guttulata, 66.

Xgutt'ulnta, 67.

liallerata, 144,

+ halterata, 95.

/ieies, 101.

helvipes, 94.

7(f7;'o/a, 268.

Jiilaris, 147.

liispanica, 62.

Holmhergii, 303.

horaria, 142.

liyalina, 79,

hgalinata, 95.

Ephemera

ignita, 120,

immaculata, 72.

inanis, 95.

japouica, 74.

Zac/eff, 142,

Icucophthalma, 208,

limhata, 50.

liueata, 63.

longicduda, 24.

lutea, 79.

J ?«<efli, 45.

I Z(//fa, 64.

J Zw/ea, 158.

t iw/ea, 268.

luteola, 175.

maculata, 60.

Xmaculata, 61.

margmata, 93.

ij; marqinaia, 79.

Xmarginata, 183.

marocana, 45.

minima, 142.

■minor, 116.

[;mortua. Hag. (1861)].
mutica, 166.

myops, 72.

Xmgops, var., 66.

natata, 67.
nervosa, 283.
nigra, 107,
J nigra, 95.
nigrimana, 28.3.
natata, 158.
novehoracana, 279,
orieutalis, 74,
parvula, 178.
phimosa, 142.

[prisca. Hag. (1861)].
2)rocellaria, 93.
[procera, Hag. (1801)],
pudica, 280.
reticulata, 79.
rosea, 126.
r«/rt, 283.
rufescens, 126,
rufula, 188,
serica, 73.
siinulans, 67.
Xsimulans, 66,
speciosa, 289.
stigma, 256.

il stigma, 93.
striata, 167.

J striata, 158.

Ephemera

X striata, 183.

X striata, 188.

suhmarginata, 94.

sulphurea, 268.

supposita, 72,

Swammerdamiana, 24,

Swam merd iana, 24.

falcosa, 93.

testacca, 161.

varia, 69.

venosa, 283.

vespertina, 103.

uiVyo, 45,

viridescens, 93.

tJ^Yrea, 302.

vitripennis, 297.

vulgatii, 69.

J milgata, 61.

J mtlgata, 63, 188.

Wappaei, 303.
Epliemeradce, Fleming

(1824).
Ephemerella, 123, 124.

(S«ea, 126.

consimilis, 130.

elougatula, 131.

escriiciiiiis, 130.

gihha, 120.

graiiJis, 128,

hispauioa, 306.

iguita, 126.

inermis, 127.

invaria, 129, 130.

notata, 305.

Walkcri, 129.
Ephemeridse, Samuuelie

(1819).
Ephemerides, Leach

(1815).
Ephemerina, Newman

(1835).
Ephemerites, idem.
Ephemermn, 24, 45,
Ephoron leuko7i, 47.
Eucharidis Seaumiiri,

79.
Euthyplocia, 36.
auceps, 38.
Hecuba, 37.

Habrophlebia, 83, 114.
fusca, 116.
laiita, 120.
mesoleuca, 120.

iXDEX.

351

Ealrophlebia
modesta, 118.
nervulosa, 117.
Picteti, 105.
iimbratilis, 119.
Hageuulus, 83, 113.
caligatus, 113.
? sp. — (Four 2 im.),
114.
Hemerohius, 24^, 4.3.
Heptageuia, 235, 265.
alpicola, 239, 286.
angusti-pennis, 286.

annulifera, 293.

aurantiaca, 259.

basalis, 298.

Bellieri, 287.

horealis, 255.

Irntmea, 218, 253.

caerulans, 270.

canadensis, 278.

cnentata, 300.

eupulata, 261.

detenninata, 233.

elegans, 268.

flava, 270.
flaveola, 279.

flavescens, 266.

flavipennis, 273.

