NATURE'S CALENDAR 187 



similar mollusks live upon dead fish and August 24 



other carrion, and thus perform a valuable 

 scavenger service in the sea. 



One finds rolling in the surf several 

 sorts of spiral shells, which the oystermen 

 call boi-ers, with good reason, for these, too, 

 are carnivorous, and creep about in search 

 of flesh, dead or alive. Coming to a bed of 

 mussels or oysters, they settle upon one, 

 and, protruding a ribbon-like "tongue" 

 studded with flinty " teeth," like a file, 

 they bore with it a round hole through the 

 shell and suck out its substance, while the 

 inmate is powerless to resist the attack. 

 Among the worst of them is one which is 

 white, almost as globular as an apple, and 

 sometimes two inches in diameter, called 

 the Natica. It creeps about almost buried 

 in the sand, under shallow water, near 

 shore, and is, therefore, easily rolled up 

 when dead; it is a shell of which the 

 hermit-crabs are especially fond. If you 

 search carefully you are pretty sure to 

 find its eggs, scattered through a glue-like 

 mass covered with sand grains, that has 

 much the shape of a " stand-up " collar, 

 and is one of the curiosities of the beach. 



One might go on a long time in descrip- 

 tion of even the comparatively few shells, 

 crustaceans, worms (in great variety), and 

 so forth, to be found upon our sandy 

 coast, or in the salt marshes, where va- 

 rious limpets and other small species live, 

 and where the mud-flats are often black 

 with multitudes of small species, one of 



