SNAILS. 89 
The body is spiral, the mantle thin, with a thickened 
edge lining the inside of an external shell. 
The indigenous members of this extensive family 
are familiar to every one. Some of them are de- 
structive and voracious’ tenants of our gardens; 
others occur to us in our summer walks, swarming 
by scores on the banks and hedgerows; and not a 
few attract our admiration by their clean globose 
shells, and by the beauty of the colours, frequently 
disposed in spiral bands, with which they are 
adorned. But the beauty of our native species is 
far surpassed by many of those from the tropics, 
many of which, especially those of the genus 
Bulimus, shine in the most gorgeous colours, 
crimson, scarlet, orange, yellow, green and blue; 
and many of them are of gigantic size. 
All the members of the family are voracious 
vegetable feeders; many of them devour indis- 
eriminately the leaves of various plants, especially 
such as are tender either from youth, or from 
incipient decay. ‘lo aid them in crushing down 
the vegetable fibre, the mouth, which is situated on 
the under part of the head, is armed with a cutting 
instrument of beautiful contrivance. The upper 
one of the two fleshy contractile lips is armed 
with a broad horny plate, the lower edge of which 
is free, very sharp, and slightly curved, forming 
in fact a knife, admirably adapted to divide the 
leaves and soft parts of vegetables, when they are 
pressed by the action of the lips against its cutting 
edge. The floor of the mouth is provided with a 
small cartilaginous tongue, covered with delicate 
transverse striz, and so disposed that by its move- 
ments it is well calculated to assist in propelling 
the food into the cesophagus. 
