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_ Nouvelle Série 1V (XXXVI), No 1

BULLETIN

DE

LACADEMIE IMPERLALE DES SCIENCES

DE

ST-PETERSBOURG
P

Nouvelle Serie IV (XXXVI)

(Feutlles 1—1/, 11.)

CONTEND.
Page.

Wild, H. Sur Vincertitude des tensions de la vapeur d’eau audessous

de 100° de Regnault, et sur les différences qui en dépendent

dans les corrections des thermometres 4 ébulition selon la mé-

thode employée pour leur vérification. . | 1— 10
Semenoff, A. Révision synoptique des Méloides dus pene lGtonbpak

BAS CMs apices 11— 20
Meinshausen, K. F. Genre Spareanium: L. Deseription systématique

des espéces et leur distribution géographique d’aprés les obser-

vations faites au Gouvernement de St. Pétersbourg. . . . 21— 41
Iwanof, A. Sur le mouvement des corps célestes dans un milient re-

2 sistant qui tourne uniformément autour du soleil... . . 43— 50
Cee G. O. Les Crustacées caspiennes. Contributions pour servir 4 la

connaissance de la faune carcinologique de la mer reece, wren! | AM! ‘

(Avec 8 planches) - : 451— gs V "|
Famintzin, A. Sur les grains de chlorophylle dans les graines. et tame :
les plantes germeantes (Avec 1 planche).. . . 75— 85

—— Delamatiére chromogéne dans les graines sda Helianthus 2 an-
nuus, et des deux pigments — jaune et vert, que l’auteur en a

obtenu. ... 87— 88
Wild, H. Du mouvement séculaire ‘de la déclinaison ‘magnétique a

St. Pétersbourg et 4 Pawlowsk (Avec 1 planche). bE stent 89—103
Nauck, A. Les canons iambiques de Jean Damascéne accompagnés

de commentaires et d’un index verborum. . . . 105—129
Grosset, Th. Matériaux pour servir 4 la connaissance de la compo-

sition chimique des eaux artésiennes A St. Pétersbourg§ . - 131—161

+0100

Imprimé par ordre de ’Académie Impériale des Sciences.
Décembre 1893. _ N. Doubrovine, secrétaire perpétuel.

Imprimerie de Académie Impériale des Sciences. BR
Vass.-Ostr., 9° ligne, Ne 12.

INVERTEBRATE
ZOOLOGY

Crustacea

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Crustacea caspia. Contributions to the knowledge of the carcinological
Fauna of the Caspian Sea, by G. 0. Sars, Prof. of Zoology at the
University of Christiania, Norway. (Lu le 14 avril 1893).

Part I.

IVES i) ey

With 8 autographic plates.

GENERAL INTRODUCTION.

The Crustacea of the Caspian Sea are as yet but very imperfectly known,
and, with the exception of the Myside, the Caspian species of which have
partly been studied by Mr. Czerniavsky, only a few scattered notes have
hitherto been published about that part of the fauna. As, howewer, the Cru-
stacea everywhere are found to represent a very essential bulk of the fauna,
it cannot fail that a closer investigation of the several forms of that class
occurring in the Caspian Sea, would give us important information about
the general character of the fauna of that isolated marine basin, and
thereby throw much light on the difficult questions about the supposed
early connexion of the Caspian Sea with other parts of the Ocean.

Through the kind intervention of Mr, S. Herzenstein, avery interesting
collection of Crustacea made by Mr. Warpachowsky during the past year
in different places of the northern part of the Caspian Sea, has been placed
in my hands for examination. The collection comprises numerous species
belonging to 3 different orders, viz., Schizopoda, Cumacea and Amphipoda.
Especially the occurrence in the Caspian Sea of Cumacea seems to me to be
of very considerable interest, on account of the exclusive marine character
of that order, and of the other 2 groups there are also several very
interesting and apparently new forms. Subsequently I have also received
some other specimens of Caspian Crustacea preserved from an earlier time
in the Zoological Museum of St. Petersburgh, and quite recently the rich
collections of Caspian Crustacea in the possession of Dr. Grimm have been

entrusted to me for investigation.
Mélanges biologiques. T. XIII, p. 899. 4*

52 6. 0. SARS, [X. S.1¥

It is thus a very considerable bulk of Caspian Crustacea, that will lie
before me, and I hope that a careful investigation of this vast material will
prove to be of considerable interest, both in systematic and biological
respects, and that several fundamental conclusions relating to the early
history of the Caspian Sea may be hence derived. I think, however, it may
be convenient to delay such a general discussion until the completion of
the systematic investigation of the several groups. On this occasion I only
wish quite briefly to indicate the general suggestions to which a preliminary
examination of the specimens has led me, and which I hope subsequently
to be enabled to support by more reliable facts.

The fauna of the Caspian Sea is, I believe, derived from 3 very differ-
ent sources. One part is of true arctic origin, and constitutes the remnant
of the primitive fauna prevailingat the early time, when a connexion between
the Caspian Sea and the Polar Sea may have existed. Another part of the
fauna is of a more southern character, and may have immigrated, at a much
later period from the Black Sea and the Mediterranean; a direct connexion
being supposed to have existed at that time. A third part of the fauna,
finally, constitutes a number of true fresh-water forms, which have adapted
themselves to living in somewhat brakish water, at the estuaries of the
great rivers debouching in the Caspian Sea. The abyssal region of the Cas-
pian Sea remains still, I believe, nearly quite unexplored. I am, however,
much inclined to believe that, on a closer investigation, the great depths of
that basin will be found to contain a peculiar abyssal fauna exhibiting a
purely arctic character.

On entering upon an investigation of the carcinological fauna of the
Caspian Sea, I have thought it right to treat of each group separately. The
present part comprises only a single family of the Schizopoda, viz., the My-
sid@. It will be shortly succeeded by 2 other parts, the one treating of the
Cumacea, the other of the Amphipoda, and perhaps subsequently a 4th part
will be added, treating of the lower Crustacea, the Entomostraca.

MYSIDZ.

As is well known, the Myside form a family of the lower stalk-eyed
Crustacea, and belong to the subdivision generally termed Schizopoda, on
account of the legs being biramous, or provided with greatly developed exo-
podites acting as powerful swimming organs. Of higher stalk-eyed Crusta-
cea only 2 species of the genus Astacus have hitherto, according to a kind
communication by Mr. Herzenstein, been recorded from the Caspian Sea,
viz., Astacus leptodactylus and A. pachypus, both being evidently fresh-

Mélanges biologiques. T. XIU, p. 400.

(XXXVI) | ORUSTACEA CASPIA, 53

water forms, which have adapted themselses to living in somewhat bra-
kish water. A species of Thelphusa is besides found in the rivers debouching
into the southern part of the Caspian Sea, but this form cannot properly be
referred to the fauna of the Caspian Sea itself. Unlike these 3 forms, the
Myside are generally regarded as being of true marine origin, though
some species are also occasionally met with in pure fresh water lakes, as
first stated with regard to the Mysis relicta of Lovén. But, as indicated by the
specific name, this species is believed to be left from a remote time, when
the lakes were in connexion with the Ocean, and this view, set forth by
Prof. Lovén, has been subsequently fully confirmed by a closer comparison
with the marine form, Mysis oculata Fabr., abounding in the arctic Ocean.
The Mysis relicta of Lovén is indeed quite certainly a depauperated descend-
ent of that species, exhibiting, as it does, a very close resemblance to imma-
ture specimens of the former’). A similar descent from true marine forms
may in all probability also be attributed to the other Myside found to inhabit
pure fresh water.

