58 Ml{. A. O. WALKER ON AMPHIPODA 



as laige as the egg-bearing females. These (and also the em- 

 bryos from the female described above) had the posterior margin 

 of the first two segments of the metasome simple, i. e. not pro- 

 duced into a dorsal tooth, and with a slight difference in the 

 sculpture of the posterior margin of the 3rd segment. In other 

 respects they are identical with the adult specimens, and there 

 can be no doubt that these diff'erences are only due to imma- 

 turity. The same thing is found in P aramjpJiithoe hicuspis 

 (Kroyer), the immature form having been made a distinct species 

 (P. monocuspis, Gr. O. Sars). Canon A. M. Norman has called 

 attention to the variability of the sculpturing of the posterior 

 margins of the segments of the pleon (metasome and urosome) 

 in Melita ohtusata (Montagu) [Ann. & Mag. Nat. Hist. ser. 6, 

 vol. iv. 1889, p. 132.] 



Fam. Attlid^, 



Genus Atyloides, Stebling, 1888. 



A. SERRATiCAUDA, Stebhiuff, Eeport on ' Challenger ' Amphi- 

 poda, p. 920, pi. 78. (PI. 11. fig. 90.) 



Cape Adare beach, after gale, Jan. 25, 1900. 



Many specimens of various ages. 



Length 12 mm. 



The above specimens diff'er from that described by Mr. Steb- 

 bing, which was taken off Melbourne in 33 fath., only in having 

 seven teeth on the posterior margin of the 3rd metasome-segment 

 instead of two. As I have pointed out under the species last 

 described, this is not of sufficient importance to warrant the 

 making of a new species. 



Genus Attlus, Leach, 1817. 



A. ANTARCTICUS, n. sp. (PL 11. figs. 91-97.) 



Cape Adare beach, April 5 & 15, 1899. 



Many of various ages. 



Body moderately compressed. Krst four side-plates not so 

 deep as the segments, increasing in width successively. Last 

 three segments of mesosome and first two segments of metasome 

 with an elevated and acutely-angled dorsal carina; carina of 

 the ^rd segment of the metasome rounded posteriorly ; the hind 

 margin of this segment forms a continuous curve loith the lower 

 margin and has four or five shallow teeth. TJrosome with a dorsal 

 depression on the 1st segment. 



