RAZOR-SHELLS. 



201 



They almost all of them live buried in the sand, or else they bore into mud 

 or even into the solid rock. To this family belong % 



The Stone-borers (Saxicavd}* These shell-fish generally bore in lime- 

 stone rocks. Wherever we have a sea-coast of mountain limestone, the sub- 

 stance of the rock is almost invariably riddled by them. Some years ago it was 

 discovered that the whole front of the Plymouth Breakwater had been attacked 

 by these excavators, and great alarm was excited for its safety. Luckily they 

 do not drive their tunnels more than six inches deep, so that unless there be 

 a new surface exposed by the destruction of the perforated part, there is not 

 much danger to be apprehended from them. 



The Razor-Shells (Sole-it),^ usually burrow in the sand, which they pene- 

 trate with their powerful foot. They are much valued for their excellence as 

 articles of food. When properly cooked (broiling is the best method), they 



FIG. 204. SAXICAVA. 



FIG. 205. ANIMAL OF RAZOR-SHELL. 



are by some thought to be superior to any other shell-fish. They lie in their 

 holes nearly in a vertical position, and move up and down in their burrows, 

 sometimes rising to the surface as if to see what is going on in the world above. 

 When the tide goes out they sink deeper. The fishermen then endeavour to 

 tempt them out, as little boys would catch birds if they could, by putting salt 

 -on their tails. The salt irritates the extremity of their siphons, and the Solen 



* Saxum, a stone ; cavo, to scoop, to bore through. t (ru\r]v, solen, a tube. 



