140 . ANIMAL LIFE ON THE 
Let US now turn our attention for a short time to 
THE LIMPET, 
whose familiar shell needs no description. Everybody 
knows his peculiarity of so firmly adhering to the rock. 
One smart tap with a suitable stone, without giving him 
previous warning by molestation, is sufficient to unloose 
him ; but if a second or third be needed, in all likelihood he 
will be smashed to pieces before he suffers himself to be 
captured. Some authorities declare that this power of 
adhesion is due to a very strong glue, which can be secreted 
at the creature's will. We have secured a pretty large 
LIMPET. 
specimen, and now let us have a view of his construction. 
Eound the rim of the valve we see a line of tentacles, 
similiar to those of the scallop, springing from the mantle, 
which also encircles the shell, and moves at any part, up or 
down, as required. In the centre is the oval-shaped foot, 
and at its margin, the head, similar in shape to that of the 
top described above, now begins to make its appearance. 
When he opens his mouth we notice he also is furnished 
with a rasp, being likewise a vegetarian ; and well down the 
head are his pair of well-shaped, muscular horns, at the 
outside base of which are the two very small, black, bead- 
like eyes. When the head is stretched out to its full 
length, we notice, in the middle of a cavity leading into the 
