CARDIAD^E. 



337 



habitant of the shell has a very large foot, with a bend or knee near 

 the middle ; its mouth is transverse and funnel-shaped, and furnished 

 with a triangular appendage. One of the peculiarities in the organ- 

 ization of these molluscs is its direct connection with their mode of life. 

 In short, these molluscs, which most commonly live on the sea shore, 



Fig. 144. Cardinal hiuns (Brocchi). 



Fig. 145. Cardium Green landicum (Chemuitu). 



and bury themselves in the sand to the depth of four or five inches, 

 are enabled to breathe, to draw water for their nourishment, and also 

 to throw off the products of digestion, by having the mantle prolonged 

 into two tubes, the orifices of which reach to the surface of the soil. 



Fig. 146. Cardium aculeatum (Linnaeus). 



Fig. 147. Cardium ednlis (Linnaeus). 



By means of these feet and an extremely curious organ of locomotion, 

 the Cardiums can at will issue from their holes and re-enter them. 

 The fishermen of the shore easily recognize the presence of these ani- 

 mals by the little jets of water which they throw up through the sand?. 