The Myside of the Caspian Sea are as far as is yet known all comprised
within the subfamily Mysine, as defined by Mr. Czerniavsky, and belong to
4 different genera, one of which is now for the first time established. Of the
8 species enumerated in the following pages, 4 are as yet not known beyond
the Caspian Sea, whereas the other 4 are stated to be common also to the
Black Sea. As above stated, most of the Caspian species have already been
described by Mr. Czerniavsky in his valuable work, «Monographia Mysi-
darum imprimis Imperii Rossici». But, as these species are treated of in con-
nexion with species from other parts of the Ocean, it is somewhat difficult
at once to get a view of those occurring in the Caspian Sea. As moreover
some of the species have been rather imperfectly described, and good habi-
tus-figures are not at all given, Ihave thought it right to re-describe all the
species, which I have had myself an opportunity of examining, and to give
both habitus- and detail-figures of all. The descriptions are made as short
and concise as possible, and are chiefly confined to the real distinctive cha-
racteristics, the oral parts being, as a rule, only treated of in one species
of every genus, as there are generally no appreciable differences to be found
in these parts in species belonging to one and the same genus. Good figures
will on the whole make a minutely detailed description superfluous. To the
descriptions are added short critical remarks on the validity of the species
and its relation to other nearly allied species, as also information as to
occurrence and distribution.

1) See G. O. Sars, Histoire naturelle des Crustacées d’eau douce de Norvége I. p. 40.
Mélanges biologiques, T. XIII, p. 401.

54 G. 0. SARS, [N. S.1V

The disintegration of the genus Mysis, as formerly defined, into seve-
ral distinct genera, according to the different structure of the antennal
scales, the telson, and the pleopoda in the male, was first proposed by Mr.
Czerniavsky in his above cited work. In a subsequent paper on the British
Myside, the Rev. Mr. Norman has adopted a similar subdivision of the
genus, but in some cases he disagrees with Mr. Czerniavsky, as regards
the limitation of the genera. Under these circumstances it would seem to be
appropriate to give an exhaustive diagnosis also of the genera, to which the
Caspian Mysidae ought to be referred.

It may be added, that I have had an opportunity of examining some
of the type specimens of Czerniavsky, which were kindly sent to me from
the Zoological Museum in St. Petersburgh for comparison and identification.

All the plates have been prepared by the autographic method, which
the author has applied in several of his other works, and which I think
may answer the purpose very well. The figures have in every case been ori-
ginally drawn by the aid of the camera lucida, and their correctness is thus
guaranteed.

Gen. 1. Paramysis, Czerniaysky, 1882.

Generic characters. — Form of body (PI. I, fig. 1, Pl. I, fig. 1) rather
robust. Carapace well-developed, and but slightly emarginated posteriorly,
its lateral lobes completely obtecting the sides of the mesosome (see PI. IT,
fig. I), cephalic part well defined by a conspicuous cervical sulcus, and hay-
ing the anterior edge evenly curved in the middle, frontal spine (see PI. I,
fig. 2) large, uncovered. Eyes (ibid.) comparatively short and thick. Superior
antenn (PI. I, fig. 3) of the usual structure, male appendage (see Pl. II,
fig. 1 & 2) well-developed and densely hirsute. Inferior antenne (PI. I, fig.
4) having the basal part considerably produced at the exterior corner, scale
very large, with the outer edge quite smooth and produced at the end to a
strong spiniform projection, tip of the scale transversely truncated, with the
inner corner not at all produced, and the apical segment nearly obsolete
(see Pl. I, fig. 5). Anterior and posterior lips (Pl. J, figs. 6 & 10), as also
the mandibles (figs. 7 & 9) of normal structure. First pair of maxillee (Pl. I,
fig. 3) with the exognath less rudimentary than usual, having in front seve-
ral strong plumose set wanting in other Myside. Second pair of maxilla
(Pl. Il, fig. 4) with the terminal joint of the palp oblong oval in form and
carrying along the outer edge strong, partly ciliated sete, exognath of a
somewhat unusual form, its outer edge being strongly curved so as to form
a broadly rounded lobe, marginal sete very unequal, the proximal ones

being extremely strong and elongated. Maxillipeds (PJ. II, fig. 5) with the
Mélanges biologiques. T, XIII, p. 402. .

(XXXVI) | CRUSTACEA CASPIA. 55

basal lobe scarcely larger than the outer masticatory lobe, otherwise of
quite normal structure. Gnathopoda (Pl. II, fig. 6) comparatively strongly
built, with the terminal joint lamellar, and armed along the exterior edge
with a row of strong denticulated spines, the outermost of which, represent-
ing the dactylus, is much the largest (see Pl. II, fig. 7). Pereiopoda (PI. II,
fig. 8) of uniform structure and rather robust, with the ischial and meral
joints somewhat expanded, tarsal part divided into 4 articulations, dactylar
joint very small, with the terminal claw slender and well defined from the
joint. Outer sexual appendages of male (Pl. II, fig. 9) of moderate size, and
slightly bilobular at the tip. Third pair of pleopoda in male (PI. II, fig. 10)
biramous, with the outer ramus shorter than the inner and simple conical
in form, terminating in a slender spine. Fourth pair of pleopoda in male (PI.
II, fig. 11) having the outer ramus much elongated, forming a slender cylin-
drical stem divided into 6 articulations, and terminating in 2 somewhat un-
equal flagella, the inner of which is the shorter and biarticulate, outer part
of both densely spinulose. Telson (PI. I, figs. 11 & 12, Pl. HU, figs 13 & 14)
much elongated and strongly attenuated distally, lateral edges spinulose,
tip slightly incised, the incision being bordered by only a few scattered
spiniform projections, terminal lobes each tipped by a strong spine. Uropoda
(see Pl. I, fig. 11) of normal structure, outer lamella much larger than the
inner.

Remarks. — The present genus, established by Mr. Czerniavsky, is
very nearly allied to the genera Mesomysis and Austromysis of the same
author, though differing from both in a few particulars, for instance in the
comparatively more fully developed carapace, the rather different shape of
the antennal scales and of the telson, and finally, in the peculiar develop-
ment of the exognath of the 2 pairs of maxilla. Mr. Czerniavsky refers to
this genus 3 species, viz., P. Baert, P. armata and P. Uliskyi, but the last-
named form is unquestionably, as will be shown farther down, not a Para-
mysis, but a true Mesomysis. As far as yet known, the genus is not repre-
sented beyond the Caspian Sea.

1. Paramysis Baeri, Czerniaysky.
(Pl. I & ID.

Paramysis Baert, Czerniavsky, Monographia Mysidarum imprimis Imperii Rossici, fasc. 2
p. 56, Pl. XXVII, Pl. XXVIII, figs 1—16, Pl. XXIX, figs 1—15.

Specific Characters, — Body (see Pl. I, fig. 1, Pl. Il, fig. 1) rather
strongly built, with the anterior division but little attenuated in front. Cara-
pace nearly obtecting the whole mesosome, leaving only the dorsal part of
last segment uncovered, lateral lobes even advancing somewhat beyond the

mesosome (see PI. II, fig. 1); cephalic part fully as broad as the 1 segment
Mélanges biologiques. T. XIII, p. 408.

