1886.] DURING THE VOYAGE OF H. M.S. 'challenger.' 115 



of the thorax ; it terminates in the middle line anteriorly in a sharp 

 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 ; 1 20 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 andfossorial 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 1 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 antenncB 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* 



