CRUSTACEA OF THE MERGUL ARCHIPELAGO. 269 
ocular portion of the rostrum is more or less prolonged back- 
wards, the crest becoming gradually less visible in one specimen 
to the middle of the cephalothorax, but in the other two not so 
far. The upper surface of the cephalothorax is rounded and 
minutely punctate. 
The postabdomen, and more especially its terminal segment, 
closely resembles that of A. Hdwardsi, the terminal segment 
being armed on its upper surface with two pairs of minute 
spines; whereas in Audouin’s species this upper surface is 
glabrous, it is more or less hairy in this species. 
The two pairs of antenne of A. Hippothoé are closely similar 
to those of A. Hdwardsi, and differ from those of A. parvirostris, 
Dana, in the complete absence of an external spine on the basal 
joint of the outer antenue. The second joint of the peduncle of 
the inuer antenne is about once and a half as long as the first, and 
the third is a little shorter than it; the peduncle is a little hairy. 
The peduncle of the outer antenne is as long as, or scarcely longer 
than, that of the inner antenna, and the basal scale, which is nar- 
rowed considerably towards the apex, and whose external more 
solid part terminates anteriorly in a spine, comparatively a little 
longer than in A. Edwardsii, is as long as the peduncle. The 
outer maxillipeds resemble those of A. Hdwardsi, but they are a 
little longer, and project with a larger or smaller portion of the 
terminal joint beyond the antennal peduncles. — 
In their outer appearance, the legs present a striking resem- 
blance to those of A. parvirostris, Dana, the legs of A. Kdwardsit 
being more slender. The arms of the anterior legs are equal 
and unarmed at the distal ends of their upper margins; in 
A, Edwardsit the internal margin of the under surface is armed 
at the distal end with a small spine; but in this species a proper 
spine does not occur there, although the distal end termi- 
nates in a sharp point. The carpopodites are quite similar to 
those of A. Hdwardsii. As regards its shape and structure, 
the larger hand of A. Hippothoé is intermediate between that of 
A. Edwardsii and that of A. parvirostris; for whereas the hand 
is less slender than in Audouin’s species, the proportion of its 
length (the fingers included) to its breadth being exactly the same 
in this species and in A. parvirostris, the distal half of the hand 
in this species is more contracted and narrower than in 4. par- 
virostris, resembling in this character A. Hdwardsi. The hand 
is rounded at its proximal end, and notched on its upper as 
