THE MUSSEL, THE COCKLE, AND THE EAZOR-SHELL. 607 



breath is carried swiftly to the bottom. He then flings himself on his 

 face, fills his bag as fast as he can, and when his breath begins to fail 

 shakes his rope as a signal, and is drawn up together with the bag. 



We now come to the large, useful, and even beautiful, family of the 

 Mussels. 



The Edible Mussel, so common in the fishmonger's shop and the 



costermouger's barrow, is found in vast profusion on — "^ts, where 



it may be seen moored to rocks, stones, and 

 fibres, alternately covered with water or left 

 dry according to the flowing and ebbing of 

 the tide. At some periods of the year the 

 Mussel is extremely injurious as an article 

 of food, though the effects seem to depend 

 greatly on the constitution of the partaker. 

 Attempts have successfully been made to prop- 

 agate the breed of mussels, and the vast 

 plantations, as they may be called, of these 

 creatures have increased to such an extent 

 that they threaten to obliterate several usei'ul 

 bays for all maritime purposes. 



The family of the Cockles, or Cardiadse, 

 so called from their heart-like shape, is well 

 represented by the common Cockle (^Cardhcm 

 edi(le) of our British shores. Generally, the 

 Cockle is a marine animal, but it sometimes 

 prefers brackish water to the salt waves of 

 the ocean. 



This mollusc frequents sandy bays and re- 

 mains about lowMvater 



mark, burying itself in 



the sand by means of 



the powerful foot, which enables it to leap to a 



surprising height. 



We now come to the well-known Solenid?e, 



or Razor-shells, so called on account of their 



shape. 



These curious molluscs always live buried in the 



sand in an upright position, leaving only an open- 

 ing shaped like a keyhole, which corresponds with the two siphon tubes. 

 These creatures are generally found at a depth of one or two feet, 

 and w^hen they make their burrows, as they are often in the habit of 

 doing, among the rocks, not even the hooked iron can draw them from 

 their retreat. 



We next come to the Pholas, the best example of which is the com- 



The MrssEL {Mytihis 

 E(hdis). 



The Cockle {Cardium 

 edule). 



