CRUSTACEA CASPIA. 277 



The urosome is gather stout, aud has the segmeuts slightly raised dor- 

 sally, without, however, forming any distinct i)rojections. They have a few 

 small hairs on the upper face, and the last 2 segments besides 2 very small 

 subdorsal spinules. 



The eyes are well developed, thougli not very large, and of an oval 

 reniform shape. The pigment in 2 of the 3 specimens examined was of the 

 usual dark hue, in the 3rd, belonging to the collection of Dr. Grimm, it 

 was almost quite absent, probably owing to the action of the spirit. 



The superior anteunaj (fig. 2) are short and stout, about twice as long 

 as the cephalon, and have the 1st peduncular joint very large and massive, 

 whereas the 3rd joint is rather small, scarcely exceeding half the length of 

 the 2nd. The flagellum is a little longer than the last 2 peduncular joints 

 combined and composed of 8 articulations. The accessory appendage is lialf 

 as long as the flagellum, and 4-articulate. 



The inferior antennse (fig. 3) scarcely exceed in length the superior, and 

 are less densely setous than in N. caspius, otherwise of a quite similar 

 structure. The flagellum is, however, less rudimentary, exceeding in length 

 the last peduncular joint, and is composed of G articulations. 



The oral parts exactly agree iu their structure with those in the type 

 species. 



The gnathopoda (figs. 4 and 5), on the other hand, are rather diff'erent, 

 being on the whole less powerfully developed than iu that species. They are 

 somewhat unequal iu size, the posterior ones (fig. 5) being, as usual, the 

 larger, and are clothed with scattered fascicles of slender bristles. The pro- 

 podos in both pairs is of a rather regular oblong quadrangular shape, being 

 not, as in N. caspms, conically tapered distally. The palm is much less ob- 

 lique, and is defined below by a distinct angle carrying 2 or 3 spines, the 

 outmost of which is rather strong. The hind margin is considerably longer 

 than the palm, and provided in the posterior pair with 3 fascicles of short 

 spiniform bristles. 



The 2 anterior pairs of pereiopoda (fig. 6) are very largely developed 

 and densely setiferous. The meral joint is large and gradually expanded 

 distally, projecting at the end anteriorly to an obtuse, densely setiferous 

 projection. The carpal joint is very broad and lamellarly expanded, carrying 

 on the posterior edge a regular series of strong curved setse, and at the 

 anterior corner a dense brush of slender bristles. The propodal joint, as in 

 N. caspius, is rather narrow and setous only at the tip. The dactylus is 

 about half the length of that joint. 



The 3 posterior pairs of pereiopoda (figs. 7 — 9) are more slender than the 

 anterior, and are, like the latter, rather densely setous, having, iu addition to 



$H3.-MaT. CTp. 185. 3 