56 @. 0. SARS, [N. Sa1¥

of metasome, and haying the anterior edge considerably curved in the middle.
Frontal spine (see Pl. I, fig. 2) rather large and freely projecting between
the insertion of the eyes. The latter (ibid.) comparatively short, scarcely pro-
jecting beyond the sides of the carapace, corneal part somewhat dilated and
distinctly emarginated on the dorsal face. Superior antennze with the pe-
duncle (Pl. 1, fig. 3) of the usual somewhat club-shaped form, its last joint
being rather dilated, and provided along the inner edge and the tip with a
dense series of strong plumose setz, inner flagellum nearly 3 times as long
as the peduncle and about half the length of the outer; male appendage
(see. Pl. II, fig. 2) not fully as long as the peduncle and of the usual struc-
ture. Inferior antenne (PI. I, fig. 4) having the basal part produced at the
outer corner to a strong triangular projection; scale very large, nearly twice
the length of the peduncle of the superior antennz, and oblong sublinear in
form, fully 3 times as long as it is broad, outer edge perfectly straight and
produced at the end to a strong spiniform projection, inner edge slightly
arcuate in its proximal part, tip narrowly truncated and carrying about 14
of the marginal setz, apical segment indicated by a slight suture cutting off
a small part of the scale at the inner corner (see Pl. I, fig. 5). Pereiopoda
(Pl. I, fig. 8) with the meral joint shorter than the ischial one and exhibit-
ing interiorly several fascicles of strong sete, tarsal part about the length of
the meral joint and having the 2 middle articulations the largest, last. arti-
culation rather small. Outer ramus of 3" pair of pleopoda in male (PI. II,
fig. 10) scarcely more than half the length of the inner; 4% pair (PI. II,
fig. 11) reaching nearly to the tip of the telson, and having the exterior
flagellum of the outer ramus about half as long as the stem. Telson (PI. I,
fig. 11, Pl. II, fig. 13) very much prolonged, considerably longer than the
last segment of metasome, and gradually tapering distally, lateral edges
nearly straight, and each armed with about 20 spinules, the outermost of
which is far removed from the tip, apical incision (see Pl. I, fig. 12, Pl. I,
fig. 14) very small, narrowly rounded at the bottom, and armed with asmall
number (from 3 to 7) of dentiform projections, terminal lobes narrow conical
and scarcely diverging, apical spine much stronger than the lateral ones.
Inner lamella of uropoda (PI. II, fig. 12) reaching but little beyond the telson,
its base not very much tumefied and having the otolith comparatively small,
inner edge armed, below the marginal set, with about 10 slender spines,
the outer 2 of which are placed at some distance from the others. Dorsal
face of body ornamented (see Pl. I, fig. 1, Pl. I, fig. 1) with dendritic rami-
fications, issuing from a number of pigmentary centres placed in the usual
manner. Length of adult female (including the antennal scales and caudal

appendages) reaching 26 mm; that of male somewhat less.
Mélanges biologiques. T. XIII, p. 404.

(Xxxvi)] GRUSTACEA, CASPIA. 57

Remarks. — This form has been rather minutely described by Mr.
Czerniaysky, but the peculiar development of the exognath of the 2 pairs
of maxilla would seem wholly to have escaped his attention. It is a very
magnificent species, and easily recognizable from most of its allies, both by
its comparatively large size and by the shape of the antennal scales and of
the telson. Besides the typical form, Mr. Czerniavsky speaks of a variety
, littoralis‘‘, observed in.a single immature specimen, which, according to
that author, distinguished itself by a somewhat larger cornea, and by the
telson being less prolonged and attenuated, and having moreover the apical
incision extremely shallow.

Occurrence. — The species has been observed in several places of the
Caspian Sea. Mr. Czerniavsky quotes the following localities: Northern part
of the Caspian Sea (Ulsky), Mangischlak (UlIsky), southern part of the
Caspian Sea (Ullsky), the harbour of Astara (Goebel), the promontory
of Zelenyi Bugor (Goebel), and for the variety, littoralis, Petrowsk or
Baku (Goebel). — The species was also represented in the collection of
Warpachowsky by a few beautifully preserved specimens, which occurred
at Stat. 15 off the Tschistyi-Bank, lying at some distance south of the
estuary of the Wolga.

2. Paramysis armata, Czerniavsky.

Paramysis armata, Czerniaysky, 1. c. fase. 2, p. 63, Pl. XXIX, figs 16—25.

Remarks. — I have only seen a fragment of this form, comprising the
anterior part of the carapace with the eyes and antennee, which was con-
tained in the type collection of Caspian Mysidz arranged by Mr. Czer-
niavsky. To judge from this fragment, the present species is very nearly
allied to P. Baeri, scarcely differing except in the eyes being comparatively
smaller, and having the corneal part far less expanded.

Occurrence. — According to Mr. Czerniavsky, a single female spe-
cimen of this form was collected by Lieutenant Ullsky of Mangischlak.

Gen. 2. Mesomys, Czerniaysky, 1882.

Generic Characters. — Form of body (see Pl. Ill, 1V, V & VI, fig. 1) more
or less slender. Carapace deeply emarginated posteriorly, and but imper-
fectly covering the posterior part of the mesosome, anterior edge not angu-
larly produced in the middle; frontal spine uncovered. Eyes (see Pl. LV, V,
VI, fig. 2) large, pyriform. Superior antenne (PI. III, fig. 2) of the usual
structure. Inferior antennze (P1. III, 1V, V, VI, fig. 3) less strongly produced
at the outer corner of the basal part than in Puramysis, scale of moderate

Mélanges biologiques. T. XIII, p. 405.

58 G. 0. SARS, [x. 8.1V

size, with the outer edge smooth and produced at the end to a dentiform pro-
jection, tip more or less obliquely truncated, with the inner corner projecting
beyond the spine of the outer, and having a small apical segment cut off by
a transverse suture. Anterior and posterior lips, as also the mandibles (PI. III,
figs 5, 6) of the usual structure. First pair of maxille (PI. II, fig. 7) with
the exognate quite rudimentary, forming only a slight lamellar ridge finely
ciliated on the edge, but without any trace of setze. Second pair of maxillz
(PI.IH, fig. 8, Pl. IV, V, VI, fig. 5) with the terminal joint of the palp oval
in form, and edged exteriorly by strong ciliated setae, exognath comparati-
vely small and triangular in form, its outer edge but slightly curved, mar-
ginal sete rather short and uniform in size. Maxillipeds (PI. III, fig. 9) with
the basal lobe rather large, outer masticatory lobe well-developed, though
scarcely as large as the basal one. Gnathopoda (PI. III, fig. 10) comparati-
vely less robust than in Paramysis, otherwise of much the same structure.
Pereiopoda (PI. Il, fig. 11, Pl. IV, V, VI, fig. 6) likewise rather similar
to those in the said genus, though comparatively less robust, with the ischial
and meral joints less expanded, tarsal part quadriarticulate, with the 1*
articulation very short and obliquely truncated at the tip, dactylar joint
small, with the terminal claw well defined from the joint and very slender
(see Pl. IE, fig. 12, Pl. V, VI, fig. 7). Outer sexual appendages of male
as also the pleopoda (PI. IV, figs 11, 12, Pl. V, VI, figs 12, 13) of a simi-
lar structure as in Paramysis. Telson (PI. III, fig. 14, Pl. IV, fig. 7, Pl. V,
VI, fig. 8) of moderate size, oblong quadrangular in form, and somewhat
tapering distally, lateral edges densely spinulose, apical sinus very shallow
or quite obsolete, its edge bordered by a dense series of spiniform pro-
jections, arranged in a regular comb-like manner. Uropoda of the usual
structure,

Remarks. — This genus was characterised by Mr. Czerniavsky as
being intermediate between JMysis s. str. and Paramysis. It comes, however,
in fact still nearer to the genus Austromysis of the same author, the type
of which is W. Helleri G. O. Sars. The latter genus was not adopted by the
Rey. Mr. Norman, who referred its species to his genus Schistomysis, founded
upon some of the species referred by Mr. Czerniavsky to his genus Syn-
mysis. I fully agree with Mr. Norman, that the 3 species W/. spiritus, M.
ornata and M. assimilis cannot properly be placed in the same genus with
M. flexuosa and M. neglecta, which, according to that author, belong to the
genus Macromysis of White. On the other hand, I think that the genus
Austromysis of Czerniavsky may be retained in the sense of that author,
including probably also the British species M. Parkeri. From the last named

genus the present one is chiefly distinguished by the less obliquely truncated
Mélanges biologiques. T. XIII, p. 406,

(xxxv1) | CRUSTACEA CASPIA. 59

antennal scales, the uniform structure of the pereiopoda, and by the very
shallow apical sinus of the telson, and its peculiar comb-like armature. Mr.
Czerniavsky refers to this genus 5 species, one of which, M. Kréyeri,
should, however, perhaps more properly be placed within the genus Austro-
mysis, whereas another form described by that author as a Paramysis, must
find its place in the present genus. As far as yet known, the genus is not
represented beyond the Caspian and Black Seas, one of the species, JM. la-
custris, having, however, been found in a lake among the mountains of
Caucasus. In the Caspian Sea the genus is represented by 5 species, one of
which is now for the first time established.

