MOLLTSCA, i. SMITH. GO 



apical whorls whitish beneath the periostracum. the embryonic one being glossy and 

 very tinely spirallv striated; the periostracum exhibits closely packed. oblique lines 

 of growth: aperture large, with a verv thin, whitish, calcareous lining, somewhat 

 roundish; pcristoine olive brownish, not thiekened on the outer margin, luit having 

 the little curved columellar edge expanded and retlexed, a thin callosity upon the whorl 

 uniting it with the outer lip. 



Greater diameter, '_'_'; height. I'D nun. Aperture. I 4 nun. long. I '_' in width. 



Station :!55 : :!00 fathoms. 



The animal lias a small oblong loot, squarish in front, and the tentacles are long. 

 slender, tapering to a sharp point, having the eves at their outer liases. As the solt 

 parts are to be investigated bv an anatomist, the radula has not Keen extracted. 

 Having the general features of \<-<n;>iifli<i and a similar kind of operculnm.it ma\ 

 for the present lie left in that genus. 



It is a most remarkable shell, and is quite distinct from any other Antarctic form 

 excepting Xco<-<>ni-li<i rcxfifn, from which it (litters in the remarkable manner in which 

 the periostracum is produced into the conspicuous carin:e. Can this be only variation ( 

 Three similar .specimens were obtained. 



L'4. X<tt'n;i ,jrix,'<i. Martens. 



Nntlt.'ii i/risi'd, .Martens, Sitz.-Ber. Gesell. Natur. Freunde, Berlin, 1878, p. 24; Watson, 

 " Challenger " Gasteropoda, p. 432, pi. XXVIII, fig. 5; Strebel, Sdrwedisch. Sudpolar- 

 Exped., Gastropoden, p. 61, pi. V, tig. (56 ; Hedley, Brit. Antaivt. Kxped. 1907-1), Biol., 

 vol. II, Mollusca, p. 7 ; Thiele, Deutsche Tiefsee Exped., vol. VII, pi. IV, tigs, 2, :! : 

 pi. VIII, tig. 44, radula. 



Natica <lrlic<itiil<i, Smith, "Southern Cross" Mollusca (1902), p. 206, pi. XXIV, fig. 6; 

 "Discovery'' Gastropoda, p. 5; Thiele, Deutsche Siidpolar-Exped., vol. XIII, p. 199, 

 pi. XII, figs. 16, 17. 



Station 316 : 190-250 fathoms. 



In the "Discovery" Report I expressed an opinion that X. ildii-ntiilit would 

 eventually prove to be merely the young state of N. f/rix<'ti, Martens, from Kergueleu 

 Island. An adult shell from Station 31G of the present collection coiitirms that 

 suggestion, and there appear to be several other described forms from these cold 

 regions which are scarcely separable. 



25. Aiiiiitn-t'/ixix nixxntiui, Smith. 



Amaur<>i>xi!< i-nxniniiii. Smith, " Discovery " Gastropoda, p. 5, pi. I. ligs. n, i; \ (]:ni7): llrdlcy, 

 I'.rit. Antarct. Exped. 1907-9, Biol., vol. II, Mollusca, p. 7. 



Stations 314, 316, 331, 3:{S, 339, 348, 355 : 140-300 fathoms. 



Yonuo- specimens were obtained at each of these stations. At this stage of 

 orowtli, with one exception, thev do not exhibit the peculiar oblique ridges upon 

 the last and penultimate whorls noted in the adult form. The operculum is horny 

 and paucispiral, as might have been expected. In every instance, as in the type, the 

 tip of the spire is invariably eroded. 



VOL. n. 



