THE LOBSTER AND OTHER CRUSTACEANS. 87 



A curious creature is the hermit-crab (Fig. 92). Select- 

 ing an empty shell, it thrusts its soft hind body into it, and 



FIG. 92. Common Hermit-crab. (Natural size.) 



uses it as a protection like Diogenes, carrying its house 

 about with it. Small hermit-crabs are abundant in little 

 shells in tidal pools along our coast. They may be put into 

 saucers filled with water and their movements watched. 



Less nearly related to the lobster are the " beach-fleas/' 

 the little active, hopping creatures one finds everywhere un- 



Fio. 93. Gammarus, from fresh water. (Much enlarged.) 



der sea-weed on the sea-shore. Similar forms (Fig. 93) are 

 common among weeds in fresh-water ponds. 



