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 JMontagu 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 vimbilicus. 

 (t. 6. f. 63.) 



Helix obscura. Miiller, Verm. 103.; Gmelin, S. N. 2661.; 

 Montagu, F. B. p. 391. t. 22. f. 5. — Turbo rupium. Da 

 Costa, p. 90., from List. Ang. t. 2. f. 8. — Bulimus hordea- 

 ceus. Brug. E. M. 334. ; Lam. Hist. viii. 236. — Bulimus 

 obscurus. Drap. Moll. Franc, p. 74. t. 4. f. 23. ; Brai-d, 

 p. 97. _t. 3. f. 19. ; Turton, Man. ed. 1. 81. f. 63. ; Jeffrei/s, L. 

 T. xvi. 343. ; Ross7n. Icon. vi. f. 387. ; Forbes and Hanley, 

 B. M. iv. 90. t. 128. 1". 7. — Lymnea obscura. Flem. Edinb. 

 Ency. vii. 78. — Bulimus obscurus i3. Hartm. N. Alp. i. 222. 

 — Merdigera obscura. Held. Lsis, 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. 



Sliell half an inch long, and about a third as much 

 broad, brown or horn-colour, semitransparent ; spire 



L 4 



