ANCYLUS. BULLEA. 15 



C. ACULEATA. Oval-dcpresscd, sliallow, with 

 longitudinal prickly ribs^ and the summit recurved 

 and lateral^ brownish whitish or chestnut ; the 

 internal partition white, i . • . t^. W. 37- 1 1. 



C. GOREENSis. Oval^ shallow^ much de- 

 pressed^ transversely wrinkled^ with the spire 

 obsolete, and the summit recurved and lateral; 

 coarse and whitish ; interior white and glossy ; 

 small. W. 37. 12. 



ANCYLUS. FLUVIATILE. 



Thin, obliquely conical; aperture oval, with a 

 pointed apex, which is inclined backwards. 

 A. LACUSTRTs. Scmi-ovute, membranaceous ; 

 vertex sub-central ; aperture ovate^ sub-oblong. 

 B. very small. T. 126. 



A. FLUviATiLis. Conoid; point of the ver- 

 tex excentral; aperture ovate; very small. B. 

 T. 125. 



LES BULLEENS. 



BULLEA. 



Thin ; somewhat involute on one side, and destitute 

 of a columella or spire ; aperture large and 

 wide. 



B. APERTA. Roundish ovate, pellucid, white, 

 faintly striated and slightly wrinkled ; almost en- 

 tirely open, i . . . i. B. W. 18. 14. 



