MOLLUSCA. 441 
sipid to the palate. It is not by any glutinous liquid, as 
it has been asserted, that this fish adheres so strongly to 
the rock ; but by the simple process of expelling the air 
from between its cloak and the roek, to which it affixes 
itself. 
The variety which is thrown into the sum of animated 
beings is so wonderfully great, that naturalists have 
reckoned more than a hundred and twenty-nine species 
of limpets, and nearly allied genera ; the difference arising 
principally out of the diversity of forms and colours of 
the shells. 
THE GARDEN SNAIL (Helix aspersa,) 
Is furnished with four tentacula, two of which are smaller 
than the others ; at the end of these tentacula, which 
u 5 
