(XXXVI)] CRUSTACEA CASPIA. 325 



The eye is well developed, with all 3 cornese distinct. 



The superior autennaj (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 antennae and oral parts do not exhibit any essential difierence 

 from those parts in the other species, and also the gnathopoda (tig. 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 mucli more strongly built, with the joints much tumefied 

 and densely setous. The longitudinal relation of the several joints is also 

 somewhat diff'erent. Thus the basal joint is comparatively less elongated, 

 and especially in tlic 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, unciliatod setae, 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 setae. 



The uropoda (see fig. 10) are moderately slender, equalling in length 

 about Vg of the metasome. The scape is provided on the inner edge with 5 

 ciliated set£e. The rami arc 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. fjraci- 

 loides, has only a single spiniform seta on tlu^ 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. 1 1) does n(jt difl'er nuicii 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. 1 6) are, as usual, 

 somewhat more elongated than in the female, and the setae of the scape are 

 longer, and G in number. The inner ramus is armed on the inner edge with 

 no less tlian 10 spinules, and exiiil)its besides tiie usual fine ciliation of 

 the edge. 



Colour. — No colouring uuxrks could be detected in the specimens 

 examined. Tliey all exhibited a uniform, wliitish colour. 



Occurence. — Of the present species, several specimens, almost exclusively 

 males, were collected by .Mr. Warpachowsky at Stat. 15, located in the 



Melanges biologiqnos. T. XHI, p. J89. •22* 



