22 THE COMirOM SNAIL. 



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

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

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

 an ascending directian, round the Columella, or centrail column, 

 as the spiral staircases in the Crj'stal Palace. 



But let us return to our Gai'den Snail, who has many near 

 relatives in Britain, several of which have beautifullj'-marked 

 and convoluted shells, as will be seen by a refei'ence to our 

 coloured illustrations, Plate I. We will introdrree them in 

 duiC order. Fig. 1, the Banded Snail, {Helix nemorcdts,) from 

 the Liitin n&mus — 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, {II. ericeforum,) 

 from erica, the I^iitin for heath; a small s}X'eie& with brown 

 Ixinds, remarkable for its large umbilicus, perforating the centre- 

 of the shell nearly through. Fig. 3, the Silky Snail, f'll. 

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

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

 glistening appear^mcc. Fig. 4, the Stone Snail, {II. lapicida,) 

 from the Latin lapts — a stone: Linnteus called the species 

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

 quenting stony places, and the ])eeuliar construction of th© 

 shell, which has a sliarp. edge nmning round each whorl; it 

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

 but which it can scarcely be suspectc^l of having hollowed 

 out for its own ac-commodation. 



Fig. 5, the Elegant C^x-lostome, f Cychstoma elegans.J On 

 turning to the dictionaiy, we find that mjeloHtomom means 

 having a circular mouth. This species is sometimes called 

 Turho elecjansi the Ix'aulifully-marked shells are often found 

 in chalk-hills covered -vWth 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; ane keeping fast hold 

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

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

 (P. widulatus;) the Latin plecta — to twist or twine, seesivs 



