60 HELICID^E. 



half. As in the last species the epidermis is raised into 

 ridges in the line of growth, but in this shell the ridges are 

 exaggerated into points. 



This is a beautiful object under a lens. It is pretty 

 generally distributed, and is found among moss and 

 dead leaves in moist shady situations. It may often 

 be passed over as a small lump of dirt owing to its 

 colour and shape. 



Var. albida. Colourless. 



3. H. POMATIA (operculate). 



Globose, solid, cream-colour banded with red, coarsely 

 striated in the line of growth ; umbilicus narrow. 



This fine shell is the largest of our snails. Though 

 common on the Continent, it is only sparingly met 

 with in a few localities in the south of England. It 

 derives its name from a Greek word (poma) signify- 

 ing an operculum, on account of the thick epiphragm 

 which it makes on retiring into winter quarters. This 

 epiphragm is formed by a secretion of the animal, and 

 hardens on exposure to the air like plaster-of-Paris. 

 "When this thick plate closes the entrance, the animal 

 retires deeper into the shell, and fortifies itself still 

 further against the cold by a succession of thin films. 



The notion that this shell was introduced by the 



