88 CLASS COXCHIFER\. 



although acid would act upon stone, it would have no 

 effect whatever on lava. 



Another curious part of the history of these shell-fish 

 is their phosphorescence, which is so bright, that it has 

 been asserted, if eaten in the dark without their being 

 cooked, it appears as if the person devouring them was 

 swallowing phosphorus. 



Phdlas ih(cliiloidt-s. 



Although not used as food in this country, they are not 

 uncommonly eaten on the shores of the Mediterranean, 

 where some large species are found. 



The species represented in the engraving is found on 

 the British coasts, imbedded in clay ; its shell is of a 

 delicate white, beautifully carved. The projecting piece 

 at the lower part of the shell in the engraving is the 

 long foot of the animal ; on the right hand, the hole 

 from which a shell has been removed is shown. 