2. Mesomysis Ullskyi (Czerniavsky).
(Pl. Ill).
Paramysis Ullskyi}) Czerniavsky, 1. ¢., fase. 2. p.65, Pl. XXVI, figs 13—23.

Specific Characters. — Body (see Pl. Il, fig. 1) very slender and elon-
gated, with the anterior division rather attenuated in front, and scarcely longer
than the 4 anterior segments of metasome combined. Carapace deeply emargi-
nated posteriorly, leaving the dorsal part of the last 2 segments of mesosome
uncovered, cephalic part scarcely as broad as the 1st segment of metasome, and
having the anterior edge nearly straight; frontal spine large, uncovered. Me-
tasome very elongated, and gradually tapering posteriorly. Eyes of moderate
size, projecting somewhat beyond the sides of the carapace, corneal part rather
expanded and distinctly emarginated on the dorsal face. Peduncles of the
superior antennze (fig. 2) conspicuously club-shaped, the last joint being con-
siderably dilated and having at the inner corner about 10 strong plumose
setee. Antennal scales (see fig. 3) of middle size, exceeding the peduncles of
the superior antenne by about '/, of their length, form oblong linear, the
breadth equalling 1/, of the length, terminal part projecting beyond the
outer corner occupying about '/, of the length of the scale, apical segment
well defined, bearing 5 of the marginal setz (see fig. 4). Pereiopoda (fig. 11)
moderately slender, with the meral joint a little shorter than the ischial
one, tarsal part somewhat longer than the former, with the 1st joint much
shorter than the other 3, which are nearly equal-sized, dactylar joint (see
fig. 12) very small, with the terminal claw nearly setiform. Telson (fig. 14)
comparatively large, exceeding somewhat in length the last segment of me-
tasome, and gradually tapering distally, lateral edges nearly straight, and
armed each with from 18 to 22 spinules, the outermost of which is some-

1) It may be noted, that this species in other parts of the work has been termed Para-
mysis Strauchi, and that the type specimens are labelled in accordance therewith.
Mélanges biologiques. T. XIII, p. 407.

60 G.:0. SARS; [N. Se1V

what remote from the tip, apical sinus (see fig. 15) rather shallow, though
well-defined, and bordered by about 24 regular dentiform projections acute
at the tip, terminal lobes slightly diverging, and each tipped by a rather
strong spine. Inner lamella of the uropoda (fig. 13) moderately tumefied at
the base, with the otolith well-developed; inner edge armed, below the mar-
ginal sete, with about 9 spines, the outermost of which is placed at some
distance from the others, not far from the tip. Body without any distinct
dendritic ramifications, but having along the back the usual pigmentary
centres. Length of adult female reaching 21 mm.

Remarks. — As above stated, this form was referred by Mr. Czer-
niavsky to his genus Paramysis. This is evidently quite erroneous, for it
is in all characteristics a true Mesomysis, as seen both from the above
description and the appended figures. In order to decide the question with
full certainty, I have felt justified to dissect one of the type specimens in
the collection of Czerniavsky. From the other species belonging to the
present genus, this form may at once be distinguished by its unusually
slender and elongated body, and the comparatively large telson. Besides the
typical form, Mr. Czerniavsky also records a variety ,.forma occidentalis‘,
which, however, most probably is only founded upon an immature specimen
of the typical form.

Occurrence. — According to Mr. Czerniavsky, 4 adult female speci-
mens of this form were collected by Lieutenant Ullsky in the mouth of the
Wolga, and thus probably in nearly pure fresh water. Another specimen
was, according to the same author, captured in the northern part of the
Caspian Sea, and a third immature specimen, that upon which the variety
, occidentalis** was founded, was apparently from Petrowsk or Baku. In the
collection of Warpachowsky this species was not represented. Except in
the Caspian Sea it has not yet been recorded.

3. Mesomysis Kowalevskyi, Czern.
(PI. TY).
Mesomysis Kowalevskyi, Czerniavsky, 1. c. fasc. 2, p. 50, Pl. XXI, Pl. XXII, figs 1—13.

Specific Characters. — Body (P1. IV, tig. 1) not nearly so slender as in the
preceding species, and having the metasome much less prolonged. Carapace
evenly emarginated posteriorly, cephalic part fully as broad as the Ist seg-
ment of metasome, its anterior edge (see fig. 2) somewhat arched in the
middle, without, however, obtecting the frontal spine, which projects freely
beyond the edge. Hyes (ibid.) rather large, pyriform, projecting somewhat
beyond the sides of the carapace, corneal part well-developed, and, as usual,

emarginated on the dorsal face. Antennal scales (fig. 3) resembling in shape
Mélanges biologiques, T. XIIJ, p. 408.

(XXXVI) | CRUSTACEA CASPIA. 61

those in the preceding species, though being perhaps a little smaller and
somewhat more obliquely truncated at the tip, terminal part (fig. 4) in front
of the outer corner occupying about 1/, of the length of the scale, apical
segment well-defined. Pereiopoda (fig. 6) of a similar structure as in M.
Uliskyi, but having the meral joint comparatively shorter, and the tarsal
part much longer than the latter. Outer ramus of the 3rd pair of pleopoda
in male (fig. 11) exceeding half the length of the inner; 4th pair (figs. 10
and 12) reaching beyond the tip of the telson, and having the exterior flagel-
lum nearly of same length as the stem of the ramus. Telson (fig. 7) scarcely
longer than the last segment of metasome, and having the outer part slightly
attenuated, lateral edges somewhat flexuous and armed each with from 18
to 20 spinules, the outermost of which is not far remote from the tip, apical
sinus (see fig. 9) well-defined, though not very deep, and bordered with
about 22 regular dentiform projections, terminal lobes, as usual, tipped
by a somewhat larger spine. Inner lamella of the uropoda (fig. 8) moderately
tumefied at the base, with the otolith rather large, inner edge armed,
below the marginal sete, with about 9 slender spines, the outer 2 of which
are placed at some distance from the others. Body everywhere ornamented
with finely dendritic ramifications issuing from a dorsal row of pigmentary
centres, arranged in the usual manner. Length of adult female reaching
18mm.

Remarks. — Although I have not had an opportunity of examining
the type specimens of Czerniavsky, which were wanting in the collection
sent to me, I cannot doubt that the above described species is that so named
by the said author, as it agrees rather well with his description and figures.
It is easily distinguishable from the preceding species by its much shorter
and stouter form of body, and the richly dendritic pigmentary ornament of
the dorsal face, as also by the comparatively shorter telson.

Occurrence. — Three specimens of this form, 2 females and 1 male,
were contained in the collection of Warpachowsky, and occurred at Stat.
28, north of the peninsula Mangischlak!). To judge from their size, they
would seem to belong to the ,,varictas major‘* of Czerniavsky, which has
not yet been recorded from the Caspian Sea. — According to Mr. Czer-
niavsky, numerous specimens of the smaller form (forma typica) were col-
lected by Prof. Kowalevsky at Petrowsk or Baku, close to the shores.

Distribution. — According to Mr. Czerniavsky, the larger form of
this species (var. major) has been recorded from 2 different localities of the

1) In a subsequent collection by the same naturalist this species was rather abundantly
represented in 2 other places, viz., at Stat. 49, between the island of Kulaly and that of Mor-
skoj, and 52, at the northern extremity of the island Swjatoj.

Mélanges biologiques. T. XIII, p. 409.

62 6. 0. SARS, [N. S. IV

Black Sea, viz., Odessa and Oczakow, being in the first-named place extract-
ed from the yentricle of Perca fluviatilis, together with M. intermedia.

