136 
GAMMARIDjE. 
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 , 
