22 THE COMMOM SNAIL. 



they are then called sinistral, or left-handed shells: such are 

 not common. If one of the twisted shells be divided length- 

 ways, it will he seen that the inside of the whorls wind in 

 an ascending direction, round the Columella, or central column, 

 as the spiral staircases in the Crystal Palace. 



But let us return to our Garden Snail, who has many near 

 relatives in Britain, several of which have beautifully-marked 

 and convoluted shells, as will be seen by a reference to our 

 coloured illustrations, Plate I. We will introduce them in 

 due order. Fig. 1, the Banded Snail, {Helix ne^noralis,) from 

 the Latin nemus — a wood or grove; the prettily- striped shells 

 of this species may be found in great plenty among the 

 roots and in the crevices of the rugged boles of old forest 

 trees, as well as in hedge-rows and in mossy banks, and other 

 situations near woods. Fig. 2, the Heath Snail, {H. ericetorum,) 

 from e7'ica, the Latin for heath; a small species with brown 

 bands, remarkable for its large umbilicus, perforating the centre 

 of the shell nearly through. Fig. 3, the Silky Snail, fH. 

 sericea,) from the Latin sericus — silk -like; the shell of this 

 species is covered with short slimy hairs, which give it a 

 glistening appearance. Fig. 4, the Stone Snail, {H. lapicida,) 

 from the Latin lapis — a stone: Linnaeus called the species 

 the Stone Cutter, probably on account of its habit of fre- 

 quenting stony places, and the peculiar construction of the 

 shell, which has a sharp edge running round each w'horl; it 

 is commonly found lodged in the cavities of loose-lying stones, 

 but w^hich it can scarcely be suspected of having hollowed 

 out for its own accommodation. 



Fig. 5, the Elegant Cyclostome, f Cyclostoma elegans.) On 

 turning to the dictionary, we find that cyclodomous means 

 having a circular mouth. This species is sometimes called 

 Turoo elegans; the beautifully-marked shells are often found 

 in chalk-hills covered with brushwood. This pretty moUusk 

 has a curious mode of travelling; the under surface of the 

 foot, which is long, is divided by a deep fissure, into two 

 narrow strips, like ribbons; these take hold of whatever the 

 creature may be moving on alternately; one keeping fast hold 

 while the other advances, in like manner to fix itself, and 

 drag the body forward. Fig. 6, the Undulated Plekocheilos, 

 (P. undulatus;J the Latin jplecto — to twist or twine, seems 



