268 CALMAN. 



assumption that the last peduncular joint of the antennae may 

 vary somewhat in length. 



Brandt's species formed the type of his genus MegalorcJicstia, 

 and was transferred by Spence Bate to the synonymous OrcJies- 

 toidca of Nicolet. I have not been able to refer to Nicolet's 

 work, but in his definition of the genus quoted in Stebbing's 

 Challenger report (p. 231), it is stated that the palp of the max- 

 illipeds is four-jointed. Mr. Stebbing, however, informs me 

 that this is an error, the figure given by Nicolet showing that 

 only three joints are present. Tahtronus of Dana is another 

 synonym of OrcJiestoidea (Stebbing, op. cit., p. 262). 



The female of 0. californiana has not been identified. It seems 

 not improbable, as Mr. Stebbing has suggested to us, that 

 Dana's 0. piigettensis may prove to be the female, the scabrous 

 character of the legs in O. californiana being the only character 

 which stands in the way of this supposition. 



Atylid/E. . 

 Polycheria osborni n. sp. 



(PL XXXII, Fig. 2.) 



This species closely resembles Polyclicria antarctica (Steb- 

 bing),^ but differs from it in the following details : 



The dorsal processes of the urosome are much less promi- 

 nent (Fig. 2, //?'). 



In the maxillipeds the outer plates are longer, nearly equalling 

 the palps and bearing each only about eleven spines on the inner 

 edge (instead of 18—19). 



The propodus of the first gnathopods is somewhat differently 

 shaped, the palmar edge, against which the dactyl closes, being 

 very short, not more than one-third the length of the dactyl. 



In the second pair of gnathopods the hand is more than twice 



^ Dexaviine antarctica Stebbing, Ann. Mag. Nat. Hist. (4) XV, 184, PI. XV, 

 A. f 1. ; Tritceta Kergueleni, Stebbing. Challenger Report Amphipoda, pp. 941- 

 945, PI. LXXXIII ; Polycheria antarctica (Stebb.) Delia Valle. Monogr. 

 Gamm, 580. 