4. Mesomysis Czerniavskyi, G. O. Sars, n. sp.
(Pl. V.)

Specific Characters. — Very like the last species, though perhaps a
little more slender in form (see Pl. V, fig. 1). Carapace having the cephalic
part scarcely narrower that the 1st segment of metasome, its anterior edge
evenly curved in the middle, frontal spine uncovered. Eyes (see fig. 2) pyri-
form, reaching somewhat beyond the sides of the carapace, corneal part
well-developed and distinctly emarginated on the dorsal face. Antennal
scales (see fig. 3) exceeding the peduncles of the superior antennee by about
'/, of their length, and oblong linear in form, but very little attenuated
distally, terminal part in front of the outer corner (fig. 4) occupying about
'/ of the length of the scale, apical segment well-defined. Pereiopoda (fig. 6)
and pleopoda (figs. 12, 13) in both sexes of much the same structure as in
M. Kowalevskyi. Telson (fig. 8) scarcely longer than the last segment of meta-
some, and about twice as long as it is broad at the base, outer part somewhat
attenuated, lateral edges but very slightly flexuous, and armed each with
about 18 spinules, apical sinus (see fig. 9) extremely shallow, nearly obso-
lete, its edge bordered with 16—18 regular dentiform projections, spines
of the outher corners not very strong. Inner lamella of the uropoda (fig. 10)
not much tumefied at the base, and having the otolith very small, inner edge
armed, below the marginal sete, with about 7 spines, the 3 outer ones being
somewhat wider apart than the 4 inner. Body without any distinct dendritic
ramifications, though having the usual dorsal pigmentary centres. Length
of adult female reaching 18 mm.

Remarks. — The present new species, which I have named in honour
of the distinguished Russian naturalist Mr. Czerniavsky, is very nearly
allied to MW. Kowalevskyi, though apparently distinct, differing, as it does,
rather conspicuously in the want of the rich dendritic ramifications orna-
menting the body of the former species, and also by the apical sinus of the
telson being so very shallow as nearly to be obsolete.

Occurrence. — Some specimens, females and males, of this form were
contained in the collection of Warpachowsky, and occurred at Stat. 27,
lying at the southern point of the Island of Kulaly, north of the peninsula
Mangischlak.

Mélanges biologiques. T. XIII, p. 410.

(XXXVI)] CRUSTACEA CASPIA. 63

5. Mesomysis intermedia, Czern.
(Pl. VI).
Mesomysis intermedia. Czerniavsky, |. ¢. fase. 2, p. 52, PI. XXII, figs. 14—20, Pl. XXIII,
figs. 1—15.

Specific Characters. — Form of body (see Pl. VI, fig. 1) nearly as in
M. Czerniavskyi. Carapace having the cephalic part about as broad as the
lst segment of metasome, anterior edge evenly arched in the middle, frontal
spine uncovered (see fig. 2). Eyes (ibid.) of the usual pyriform shape and
projecting laterally somewhat beyond the sides of the carapace, corneal part,
as seen from aboye, reniform in shape. Antennal scales (see fig. 3) exceed-
ing the peduncles of the superior antennz by considerably more than /,
of their length, and oblong rhomboidal in form, the apex being rather obli-
quely truncated, with the terminal part in front of the outer corner (see fig.
4) occupying more than '/, of the length of the scale, apical segment well
detined. Pereiopoda (fig. 6) rather slender, with the ischial and meral joints
comparatively less dilated than in the other species, tarsal part scarcely
longer than the meral joint, dactylar joint (fig. 7) of the usual structure.
Pleopoda (fig. 12, 13) scarcely differing from those in the other species,
except that the outer ramus of the 3rd pair in male (fig. 12) appears somewhat
smaller, scarcely exceeding half the length of the inner. Telson (fig. 8) about
the length of the last segment of metasome, and rather attenuated distally,
lateral edges nearly straight, and armed each with from 16 to 19 spinules,
the outmost of which is not far remote from the tip, apical sinus (see fig. 9)
quite obsolete, the terminal edge being transversely truncated and bordered
with a regular series of 14 acute dentiform projections, spines of the outer
corners not very strong. Inner lamella of the uropoda (fig. 10) considerably
tumefied at the base, with the otolith very large, inner edge armed, below
the marginal sets, with 4 spines only, the outmost of which is rather remote
from the apex. Body without any distinct dendritic ramifications, though
having the usual dorsal pigmentary centres. Length of adult female scarcely
exceeding 12 mm.

Remarks. — The present species has been rather imperfectly described
and figured by Mr. Czerniaysky, and as I moreover have not had an op-
portunity of examining his type specimens, I should have been in considerable
doubt about the identity of the species here described, if there were not a
single very prominent feature, in which both forms would seem perfectly to
agree, viz., the peculiar want of any true apical sinus on the telson, its apex
being transversely truncated, though exhibiting the usual comblike arma-
ture of the edge. Besides this characteristic, the present species is easily
distinguishable from the 3 preceding ones by the much more obliquely trun-

Mélanges biologiques. T. XIII, p. 411.

64 @. 0. SARS, [N. S.1V

cated antennal scales, and by the comparatively more slender pereiopoda.
It is also of rather inferior size. Mr. Czerniavsky records also of this spe-
cies 2 forms or varieties; the one, ,,forma typica‘ is said to have the apical
sinus of the telson very shallow or scarcely distinct, the other, ,,forma
truncata‘‘, to have the telson nearly transversely truncated at the tip. In
the figures, however, the telson is everywhere represented as quite trans-
versely truncated, without any trace of an insinuation of the apical edge.

Occurrence. — A few specimens, males and females, of this species were
contained in the collection of Mr. Warpachowsky, and occurred at Stat.
15, together with Paramysis Baeri. According to Mr. Czerniavsky, 5
specimens of the typical form were collected by Prof. Kowalevsky at Pe-
trowsk (?).

Distribution. — Black Sea: a single specimen of the ,.forma truncata‘,
extracted from the ventricle of a Perca fluviatilis, caught at Odessa (Czer-
niavsky).

6. Mesomysis aberrans, Czern.

Mesomysis aberrans, Czerniavsky, 1. c. fase. 2, p. 54, Pl. XXIII, figs. 16—21.

Remarks. — I have not myself had an opportunity of examining this
form, but it may be here mentioned, as it is stated to occur in the Caspian
Sea. To judge from the description and figures given by Mr. Czerniavsky ,
this species is very nearly allied to M. intermedia, differing, however, by
the anterior edge of the carapace being so much produced in the middle as
to nearly quite obtect the frontal spine, and by the apical edge of the telson
being not transversely truncated but even somewhat convex, though armed
in the usual manner.

Occurrence. — The specimens examined by Mr. Czerniavsky, were
collected by Prof. Kowalevsky at Petrowsk (?).

Gen. 3. Katamysis, G. 0. Sars, n.

Generic Characters. — Form of body (see P]. VII, figs 1 and 21) short
_and stout. Carapace imperfectly obtecting the posterior part of mesosome,
and having the cephalic part rather short, with the anterior edge angularly
produced in the middle; frontal spine present. Kyes (see fig. 2) scarcely
expanded distally. Superior antenne (fig. 3) of the usual structure, male
appendage very large and densely hirsute (see fig. 21). Inferior antennie
(fig. 4) with the basal part scarcely at all produced at the outer corner,
scale very short, rhomboidal in form, with the outer edge smooth and ter-
minating in a dentiform projection, inner corner much produced and exhi-

biting a distinct apical segment (fig. 5). Anterior lip (fig. 6) armed in front
Mélanges biologiques, T. XIII, p. 412,

(XXXVI) | CRUSTACEA CASPIA. 65

with a strong spiniform projection; posterior lip (fig. 7) of the usual shape.
Mandibles (fig. 8 & 9) comparatively large, with the palp well-developed
and edged with ciliated setae. First pair of maxille (fig. 10) having the
masticatory lobe very narrow and attenuated, exognath forming only a small
laminar expansion ciliated at the edge. Second pair of maxille (fig. 11)
with the terminal joint of the palp oval in form, and having only a very
restricted number of setze on the outer edge, exognath not very large, and
triangular in form, with comparatively few marginal sete. Maxillipeds (fig.
12) with the basal and masticatory lobes well-developed. Gnathopoda (fig.
13) extremely robust, with the joints very much dilated, the meral and
tarsal ones being much the largest, terminal joint (fig. 14) scarcely lamellar,
and having at the tip several very strong and claw-like spines. Pereiopoda
short and stout, the 2 anterior pairs (fig. 15) with the tarsal part well
defined, and composed of 3 articulations; the 4 posterior pairs (fig. 17) having
the tarsal part quite rudimentary, and armed with strong, claw-like, incurved
spines, dactylar joint in the former (fig. 16) normal, in the latter (fig. 18)
nearly obsolete. Pleopoda of male (fig. 22, 23) modified in a similar manner
as in the 2 preceding genera. Telson (fig. 20) not very large, and triangu-
lar in form, tapering to an obtuse point bearing 2 strong spines, lateral
edges spinulose. Uropoda (fig. 19) with the inner lamella but littie shorter
than the outer.

