CLAUSILIA. 
183 
Moll. Franc, ii. 348. t. 23. f. 2 — 9. — Turbo bldens. CJiemn. 
C. ix. 119. f. 960. n. 1.; Penn. B. Z. 131. — Turbo per- 
versus, var. Pulteney., Dors. 46. — Pupa bidens. Drap. 
TahL 61. — Clausilia derugata. Jeffreys., Linn. Trans, xvi. 
354. — Clausilia lucida. Menhe, Syn. 129. — Clausilia 
ungulata. Beck. — Odostomia laminata. Flem. E. Ency. 
vii. 67. 
In beech woods, among decayed leaves, and on 
the bark of trees, especially in a chalky soil. 
Animal pale fulvous; upper tentacles long, cla- 
vate. (^Sturm, Fauna ^ t. .) 
Shell half an inch long, of a glossy reddish horn- 
colour and nearly smooth ; spire composed of twelve 
raised volutions ; aperture roundish-oval with a white 
thick margin attached at the upper part of the body 
volution, with two laminar folds, one of them straight 
and placed near the top of the aperture and almost 
central, the other curved and in the middle of the 
pillar lip, frequently crenate ; and deep within the 
mouth are three or four permanent ridges which are 
visible on the back at the outside when held before 
a strong light. 
Varies greatly in size, ventricoseness, and colour, 
being sometimes greenish white and transparent. 
Montagu (^Test Brit 359.) considered the white 
variety as a shell deprived of its brown epidermis, 
but the periostracum is as distinct on the greenish 
white shell as on the brown specimen; both the 
shell and the periostracum are differently coloured, 
or rather uncoloured in that variety, from the ab- 
sence of the colouring matter. 
Dr. Turton, by an oversight, first describes the 
operculum as emarginate, and then makes his third 
