That course of Mollusca which includes the bivalve shells; the Lamellibranchiata. See mollusca.
In Lamarck's system of category, headless mollusks with bivalve shells: a loose synonym of Lamellibranchiata, but including the brachiopods, that are today put into another type of course.
Disencumbered for the brachiopods, the Conchifera correspond to the Acephala testacea of Cuvier, or to the Lamellibranchiata of De Blainville and modern naturalists. Also known as Conchophora, Acephala, Endocephala, Lipoccphala, and Pelecypoda.
In Gegenbaur's system of category, 1 of 2 primary divisions associated with Mollusca; the Mollusca of authors overall, exclusive of Placophora or chitons.