(XXXVI) | CRUSTACEA CASPIA. 305 
inner edge with 6 ciliated setæ, 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 setze. 
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 setæ, 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 setæ, 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 setæ 
Mélanges biologiques. T. XIII, p. 469. 
