198 "TERRA NOVA" EXPEDITION. 



he refers to T. gracilis. The uropods are six-jointed, the terminal joint very small. 

 The body is furnished with a few scattered setae on the anterior margins of its somites, 

 and a tuft of strong plumose setae on the lateral parts of the first and second somites 

 of the abdomen. The egg-pouch is single, and in this respect agrees with Vanhoffen's 

 observations on this species, in contrast with the double egg-pouch found in T. litoralis. 

 I can find no valid character to separate this specimen from T. gracilis, but in the 

 absence of a male specimen I cannot be sure of the identity. T. ohlinii, Stebbing, from 

 the Falkland Islands, seems to be very closely related to T. gracilis, and the only really 

 important point of diff'erence lies in the uropods, which are, like those of T. gracilis, 

 six-jointed ; but the terminal joint is nearly as large as the penultimate, and not minute 

 as in T. gracilis. If the present specimen really belongs to T. gracilis, the distribution 

 of the latter is considerably extended, as it has previously only been found at the Cape, 

 St. Paul, Ceylon, Kerguelen and New Amsterdam, localities all to the South of the 

 Indian Ocean. 



3. Tanais novae- zealandiae, G. M. Thomson (?). PI. I, figs. 1-5. 



T. novae-zealandiae, G. M. Thomson, 1879, p. 417, pi. XIX, figs. 5, 6 ; 1881, p. 207, pi. VII, 

 fig. 3 ; Thomson and Chilton, 1886, p. 151 ; Hutton, 1904, p. 262 ; Chilton, 1909, p. 669 ; 

 Thomson, 1913, p. 245 ; Vanhoffen, 1914, p. 465. 



Occurrence. — Station 96, 7 miles E. of North Cape, New Zealand, 70 fathoms, 

 bottom fauna, one male, 5 '5 mm. 



Remarhs. — The only serious difference I can find between this specimen and 

 Thomson's description is in the uropods. In my specimen the uropods (fig. 5) consist 

 of a moderately large basal joint and a seven-jointed terminal portion, the first joint of 

 which shows traces of being a double joint laterally, but I could not trace the line 

 of separation across the joint, and the terminal joint is very small. 



Thomson describes the uropods in his species as five-jointed, but from his figure it 

 is obvious that this number does not include the basal joint, and it seems possible that 

 he also overlooked the minute terminal joint. This would make the difference between 

 Thomson's species and my specimen one or at most two joints extra in the uropods. 

 Thomson's specimen measured 4"5 mm., mine measures 5'5 mm. Vanhoffen has shown 

 that in T. gracilis the number of joints in the uropods increases with age, and it is 

 possible that the differences in the present instance may be explained on similar 

 grounds. I do not feel justified in instituting a new species on this difference, because 

 otherwise there is the closest agreement between the two forms. I give, herewith, 

 figures of some of the appendages of my specimen for comparison with future specimens. 

 The species has six segments in the urosome, and thus belongs to the genus Tanais in 

 the wider sense, and not in the restricted sense as used by Sars. The specimen still 

 retains traces of an extensive development of pigment, giving a mottled or marmorate 

 appearance to the animal. 



