CRUSTACEA CASPIA. 303 



Tlie form of tlie body (see tig. 1) is ou the whole much like tluit iu the 

 2 preceding species, tliougli periuaps a little more slender than in G. cheli- 

 corne. * 



The ceplialou about equals in length the first 2 segments of the meso- 

 sonie combined, and lias the frontal edge slightly angular in tlie middle. The 

 lateral lobes are rather prominent, and narrowly rounded at the tip. 



Tlie coxal and epimeral plates do not differ essentially from those iu G. 

 chelicorne, and the urosome (fig. s'l exhibits likewise a similar appearance 

 to that in the said species, the last 2 segments being less sharply defined. 



The eyes are small, and, as usual, placed at the bases of the lateral 

 lobes of the cephalon. 



V The superior antennre are rather different in the two sexes. In the female 

 they are (fig. 2) comparatively short, scarcely attaining '/g of the length of 

 the body, and are rather sparingly setous. The 1st joint of the peduncle is 

 about the length of tlie other 2 combined, and is armed below with 4 — 5 

 small spinules. The 2nd joint has a similar spinule in the middle of the 

 posterior edge. The flagellum is shorter than the peduncle, and composed of 

 about 9 articulations. In the male these antennae (see figs. 1 and 4) are 

 much more fully developed, and have the peduncle densely clothed with 

 fascicles of slender bristles. TJie 2nd peduncular joint is considerably elon- 

 gated, fully equalling in length the 1st one, but is, as usual, much narrower. 

 The flagellum scarcely exceeds iu length the last 2 peduncular joiuts com- 

 bined, and is composed of about 12 articulations. 



The inferior antenna; likewise exhibit a rather different appearance in 

 the two sexes, being in the male (see fig. 1) much more fully developed than 

 iu the female (fig. 3), attaining in the former almost the length of the whole 

 body. The penultimate joint of the peduncle gradually widens distally, and 

 is produced at the end posteriorly (see fig. 5) into a strongly incurved spini- 

 forni projection, at the base of which is a small, slightly bilobed expansion. 

 The last peduncular joint is rather elongated, being nearly as long as the 

 penultimate one, but, as usual, much narrower, and of simple cylindric form. 

 It is armed, at a short distance from the base inside, with a stout recurved 

 prominence, but it has no spine at the end. The flagellum is shorter than 

 the last peduncular joint, and exhibits the usual structure. 



The gnathopoda scarcely differ in their structure from those in the 2 

 preceding species. 



The 2 anterior pairs of pereiopoda (fig. 6) are, on the other hand, con- 

 siderably shorter and stouter, with some of the joints lamellarly expanded. 

 The basal joint is rather broad, with the anterior edge curved and fringed 

 with about 10 slender seta\ The meral 'joint is considerably expanded, 



*n3.-MaT. CTp. ail. 29 21* 



