THE HORSESHOE CRAB 



idly shrinks in bulk, and not only draws its 

 entire body into the shell, but shuts the door 

 after itself with a tightly fitting, horny oper- 

 culum. This sea-snail, like all dwellers in or 

 near the sea, has a tremendous appetite, and 

 devours all sorts of game, dead and alive. It 

 is particularly fond of other members of the 

 same group of mollusks, and, in order to suck 

 out their insides, it has a habit of boring a 

 little hole through their shells as smoothly as 

 if it had used a drill. This it does by means 

 of a fleshy ribbon armed with rows of teeth 

 that it conceals in its mouth, an instrument 

 known as the lingual ribbon. Everywhere 

 along the beaches curious sand collars, as the 

 children call them, are to be found. These 

 are shaped like the small boy's broad collar 

 and are open in front. When wet they are 

 flexible, and, if held up to the light, they are 

 seen to be studded with small, round trans- 

 parent bodies. These are the eggs of the sea- 

 snail, and she makes for them these curious 

 egg cases of sand granules firmly glued to- 

 gether. 



Lining the beach in windrows are generally 

 to be found the pretty shells of another mol- 

 lusk, which I shall call the wicker-basket shell, 



265 



