BULIMUS. 
151 
and reflected, forming an umbilicus behind the 
pillar. 
The shell varies considerably' in size and ventri- 
coseness; also in colour, being sometimes whitish 
horn colour, and semitransparent, arising, as in other 
varieties of the kind, from a disordered state of the 
animal preventing the secretion of the colouring and 
chalky matter. 
It appears to grow slowly ; for Montagu observes 
that scarcely one in ten of the shells he found had 
their mouths perfected ; when young the shell, as in 
the next, is short, conic, and trochus-like, with a 
sub-quadrangular mouth, (T. B. 395.) 
65. 2. Bulimus ohscurus. Dusky Twist Shell.— 
Shell oval-oblong, brown, with the peristome 
white and reflected, forming a small umbilicus, 
(t. 6. f. 63.) 
Helix obscura. Milller^ Verm. 103.; Gmelin., S. N. 2661.; 
Montagu., F. B. p. 391. t. 22. f. 5. — Turbo rupiuni. Da 
Costa, p. 90., from List. Ang. t. 2. f. 8. — Bulimus hordea- 
ceus. Drug. E. M. 334. ; Lam. Hist. viii. 236. — Bulimus 
obscurus. Drap. Moll. Franc, p, 74. t. 4. f. 23. ; Brard, 
p. 97. t. 3. f. 19. ; Turton, Man. ed. 1. 81. f. 63. ; Jeffreys., L. 
T. xvi. 343. ; Bossm. Icon. vi. f. 387. ; Forbes and Hanley, 
B. M. iv. 90. t. 128. f. 7. — Lymcea obscura. Flem. Edinb. 
Ency. vii. 78. — Bulimus obscurus /3. Hartm. N.Alp. i. 222. 
— Merdigera obscura. Held. Isis, 1837,917. — Bulimulus 
obscurus. Beck, Ind. 71. — Helix stagnorum. Pulteney, 
Dorset. 49 (?). — Ena obscura. Leach, Moll. Syn. 81. 
In woods and old walls, under stones or moss. 
Animal rosy grey ; foot thick, paler ; upper ten- 
tacles subulate. 
Shell half an inch long, and about a third as much 
broad, brown or horn-colour, semitransparent ; spire 
