CRUSTACEA CASPIA. 345 



The urosome (conip. fig. 19) does not exhibit any distinct dorsal pro- 

 jections; but each segment has, in the middle of the dorsal face, a fascicle 

 of fine hairs. In th^ 2nd segment 2 small spinules are found among the 

 hairs, and this segment has moreover on each side of the dorsal face an 

 obliquely transverse row of 3 somewhat stronger spines accompanied by 2 

 or 3 small hairs. In the last segment occurs a similar row of lateral spines, 

 but their number is here only 2 on each side. 



The eyes (see fig. 2) are of moderate size and oblong oval in form, being 

 placed close to the anterior edges of the cei)halou, and extending below 

 nearly to the inferior edge of the lateral lobes. They have the visual elements 

 well developed and the pigment dark. 



The superior antennae (fig. 3) are not very much elongated, scarcely ex- 

 ceeding in length Vg of the body, and but sparingly supplied with short bristles. 

 The joints of the peduncle successively diminish in size, the last one being 

 about half the length of the 1st. The flagellum somewhat exceeds the peduncle 

 in length, and is composed of only 9 articulations. The accessory appendage 

 is very small, considerably shorter than the last peduncular joint, and is 

 composed of only 2 articulations, the last of which is extremely minute. 



The inferior antennae (fig. 4) are considerably shorter than the superior, 

 and have the last 2 jctints of the peduncle nearly of same length, and pro- 

 vided with scattered fascicles of slender bristles. The flagellum is about half 

 the length of the peduncle, and composed of 5 articulations. 



The anterior gnathopoda (fig. 5) are comparatively small, with the car- 

 pus rather short and expanded below to a rounded setiferous lobe. Thepro- 

 podos is oval quadrangular in form, with about 3 fascicles of bristles below, 

 and a single one above, near the tip. The palm is short and almost trans- 

 verse, being defined below by an obtuse augle carrying a few slender spines 

 and several bristles. The dactylus is not very strong. 



The posterior gnathopoda (fig. 6) are not at all stronger than the ante- 

 rior, but a little more slender, with the carpus somewhat larger, and the 

 propodos louger in proportion to its breadth. 



The 2 anterior pairs of perciopoda (fig. 7) are rather narrow and edged 

 with fascicles of slender spines. 



The 3 posterior pairs of pereiopoda (figs. 8 — 10 are on the whole com- 

 paratively short and stout, and have their outer part edged with fascicles of 

 slender spines. The last 2 pairs are about same length, whereas the ante- 

 penultimate pair are, as usual, somewhat shorter. In all pairs the carpal joint 

 is comparatively short and thick, not nearly attaining to the length of the pro- 

 podal one. The basal joint of the antepenultimate pair (fig. 8) is subquadrangular 

 in form, with the posterior edge nearly straight, and the infero-posteal corner 



$n3.-M.iT. c-Tp. 325. 3 



