HELICIDJE. 173 



an opake white; whorls 4 J ; umbilicus large, 



exposing the second whorl. 

 Helix nitidula. Drap. 117. t. 8. f. 21, 22. ; Gray, 



Med. Repos. 1821. 239.; Shepp. Linn. Trans. 



xiv. 160. ; Alder, Cat. 134. 49. ; Mag. Zool. $ 



Bot. ii. 107.; Jeffreys, Linn. Trans, xiii. 340. 

 Var. 1 . Helmii, transparent greenish white. Alder, 



1. c. 107. 

 Helix Helmii, Gilbertson, MSS. British Museum. 



Inhab. hedge sides, under stones, &c. 



Animal dark lead-colour. (Sturm, t. 12.) 



Shell about three tenths of an inch in diameter. 

 Differs from Z. cellaria in being smaller, rather more 

 convex above, and more concave beneath ; of a dull 

 lustre, darker colour, and more strongly wrinkled 

 above; the umbilicus is larger, and the aperture set 

 at a less oblique angle ; the opake white, also, is not 

 so much diffused over the base of the shell, but it is 

 confined to the edge of the umbilicus. The animal 

 is of a darker colour. (Alder.) 



Mr. Gilbertson thinks that there are some pecu- 

 liarities in the habit of the animals, together with the 

 white colour of the variety of the shell, which induces 

 him to consider Z. Helmii as distinct from Z. niti- 

 dulus, but as yet he has not published his observations 

 on it 



52. 9. ZONITES radiatulus. Rayed Snail, (t. 5. 

 f. 137. and 50. ?) Shell depressed, horn-coloured, 

 rather shining, transparent, regularly striated ; 

 3J or 4 whorls, flattened at their junction 

 with the inner ones, over which the striae 

 appear continuous and strongly marked, giving 

 i 3 



