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Show 1886.] DURING THE VOYAGE OF H.M.S. 'CHALLENGER.' 115 of the thorax ; it terminates in the middle line anteriorly rostral prolongation. The free thoracic segments increase in length, but decrease in width up to the fourth, but there is less difference between the first three than between the third and fourth ; the fourth and fifth segments are subequal; the sixth is shorter, but not perceptibly narrower than the fifth ; in the first segment the epimera are prolonged into a spine ; on the fourth and fifth segments are two knob-like projections on either side, equidistant from each other, and from the epimeron ; on the terminal segment there is a single process; the five anterior abdominal segments are subequal, and furnished laterally with sharp spiny epimera. The caudal shield is hourglass-shaped, being constricted in the middle, it narrows rapidly to the obtusely pointed extremity. The outer flagellum of the antennules has eight joints, the inner only three. The uropoda are extremely elongated ; the endopodite has two joints, the exopodite six. Kerguelen ; 120 fathoms. TYPHLAPSEUDES, nov. gen. This genus is distinguished from Apseudes by the almost complete disappearance of the ocular lobes, which are represented by a small triangular process without any trace of ocular structures; by the absence of an exopodite to the chelipeds and fossorial limbs; and by the fact that the exopodite of the abdominal appendage is distinctly bi-articulate. In the last character this genus agrees with Sphyrapus. 1. TYPHLAPSEUDES NEREUS, n. sp. This species attains to a length of about 10 millim. The body is somewhat flattened and depressed, very much wider anteriorly than posteriorly; the cephalothorax terminates in front in a sharp rostrum; to the outside of the antennules is the triangular pointed ocular lobe, which contains no optic structures; some way below this is a pointed lateral process. The free thoracic segments diminish in breadth, but increase in length up to the fifth ; the sixth is narrower but shorter than the fifth ; the epimera of the first thoracic segment project as a spiny process; the lateral margins of all but the first two segments are furnished with a short spine placed halfway between the epimera and the anterior margin of the segment; on the ventral median line of the thoracic segments is a spiny process ; similar minute spines exist upon the abdominal segments. The abdominal segments with the exception of the last are furnished with small pointed epimera; the last segment is as long as four of the anterior segments, it terminates in a straight truncated extremity, in the middle of which is a short knob-like process. The antennae have a rudimentary exopodite. The chelipeds and fossorial limbs are normal in structure, but possess no exopodite. The uropoda are extremely long, as in Apseudes. Station 23 ; 450 fathoms. 8* |