CRUSTACEA CASPIA. 483 



laterally, at the insertion of the uropoda, with a number of similar spines, 

 somewhat irregul^rlj- arranged. 



The eyes are very small and rounded, being placed, as usual, at the 

 bases of the lateral lobes. 



The superior auteuu;e are of about same structure in the two sexes, 

 being rather slender and but sparsely setiferous. In the female they nearly 

 attain half the length of the body, and have tlie 1st joint of the peduncle 

 about as long as the 2nd, and armed below witli 2 distant spines. Tiie 

 flagellum somewhat exceeds the peduncle in leugtli, and is composed of 

 about 14 articulations. 



The inferior antenna3 are, as usual, somewliat different in the two sexes. 

 In tlie female (see figs. 18, 19) they are of moderate size, with tlie pen- 

 ultimate joint of the peduncle but slightly widening distally, and produced 

 at tlie end to a very acute spiniforra process reaching about to the middle 

 of tlie last peduncular joint. The latter is somewliat sliorter than the pen- 

 ultimate one, and simple cylindric, without any trace of a lateral denticle, 

 but with a very slight, uodiform prominence at the end inside. The flagellum 

 does not attain to quite the length of the last peduncular joint, but exhibits 

 tlie usual structure. 



In the male tliese antennae (fig. 26) are much more strongly developed, 

 and are especially distinguished by the large size of tlie thumb-like process 

 issuing from the penultimate joint of the peduncle. This process is rather 

 broad at the base, of an almost lanceolate form, and extends as far as the 

 end of the last peduncular joint. It has, moreover, inside, near the base, a 

 distinct, though rather small, dentiform projection, of wliicli only a very 

 slight rudiment is found in tlie female. The last joint of tlie peduncle is 

 produced at the end inside to a well-defined conical projection, which is 

 crossed by the tip of the thumb-like process of the preceding joint, when 

 bent in against it, whereby these antennte acquire a complete cheliform 

 character, as is the case in both sexes of C. chelirorne. 



The gnutliopoda resemble in structure those in the otiier species, with 

 tills difference, liowevor, that the posterior ones (fig. 20) Jiave the dactylus 

 smooth, with only a few slender hairs, whereas in all the other Caspian 

 species, it is coarsely denticulate inside. 



Tlie 2 anterior pairs of pereiopoda (fig. 21) are considerably more 

 slender than in C chelicorne, more resembling in this respect those in G. 

 nohile, the meral joint being but very slightly expanded. This joint does 

 not, however, in either of the two sexes exhibit that dense supply of setae 

 characteristic of the last-named species. The dactylus is extremely slender 

 and elongated, even exceeding somewhat the propodal joint in length. 



'l'U3.-llaT. CTp. 313. 63 



