PTEROCYCLOS. 1 1 



Cyclost. fasciatum Button, MS. B. M. 



Cyclost. albus Hutton, MS. B. M. 



Aper. semistriatum Pfeiff. 1. c. 104. n. 13. 



a — c. Banks of Ganges. 



§§ Whorls in front of axis keeled. Peristome straight. — P o t e r i a 

 Gray, Syn. Brit. Mus. 1840, 1842, 91. 



27. Cycxotus lineatus. 



Cyclostoma jamaicense Sow. Thes. Conch, i. 96. n. 15. t. 23. f. 12, 



13., not Gray. 

 Aper. jamaicense Pfeiff. 1. c. 104. n. 3. 



a. Jamaica. 



b, c. Jamaica. Presented by Eev. Barham Zincke. 



28. Cyclotus jamaicensis. 



Cyclost. corrugatum Menke, Cat. Malak. 10.; Sow. Proc. Zool. Soc. 

 1843, 30., Thes. Conch, i. 95. t. 23. f. 10, 11.; Pfeiffer, Kwster, 

 Chemn. Conch. Cab. 17. n. 8. i. 19. t. 2. f. 13, 14. 



Turbo jamaicensis Chemn. Conch, xi. t. 209. f. 2057, 2058. 



T. (Cyclostoma) jamaicensis Gray in Wood's Cat. Supp. t. 6. f. 3. : 

 Lister, Conch, t. 55. f. 51.; Shane, Jamaica, ii. t. 240. f. 84. 



Aper. corrugatum Pfeiff. 1. c. 104. n. 4. 



a — h. Jamaica. 



i — k. Jamaica. Presented by Professor C. B. Adams. 

 I, m. Jamaica. Var. with operculum ridges higher. Pre- 

 sented by Rev. Barham Zincke. 



2. PTEROCYCLOS. 



Operculum shelly, many whorled, spirally lamellated, externally 

 very convex, internally concave. — Shell broadly umbilicated, 

 rather discoidal. Peristome double ; the internal short, cut on 

 the right margin, the external dilated above into a roof-shaped 

 beak. 



Spiraculum Pearson, Journ. As. Soc. Bengal, ii. 590. 1833 ? 



Steganotoma Troschel, Wiegm. Arch. 163, 1837 ; Philippi, Abbild. 

 und Besch. 1844. 



Pterocyclos Benson, Journ. Asiat. Soc. Bang. 1832, i. 11., Zool. 

 Jour.v. 462. 1834; Gray, Syn. B. M. 1840, 133., 1842, 91, 

 Proc. Zool. Soc. 1847, 182.; Troschel, Menk. Z. f. Malak. 1847, 

 44.; Pfeiffer in Menke mid Pfeiffer, Z.f.Malak.'l847. 



Cyclostoma sp. Sow. Thes. Conch. 



A 6 



