382 APTERA. 
due warning ; the muscle then closes it^ 
shells, and secures its food. 
Lucy, I think it is but fair that the 
muscle should be rewarded for the shelter 
it gives to its little guest. 
Mother, On the coast of America a 
species of small crab is found, which 
preys upon muscles and scallops, by an 
ingenious stratagem. It watches till they 
open their shells, and then dexterously 
pops in a small stone, which effectually 
prevents their closing: it then sociably 
summons its friends to the feast, and they 
devour the poor animal at their leisure. 
Lucy. They are really clever little 
creatures. Indeed^ mamma, I find the 
crab almost as entertaining as I thought 
the spiders. 
Mother. There are many singular 
facts related of the different species : 
the history of the land crab will, J think, 
interest you. 
