120 POPULAE BRITISH CONCHOLOGY. 



from it so scientifically by the fish, as to be quite unavailing 

 to lure them to their doom. The British species are — 

 P. vulgata (or common Limpet) : shell conical, jigged at the 



edges, with the substance of the shell of a greenish 



or greyish colour, and the spatula, or central surface, 



opaque white ; the rays vary in brightness and depth ; 



ribs few and broad. 

 P. athletica : substance of the shell white; the ribs numerous, 



narrow, and elevated; spatula tinged with orange. 



Animal much lighter in colour than P. vulgata, 



Not popular with the fishes. 

 P. peUucichy or Transparent Limpet. 



On this species Mr. Hanley remarks : " The two varieties 

 of this elegant limpet differ so remarkably from each other 

 as strikingly to illustrate the effects of habitat and food 

 upon colour and solidity. The most typical pellucida feed 

 upon the leaves of fuci ; the aberrant IcBvis, upon the roots 

 and stalks, in which, indeed, it is wont to imbed itself. The 

 former is thin, semi-transparent, of a dark olive when adult, 

 of an ochraceous yellow when young, is regular in shape 

 (which ranges from sub-elliptic to rounded ovate), and is 

 adorned with more or less interrupted rays of lustrous ma- 

 zarine blue." The other is a thicker, less regular, less 

 transparent, ' pinched up ' shell. 



