UNIVALVES. — HELIX. 131 



Division X. — Shell sub-umbilicated, pyramidal, and 



SUMMIT OBTUSE. 



Epistylium — Bee-hive. Papilla — Nipple. 



Division XL — Shell ventricose, pellucid, and aper- 

 ture OVATE. 



Family 1. — Imperforate. 



* Stagnalis — Lake, Inflata — Inflated. 



Fragilis — Brittle. Opaca — Opaque. 



*PaIustris — Marsh. *Tentaculata — Dusky. 



*Fossaria — Ditch. *Lutea — Yellow. 



Albicans — White. Sicula — Sicilian. 



*Putris — Thin- yellowish, *Glutinosa — Membranous. 



Peregra — Horny. ^Leevigdita.- Smooth flesh-colour. 



*Limosa — Rough. Balthica — Baltic. 



Truncatula — Truncated. Neritoidea — Nerite-shaped. 



Family 2. — Umbilicated. 

 Repanda — Ve7itricose. *Canalis — Channelled. 



*Auricularia — Eared. 



Division XIL — Turreted. 

 Family 1. — xipex truncated. 

 Consolidata — Flat-tipp'd. Truncata — Flag. 



DecoUata — Truncated. Calcaria — Chalkjf. 



Contoita-plicata — Coiled-plaits. 



Family 2. — Apex acute. 

 Cuspidata — Pointed. Octona — Slerider. 



Plicaria — White-spotted. Columna — Column. 



Undulata — Waved. Incumbens — Tawny-strip' d. 



Vibex — Red-marked. *Acuta — Double-handed. 



Crenata — Crenated. Undata — Undulated. 



Fuscata — Brown-clouded. Fluviatilis — River. 



*Peregrina — Eight-whirl' d. Turbinata — Turbinated. 



Carinula — Brown-lin' d. 



Division XIIL — Shell depressed, spire flattish, aper- 

 ture VERY LARGE, EXPOSING THE WHOLE INSIDE. 



Perspicua — Large-mouthed. Haliotoidea — V'. nus's-ear. 



