(xxxvn] CRUSTACEA. CASPIA. 57 
Remarks. — This form has been rather minutely described by Mr. 
Ozerniavsky, but the peculiar development of the exognath of the 2 pairs 
of maxillæ 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 àntennal 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 (Ullsky), Mangischlak (Ullsky), 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, Czerniavsky, l c. fasc. 2, p. 68, 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 antenne, which was con- 
tained in the type collection of Caspian Myside 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, Czerniavsky, 1882. 
Generic Characters. — Form of body (see Pl. IH, IV, 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. IV, V, 
VI, fig. 2) large, pyriform. Superior antenne (Pl. IH, fig. 2) of the usual 
structure. Inferior antenne (Pl. III, IV, V, VI, fig. 3) less strongly produced 
at the outer corner of the basal part than in Paramysis, scale of moderate 
Melanges biologiques. T. XIII, p. 405. 
