162 HELICIDJE. 



fossils. It has been recorded by M. Grateloup as occur- 

 ring at Dax in the Department of the Landes, and 

 by M. Terver at Lyons ; but it has probably been passed 

 over in other parts of Europe as a variety of Z. glaber, 

 which is not uncommon in France, Germany, and Swit- 

 zerland. 



This snail has a very strong and pungent smell of gar- 

 lic, especially when it is irritated ; and I have perceived 

 it at a distance of several feet from the spot. Having 

 found living specimens under stones in a bed of wild 

 garlic, I thought at first that they might have fed upon 

 this herb and thus acquired the peculiar odour ; but I 

 afterwards observed that this scent was quite as power- 

 ful in specimens collected on an open down where there 

 was no garlic. Mr. Norman informs me that the scent 

 varies in intensity, and is sometimes scarcely perceptible, 

 even after considerable irritation of the animal. 



It differs from Z. cellaritis, the young of which it re- 

 sembles in the darker colour of its body and shorter 

 tentacles, as well as in the spire of its shell being more 

 produced, the mouth narrower, and the umbilicus more 

 open. If the two shells are held sideways, with the 

 mouth towards the observer, the last whorl of Z. cella- 

 rius will appear deeper than in the other shell. 



There has been much controversy among Continental 

 writers as to whether this species is distinct from the 

 Helix glabra of Studer. I incline to the opinion of 

 Schmidt, that they are different. One test mentioned 

 by this author in support of his view is rather curious, 

 viz., that Z. alliarim wants the bitter flavour of the other 

 species ! I much doubt if all conchologists would relish 

 making such experiments. 



