REPORT ON THE ISOPODA. 123 



Typhlotanais brachyurus, F. E. Beddard (PL XVI. fig. 7). 



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



From the same station which yielded Bathytanais bathybrotes (a species presently to 

 be described) three specimens of a Tanaid were dredged, which evidently belong to a 

 different species, by reason of the elongated body and the complete absence of eyes. This 

 species appears in fact to belong to the genus Typhlotanais. 



The length of the largest specimen is 8 mm. 



The cephalothorax is hardly longer than the first free thoracic segments ; it is pro- 

 duced between the eyes into a short pointed rostrum ; the ocular lobes are entirely absent. 



The segments of the thorax are greatly elongated and narrow ; the first segment is 

 one-third less than either of the two following, which are equal ; the fourth segment is 

 hardly shorter than the third ; the fifth and sixth segments decrease regularly in length, 

 the fifth being about as long as the first. 



In a second specimen the proportional length of the several segments was as nearly 

 as possible the same. The first pair of appendages are attached close to the anterior 

 extremity of its segment ; the second and third pairs move progressively a little 

 further back, but the difference in position is very slight, and is only just recognisable ; 

 the third pair are attached near the middle of the segment as is the case with other 

 species. The three posterior pairs of appendages are attached close to the posterior 

 margin of their segment. There is no ventral spine on the first free segment. 



The abdomen is short, not so long as the last two segments of the thorax taken 

 together ; the five anterior segments are subequal ; the sixth is as long as the last three. 



The antennules are rather shorter than the cephalothorax ; in all the three specimens 

 they present characters which are usually confined to the females in this and allied 

 genera ; that is to say, they consist of three joints, of which the basal is the stoutest ; 

 the second joint is considerably shorter than the third. 



The antennse are a little shorter and more slender, and likewise consist of three joints, 

 of which the middle one is the longest. 



The chelipedes are short and stout ; the distal extremity of the penultimate joint is 

 furnished with three or four blunt tubercles just before its termination in a sharp point 

 which overlies the extremity of the sixth joint. 



Of the remaining thoracic appendages the three anterior are more slender than the 

 three posterior ; in the latter the basal joint is extremely large and swollen. 



All the abdominal appendages are present. 



The uropoda are biramose, the exopodite being rather shorter than the endopodite ; 

 the latter is two-jointed ; the exopodite consists only of a single joint. 



Station 246, Mid North Pacific, July 2, 1875; lat, 36° 10' N., long. 178° 0' E. ; 

 depth, 2050 fathoms; bottom temperature, 35° - l F.; Globigerina ooze. 





