92 Beautiful Shells. 
THE MUSSEL AND THE COCKLE. 
It is in the Dimyaria division of the Conchifera 
that we must look for those familiar bivalves, the 
Mussel, or, as it is sometimes spelled, Muscle, and 
the Cockle; the former, called in scientific language 
Mytilus, which in Latin means simply a shell-fish ; 
and the latter Cardiwm, which may have reference 
to the hinge of this bivalve, or the heart-shape 
assumed by several of the species ; cardo, in Latin, 
signifying the hinge of a gate, and cardesco, a stone 
in the shape of a heart. 
It is to the Mytilide family that we shall first 
direct our attention; and here we find the Com- 
mon or Hdible Mussel (M. edule), and many other 
species, in all of which the shell is more or less 
elongated or lengthened out, and pointed at one 
end. The members of this family are abundant 
on most rocky coasts, where facilities are afforded 
for the mollusks to moor themselves to rocks, 
stones, and other substances covered at high-water, 
but left dry by the retreating tide. They are not, 
however, confined to shores of this description, but 
are sometimes found in vast numbers on low sandy 
or pebbly flats, which run far out into the sea; these 
are called beds of Mussels, and are, like the Oyster 
