Land-snails 353 



through tlie destruction oi' tlie forests." Its shell is 

 closed in winter by a very thick white epiphragm. 



The Lapidary Snail {H, lapicida), though it has 

 a depressed shell like the Cheese Snail, has the spire 

 distinctly raised and the periphery sharply keeled. 

 The colour is dark ruddy-brown, paling to a dirty 

 yellow in places. The mouth is oval, with a notch 

 corresponding to the keel : the thickened white lip 

 expanded, and forming a complete peristome. The 

 umbilicus is large and deep. The epidermis is very 

 finely granulated, so that through a lens it has the 

 roughness of a fine file. Probably, as Jeffreys 

 suggests, this appearance may have led to the belief 

 current in Linna3us' day, that this snail bored into 

 wood and stone. It was owing to this 

 belief that Linnasus called it lapicida 

 or the Lapidary, but though Jeffreys 

 terms this an inappropriate name, it ^^' ^'^ 

 is not so when one regards the shape of the shell with 

 its sharp keel, much resembling the polishing wheel 

 of tlie cutter of precious stones. The Lapidary Snail 

 has only been found in England and Wales, so far as 

 these islands are concerned, and it extends no farther 

 north than Yorks. It is most frequent on soils of a 

 calcareous nature, though by no means restricted to 

 them. It is a very difficult snail to find in dry 

 weather even in places where it is abundant, but 

 after a heavy summer shower it may be found in 

 thousands on trees (especially beech) and palings. It 

 is remarkable how well its form is adapted for con- 

 cealment in both these situations. When at rest on 

 beech trunks it is the exact counterfeit of the low- 

 knobbed excrescences on the smooth grey bark, and 



