REPORT ON THE ISOPODA. 121 



considerably more slender than the three posterior pairs, which are stout. This difference 

 between the anterior and posterior thoracic appendages is extremely well marked. 



As is usual in the genus Tanais the fourth and fifth appendages of the abdomen are 

 aborted ; the three first pairs are well developed ; they consist of a triangular basal joint, 

 and two rami which are broad and crescentic in form and fringed with numerous long 

 hairs. 



The uropoda are of unusual length ; they are longer than the abdomen ; each consists 

 of about twelve joints, the basal joint being much the longest and stoutest ; the distal 

 joints gradually decrease in diameter but increase slightly in length. 



This species appears to be a true Tanais by reason of the abortive fourth and fifth 

 pairs of abdominal appendages ; it differs, however, from the typical species in the 

 specialization, as regards size, of the thoracic limbs, and in the great length of the uropoda ; 

 this last character is found in Tanais willemoesii though hardly to so marked a 

 degree. 



Off Prince Edward Island; depth, 50 to 150 fathoms. 



Typhlotanais, G. 0. Sars. 

 Typlilotanais, G. 0. Sars, Revision, &c, Archiv f. Math, og Nat., voL vii. p. 33. 



This genus comes nearest to Paratanais, and is chiefly to be distinguished from it by 

 the complete absence of eyes. 



It contains a large number of species, most of which have been at present but briefly 

 described. I am not, therefore, perfectly satisfied as to the distinctness of the two follow- 

 ing species, which I describe as new with a certain reservation. 



The occurrence of the genus at Kerguelen is interesting, as it has hitherto been only 

 known from the North Sea and the Mediterranean. The depth at which Typhlotanais 

 brachyurus (see p. 123) was dredged far exceeds the range of the genus as hitherto known. 



Typlilotanais kerguelenensis, F. E. Beddard (PL XVI. figs. 1-3). 



Typhlotanais lierguelenensis, F. E. Beddard, Proc. Zool. Soc. Lond., 1886, pt. i. p. 117. 



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



The eephalothorax is short and wide ; it is prolonged between the antennas into a short 

 pointed triangular process ; on either side of the eephalothorax, external to the articulation 

 of the antennules, the eephalothorax ends in an acutely pointed process, which is, however, 

 not segmented off and shows no trace of any ocular structures. 



The first segment of the thorax is rather shorter than the rest, which are subequal, 

 diminishing slightly towards the posterior end of the body ; the lateral margins of those 



(zool. chall. exp. — paet xLvin. — 1886.) Ebb 16 



