BIVALVEn.
[L. bis, twice, and valve. L. valva]
An animal having two valves, or a shell consisting of two parts which open and shut. Also a pericarp in which the seed-case opens or splits into two parts.
BIVALVE
BIVALVULAR, BIVALVOUS, a. Having two shells or valves which open and shut, as the oyster and the seed cases of certain plants.