THE SHELL-FISH OF THE COAST. 



17 



tract immediate attention is the pear-conch, which 

 is about the largest shell of the coast, — indeed, one 

 of the largest shells of the entire North American 

 coast. Not uncommonly the animal is found within 

 the shell, where, it will be observed, it has closely 

 withdrawn itself, partially closing up the aperture 

 by means of a horny disk attached to its foot, known 

 as the ' operculum.' Thus shut up in its house the 

 animal is fairly secure from its enemies, and, if suf- 

 ficiently fortunate to regain the incoming waters, 

 may again rejoice in its favorite haunts. But too 

 long exposure to the dry 

 atmosphere will prove 

 fatal to it, as it like- 

 wise would to the greater 

 number of marine snails. 

 The pear-conch, of 

 which we recognize two 

 species, one furnished 

 with tubercles on the an- 

 gles of its whorls {Fulgur 

 carica), and the other 

 practically devoid of tu- 

 bercles, and showing a ca- 

 nalicule running around 

 the tops of the whorls (F. 

 canalieulaius), inhabits the 

 tidal zone, where it buries 

 itself to the depth of a few 

 inches in the sand. Its 

 presence can frequently be detected by hollows in 

 the sand, into which it has introduced itself by bur- 

 h 2* 



FDLGUR CANALICOT.ATU3. 



