78 Beautiful Shells. 
bivalve shells whose edges are toothed, or, as it is 
said, pectinated. In the scallop and the cockle shells 
this peculiarity is more observable than in those of 
other members of the class, and these form the 
typical, or, so to speak, pattern genus, pecten. 
Thirdly, the Common Oyster is a Monomyarian 
Conchifer. Ah! that’s something like a name for 
the acephaloid monarch! Look at these two words, 
mono-myarian, di-myarian. You know, of course, 
that mony-syllable means one syllable, and dis- 
syllable means two. You sometimes hear of a 
person who leads a monotonous life, and you think, 
perhaps, of the Oyster shut up in his shell all alone, 
one by himself. This notion you now know to be a 
false one, although it is true that he has but one 
abductor muscle, and therefore belongs to the 
division of the Pectinide family called Monomyaria, 
while the Pearl Oyster has two, and therefore 
belongs to that termed Dimyaria. If, as they say, 
there is reason in the roasting of eggs, surely there 
must be in the names given to the classes and 
divisions of shells. We hope to have succeeded in 
making the why and the wherefore in this case 
somewhat plain; one—two—and away we go out of 
this maze of hard names. But what about the 
abductor muscle, above spoken of? Well, this 
