THE CLAM. 



shore, or cove of sand, where you may not take many 

 clamps." This shows that the clam was once called a 

 clamp an appropriate name, as we shall see. 



The long clam and the round clam are those which 

 John Smith referred to. Sometimes these animals may 

 be found with their valves open. In this condition, 

 should a finger be inserted into the opening, the two 

 valves of the shell will instant- 

 ly close ; and if the finger is 

 caught, its owner will know by 

 experience that the clam is a 

 clamp a very close pinching 

 clamp. Oysters are still more 

 severe pinchers; hence they 

 might also have been named 

 clamps. 



To speak intelligently of 

 the clam, its various parts 

 must be named. The two 

 half shells have already been 

 called valves. Looking at the 

 figure, the thick edge of the closed shell is the back 

 (b). Each of the knobs on the back is called an umbo ; 

 together they are called umbones. Between the um- 

 bones on the back is the hinge. The sharp edge 

 is the ventral edge (v). The large end of the whole 

 shell is the front end (/); and the smaller end is the 

 rear end (r). Holding the shell with its back up and 

 the rear end toward you, the valve on the right-hand 

 side is the right valve, and the other is the left valve. 

 The largest half shell of the oyster is always the left 

 valve, and lies downward. 



Long Clam. 



