CRUSTACEA CASPIA. 283 



they are deep, and exhibiting a distinctly projecting corner just below the 

 posterior emargination. The 3 posterior pairs are small and bilobed. 



The epimeral plates of the metasome are well developed and (juite 

 smooth. The last pair are nearly rectangular, and do not exhibit any trace 

 of the oblique row of bristles found in the 3 preceding species outside the 

 lateral corners. 



The urosome is of moderate size and perfectly smooth above. 

 The eyes are distinct, though not very large, and of an oval reniform 

 shape, with dark pigment. 



The superior antennaj (fig. 2) are considerably more elongated than in 

 the 3 preceding species, being about 3 times as long as the cejjlialou. The 

 1st joint of the peduncle is very large, fully twice as long as the other 2 

 combined, and is densely setous on the outer edge. The 3rd joint is about 

 half as long as the 2nd, both being densely setous outside. The flagellum 

 considerably exceeds half the length of the peduncle, and is composed of 

 about 1 1 articulations. The accessory appendage is half as long as the 

 flagellum, and 6-articulate. 



The inferior antennae (tig. 3) are about equal in length to the superior, and 

 are rather strongly built, being generally bent in a genicular manner. The 

 basal joint is very large and globular. The antepenultimate and penultimate 

 joints of the peduncle are both expanded posteriorly to short setiferous 

 lobes, that of the penultimate joint having, moreover, outside 2 oblique rows 

 of short spines. The last peduncular joint is simple cylindric and nearly as 

 long as the penultimate one. It has posteriorly several fascicles of slender 

 bristles and outside 4 oblique rows of small spines. The flagellum is fully 

 as long as the 2 outer joints of the peduncle combined, and is composed of 

 10 articulations. 



The gnathopoda (figs. 4, 5) are rather powerful and somewhat unequal 

 in size, the posterior ones (fig. 5) being, as usual, the larger. The propodos 

 of the anterior gnathopoda (fig. 4) is quadrangular in shape, that of the 

 posterior ones (fig. 5) considerably broader and more pronouncedly quadrate 

 in outline. In both pairs the palm is nearly transverse and defined below by 

 a distinct angle, to which are secured 3 spines, tlie outmost of which is 

 particularly strong. The hind margin is somewhat longer than the palm, and 

 exhibits in its outer part 3 or 4 fascicles of short bristles. 



The 2 anterior paii-s of pereiopoda (fig. 6) are moderately strong, with 

 the meral joint rather large and densely setiferous on the posterior edge. 

 The carpal joint is, on the other hand, but very little expanded, and is pro- 

 vided posteriorly, in addition to the settu, with 3 strong spines. The propodal 



$ii3.-MaT. CTp. 191. 9 



