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Show 1 16 MR. F. E. BEDDARD ON ISOPODA COLLECTED [Feb. 2, LEIOPUS, nov. gen. This genus is closely allied to the last, but differs in that the chelipeds and fossorial limbs have an exopodite. The chelipeds are extremely slender and delicate in their structure, and this, together with the characters of the abdominal appendages, serves to distinguish the genus from Apseudes. 1. LEIOPUS LEPTODACTYLUS, n. sp. This species attains to a length of 13 millim. The cephalothorax is prolonged in front into a long rostrum ; the ocular lobes are large and pointed anteriorly ; there is no trace of any optic structures; behind the ocular lobes are two long spiny processes, one on either side. The first free segment of the thorax is as wide as the cephalothorax; the following segments decrease in width, the first suddenly, the rest more gradually ; the length of these segments increases up to the fourth ; the fifth is of equal length with the fourth, the sixth rather shorter ; the first segment has well-developed spiny epimera; the last three segments of the thorax have also short spines upon the epimera, which are wanting in the intermediate segments; upon all the free thoracic segments, with the exception of the first, are a pair of long lateral spines like those of Typhlapseudes, but longer. On the ventral surface of both the thoracic and abdominal segments, with the exception of the last, is a median spine. The abdomen is much as in the last-described species. The outer flagellum of the antennules has twenty-seven joints, the inner only six. The antenna? have a rudimentary exopodite. The chelipeds are very slender and delicate. The uropoda are as in Apseudes. Station 78; 1000 fathoms. Fam. TANAIDJ:. Genus TANAIS, Audouin & Milne-Edwards. 1. TANAIS HIRSUTUS, n. sp. The extreme length of this species is 9 millim. The body is elongated, the anterior region is wider than that which follows; the last thoracic segment and the first three abdominal segments are again wider, after which the body narrows towards the termination. The cephalothorax has a short obtuse rostrum ; the two first segments of the thorax are short and subequal, the third segment is narrower but longer; the two following segments increase progressively in length, the first is about twice the length of the preceding segment; the last thoracic segment is wider than the preceding, but shorter. The first three segments of the abdomen are wider as well as longer than the following; the terminal segment ends in a blunt, rounded extremity. The antennules have a three-jointed peduncle and a two- or three-jointed palp ; the extremities of the joints of the peduncle are surrounded by a circle of fine delicate plumose hairs of great length. The antenna? are similarly beset |