a 
are narrow lateral teeth ; the valves shut closely all around. 
The Beach Clam, Mactra solidissima Chemnitz, is a 
smooth, yellowish-white shell. It grows to a very large size, 
and is so abundant that one cannot walk the beach without 
seeing quantities of them. 
Frequently they are found with a very neatly bevelled round 
hole near the beaks. This is the work of the Natica, a fat and 
good-natured looking mollusk, but secretly most blood-thirsty. 
Boring along through the sand, like a mole, goes the Natica 
until he finds a clam ; he then brings his tongue, armed with 
rows of sharp teeth, into play, and bores a hole through the 
shell of his victim, through which the soft tissues may be eaten 
at leisure. This is a very ingenious way for Natica to get a 
meal, but the feelings of the clam at being bored to death are 
not pleasant to think about ; but it is the way of the world. 
‘* Big fleas have little fleas 
And smaller fleas to bite ’em; 
And these again have other fleas, 
And so ad infinitum.’ 
A little brother of the big fellow last pictured is the Little 
Beach Clam, Mactra lateralis Say. The 
shell is small, thin and differs from young 
of the larger species in having a rather 
sharp and distinct ridge running from the 
beaks downward and backward ; in being 
more triangular and less compressed. It 
has also less of a yellow tint than I. sol- 
.Fig. 20. Mactra lateralis. 
idissima. 
The Smooth Cockle, Cardium mortoni Conrad, is rather 
rare on the N ew Jersey coast, but common southward. Car- 
~, 
