(XXXVI) | CRUSTACEA CASPIA. 325 
The eye is well developed, with all 3 corne distinct. 
The superior antennæ (fig. 3) have the basal joint comparatively short 
and thick, whereas the 2 succeeding ones are rather slender and nearly 
equal-sized. The flagella are normally developed. 
The inferior antennæ and oral parts do not exhibit any essential difference 
from those parts in the other species, and also the gnathopoda (fig. 4) are 
constructed upon the very same type. 
Of the legs the 2 anterior pairs (figs 5 and 6) are normally developed, 
and resemble those in P. gracilis. The 3 posterior pairs (figs 7, 8, 9), on 
the other hand, are much more strongly built, with the joints much tumefied 
and densely setous. The longitudinal relation of the several joints is also 
somewhat different. Thus the basal joint is comparatively less elongated, 
and especially in the last pair (fig. 9) very short and thick, bulging out 
considerably on the outer side. The meral joint is in all pairs very large, 
whereas the propodal one is quite short, of an oval form, and fringed on the 
inner edge with the usual strong, unciliated setæ, which are more developed 
on the 2 last pairs than on the antepenultimate ones. The rudimentary ex- 
opodite, issuing from the basal joint of the former, is distinctly biarticulate, 
and carries the 2 usual plumose sete. 
The uropoda (see fig. 10) are moderately slender, equalling in length 
about 1, of the metasome. The scape is provided on the inner edge with 5 
ciliated sete. The rami are nearly equal-sized, and about the length of the 
scape. The inner ramus has on the inner edge only 3 spinules in addition to 
the 2 unequal spines issuing from the tip. The outer ramus, as in P. graci- 
loides, has only a single spiniform seta on the inner edge near the tip, and 
2 apical ones of unequal length. 
The telson (ibid.) exhibits a similar, semi-elliptical form to that in the 
2 preceding species. 
The adult male (fig. 11) does not differ much from the female, as regards 
the general from of the body, and is also of about same size. It is however 
easily recognizable by the sexual characteristics, which are displayed in much 
the same manner as in the other species. The uropoda (fig. 16) are, as usual, 
somewhat more elongated than in the female, and the sete of the scape are 
longer, and 6 in number. The inner ramus is armed on the inner edge with 
no less than 10 spinules, and exhibits besides the usual fine ciliation of 
the edge. 
Colour. — No colouring marks could be detected in the specimens 
examined. They all exhibited a uniform, whitish colour. 
Occurence. — Of the present species, several specimens, almost exclusively 
males, were collected by Mr. Warpachowsky at Stat. 15, located in the 
Mélanges biologiques. T. XII, p. 489. 995 
