​MOLLUSCOIDA, a name long employed to denote a division of the animal kingdom which contained Brachiopods (q.v.), Polyzoa (q.v.), and Tunicata (q.v.), the members of the three groups having been supposed to resemble the Mollusca. As it is now known that these groups have no relation to molluscs, and very little to one another, the name Molluscoida has been abandoned.