THE OPEN SEA BEACH 279 



suddenly squatting down, and disappearing; so 

 closely does it mimic the color of its environment 

 that it generally eludes its enemies. Without 

 doubt its common name was suggested by its 

 ghost-like appearance. There are sand fleas 

 (Orchestia) which burrow in the sand, and are as 

 lively as the insect from which they are named, 

 and the shore is sometimes almost covered with 

 hermit crabs (Paguridae) of a number of species. 

 They live mostly in dead, empty shells, the tail 

 being soft and provided with a pair of hooks at its 

 end for holding to the home chosen. When, by rea- 

 son of increasing growth, this crab finds its tene- 

 ment too small it hunts for a larger one, and is 

 quite indifferent as to what kind ; it may sometimes 

 go into a sponge or even the tube of a plant stem. 

 Once on the southwest coast I was fortunate 

 enough to witness a change of habitation. A good 

 sized hermit in a shell of Fulgur pyrum was moving 

 about among a number of dead shells, apparently 

 with the feeling of a man looking at houses to let. 

 At last it found a shell of Polinices duplicate, 

 which was larger than its dwelling but very dif- 

 ferently shaped. It moved around it several 

 times, peered into it, probably to see if it was in 



