66 CAPRELLIDA. 
LATREILLE, in Nouv. Dict. d’Hist. Nat. 2nd Edit. 
vi. p. 433. Dzsmarzst, Consid. Crust. p. 277 
(not of Johnston). Spence Bare, Ann. Nat. 
Hist. 2 ser. xix. p. 151. 
Oaprella acuminifera. 
Tuts species may readily be detected from any other 
by the peculiarly vaulted or skull-like head, together 
with the tuberculated character of the body. The first 
segment of the body is short. The three next are longer 
than the first, equal to each other, and surmounted by 
three dorsal blunt teeth, or tubercles. The two anterior, 
immediately over the articulation of the second pair of 
legs, are sublateral and parallel. The third is central, and 
situated upon the posterior margin. The last three seg- 
ments are short, and each is furnished with only two 
sublateral parallel tubercles, which are surmounted by nu- 
merous small, bead-like tubercles. The superior antennz 
are not half the length of the animal. The inferior 
antennze are not longer than the peduncle of the superior. 
The first pair of legs are small, the hand being ovate 
and the palm slightly convex and imperfectly defined. 
The second pair of legs articulate with the second seg- 
ment of the body, posteriorly to the centre. They have 
the hand in the male very large, rounded on the back, 
and hollow below (in some specimens we have seen 
inflated membranous sacs filling the palm), being defined 
posteriorly by a sharp tooth, and armed anteriorly with a 
small point that marks the position where the lateral 
walls of the palm unite together anteriorly. The finger 
is much curved, and armed with two obtuse teeth upon 
the inner margin. The three posterior pairs of legs are 
of equal length, and adapted for prehensile use. 
In the female the tubercles upon the back are less 
conspicuous than in the male, and the second pair of legs 
have the hand smaller, of an oval form, the palm being 
slightly convex, defined by a small process, armed with 
