1886.] DURING THE VOYAGE OP H.M.S. 'CHALLENGER.' 117 



with fine hairs. The uropoda are uniramous and consist of twelve 

 joints. 



Off Prince Edward's Island ; 50-150 fathoms. 



Genus Typhlotanais, G. O. Sars. 



1. Typhlotanais kerguelenensis, n. sp. 



The individuals of this species measure up to 3 niillim. in length. 

 The cephalothorax is short and wide ; it is prolonged between the 

 antennae into a short pointed triangular process ; eyes completely- 

 aborted. The first segment of the thorax is shorter than the rest 

 which are subequal, diminishing slightly towards the posterior 

 extremity of the body ; the first segment has a compressed forwardly- 

 directed spine arising from the median ventral surface ; there is a 

 trace of a similar process on the second segment. The first pair of 

 thoracic appendages arise close to the anterior border of their 

 segment, the second pair further back, the third pair from about 

 the middle of the segment ; the three posterior pairs of thoracic 

 appendages arise close to the posterior boundary of their segments. 

 The antennules are about as long as the cephalothorax. The 

 chelipeds are rather slender. The uropoda are biramose, the outer 

 ramus one-jointed, the inner two-jointed. 



Kerguelen, Christmas Harbour ; 120 fathoms. 



2. Typhlotanais brachyurus, n. sp. 



The length of this species is 8 millim. The cephalothorax is hardly 

 longer than the first free thoracic segment; the first thoracic segment 

 is one third less than either of the two following, which are sub- 

 equal ; the fourth segment is hardly shorter than the third, the fifth 

 and sixth decrease progressively. The first pair of appendages is 

 attached close to the anterior border of the segment ; the two following 

 pairs are moved a little way back, but are still quite close to the 

 anterior extremity of their segments ; the three posterior pairs are 

 attached close to the posterior border of their segments. There is 

 no ventral spine on the first free segment. The abdomen is short, 

 and not so long as the last two segments of the thorax. The 

 antennules are rather shorter than the cephalothorax. The chelipeds 

 are short and stout. As in tlie last species, the three following pairs 

 of appendages are more slender than the three posterior pairs. The 

 uropoda are as in the last species. 



Station 246 ; 2050 fathoms. 



Neotanais, nov. gen. 

 This genus comes nearest to Heterotanais, but differs in the great 

 length of the endopodite of the uropoda, and in the fact that the 

 chelae are fully developed and of the normal structure in the male ; 

 a well-marked character of this genus is the specialization of the 

 thoracic appendages into an anterior and posterior series ; in the 

 first three pairs the distal joint of the limb is a single, somewhat curved 



