284 CYCLOSTOMID^. 



Ctenopoma, Shuttleworth. 



Distr. — 26 sp. West Indies. C. bilabiatum, d'Orb. (Ixxvi, 

 75, TG). 



Shell ovate or cylindrically turreted, truncate ; aperture sub- 

 circular ; peristome expanded, mostly duplicate ; umbilicate or 

 perforate. Operculum testaceous, rather narrowly spiral, the 

 whorls obliquely sulcate, nucleus nearly central. 



Cyclotopsis, W. T. Blanford. 

 Distr. — 3 sp. India, Mauritius. G. semistriata, Sowb. (Ixxvi, 

 11). 



Shell widely umbilicate, turbinately depressed, spirally lirate ; 

 aperture subcircular. Operculum multispiral, duplex, membran- 

 aceous within, testaceous externally with the margins of the 

 whorls elevated. 



Choanopoma, Pfeiffer. 



Distr.— 5b sp. W.Indies. C. Zima, C. B. Ad. (Ixxvi, 78, 19). 



Shell giobular-turbinated or turreted, spire frequently trun- 

 cated ; aperture suboval or circular ; peristome usually double, 

 reflected. Operculum testaceous, the margins of the whorls 

 usually free, ribbed. 



LioiNA, Gra3\ Last whorl sometimes detached near the aper- 

 ture ; peristome subreflected. G. evoluta, Reeve (Ixxvi, 80). 



JAMAiCEA, C B. Adams. Shell umbilicated, globular-conic ;. 

 peristome simple or double, straight or reflected. Operculum 

 externally convex, its whorls obliquely striated, sublamellar. 

 G. anomala, Ad. (Ixxvi, 81). 



Chondropoma, Pfeifi'er. 



Distr. — 100 sp. West Indies. C magwf/icwm, Salle (Ixxvi, 82). 



Shell oblong-turreted, or globular-turbinated, frequently the 

 apex is truncated ; aperture oval ; lip simple or more or less 

 double, nearly direct, a little expanded or reflected. Operculum 

 oval, subcartilaginous, flat, paucispiral. 



CiSTULA, Gra3^ 



Distr. — 42 sp. West Indies and neighboring continent. G. 

 Sauliee^ Sowb. (Ixxvi, 83). 



Shell globular-conic or oval, or oblong-turreted, apex usually 

 truncated ; aperture oval ; peristome single or double, reflected. 

 Operculum thin, cartilaginous, paucispiral, with rapidly enlarging 

 whorls. 



TuDORA, Gray. 



Distr. — 34 sp. West Indies and neighboring continent. T. 

 mumia, Lam. (Ixxvi, 84). 



Shell oval-oblong or turreted ; aperture oval, angular posteri- 

 orly ; peristome single or double, expanded. Operculum oval, 



