T. XIIl] CRUSTACEA CASPIA. 477 



(Stat. 58 and 59) belong to the western part of the North Caspian Sea, 

 whereas the other 2 (St. 61 and 66) are located far north, at some distance 

 from the mouth of the Ural. 



3. Pseudocuma rostrata, G. 0. Sars, n. sp. 

 (PI. IV). 



Specific Characteristics $. — Body rather stout, with the anterior division 

 fully as long as the posterior, and nearly fusiform in shape. Carapace some- 

 what attenuated in front, and having on each side 3 oblique folds, 2 of which 

 limit the branchial region, the 3rd crossing it in the middle; ocular lobe 

 narrowly triangular with the visual elements less distinct; pseudo-rostral 

 projection exceedingly prominent and acuminate at the tip; antero-lateral 

 corners but slightly projecting, and defined above by an angular notch. Free 

 segments of mesosome keeled dorsally, the keel being elevated to compara- 

 tively low projections somewhat increasing in size posteriorly, that of last 

 segment the most prominent and triangular of form. Antennse, oral parts 

 and legs nearly as in the 2 preceding species. Uropoda rather short and 

 robust, scarcely exceeding in length % of the metasome, rami equal-sized 

 and about the length of the scape, each terminating in a strong spine and 

 having the inner edge minutely serrate. Telson transversely quadrangular. 

 Length of adult female 8 mm. 



Remarks. — The present species is easily distinguishable from either of 

 the 2 preceding ones by the strongly prominent and acuminate pseudo-rostral 

 projection, as also by the oblique folds running across the sides of the cara- 

 pace. In the structure of the limbs it shows itself however to be nearly 

 related to the former. Also of this form, only female specimens have hitherto 

 come under my inspection. 



Description of the female. 



The largest specimen, a fully grown ovigerous female, measures in length 

 8 mm, this form also being thus of a much larger size than either of the 2 

 earlier known species. 



The general form of the body (see figs. 1 and 2) is rather stout, with 

 the 2 chief divisions sharply marked off from each other, and of about equal 

 length. As seen from above (fig. 1), the anterior division exhibits a some- 

 what fusiform shape, with the greatest breadth at some distance behind the 

 middle, whence it rapidly tapers anteriorly. Viewed from the side (fig. 2), 

 the dorsal face appears slightly arched and irregularly indented in its pos- 

 terior part, on account of the projections issuing from the free segments of 

 the mesosome. 



Bulletin N. S. IV (XXXVI) p. 313. 34 



