378 Shell Life 



as compared with twelve or thirteen in the other 

 species. The mouth is much the same as in bidentata. 

 One mark of distinction given by authors is the 

 presence in rolphi of several minute teeth between 

 the folds on the pillar ; but this is not reliable, for I 

 have specimens of bidentata with these teeth. The 

 chief difierences between the two consist in the more 

 slender proportions of bidentata, the coarser ridges of 

 Tolplii, the larger and broader mouth of the latter, 

 and its lio^hter colour. It occurs amono^ dead leaves 

 and under the bark of trees. It is distinctly local, 

 its distribution in these islands being restricted to 

 the following English counties : — Hants north, Sussex, 

 Kent, Surrey, Berks, Gloster east, and Notts. 



The family Stenogyridw is represented in this 

 country by two genera and three species of small 

 snails. The animals have the radula teeth arranged 

 as follows : central tooth small and narrow, the 

 lateral teeth much larger, with their ends divided 

 into three points, of which the central is the largest, 

 and the marginal teeth are similar to the laterals, 

 but swollen. The shell is a long dextral S2:>iral 

 w4th a blunt apex, more or less translucent and 

 shining. 



The Slippery Moss-snail (Feritssacia lubrica) well 



deserves its name, for it is so excessively 



glossy that it readily slips through the fingers 



and vanishes among the moss. There are 



only five whorls of a pale yellow-brown tint, 



M^o'ss-7n'aii transparent, the last whorl being equal to 



half the shell. Mouth nearly oval, the lip 



thickened within and rounded. It is found among 



moss and at the roots of grass; also under stones, 



