Univalve
From Biology-Online Dictionary | Biology-Online Dictionary
univalve
(Science: zoology) A shell consisting of one valve only; a mollusk whose shell is composed of a single piece, as the snails and conchs.
most univalves are spiral and are the shells of gastropods, but many belong to cephalopods and pteropods. A large number of univalves belonging to the gastropods are conical, cup-shaped, or shieldlike, as the limpets.
Origin: Uni- _ valve: cf. F. Univalve.