206 THE SEA SHORE 



is the large, flat process inside the left valve for the attachment of 

 the internal cartilage. An allied species, Mya truncata, is often 

 found abundantly in company with the above, and may be known 

 by the abruptly squared posterior end. 



Other species of the Myacidce inhabit our shores, including the 

 little Basket shell (Corbula nucleus), the left valve of which is 

 much smaller than the right, which overlaps it. The latter, also, 

 is covered with epidermis, while the former, which is flat, is quite 

 naked. 



We now come to the interesting family of Eazor shells 

 (Solenidce), specimens of which are washed up on almost every 

 sandy beach, while the living molluscs may be dug out of their 

 burrows at low-water mark. The shells are elongated, gaping at 

 both ends with an external ligament ; and the hinge has usually 

 two teeth in one valve and three in the other. The foot of the 



FIG. 139. Solen siliqua 

 The valves have been separated and the mantle divided to expose the large foot 



animal is cylindrical, large and powerful ; and the siphons are 

 short and united in the long species, but longer and only partially 

 united in the shorter ones. The gills axe long and narrow, and 

 are prolonged into the inhalent siphon. 



These molluscs lie vertically in their deep burrows at low-water 

 mark, the opening of the burrow having a form resembling that 

 of a keyhole. While covered with water they occupy the upper 

 portion of their abode, but sink to a depth of a foot or more when 

 the tide goes out. As we walk along the water's edge at extreme 

 low tide we may observe jets of water that are shot into the air 

 before us. These are produced by the sudden retreat of the 

 ' Bazor-fish ' to the bottom of its burrow when alarmed by the 

 approaching footsteps. Owing to this wariness on the part of the 

 mollusc, and to the considerable depth of its burrow, specimens 

 cannot be obtained by digging without much labour ; but if a little 

 salt or some other irritant be dropped into the hole, the animal 



