62 POPULAR CONCHOLOGY. 



and a foot or short thick muscle, which is flat 

 at the end, at the other. — 10 species recent, 

 and 1 fossil. 



These animals inhabit indurated mud or 

 clay, wood, and stone, into which they bore 

 when young, and in which they continue to 

 reside until their death; it is not decidedly 

 known in what manner these soft-bodied ani- 

 mals, inhabiting so fragile a tenement, are able 

 to penetrate hard substances, unless it be by 

 aid of a corrosive agent : they are, from their 

 habits, exceedingly destructive to piers or 

 wooden buildings under water. The breakwater 

 at Plymouth, soon after its erection, was at- 

 tacked by Pholades ; it is constructed of lime- 

 stone. * In order to counteract their operations, 

 nails are closely driven into piles that lie under 

 water, as is the case with the pier at South- 

 ampton. 



The generality of the species are milky 

 white, and elegantly marked with rows of 

 small prickles: they are not used in this 

 country as food, but on the shores of the Me- 

 diterranean, where some large species are 



* Penny Cyclopaedia, art. Pholas. 



