CRUSTACEA CASPIA. 361 



ing and angular. In the penultimate pah- (fig. 7) the basal joint is some- 

 what more elongated and slightly expanded in its proximal part, gradu- 

 ally tapering distally. The last pair (fig. 8) are about same length as the 

 penultimate, but are markedly distinguished by the much larger size 

 of the basal joint. This exliibits a rather regular oval form, with the 

 posterior edge evenly curved, and, as in the preceding pairs, densely fringed 

 throughout with comparatively short bristles; its infero-posteal corner pro- 

 jects below as a narrowly rounded lobe, reaching about to the end of the 

 ischial joint. Of the outer joints, the carpal one in all 3 pairs is rather elong- 

 ated and slender, exceeding in length both the meral and the propodal joints. 

 The dactylus is not very strong, and has near the tip a small bi'istle. 



The anterior pairs of uropoda (figs. 9 and 16) have the rami sublinear 

 in form and armed with scattered lateral spines, their tip carrying only a 

 single spine accompanied by 2 small denticles. 



The last pair of uropoda (fig. 10) are of moderate size, and, as in most 

 other Caspian Gammari, have the inner ramus veiy small and scale-like, 

 with a single minute apical spinule and several slender bristles on the in- 

 ner edge. The outer ramus is about twice the length of the basal part and 

 slightly tapers distally. It is fringed all round with numerous slender, 

 partly ciliated setae, and has besides, on the outer edge, 3 fascicles of spines; 

 the terminal joint is extremely minute. 



The telson (fig. 11) is about as long as it is broad, and is, as usual, 

 divided by a deep cleft into 2 halves, eacli of which carries on the narrowly 

 truncated tip 3 or 4 spines, but no trace of any lateral ones. 



The achiU male (fig. 12) generally attains a considerably larger size 

 than the female, its length amounting to 22 mm. 



It does not difler conspicuously in its general form from the female, but 

 is easily recognizable by the much stronger development of the gnathopoda. 



As in the female, these limbs (figs. 14, 15) are somewhat unequal, the 

 posterior ones (fig. 15) being considerably stronger than the anterior 

 (fig. 14). Thepropodos in both pairs, but especially in the posterior ones, is 

 very large and tumid, though of a similai- shape to that in the female. 



Of the other appendages, the last pair of pereiopoda somewhat differ 

 in the basal joint being narrower and less expanded than in the female, with 

 the posterior edge nearly straight, and the last pair of uropoda appear a 

 little more elongated and still more densely setons. 



Occurrence. — This species would seem to be one of the most frequent 

 Amphipoda of the Caspian Sea. It has been collected by Mr. Warpachow- 

 sky in no less than 14 different Stations, and in some of them in great 

 abundance. Of these Stations, one (St. 2) is located off the Tschistyi-Bank, an- 



*H3.-ilaT. CTp. 341. 19 



