238 Transactions.—Z oology. 
Spence Bate, in the British Museum Catalogue of the Amphipodous 
Crustacea, has overlooked the remarkable sexual differences which charae- 
terize the Oxycephalide, not only in this genus, but also in Rhabdosoma, in 
which he describes the male of R. armatum as a separate species, R. whitei. 
The distinctive characters have been clearly brought out by Dr. Claus in a 
paper on ** Die Gattungen und Arten der Platysceliden,” which however is 
not readily accessible to New Zealand students. In this paper, Dr. Claus 
describes Oxycephalus piscator, Edw., at considerable length, and unites 
O. tuberculatus, Sp. Bate, and O. oceanicus, Guérin-Méneville, to it—the latter 
being a young male. He also gives brief descriptions of six new species, 
from all of which the following species is quite distinct, though apparently 
nearest O. latirostris, a Lagos species. The brevity of the descriptions 
however, and the want of illustrations, render this resemblance somewhat 
doubtful. 
1. OXYCEPHALUS EDWARDSI, n. sp. Plate xii., figs. 14-21; pl. xiii., fig. 1. 
Male.—The head is widely dilated and produced into a long sharp snout. 
This snout is more or less sharply ridged on the upper surface, and nearly 
flat on the under-side, the margins being sharply bent inwards. The sides 
of the head are nearly completely occupied with the eyes, which resemble 
those of Phronima. The sides of the head are not in close contact below, 
but form a long groove in which the posterior antenna lie folded. The 
anterior antenn® are placed in front of the head just under the base of the 
beak ; they depend nearly vertically, and have their concave side turned 
outwards. The peduncle has two short basal joints, and then a long, very 
stout, curved joint, the whole inner (convex) surface of which is thickly 
coated with olfactory sete. The flagellum, which projects nearly at right 
angles from the extremity of the peduncle, is very small and 3-jointed. 
The posterior antenne are placed almost behind the head, and their 
joints lie folded closely together in the groove under the cephalon, in a 
zigzag manner ; when extended, they are two or three times as long as the 
head and snout. Dr. Claus calls these organs 5-jointed ; they have 4 long, 
subequal joints, which are extremely slender, but a little dilated at their 
ends, with a minute terminal hook-like claw, which appears only to be pre- 
sent in mature males. The mandibles are much reduced in size, and 
project down, behind the insertion of the antenne, as small tooth-like 
organs furnished with a slender 8-jointed palp. These and the very much 
reduced maxillipedes are the only mouth-organs present; and the latter 
are of very simple structure, consisting each of an oval smooth plate, with- 
out any trace of hairs or teeth, The gnathopoda are relatively small, and 
the first pair are only about half the size of the second. In both pairs the 
basos is elongated, and the carpus produced on its inferior margin into a 