Remarks. — The present new genus is chiefly distinguished by the very
remarkable reduction of the terminal part in the 4 posterior pairs of perei-
opoda, which thereby look as if they were mutilated. The structure of the
antennal scales somewhat resembles that in the genus Austromysis, but the
telson is constructed upon a totally different type, not being incised poste-
riorly, but terminating in an obtuse point. Also in the structure of the oral
parts and that of the gnathopoda, the genus exhibits several well-marked
differences from its nearest allies. The genus is as yet only represented by
a single species, to be described below.

7 Katamysis Warpachowskyi, G. O. Sars, n. sp.
(Pl. VII)

Specific Characters. — Body (see P]. VII, fig. 1 and 21) of rather robust
form, and having the anterior division somewhat tumefied. Carapace deeply
emarginated posteriorly, leaving the dorsal part of the last 2 segments of
mesosome quite uncovered, cephalic part fully as broad as the 1** segment
of metasome, and having the anterior edge (see fig. 2) rather produced in
the middle, forming a distinct, nearly right angle, which, however, does not
quite obtect the frontal spine. Metasome not much prolonged, and rather

Meélanges biologiques. T. XIII, p. 418. 5

66 G. 0. SARS, [N. S.1V

attenuated distally, with its last segment, as usual, the longest. Eyes (see
fig. 2) not very large, and but little projecting laterally beyond the sides of
the carapace, form nearly cylindrical, the corneal part being scarcely at all
expanded and but very slightly emarginated on the dorsal face. Superior
antennz with the last joint of the peduncle (fig. 3) having only a few ciliat-
ed setze at the inner corner, male appendage (see fig. 21) fully as long as
the peduncle. Inferior antenne (fig. 4) with the basal part rather thick, and
forming at the outer corner only a very slight obtuse expansion, scale but
very little exceeding the peduncle of the superior antennz, form pronounced
rhomboidal, the outer part in front of the exterior corner occupying nearly
half the length of the scale, apical segment (fig. 5) very distinct and bearing
5 of the marginal setee. Gnathopoda (see fig. 14) having at the tip 5 spines,
the 3 outer of which are not ciliated and claw-like, the 2 inner ones ciliated
in the middle and terminating in a setiform lash. The 2 anterior pairs of
pereiopoda (fig. 15) having the ischial and meral joints rather expanded and
nearly of equal length, the latter edged interiorly with several short spines
in addition to the sets, tarsal part much shorter than the meral joint, with
the Ist articulation rather broad and armed interiorly with several strong
spines, dactylar joint (see fig. 16) small, with the terminal claw well defined
from the joint and setiform. The 4 posterior pairs of pereiopoda (fig. 17)
having the meral joint strongly incurved, forming a genicular bend with the
ischial one, tarsal part represented by a single very short and thick articu-
lation firmly connected with the meral joint, and having in front 4 strong
claw-like spines disposed in pairs (see fig. 18), dactylar joint forming only
a very minute and pellucid lobe, mostly hidden between the spines and sete
issuing from the tarsal joint. Third pair of pleopoda in male (fig. 22) having
the outer ramus a little longer than the inner; outer ramus of 4th pair (fig.
23) reaching beyond the tip of the telson, outer flagellum nearly twice the
length of the inner. Telson (fig. 20) much shorter than the last segment of
metasome, and not nearly twice as long as it is broad at the base, outer
part considerably tapering, lateral edges nearly straight and converging,
being each armed with about 12 spinules, of which the 3 proximal ones
are somewhat larger than the 4 or 5 succeeding ones, which are placed
somewhat more apart, the outer 4 spinules on each side successively increas-
ing in length distally, apical spines much stronger than the others, and
having between them a very small dentiform projection, which sometimes
is minutely bidentate at the tip (see fig. 24). Inner lamella of the uropoda
(see fig. 19) considerably projecting beyond the telson, and moderately tume-
fied at the base, with the otolith of middle size, inner edge armed, below

the marginal sete, in its whole length, with about 13 spines, successively
Mélanges biologiques. T. XIII, p. 414.

(XXXVI) | CRUSTACEA CASPIA. 67

increasing in length, the outmost issuing from the tip itself. Body exhibit-
ing dorsally the usual row of pigmentary centres, which only show a slight
attempt to a dendritic ramification. Length of adult female 8 mm.

Remarks. — The present peculiar Mysidian, which I have much plea-
sure in dedicating to its discoverer, Mr. Warpachowsky, cannot be con-
founded with any of the other known forms. In its outer appearance it bears
a certain resemblance to some of the species of the genus MMysidopsis, for
example Mysidopsis didelphys, and the telson is also of a rather similar aspect
to that of the said species; but the rhomboidal shape of the antennal scales
at once distinguishes this form from any of the species of AZysidopsis. The
peculiar, as it were, mutilated appearance of the posterior pairs of pereio-
poda may also, without dissection, be easily observed.

Occurrence. — Of this form 4 specimens were contained in the collec-
tion of Warpachowsky. They occurred at Stat. 27, together with Meso-
mysis Czerniavskyi and Limnomysis Benedeni ').

Gen. 4. Limnomysis, Czern., 1882.

Generic Characters. — Form of body (see Pl. VIII, figs. 1 and 18)
comparatively slender. Carapace imperfectly obtecting the posterior part
of mesosome, cephalic part well-defined, and having the infero-lateral cor-
ners acutely produced and the anterior edge considerably arched in the
middle, frontal spine wanting. Eyes (see fig. 2) elongate and narrow, and
separated in the middle by a rather wide interval. Superior antenne with
the peduncle (fig. 3) but little dilated at the tip, male appendage (figs. 19,
20) small and simple of structure, not hirsute, but only finely ciliated. In-
ferior antenne (figs. 4 and 21) with the basal part considerably produced
at the outer corner, scale narrow lanceolate, bearing on both edges strong
ciliated sete, apical segment rather large and peculiarly modified in the
male (see fig. 21, 21*). Anterior and posterior lips (figs. 5, 7) of the usual
structure. Mandibles (fig. 6) of moderate size, palp having the terminal
joint comparatively short. First pair of maxillee (fig. 8) of normal struc-
ture; 2nd pair (fig. 9) having the terminal joint of the palp oblong oval in
form, with the outer edge minutely serrated and setiferous, exognath compa-
ratively large, oblong triangular in form, with numerous rather short mar-
ginal sete. Maxillipeds (fig. 10) with the basal lobe unusually large, masti-
catory lobes, on the other hand, very small. Gnathopoda (fig. 11) rather
slender, with the terminal joint (fig. 12) lamellar, and edged roundabout
with numerous slender spines, each terminating in a setiform lash. Pereio-

1) Some additional specimens of this Mysidian were contained in a subsequent collection,

and occurred at Stat. 52.
Mélanges biologiques, T. XIII, p. 415. 5*

68 G. 0. SARS, [N. S.1V

poda (fig. 13) of uniform structure and comparatively slender, with the
ischial and meral joints but little expanded, tarsal part divided into 3 arti-
culations, the 1st of which is much the largest, dactylar joint (see fig. 14)
having the terminal claw rather strong and not defined from the joint. Outer
sexual appendages of male (fig. 22) comparatively small. Third pair of ple-
opoda in male (fig. 23) simple, not biramous, but having the proximal part
considerably tumefied; 4th pair (fig. 24) distinctly biramous, inner ramus
of the usual structure, outer one not much prolonged, and forming a some-
what irregular stem, not being divided into any articulations, and terminat-
ing ina single spiniform flagellum, smooth at the edges. Telson (fig. 16)
not very large, with the outer part considerably attenuated, lateral edges
spinulose, tip insinuated in the middle, the sinus (fig. 17) being bordered
with a number of small dentiform projections, terminal lobes each armed
with a strong apical spine. Uropoda (fig. 15) with the inner lamella much
shorter than the outer and considerably tumefied at the base.

