T. XIIl] - CRUSTACEA CASPIA. 469 



inner edge with 6 ciliated setae, and from its outer corner issues a much 

 larger, anteriorly-curving seta, densely plumose throughout. Of the joints 

 composing the terminal part, the carpal one is the largest, and carries on 

 the inner edge a series of short ciliated setae. 



The legs are 5 pairs in number, corresponding to the 5 exposed seg- 

 ments of the mesosome. They originate each from a short piece firmly 

 connected to the inner side of the epimera, and representing their coxal 

 joint (see fig. 2). By dissection this joint, however, remains in connexion 

 with the segments, the true movable articulation being between that joint 

 and the basal one. 



The 1st pair of legs (fig. 13) are much the longest and of a very slender 

 form. They are stretched anteriorly, and closely applied against the inferior 

 side of the carapace, only their outer part curving downwards by a more or 

 less strong geniculate bend (see fig. 2). Fully extended, they about equal in 

 length the carapace and the 2 first free segments of the mesosome combined. 

 In their structure they exhibit a close resemblance to the posterior gnatho- 

 poda. As in the latter, the basal joint is very large, fully as long as the 

 remaining part of the leg, and exhibits, somewhat above the middle, a strong 

 curvature. Its proximal part is somewhat dilated, to receive the strong 

 muscles joining the exopodite, and has a ridge running along its outer side. 

 Along the inner edge of the joint there is a series of plumose setae, and from 

 the outer corner a similar seta issues. The terminal part of the leg rapidly 

 tapers distally, and has all the joints well defined and clothed with scattered 

 bristles, some of which are ciliated. The ischial and meral joints are rather 

 short and thick, being connected by a very oblique articulation, and also the 

 articulation between the meral and carpal joints appears very oblique, 

 though in an opposite manner. The 3 outer joints are rather slender, and 

 successively decrease in size, the most movable articulation being between 

 the carpal and propodal joints. The terminal or dactylar joint is very narrow, 

 linear, and terminates with 3 slender curved spines, the second of which is 

 the longest. The exopodite does not differ from that of the posterior gnatho- 

 poda, except in the basal part being somewhat thicker, and having at the 

 end outside a plumose seta. 



The 2nd pair of legs (fig. 14) are much shorter than the 1st, and, like 

 the latter, generally curved anteriorly. The basal joint is rather massive, 

 though considerably shorter than the terminal part, and but slightly curved. 

 It is provided along the inner edge with 6 strong plumose setae, and has on 

 the outer corner a somewhat smaller seta. The ischial joint is very short, 

 though well defined, and carries inside a strong plumose seta. The meral 

 joint is rather thick, nearly quadrangular in form, and has 2 plumose setae 



Bulletin N. S. IV (XXXVI) p. 305. 



