62 RAMBLES IN SEARCH OF SHELLS. 



Only one species of glass snail (Vitrina) inhabits 

 this country ; although a second formerly did so, 

 as proved by its occurrence in our upper tertiary 

 strata. Vitrina pellucida (PL VII., fig. 6) is not 

 uncommon under dead leaves, moss, and roots in 

 woods and shady places, and seems partial to mois- 

 ture, being always more active after rain. The shell 

 is very thin, brittle, glossy, and transparent ; the 

 spire is short and blunt, the suture very slight, and 

 the mouth nearly oval ; in shape not unlike the shell 

 of Zonites. The best time to look for this species is 

 in autumn ; but care should be taken in turning over 

 dead leaves, moss, &c., in search of it?, since from its 

 extreme brittleness the shell is very easily destroyed. 

 It would seem that the animal inhabiting it is a 

 favourite morsel with the Hedgehog ; numerous frag- 

 ments of shells having been found from time to 

 time in stomachs examined. This is also the case 

 with some species of Zonites. 



Where the soil is calcareous, search may be made 

 for the needle agate shell, Achatina acicula (PL VIII., 

 fig. 2), which is often found some inches below the 

 surface. To give some idea of its appearance, it may 

 be observed that specimens before now have been 



