SHELLS WITHOUT CANALS 215 



where you could watch the speckled trout in the deep 

 holes ; perhaps it was in the woods, where there were 

 great trees watching over you that had been growing 

 for centuries; perhaps it was by the seashore, where 

 you could lie awake at night and hear the waves 

 pounding away on the granite rocks or breaking into 

 foam on the sandy beach; perhaps it was in a field, 

 or even in a back yard; but anywhere under a tent 

 there is a charm which you cannot get anywhere else, 

 try as hard as you may. 



Now there is a whole g^rouD of mollusks which live 

 in tents all their lives, and the}^ always pitch their 

 tents on the rocks. And each tent is just big enough 

 for one camper to live in; and it the camper grows 

 he builds on an addition to the edge of his tent, and 

 keeps it just big enough to cover him whenever he 

 settles down tor a good night's rest. 



When you went camping you set up poles and 

 spread the tent-cloth over them, and fastened all 

 down with ropes and pins. But our little moUusk 

 campers make their tents of shell, and they are so stiff 

 and firm that there is no need of poles and ropes to 

 keep them spread. 



These little campers are called limpets, and their 

 coverings are sometimes called saucer-shells, for some 

 of their empty tents when turned over might be used 

 for little shallow dishes, like very small saucers. On 

 the coast of Mexico there are some that are large 

 enough for mush-bowls, but they do not grow so large 

 in our part of the ocean. 



The west coast of America abounds in limpets. 

 Some species cling to rocks which are seldom covered, 



