400 



Pult. Cat. Dorfet. p. 45. 



Br. Zool. No. 114. t. 79 ? 



Turt. Lin. iv. p. 497 ? 

 Turbo membranaceus. Lin. Trans, v. p. 2. t, 1. f, 14. 15. 



(Adams) — Turt. Lin. iv. p. 500. 

 Strombifonnis aibus. Da Cojia, p. 116 ? 



H. with a fub-conic, fub-pellucid, light horn-coloured 

 fliell, with feven, and rarely eight, flattifti fpires, ter- 

 minating in a fine point, and furnifhed with from fifteen 

 to eighteen faint ribs, on the three largeft whirls ; the 

 fuperior volutions fmooth : apex frequently purplifh : 

 aperture oval, lips thickened within,' white ; the margin 

 of the outer lip thin, a little reflexed, and ufually 

 of a purplifli-brown ; the bacK of the outer lip a little 

 gibbofc, and generally whiter than the reft of the fheU^ 

 pillar lip fpreads confiderably on the body whirl; Colu- 

 mella within undulated, forming a fmall elevation, l,ike 

 an obfolete tooth. 



The aperture is a ftrong chara61er ; it is nearly half 

 the (hell, and confcquently makes the body volution pro- 

 portionally large; it (lands a little oblique, confiderably 

 expanded at the margin, which is reflexed, and is con- 

 traded in the throat by the thickening of the fliell. 



A variety is much more thin and pellucid, fome quite 

 deftitute of ribs ; others only partially ribbed on the up- 

 per part of one or two of the largeft volutions ; thefc are 

 frequently flreaked longitudinally with brown, fome- 



times 



