136 GAMMARID^E. 



length of the first, and more slender ; the third is very 

 short ; the flagellum is scarcely as long as the peduncle. 

 The inferior antennae are about one-third the length of 

 the animal ; the peduncle is longer than the superior 

 antennae, of which the penultimate joint is twice the 

 length of the ultimate ; the flagellum is scarcely as long 

 as the peduncle. The mandibles have no appreciable 

 distinction from those of A. Gaimardii. The foot-jaws 

 have the antepenultimate joint reaching scarcely to the 

 extremity of the squamose process of the preceding 

 joint; the penultimate joint is nearly as long as the 

 one before it, and itself is longer than the finger, which 

 terminates in a sharp nail ; the spines upon the squamose 

 plate differ from those in A. Gaimardii in form as well 

 as in length ; they are eight in number, and rapidly 

 increase in size from the base to the top of the 

 plate ; their form is that of a lancet-blade, slightly 

 hooked at the point, and narrowed at the base ; the 

 apex of the plate is crowned with three hairs, or long 

 spines. The arms and two following pairs of legs re- 

 semble those of A. Gaimardii, as well as the fifth pair 

 of legs, except that the second joint is quite as broad 

 as long. The sixth pair have the second joint quad- 

 rate, with the postero-inferior margin slightly produced 

 downwards. The second joint of the last pair is not 

 so much postero-inferiorly produced as in A. Gaimardii, 

 and the penultimate joint is broader. The caudal ap- 

 pendages scarcely differ from those of the other species, 

 except that the branches are not proportionally so long, 

 and their margins are less numerously and regularly 

 fringed with spines. The terminal scale is long, narrow, 

 and split from the apex nearly to the base, and the late- 

 ral margins are bent to an angle. 



The colour scarcely differs from that of A. Gaimardii, 