Remarks. — The present genus, established by Mr. Czerniavsky, is
nearly allied to the genus Diamysis of the same author, the type of which
is Mysis bahirensis G. O. Sars. It distinguishes itself, however, by the
more slender form of the body, the much fuller development of the apical
segment of the antennal scales and the peculiar modification of this segment
in the male, moreover by a somewhat different form and armature of the
terminal joint of the palp in the 2nd pair of maxillz, as also by the uniform
structure of the pereiopoda and the structure of their dactylar joint, and
finally, by the somewhat different structure of the 4th pair of pleopoda in
the male. The 3 genera Potamomysis, Euxinomysis and Onychomysis of the
same author, would likewise seem to come rather near to the present one,
though being apparently distinct. Mr. Czerniavsky refers to this genus
3 species, viz., L. Brandtii, L. Benedeni, and L. Schmankewiczi, the last 2
of which, however, are only founded upon the 2 sexes of one and the same
species, that described below, whereas the first named would seem to be
distinct. The genus has not yet been known from the Caspian Sea.

8. Limnomysis Benedeni, Czern.
(Pl. VIII).
Limnomysis Benedeni, Czerniavsky, 1. c. fasc. 1, p. 124, Pl. X, figs. 13—24, Pl. XI.
Syn.: Limnomysis Schmankewiezi, Czern. (male).
» Mysis relicta, var. pontica, Grebnitzki (according to Czern.)
Specific Characters. — Body (see Pl. VIII, figs 1 & 18) slender and
elegant in form, with the anterior division but little tumefied, and the poste-

rior one evenly attenuated. Carapace deeply emarginated posteriorly, leav-
Mélanges biologiques. T. XIII, p. 416.

(XXXVI) | CRUSTACEA CASPIA. 69

ing the dorsal part of the last 2 segments of mesosome quite uncovered, la-
teral lobes not even obtecting the sides of the last segment (see fig. 18),
cephalic part about as broad as the Ist segment of metasome, and having
the infero-lateral corners produced to acute anteriorly curving projections,
rather conspicuous also in the dorsal view of the animal (see fig. 1 & 2),
anterior edge considerably produced in the middle, though evenly rounded
at the tip. Eyes (see fig. 2) rather narrow, nearly cylindrical in form, and
considerably projecting laterally beyond the sides of the carapace, corneal
part but slightly expanded, and occupying dorsally only 1/, of the length of
the eye, its inner edge nearly straight. Superior antennz with the peduncle
(fig. 3) but little longer than the eyes, last joint having in female only a
single plumose seta at the inner corner, the latter being in male (see fig. 19)
produced to a narrow digitiform process, male appendage (fig. 20) scarcely
more than half the length of the peduncle and very narrow. Inferior antenne
(figs. 4 & 21} with the outer corner of the basal part produced to a very
strong anteriorly curving spiniform projection, scale in female (fig. 4) about
twice the length of the peduncle of the superior antenne, and regularly lan-
ceolate in form, about 4 times as long as it is broad, with the inner edge
somewhat arched in its proximal part, apical segment occupying about 1/, of
the length of the scale and bearing 12 of the marginal sete, 3 issuing from
the tip; apical segment in male (see fig. 21) freely movable upon the remain-
ing part of the scale, by the aid of a strong muscle quite wanting in female,
its tip (fig. 21) produced to a spiniform or nearly hook-shaped point curved
downwards. Gnathopoda (fig. 11) with the basal part very large and fringed
interiorly with strong plumose setae, apical spines (see fig. 12) about 13 in
number, all of same appearance, though the median one (the dactylus) ap-
pears a little stronger than the others. Pereiopoda (fig. 13) with the ischial
and meral joints nearly equal-sized, and having on the inner edge numerous
fascicles of slender sets, tarsal part about same length, with the 1st joint
somewhat longer than the other 2 combined, 3rd joint (see fig. 14) forming
at the end interiorly a slight nodular projection armed with 2 short spines,
dactylar joint (ibid.) very small and having at the base of the terminal claw
2 somewhat unequal spines. Outer sexual appendages of male (fig. 22) di-
stinctly bilobular at the tip, the anterior lobe more projecting and fringed
with long stiff bristles. Fourth pair of pleopoda in male (fig. 24) reaching
scarcely to the end of the last segment of metasome, basal part produced
at the outer corner to a triangular projection, outer ramus somewhat irre-
gularly twisted, having the inner edge biangular on the middle and armed,
at the base of the flagellar part, with a small hooked projection. Telson

(fig. 16) much shorter than the last segment of metasome, and rather broad
Meélanges biologiques. T. XIII, p. 417.

70 G. 0. SARS, [N. S. IV

at the base, its outer part being abruptly constricted and slightly attenuated
distally, lateral edges somewhat concaved, and armed each with about 10 spi-
nules, the 6 proximal ones being separated by a longer interval from the
three or four outer ones, which are placed somewhat more apart, apical sinus
(see fig. 17) rather shallow and rounded at the bottom, its edge exhibiting
about 5 dentiform projections, terminal lobes scarcely diverging and tipped
each with a rather strong spine. Inner lamella of the uropoda (fig. 15) consi-
derably projecting beyond the telson, and having its basal part very much
tumefied, with the otolith rather large, inner edge armed, below the marginal
sete, with only a single spine, which has its place just behind the auditory
apparatus. Body without any distinct pigmentary ornament, the usual dorsal
pigmentary centres being even quite wanting, with the exception of a single
somewhat ramified pigmentary spot located on the basal part of the telson.
Length of adult female 10 mm.

Remarks. — The very peculiar sexual difference in the structure of the
antennal scales in this form has misled Mr. Czerniavsky to describe
the 2 sexes as 2 different species. For his L. Schmankewiczi is without any
doubt only the male of his LZ. Benedent. From L. Branati the present spe-
cies would seem to differ by a somewhat different shape of the antennal scales,
but otherwise both forms seem to be very nearly allied, and their specific
difference may thus perhaps be questioned. M. Czerniavsky records of
his species LZ. Benedeni 3 forms or varieties, viz., forma aestuarica, f.inter-
media, and f. similis, chiefly distinguished only by small differences in the
form and armature of the apical sinus of the telson. The form here described
would seem to agree most nearly with the forma aestuarica, which may be
regarded as the typical form.

Occurrence. — Several specimens of this species were contained in the
collection of Warpachowsky, and occurred in 3 different stations, viz.,
St. 15, 27 and 28. In the 2 first-named Stations, however, only solitary
specimens were collected, whereas in Stat. 28 the species would seem to
have occurred rather plentifully ?),

Distribution. — Black Sea. According to Mr. Czerniavsky a few spe-
cimens of the typical form (aestuarica) were collected by Mr. Grebnitzki
at the mouth of the river Dniester, and were recorded by that author as
Mysis relicta, var. pontica; the 2 other varieties were collected by Prof.
Mecznicow at Liman Berezan (near Oczakow).

1) This form was also abundantly represented in a subsequent collection, and occurred in
4 different Stations, viz., St. 49, 50 (off Tschistyi Bank), 51 (at the island of Kulaly), 52.

Melanges biologiques. 'T. XII, p. 418.

(XXXVI) | CRUSTACEA CASPIA. 71

Explanation of the Plates.
Pl, I.

