Trochus. 61 
other, which is free, you will see coiled in a 
beautiful spiral manner, within the cavity of the 
stomach. 
By allowing this tiny thread to stretch itself on 
a plate of glass, which is easily done by putting a 
drop of water on it first, which may then be drained 
off and dried, you will find that it is in reality an 
excessively delicate ribbon of transparent cartila- 
ginous substance or membrane, on which are set 
spinous teeth of glassy texture and brilliancy. They 
are perfectly regular, and arranged in three rows, of 
which the middle ones are three-pointed, while on 
each of the outer rows a three-pointed tooth alter- 
nates with a larger curved one, somewhat boat-like 
in form. All the teeth project from tne surface of 
the tongue on hooked curves, and all point in the 
same direction.” 
And with this curious piece of mechanism the 
little Winkle works away and cuts down swathe 
after swathe of the minute vegetation, just as a 
mower does the meadow grass; only the mollusk 
eats as he goes, and so gets payment for his labour; 
the man has it in another and to him more useful 
form. We might tell avery long story about these 
Tops and Winkles, which are nearly related to each 
other, but must now pass on to describe the rest of 
9) 
