(XXXVI)] CRUSTACEA CASPIA. 317 



The gnathopoda (figs. 4 and 5) are likewise somewhat more robust, 

 especial!}- the posterior ones (fig. 5), though otherwise exhibiting the struc- 

 ture characteristic of the genus. 



As to the legs (figs. 6 — 10), tiiey are on the whole much more strongly 

 built than in the 3 preceding species. On the 1st pair (fig. 6) the basal joint 

 is scarcely longer than the 4 succeeding joints combined, and the latter are 

 comparatively broader and more laminar than in those species, whereas the 

 terminal joint has conserved its narrow linear form unaltered. 



The 2nd pair of legs (fig. 7) are much curved and extremely robust, other- 

 wise of the usual structure. 



The 3 posterior pairs of legs (figs. 8 — 10) likewise exhibit an unusually 

 robust appearance, and are distinguished by the large size of the meral 

 joint, which is fully twice as long as the carpal one. The dactylar joint, 

 moreover, is unusually strong and claw-like, whereas the modified setae 

 issuing from the 2 preceding joints are comparatively short. Tiie rudimen- 

 tary exopodite, present in the penultimate and antepenultimate pairs, is very 

 small, though consisting of 2 well-defined articulations and carrying the 2 

 usual, plumose setae (see figs. 8 and 8 a). 



The uropoda (see fig. 11) are comparatively shoi-t and stout, scarcely 

 exceeding in length V^ of the metasome. The scape is rather massive, and 

 provided on the inner edge with 4 strong spines. The rami are very unequal, 

 the inner one being by far the larger and about tiie length of the scape. It 

 carries on the inner edge 4 short spines and on the tip 2 unequal ones, the 

 outer of which is about half as long as the ramus. The outer ramus is about 

 ^ "the length of the inner, and terminates with 2 very unequal, slender spines, 

 the inner of which attains the length of the whole ramus; it moreover car- 

 ries on both sides, near the tip, a small seta. 



The telson (ibid. fig. 12) is very small, and exhibits a nearly semicircu- 

 lar form, the tip being evenly rounded. 



DesiriptioD of (he male. 



(PI. VI). 



The length of adult male specimens docs not exceed that of the female. 

 The general appearance is, however, rather different (see tigs. 1 and 2), the 

 body being comparatively much more slender, with the anterior division nut 

 nearly so tumid, and also less boldly vaulted above. The carapace exhibits a 

 somewhat different form, being less attenuated in front, and having the 

 pseudo-rostral projection shorter and more obtuse, whereas theantero-iaterai 

 corners are much more prominent and nearly rectangular. 



Melanges biologiriucs, T. XIII, p. -ISl. 



