TRIDACNID^:. 



429 



borne the buffeting of a comparatively shallow and turbulent sea will be poor and stunted." 

 The Clams are generally attached by the upper valve. The animal is edible, and is con- 

 sidered a great delicacy. About 

 fifty species of Clams are known. 



THE Tridacnids are easily 

 known by their deeply waved 

 shells, with the indented edges 

 fitting into each other, and the 

 overlapping foliations of the sur- 

 face. Although separated from 

 the true Clams, they are popularly 

 called by the same name. The 

 YELLOW CLAM is represented as 

 it appears when buried in a mass 

 of white madrepores, and is given 

 in this attitude for the purpose 

 of exhibiting the interlocking 

 edges and the bold foliations. 

 A well-known species, called from 

 its enormous dimensions the 

 GIANT CLAM (Tridacna gigas\ 



was formerly rare, but is now THORNY CLAM.-Cta - 



tolerably plentiful. It attains to 



a gigantic size, sometimes weighing more than five hunded pounds, and containing an 

 animal which weighs twenty pounds, and can furnish a good dinner to nearly as many 





SPOTTED BEAR'S-PAW CL\M.-Hlppopus maculate 



YELLOW CLAM.-Trldacna crocea. 



persons. The natives of the coasts on which it is found namely, those of the Indian 

 seas are extremely fond of this creature, and eat it without any cooking, just as we eat 

 oysters* The substance of the shell is extremely thick and solid, and enables it to be 

 used for many ornamental purposes. 



