(xxxv1)] CRUSTACEA CASPIA. 323 
The adult male (fig. 11) looks very like that of the last-named species, 
but is somewhat less slender, with the anterior division of the body compa- 
ratively thicker and more vaulted above. The sexual characteristics also, 
are, on the whole, developed in a very similar manner, and need not there- 
fore be treated in detail. The eye (see the figure on the left side) is very 
large, and has the corneæ strongly vaulted and highly refractive. The uropoda 
(fig. 12) only differ from those of the female in the greater number (10) of 
marginal spinules with which the inner ramus is armed, and in the finely 
ciliated edge. 
Colour. — Unlike what was the case with the specimens of P. gracilis, 
those of the present form exhibited an ornament of distinct, reddish brown, 
stellate, pigmentary spots very similar to that stated in the 3 first described 
species. 
Occurrence. — I have only had an opportunity of examining a few spe- 
cimens of this form. They were collected by Mr. Warpachowsky at 3 dif- 
ferent Stations, one of which (St. 51) was located between the islands of 
Kulaly and Morskoj, the second (St. 53) at some distance North of these 
islands, and the third (St. 63) in the eastern part of the north Caspian Sea, 
south of the mouth of the Ural. 
7. Pseudocuma tenuicauda, G. O. Sars, n. sp. 
(Pl. IX). 
Specific Characteristics. — Body somewhat less elongated than in the 2 pre- 
ceding species, with very thin and pellucid integuments. Anterior division of 
the body sharply marked off from the posterior, and considerably exceeding 
it in length, being oblong in form, and nearly of same height throughout. 
Carapace in female scarcely longer than the exposed part of the trunk, and 
having the branchial regions but faintly defined; pseudo-rostral projection 
comparatively small, horizontal; antero-lateral corners obtusangular. Free 
Segments of mesosome rather deep, and quite smooth above, the 2 posterior 
ones unusually massive, and filled on the sides with strong muscles. Meta- 
some extremely narrow, cylindrical. Eye well developed. Antenne, oral parts 
and gnathopoda scarcely differing from those in the 2 preceding species. The 
2 anterior pairs of legs rather slender, and of the usual structure; the 3 
posterior pairs unusually strongly built, with the propodal joint much shorter 
than the carpal one, and oval in form. Uropoda moderately slender, and hay- 
ing the scape fringed inside with ciliated setze, rami equal-sized, and about 
the length of the scape, the inner one in female having only 3 marginal 
spinules. Telson semi-elliptical in form. Length of adult female scarcely ex- 
ceeding 3', mm, that of male about the same. 
Mélanges biologiques. T. XIII, p. 487. 92 
