CHAPTER I1.—OvystTers iS SCALLOPS. 
We will begin with the most simply organized class of mollusks, those having 
bivalve shells. The animal has broad gills on each side of the body, to which water is 
brought by a tube. The food consisting of minute creatures is also strained out of this 
water. They havea fleshy ‘“‘ foot’’ used for digging, but no head or eyes. © 
The oysters and scallops differ from other bivalve shells in 
having only one muscle for pulling the valves together. The 
place where the muscle is attached to the shell is at about the 
middle of each valve. They lie upon one side, instead of stand- 
ing upon the end or edge, as other bivalves do, and the under 
valve becomes flattened in consequence. They move about so 
little when a residence has once been selected, that the “ foot” 
is all but lost from sheer want of exercise. 
The first of this tribe (at least on bills-of-fare) is the Oyster 
Ostrea virginica Gmelin, a bivalve of such broad repute as 
to need no introduction to us; for Ostrea has been talked of, 
written about and eaten since before the founding of Rome. 
Our oysters build a 
rough, rude, irregu- 
lar shell, and the mus- 
cle-sear or “eye” is of 
a dark purple color. 
Next to the Oys- 
ters come those pretty 
Fig. 4. Anomia sig 
Anomia simplex Orb. “ Anomia” means nameless; but they 
have several names for all that; “Saddle-oysters” is one of 
11 
little seale-like golden , 
and silver shells 2a». 
which dot the sands, «»: 
micSc 
