96 



Shell Life 



margin. The animal is of a creamy tint, and the 

 mantle forms two short tubes behind, whose mouths 

 are fringed with delicate tentacles. The long foot is 

 broad at the base, but runs to a sharp point. By the 

 aid of this powerful instrument the C^qorina burrows 

 in the muddy sand, but not deeply, as may be gathered 

 from the shortness of the tubes and the sculpture of 

 the shell, slight as that is. It is found on all our 

 coasts, at all depths from low" water to 100 fathoms. 



The Heart-Cockle {Isoeardia cor) when viewed 

 from the side appears almost round, but from either 

 end it is seen to be more com- 

 pletely heart-shaped than Cyprina. 

 The beaks are curved spirally 

 towards the front, and from this 

 point they present the appearance 

 of the illustration. The thick 

 shell is yellowish white in colour, 

 but this is quite hidden beneath 

 the red - brown epidermis, which bears stiff short 

 hairs set in numerous lines radiating from the beaks. 

 The thick, broad hinge-plate bears two cardinal teeth 

 and two laterals. All these interlock and form a 

 powerful safeguard against the shifting of the valves. 

 The animal is whitish, the borders of the mantle 

 orange, and the strong tri- 

 angular foot of the same 

 colour. The siphons are very 

 short, with broad, fringed 

 openings which are at the 



centre of the lower margin. Full-grown specimens 

 average 4 inches across the longer axis of the shell, 

 and almost as much at right angles to it. The 



Heart-Cockle 



Beaks of Heart-Cockle 



