T. Xlll] CRUSTACEA CASPIA. 497 



the 2 preceding species deeply cleft in the middle, its lateral halves somewhat 

 projecting and obtusely rounded at the tip; antero-lateral corners nearly 

 rectangular. Exposed part of trunk without any keel or projections, its last 

 segment comparatively small. Metasome poorly developed, scarcely attaining 

 the length of the anterior division of the body. Eye well developed, with all 

 3 corneae distinct. Antennae and legs apparently of the normal structure. 

 Uropoda comparatively small, with the rami equal-sized and exceeding 

 the scape in length, each terminating in a rather strong spine, the inner one 

 minutely serrated inside. Telson semicircular. Length of adult female 

 scarcely exceeding 3 mm. 



Remarks. — This is a very distinct species, easily recognizable by the 

 unusually short and stout form of body, the scabrous integuments and the 

 shape of the carapace. 



Description of the female. 



The solitary specimen examined, a fully grown ovigerous female, does 

 not exceed a length of 3 mm, and this form belongs thus to the smaller 

 species of the genus. 



The general form of the body (see figs. 12 and 13) is exceedingly short 

 and stout, more so than in any of the other known species, and the 2 chief 

 divisions appear very sharply marked off from each other. The anterior 

 division is rather tumid and of an ovoid form, with the greatest breadth 

 about in the middle. As seen from above (fig. 1 1), it tapers gradually both 

 anteriorly and posteriorly. In a lateral aspect (fig. 12), the dorsal face ap- 

 pears gently arched, and the anterior extremity somewhat truncated. 



The integuments are rather strongly incrusted, and exhibit everywhere 

 a distinct squamous structure, the squamulae being elevated to small pro- 

 jecting spikes, thus giving the surface a scabrous character. 



The carapace is comparatively large and deep, exceeding in length the 

 exposed part of the trunk, and exhibits, as seen from the side (fig. 12), a 

 somewhat quadrangular form, with the upper contour nearly horizontal, 

 though somewhat interrupted in the middle by the projecting branchial 

 regions. In a dorsal view (fig. 1 1 ), it has its greatest breadth quite posteriorly, 

 and appears somewhat instricted in the middle. The branchial regions are 

 distinctly defined and, as in the 2 preceding species, very sharply marked off 

 in front from the gastric area. The latter is flattened, without any distinct 

 keels, and terminates in front in a well defined, though rather short and 

 broad ocular lobe. On each side of the gastric region a very conspicuous 

 horizontal crest runs forwards, terminating at the tip of the pseudo-rostral 

 projection. The latter appears, when the animal is viewed from the side 



Bulletin N. S. IV (XXXVI) p. 333. 



