Eleventh Class.—Conchifera.
Two Orders.—1st. Bimusculosa, two muscular impressions.
2nd. Unimusculosa, one muscular impression.
CONCHIFERA,
SHELL-BEARERS.
"This class," observed Mr. Elliot, "contains all the bivalves of Linnæus, and some genera taken from the univalves and multivalves.
"The animals of this class are shell-bearers or carriers, they remain constantly fixed in their habitations: the body is fastened to the shell by one or two strong muscles: when the shell is vacant we find the cicatrix. Refer to your explanation of terms, and you will find the word.