CALIGID^. 263 



Tlie parts corresponding to the foot-jaws are well de- 

 veloped. They are three pairs. The first pair (t. XXXIV, 

 f, 5 c) — the posterior antennae of Kroyer — is situate be- 

 tween the siphon and antennEe, and consists of two articu- 

 lations ; the basal broad and fleshy, the terminal tapering 

 to the extremity, which is in form of a strong hook. 

 At a little distance from, and external to, the extremity 

 of this joint, we see a stout, horny-looking, hooked spine, 

 springing from it. The second pair (t. XXXIV, f. 5 k) 

 is longer than the preceding, and consists of two articu- 

 lations ; the basal more slender than that of the first pair, 

 and the terminal still more so, of considerable length, and 

 ending in two or three falciform claws, the edges of which 

 are armed with small teeth. The third pair (t. XXXIV, 

 f. 5 i) is longer than the two preceding, though not 

 so long as the second. It is cheliform, and differs a 

 little in the two sexes. In the male, it consists of a 

 large, fleshy, basal joint, which has articulated to it a 

 stout claw, curved inwards, and having a small seta near 

 its apex. In the female, the basal joint is smaller, and 

 less fleshy, and the terminal is longer and larger than in 

 the male. These foot-jaws constitute real organs of pre- 

 hension, and it is by means of them that the animal 

 fastens itself upon its prey. 



The true feet, or natatory feet, consist of four pairs, 

 three of which are attached to the thoracic segment of the 

 carapace, while the fourth springs from the penultimate 

 ring of the thorax. The first pair (t. XXXIV, f. 5 /■) has 

 three articulations. The basal joint is of a cylindrical 

 form, and the second is similar in size and form, but with 

 numerous very short seta3 on under margin. The third, 

 or terminal, is about one half the size of the others, and 

 has on its inferior edge three long, finely-ciliated setse, 

 nearly as long as the preceding joint of the leg, and at 

 the apex four short, stout, naked setee. The second pair 

 (t. XXXIV, f. 5 /) is composed of two basilar joints, the 

 first short, and provided with a long ciliated seta on its 

 under surface ; the second very large, becoming broader 



