1886.] DURING THE VOYAGE OF H.M.S. ‘CHALLENGER.’ 119 
Genus Pararanats, Dana. 
1. PARATANAIS BATHYBROTIS, 0. sp. 
The single specimen measures 4 millim. The cephalothoracic 
shield is about as long as the following two segments of the thorax ; 
it is prolonged anteriorly into a wide obtusely pointed rostrum. Eyes 
are present and well developed. The first segment of the thorax is 
rather shorter than the rest, which are subequal. The length of the 
abdomen is about one fourth of that of the entire body. The 
antennules have a very characteristic form; they are composed of 
four joints ; the basal joint is as long as the rest of the appendage, 
and is extremely wide and flattened ; the following joint is short and 
wide ; the third joint is no longer, but is narrower ; the terminal joint, 
which represents the flagellum, is short and conical in form. The 
antenne are shorter than the autennules, but, like them, consist of 
four joints ; the first joint is wide and flattened, the second joint bas 
the same shape, but is shorter, the third joint is narrow and cylin- 
drical ; the distal joint is short and narrows towards its termination, 
Station 246; 2050 fathoms. 
2. PARATANAIS DIMORPHUS, 0. sp. 
A very considerable number of individuals of a small species of 
Paratanais were dredged in shallow water at Kerguelen, which are to 
be distinguished by a very pronounced sexual dimorphism. The 
female is like many other species of the genus; but the male is 
remarkable on account of the more slender body and the great 
difference in the structure of the chelipeds. Both males and females 
measure, in most cases, 3 mm.in length. In the male the cephalo- 
thorax is rather long and narrow, and equals in length the first three 
segments of the body together with half of the fourth; the first free 
segment of the thorax is the shortest; the second is twice the 
length of the first; the third ‘segment is half as long again as the 
second ; the fourth and fifth are subequal and about half as long 
again as the third ; the last segment is about equal in length to the 
third. The abdomen equals in length the last two thoracic segments. 
The antennules consist of five joints; the antenne of six. In the 
female the antennary organs are shorter, the antennules being three- 
jointed and the antennze five. The chelipeds are long; both the 
moveable and the fixed ‘ finger’ are of great length; the latter is, 
however, not as in other Tanaids a mere prolongation of the penulti- 
mate joint, but is freely moveable, being articulated with it. In the 
female the chelipeds are quite normal in structure. The wropoda 
are biramose, each ramus being two-jointed. 
Kerguelen, Christmas Harbour, 120 fathoms. 
Fam. ANCEIDS. 
Genus Anceus (PraAn1za), Risso. 
1. ANCEUS BATHYBIUS, D. sp. 
Only a single fragment of this species was obtained from deep- 
water ; the abdomen was entirely wanting. The specimen is a male 
