38 Beautiful Shells. 



hollow; wheii tlie latter, tlie open end is ciuloJ tli3 

 JJmhilicuSj meaning tlie navel or centre. TIiq 

 opening at tlie bottom, from Vv^Licli tlio animal 

 issues, is tlie last portion finisliecl, and tliis is called 

 the aperture, a Latin word adopted into the English 

 dictionary. Some of these Ilelices are wide and flat> 

 even hollow and cup-like, with the whorls rising 

 above the pillar — these are called dUcold shells > 



DISCOID. TURBINATED. 



others which are long and narrow, with projecting 

 spires, are termed turhlnated shells : the former 

 being more or less flat or disk-like, the latter 

 twisted, whirling, like a spinning-top, from the 

 Latin turlo — a whirling, a turning round. 



If we take a Common Snail, and plunge it into 

 boiling water, which will instantly kill it, so thai> 

 it can be removed from the shell, we shall find 

 the whole of that part of the body which was 

 lodged in the upper whorls, or spiral part of the 

 shell, is covered with a thin membrane or skin ; 

 this is called the mantle, and that portion of it 