Paramysis Baeri, Czern.

Fig. 1. Adult female, viewed from the dorsal face.
. Front part of the body, with the eyes, superior antennze (with the bases of the flagella)
and right antennal scale, somewhat more strongly magnified; dorsal view.
» 8, Peduncle of the right superior antenna, with the bases of the flagella; viewed from
above.
» 4, Basal part of the left inferior antenna, with the scale (without the marginal setae) and
the base of the flagellum; dorsal view.
» 5. Outer part of the scale, more strongly magnified, showing the rudimentary apical seg-
ment at the inner corner.
6. Anterior lip, viewed from below.
» 7. Mandibles, anterior and posterior lips in situ, ventral view.
8
9

bo

. Mandibular palp, somewhat more strongly magnified.

. Masticatory parts of the mandibles.

» 10. Posterior lip.

» 11. Extremity of the tail, with the telson and the right uropod (without the marginal sete) ;
dorsal view.

» 12. Tip of the telson, more highly magnified.

P)e. 1;
Paramysis Baeri, Czern.

(Continued).

Fig. 1. Adult male, viewed from left side.

» 2. Peduncle of left superior antenna in male, viewed from below, exhibiting the male
appendage, the hairs of which have been removed in order to show the band-like
insertion of the latter.

3. First maxilla.
4, Second maxilla.
5. Maxilliped with exopodite and epipodite.
» 6. Gnathopod.
7. Terminal joint of the latter, more highly magnified.
8. Pereiopod of 2nd pair.
» 9. One of the outer sexual appendages of male.
» 10, Third pleopod cf male.
» 11. Fourth pleopod of male.
» 12. Inner lamella of left uropod (without the marginal set).
» 138. Telson viewed from the dorsal face.

» 14. Tip of telson of another specimen, with only 3 dentiform projections at the botto :
of the apical incision.

Pl. Il.
Mesomysis Ulskyi, (Czern.

Fig. 1. Adult female, dorsal view.

» 2. Peduncle of right superior antenna, with the bases of the flagella, viewed from
above.

» 3. Basal part of left inferior antenna, with the scale (without the marginal set) and the
base of the flagellum, dorsal view.

Meélanges biologiques. T, XIII, p. 419.

72 G. 0. SARS, [N. 8. IV

4. Extremity of the scale, more highly magnified.

5. Right mandible with palp.

6. Masticatory part of left mandible.
» 7, First maxilla.

8. Second maxilla.

9. Maxilliped with exopodite and epipodite.
» 10. Gnathopod.

11. Pereiopod of 2nd pair.

12. Extremity of the latter, more highly magnified, showing the structure of the dac-

tylar joint.

» 13. Inner lamella of right uropod (without the marginal set).
» 14, Telson, viewed from the dorsal face.
» 15. Tip of the telson, more highly magnified.

BLY:
Mesomysis Kowalevskyi, Czern.

Fig, 1. Adult female, dorsal view.
» 2. Front part of the body, with the eyes and antennz, dorsal face.
» 8. Basal part of left inferior antenna, with the scale (without the marginal sets) and the

base of the flagellum, dorsal view.
4, Extremity of the scale, more highly magnified.
5, Second maxilla.
6. Pereiopod of 2nd pair.
» 7, Telson, viewed from the dorsal face,
8. Inner lamella of left uropod (without the marginal set),
9, Extremity of the telson more highly magnitied,
» 10. Outer part of the tail of an adult male, viewed from left side, exhibiting the pleopoda
and caudal appendages.
» 11. Third pleopod of male.
» 12. Fourth pleopod of same.

Pl Vie
Mesomysis Czerniavskyi, G. O. Sars,

Fig. 1. Adult female, dorsal view.

. Front part of the body, with the eyes and antennz; dorsal view.

» 8. Basal part of left inferior antenna, with the scale (without the marginal sete) and
the base of the flagellum.

» 4, Extremity of the scale, more highly magnified.

» 5, Second maxilla.

6. Pereiopod of 2nd pair.

» 7, Extremity of the latter, more highly magnified.

8. Telson, viewed from the dorsal face.

» 9. Extremity of the latter, more highly magnified.

» 10. Inner lamella of left uropod (without the marginal set).

» 11. Male appendage of the superior antenne.

» 12. Third pleopod of male.

» 18. Fourth pleopod of male.

4
bo

PIV.
Mesomysis intermedia, Czern.
Fig. 1. Adult female dorsal view.
» 2. Front part of the body, with the eyes and antenne; dorsal view.
3. Basal part of left inferior antenna, with the scale (without the marginal sete) and
the base of the flagellum.
Mélanges biologiques. T. XII, p. 420.

(XXXVI) | CRUSTACEA CASPIA. 73

4, Extremity of the scale, more highly magnified.

5. Second maxilla.

6. Pereiopod of 2nd pair.

7. Extremity of the latter more highly magnified.

8. Telson, viewed from the dorsal face.

9. Extremity of the latter, more highly magnified.

10. Inner lamella of left uropod (without the marginal setz).

11. Tail of an adult male, viewed from left side, showing the pleopoda and caudal
appendages.

12. Third pleopod of male.

13. Fourth pleopod of male.

Pl. VII.
Katamysis Warpachowskyi, G. O. Sars.

1. Adult female, dorsal view.
2. Front part of the body, with the eyes and antennz, dorsal view.
3. Peduncle of right superior antenna, with the bases of the flagella.
4. Basal part of left inferior antenna, with the scale (without the marginal sete) and
the base of the flagellum.
5. Extremity of the scale, more highly magnified, exhibiting the apical segment.
6. Anterior lip, from below.
7. Posterior lip.
8. Right mandible with palp.
9. Masticatory part of left mandible.
10. First maxilla.
11. Second maxilla.
12. Maxilliped with exopodite and epipodite.
13. Gnathopod.
14. Terminal joint of the latter, more highly magnified.
15. Pereiopod of 2nd pair.
16. Extremity of same, more highly magnified.
17. Pereiopod of 3rd pair.
18. Extremity of same, more highly magnified.
19. Right uropod (without the marginal sete).
20. Telson, viewed from the dorsal face.
21. Adult male, viewed from left side.
22. Third pleopod of same.
23. Fourth pleopod of same.
24. Tip of the telson of same.

Pl VL

Limnomysis Benedeni, Czern.

1. Adult female, dorsal view.

2. Front part of the body, with the eyes and antenne, dorsal view.

3. Peduncle of right superior antenna, with the bases of the flagella.

4. Basal part of left inferior antenna, with the scale (without the marginal set) and the
base of the flagellum.

5. Anterior lip, from below.

6. Left mandible with palp, and masticatory part of the right one.

7. Posterior lip.

8. First maxilla.

9. Second maxilla.

10. Maxilliped with exopodite and epipodite.

11. Gnathopod.

i
bo

. Terminal joint of the latter, more highly magnified.
Mélanges biologiques, T. XIII, p. 421.

G. 0. SARS, CRUSTACEA CASPIA. [N. S.1V

. 13. Pereiopod of 2nd pair.

14. Extremity of same, more highly magnified, showing the structure of the dactylar joint.
15. Right uropod (without the marginal sete).

16. Telson, viewed from the dorsal face.

17. Extremity of same, more highly magnified.

18. Adult male, viewed from left side.

19. Peduncele of left superior antenna of male, viewed from below.

20. Male appendage of same, more highly magnified.

21. Basal part of left inferior antenna of male, with the scale and base of the flagellum.
21* Tip of the scale, more highly magnified.

2. One of the outer sexual appendages of male.

3. Third pleopod of male.

4. Fourth pleopod of male.

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Melanges biologiques, T. XIII, p. 422.

G.Q.Sars Crustacea caspia.

Myside. Pl. 1.

G.0.Sars autogr.

Paramysis Baeri, Czern.

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G.0.Sars Crustacea caspia.

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G.0.Sars Crustacea caspia.

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G.0.Sers autogr.

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G.0.Sars Crustacea caspia.

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