102 



CHAPTER VII. 

 THE EDIBLE SNAIL. Helix pomatia. 



THE snail is a terrestrial animal, feeding on leaves and other 

 vegetable matter which it rasps off with its toothed tongue 

 or odontophore. The dorsal surface of the body carries a 

 spirally coiled univalve shell, which lodges most of the viscera, 

 and within which the entire animal can be withdrawn for 

 protection. It breathes air by means of a pulmonary chamber, 

 formed by a fold of skin the mantle on the dorsal surface. 

 It is hermaphrodite, but incapable of self- fertilisation. 



The edible snail occurs in many parts of England, and 

 can be readily obtained from dealers in Paris. On account of 

 its large size it is preferable to the commoner English species, 

 H. aspersa, to which, however, the following description will 

 apply with but slight modification. 



Snails are best killed by drowning them in water, when 

 they die in an expanded condition in about two days. In 

 winter the mouth of the shell is closed by a plate of calcified 

 mucus, the epiphragm, which must be removed before putting 

 the snail in water. When dead the snail should be put into 

 weak spirit for a short time before it is dissected, in order to 

 coagulate the mucus. 



I. EXTEENAL CHAKACTEES. 



A . Before Removal of the Shell. 



1. The shell is a right-handed conical spiral, each turn of 

 which overlaps and conceals the greater part of the 

 preceding turn. In the fully formed shell there are 

 about four and a half turns in the spiral. 



