284 PYRAMlDELLIDiE. 



the simple and moderately oblique suture ; tliey manifestly 

 taper above, swell out rather below the middle, and incline 

 inward at their bases. The anterior slope of the subventri- 

 cose body is gradual and rounded ; its periphery is not in 

 the least angulated ; there is no umbilicus, but at most an 

 indented chink or a slight cleft. The mouth, which has a 

 moderate projection, fills nearly three-sevenths of the entire 

 length ; it is of an oblong-ovate figure, being well rounded 

 below, and gradually attenuated (not sharply contracted) 

 above. There is a decided basal recedence of the outer lip, 

 which is simple, acute, and continuously arched ; it is quite 

 smooth internally. The inner lip runs, for the most part, 

 in a straightish oblique line, and is furnished in the middle 

 with an obscure blunt retired oblique fold ; the pillar lip, 

 however, curves anteriorly, and is moderately but not 

 broadly reflected throughout. The basal diameter is about 

 two-fifths of the length ; tlie latter is only the tenth of an 

 inch. 



The animal was not observed ; the shells were taken in 

 Zetland. 



O. llissoiDEs, Hanley. 



Imperforate, tapering, extremely thin, not much shining, 

 smooth, but usually with scratch-like lines of increase ; whorls 

 merely convex, of quick increase ; penult rather high ; apex 

 blunt : reflection of the pillar lip extremely slight, if any : fold, 

 small and very retired, yet distinct. 



Plate XCVI. tig. 4, 5. 



Odnnlomiu i-cidaris, Macgilliv. Moll. Abcrd. p. 154 (copied Brit. Marine Conch. 



p. 2.59) ; and Brown, 111. Conch. G. B. p. 129, MJaniinki 



scalaris) ? 



„ liissoides, Hanlky, Proc. Zool. Soc. 1844, p. \\] ; Brit. Marine Concli. 



p. xxxvi. (f. 9, badly). — .Tkkfiievs, Ann. Nat. flist. 



new scr. vol. ii. p. .337. 