XflavipeiiHis, 291.
fluminutn, 289.
forcipula, 286.
/?<«(■«, 252.
yoZZ/c«, 236, 272, 325.

geuimata, 303.
guttata, 301.
insignis, 288.
ititerpuuctata, 267, 323
iridaiia, 259, 302.
lateralis, 294.
longicauda, 284.
luridipennis, 280.
maculipennis, 301.
montana, 302.
nigrimuna, 284.
w'Va^ff, 255.
obscura, 294.
Picteti, 284.
tpudica, 133, 280, 298.
pulchella, 299.
purpurascens, 284.
quebecensis, 297.
semicolorata, 256.
semitincfa, 257.
simplex; 300.

SECOND SERIES. —

lleptdgcnia

.suJphurea, 236, 268.

sylvicola, 322.

termiuata, 299.

torrida, 233.

venosa, 284.

vicaria, 280.

vitrea, 254.

volitans, 273, 291, 292.

zehrata, 292, 293.
Hesagenia, 48.
albivitta, 49.
albivittata, 49.
."^ atrostoma, 28.
bilineata, 50.
decolorafa, 41.
J limbata, 55.
mexicana, 50.
munda, 53.
variabilis, 55.
venusta, 54.
Homoeoueuria, 35.
Salviuife, 36.

Iron, 235, 244.

longimauus, 236, 245.

nitidus, 236, 246.
Isonychia, 204.

ferruginea, 205.

ignota, 205.

manca, 206, 210.

Jolia, 42.
Roeseli, 43.
Eoesebi, 43.

Laehlauia, 34.

abnormis, 35.

lucida, 35.
Leptohypbes, 140.

eximius, 140.
Leptophlebia, 82, 91.

annulata, 85.

auriculatd, 112.

australasica, 86.

australis, 86.

castauea, 95.

ciucta, 95.

colombicB, 110.

costaUs, 89.

cup i da, 101.

debilis, 98.

dentata, 88.

dislocans, 112.

elongatula, 131.
ZOOLOGY, VOL. III.

Leptopiilcbia

femoralis, 85.

fusca, 116.

furcifera, 87.

gregalis, 98.

helvipes, 94.

inconspicua, 87.

Kriieperi, 281.

niarginata, 93.

memoriabs, 98.

mesoleuca, 120.

Meyeri, 95.

modesta, 118.

mollis, 97.

uebulosa, 103.

nodularis, 89.

II pallipes, 98.

Picteti, 105.

? prsepedita, 99.

[prisca, Etc. (1871)].

rufivenosa, 99.

sc^Yo, 190.

signata, 108.

strigata, 88.

submarginata, 94.

Taprobanes, 85.
tristis, 135.
vaeiva, 97.
vespertina, 104.
Libella, 352.
J Limulus pennigerus, 151.

Macrocercus, 352.
Metamonius, 201, 208.
aiieeps, 209.

Oligoneuria, 29.

aiiomala, 30.

i aiiomala, 31.

gar-umnica, 31.

?j«7Z«Wrt, 31, 32.

rlieuaua, 31.

Triineuiana, 32.
Onisc-igaster, 201, 223.

Wakefieldi, 224.
Oxgcypha discolor, 139.

lactea, 143.

luctuosa, 146.

Oldendorfii, 191.

Paegniodes, 261.

cupulatus, 236, 261.
Palingeuia, 23.

a?&a, 47.

albicans, 39.

Palingeuia
albifilum, 39.
J albifilum, var., 40.
ampla, 86.
annulifera, 293.
? atrostoma, 28.
bicolor, 221.
bilineata, 50.
J bilineata, 55.
Colombia, 110.
concinna, 101.
continwa, 49.
curta, 40.
decolorata, 41.
dorsalis, 41.
dorsigera, 49.
flavescens, 266.
fuliginosa, 25.
Lgigas, Hag. (1854)].
Hecuba, 37.
horaria, 45.
humeralis, 202.
indica, 47.
interpunctata, 267.
javauica, 27.
lata, 26.
latipennis, 39.
limbata, 50.
+ limbata, 55.
longicauda, 24.
t longicauda, var., 43.
[';«ae/-o^;s, Pict. (1854)].
Nappii, 304.
natata, 67.
iiebulosa, 103.
occulta, 50.
pallipes, 101.
papuana, 27.
puella, 47.
pulchella, 299.
Savignyi, 46.
sibiriea, 26.
teuera, 27.
terminata, 299.
tolosana, 43.
y«>yo, 45.
viridescens, 50.
vitrea, 254.
vittigera, 76.
Pentagenia, 75.

quadripunctata, 77.
vittigera, 76.
Polymitarcys, 43.
alb us, 47.
indicus, 47-

i7

352

INDEX.

