Mussel and Cockle. 95 



are then more slender than those produced at 

 leisure, and, of a consequence, weaker. On some 

 parts of the Mediterranean coast, as in Sicily, 

 gloves and other articles have been manufactured 

 from the threads of this mollusk. They resemble 

 very fine silk in appearance. 



The foot of the Cockle, of which we here give 

 a figure, is commonly employed in scooping oub the 

 mud or sand, beneath which it 

 conceals itself; this useful limb 

 assumes the form of a shovel, 

 hook, or any other instrument 

 necessary for the purpose; it 

 appears to be a mass of muscular fibres, and to 

 possess great power. As a boatman in shallow 

 water sends his vessel along by pushing against 

 the bottom with his boat-hook, precisely so does 

 Mr. Cardium travel ; he doubles up his foot into a 

 club, and by an energetic use of it as a propeller, 

 makes considerable headway along the surface of 

 the soft sand beneath the waters. In this way, 

 too, some members of the genus solen force their 

 way through the sand ; while those called Tellina 

 spring to a considerable distance, by first folding 

 the foot into a small compass, and then suddenly 

 expanding it, closing the shell at the same time with 



