ZONITES. 169 



Habitat : Under fallen trees and among dead leaves 

 and moss in shady woods. The tract of country over 

 which it is diffused comprises the South and South-west 

 of Scotland, North of England, West and South of 

 Ireland, North and South Wales, Isle of Wight, and 

 Cornwall ; but it is a local species. The variety is from 

 South Wales, Cork, and Connemara. 



This species has been considered peculiar to Great 

 Britain, and to be the only land-shell which does not 

 inhabit any other part of the world ; but I have reason to 

 believe that the greenish-white variety is the Helix vi- 

 trina of Ferussac, as well as the H. viridula of Menke, H, 

 petronella of Charpentier, and probably also the H. clam 

 of Held. In the ^ Malakozoologische Blatter ^ for 1858 

 will be found a critical dissertation by Von Wallenberg on 

 the Helix viridula of Menke compared with Z. purus, in 

 wdiich the author showed that these were quite different 

 species ; and I can answer for the identity of Z. exca- 

 vatus var. vitrina (or viridula) with the H. petronella of 

 Charpentier, having found specimens of the latter on the 

 Corner glacier in Switzerland at a height of about 7000 

 feet above the sea-level, and afterwards compared them 

 with the types in Charpentier^ s collection at Devens 

 while I was on a visit to that eminent naturalist. In a 

 letter which is now before me from the late M. Char- 

 pentier, dated 28th August, 1854, he says the H. vi- 

 trina of Ferussac (but not that of Wagner, which is a 

 Brazilian species) is identical with his own H. petronella, 

 and that it is very different from H. radiatula, with which 

 it has only a slight relation in respect of the striae. Fe- 

 russac did not give any description of his species. Instead 

 therefore of the present species being exclusively British, 

 it likewise appears to inhabit Lapland, Finland, Ger- 

 many, and Switzerland. The publications of Alder and 