Polymiiarchys

Savignyi, 46.

virgo, 45, 46.
Potamanthus, 78.

cBneus, 126.

annulatus, 85.

apicalis, 126.

irunneus, 116.

caligatus, 113.

castane.us, 95.

cinetus, 96.

X cinetus, 120.

eoncinnus, 101.

costalis, 89.

cupidus, 101.

dilectus, 126.

(/iZi^^MS, 126.

disjjfir, 94.

erythrocephalus, 126.

erythropthdhnus, 126.

expeclaiis, 72.
fasciatus, 72, 84.
femoralis, 85.

Ferreri, 80.
fuscus, 116.

Geerii, 94.

gibhus, 126.

J Jtalteratus, 96.

helvipes, 94.

hyalinus, 96.

inatiis, 96.

Jr'otamanthus

II inanis, 296.

Krueperi, 281.

luteus, 79.

marginatiis, 93.

J marginatiis, 105.

mesoleitciis, 120.

■minor, 116.

modestus, 118.

nebulosa, 103.

odonatus, 103.

[priscus, Pict. (1854)J.

roseus, 126.

Sieicerlii, 296.

stigma, 93.

submarginatus, 94.

talcosus, 93.

Vogleri, 296.
Prosopistoma, 149.

foliaeeum, 150.

punctifrons, 151.

variegatum, 152.

Ehithrogena, 235, 250.
alpestris, 255.
aurantiaca, 236, 259.
borealis, 255.
elegantula, 253.
germauica, 260.
Hageni, 253.
hybridn, 256.

Bhithroyena

jejuna, 252.

manifesta, 253.

nivata, 236, 255.

semicolorata, 236, 256.

semifincta, 257.

J semitincta, 255.

vitrea, 254.
Rhoeiiantlius, 81.

speciosus, 81.

+ Semblis, 24.

J marginata, 24.
Siphlonurus, for srj.
Siphlurus, 201, 214.

(die mans [for sey.],
219.

alteruatua, 219.

? anceps, 209.

anriulatus, 219.

? «;•<■(/««, 206.

armatus, 216.

bicolor, 221.

J debilis, 253.

femoratus, 220.

? Xfeinoratus, 211.

flavidus, 216.

lacustris, 217.

Liima'anus, 217.

niirus, 221.

occidentalis, 218.

Siphlurus

qiiebecensis, 297.

'r* siccus, 208.

sp. -, 223.

typieus, 222.
Spauiopblebia, 33.

pallipes, 34.

Trailia>, 33.

Teloganodes, 134.

major, 136.

tristis, 135.
Thalerosphyrus, 232,

determiuatiis, 233.

torridua, 233.
Thraulus, 83, 106.

bellus, 107.

Colombia?, 110.

exii^uus, 108.

Ijetus, 110.

lepidus, 109.

mexicauus, 109.

signatus, 108.

sp.

?

(nos. 32 & 37,

Ceylon), 108.
sp. — (Costa Rica), 109.
vitripenuis, 297.
Tricorytlms, 138.
discolor, 139.
? sp. — (nymph), 140.
Taricauda, 139.

PRINTED BY TAYLOR AND FRANCISj RED LIO.N' COURT, FLEET STREET.

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inopiTiatus

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P Nameless. 9, F, PHEMERE,i.LA . 10-11, BAETIS . IP., CENTROPTILUM. 13, AMELETUS.

3, m /

2nd Ser. ZOOLOGY.]

[VOL. III. PART 1.

