ANCYLUS. BULLEA. 15 
C. acuLEATA. Oval-depressed, shallow, with 
longitudinal prickly ribs, and the summit recurved 
and lateral, brownish whitish or chestnut; the 
internal partition white. 2...344. W. 37. LI. 
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. LACUSTRIS. Semi-ovate, 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- 
litelyopen. §2...3. B. .W..18. 14. 
