34 Beautiful Shells. 
THE COMMON SNAIL 
Is called by naturalists Helix aspersa, the generic 
name being derived from a Greek work signifying 
spiral, and having reference to the shape of the 
shell; the plural is Helices, a term applied to all 
convoluted or twisted shells, which terminate in a 
point like a church spire: a spiral-shelled fossil is 
called a helicate. ‘The specific name comes from the 
Latin asper—rough; whence also our English word 
asperity—roughness, and several others. The Heli- 
cide, or Helix family, is that which includes the 
land shell Snails and the naked Slugs, and in this 
family there are several genera; they are distin- 
guished from the shelled water Snails, both sea and 
river, by having a different breathing apparatus, 
and some other points of internal construction which 
it is not necessary to describe here. 
The Common Snail has a mouth, of which it 
makes good use, as market gardeners well know, 
and yet this mouth is not furnished with teeth; 
instead of these, the upper lip, which is of a horny 
texture, is what is called dentated, from the Latin 
dentus—a tooth, that is, divided or separated, so as 
to present somewhat the appearance of a row of 
teeth in the jaw; this lip is of an arched form, and 