THE

TRANSACTIONS

OF

THE LINNEAN SOCIETY OF LONDON,

A REVISIONAL MONOGRAPH OF EECENT EPHEMERID.E

OR MAyFLIES.-PARTL

BY

The Eev. A. E. EATON, M.A.

{Communicated by Sir John LuishocK; Bart., F.R.S., Prcs. Liuu. Soc.)

NOTICE. — This Memoir will form Vol. 3. Vol. 2 is being simultaneously continued in Parts.

LONDON:

PRINTED FOR THE LINNEAN SOCIETY

BY TAYLOK AND FRAiN'ClS, RKD LION COURT, FI.KET STr.EET.

SOLD AT THE SOCIETV's APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W. ;
AND BY LONGMANS, GREEN, READER, AND DYER, PATERNOSTER-ROW.

December 1883.

o,;l^

2nd Ser. ZOOLOGY.]

StCm^z-f/j:

[VOL. III. PART 3.

THE

rRANSACTIONS

OF

THE LINNEAN SOCIETY OF LONDON.

A EEVISIONAL MONOGEAPH OF RECENT EPHEMERIDJ]

OR MAYFLIES.-Part IIT.

BY

The Rev. A. E. EATON, M.A.

{Commumcated by Sir John Lubbock, Bart, F.R.S., Pres. Linn. Soc.)

NOTICE.-This Memoir will form Vol. 3. Vol. 2 is being simultaneously

continued in Parts.

LONDON:

PRINTED FOR THE LINNEAN SOCIETr

BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD AT THE SOCIETJf's APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W. ;
AND BY LONGMANS, GREEN, READER, AND DYER, PATERNOSTER-ROW.

April 1885.

2nd Ser. ZOOLOGY.]

an. /2. /fU

[VOL. III. PART 4.

THE

7

TRANSACTIONS

OF

THE LINNEAN SOCIETY OF LONDON.

A REVISIONAL MONOGRAPH OF RECENT EPHEMERID.E

OR MAYFLIES.-PART IV.

BY

The Eev. A. E. EATON, M.A.

{Communicated by Sir John LuBBor-K, Bart., F.R.S., Pres. Liun. Soc.)

NOTICE — This Memoir will form Vol. 3. Vol. 2 is being simultaneously continued in Parts.

LONDON:

PRINTED FOR THE LINNEAN SOCIETY

BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD AT THE SOCIETYT's APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W.
AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW.

December 1885.

JC>-<L 0 4 ^

2nd Ser. ZOOLOGY.]

[VOL. III. PART 5.

THE

C,^^'Z

TRANSACTIONS

ilLi. /9n-

.^.

OF

THE LINNEAN SOCIETY OF LONDON.

A EEVISIONAL MONOGRAPU OF RECENT EPHEMERIDJ;

OR MAYFLIES.-PAET V.

BY

The Rev A. E. EATON, M.A.

{Communicated by Sir John Lubbock, Bart., P.R.S., Pres. Limi. Soc.)

NOTICE. — This Memoir will form Vol. 3. Vol. 2 is being simultaneously continued in Parts.

LONDON:

PRINTED FOB THE LINNEAN SOCIETY

BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD AT THE SOCIETV's APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W.,
AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW.

Decemher 1887.

•2/«5/ V / 2.

2nd Ser. ZOOLOGY.]

t^ S. ?'^^

[VOL. III. PART 6.

THE

TRANSACTIONS

OF

THE LINNEAN SOCIETY OE LONDON.

A REVISIONAL MONOGRAPH OF RECENT EPHEMERIDJl

OR MAYFLIES.-PAET VI.

BY

The Rev. A. E. EATON, M.A.

(Communicated by Sir John Lubbock, Bart., F.R.S., Pres. Linn. Soc.)

NOTICE.-This part concludes Volume 3. Vol. 2 will also shortly be completed.

LONDON:

PRINTED FOR THE LINNEAN SOCIETY

BY TAVLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W.,
AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW.

March 1888.

4

3 2044 093 362 424