30 HELICID-H. 



Z. CRYSTALLINUS. Midler . PL V, fig. 11. 



Minute, nearly flat, glossy, a milky white colour, almost transpa- 

 rent ; mouth lunate ; umbilicus small. 



Helix crystallina, Mull. 



This is the smallest of the British Mollusks at present 

 comprised under the name Zonitcs, and is a sparkling 

 and perfectly transparent little gem. It may be dis- 

 tinguished from all the others by the closeness of the 

 whorls, which are also more numerous than those of 

 purus, which it most nearly resembles. The shell is 

 seldom more than an eighth of an inch in diameter. 



Hdb. Almost every locality furnishes this species. 

 It is found in woods, hedge-rows, and mossy fields, 

 though seldom in very great numbers. Like most of 

 the other species it seems to prefer a damp to a dry 

 situation, and is frequently a little beneath the surface 

 of the earth. 



HELIX. LinncBus. 



Shell More or less spiral, globose or discoid ; outer lip thick- 

 ened ; variously coloured, without an epidermis ; mouth 

 lunated. 



Ainmal With four tentaculce, an elongated depressed foot ; 

 tail lanceolate ; body produced and spiral. 



H. APERTA. Born. PL VI, fig. 1. 



Shell subglobose, thin, brownish green colour, somewhat wrinkled ; 

 mouth large and wide. 



Helix naticoides, Drop, fyc. 



In deference to the authority of Professor Forbes and 

 S. Hanley we retain this Helix as a British species. 

 Only one mutilated specimen has been discovered, and 

 that in the island of Guernsey, no doubt having been 

 brought over from France, in the south of which coun- 

 try they are abundant, and are eaten in Provence as 

 a delicacy. The above specimen is in the British 

 Museum. 



Hob. Hedges amongst nettles. 



