HippuriteHip"pu*rite\, n. [Gr. ? decked with a horse's tail; "i`ppos horse + ? tail: cf. F. hippurite.] (Paleon.) A fossil bivalve mollusk of the genus Hippurites, of many species, having a conical, cup-shaped under valve, with a flattish upper valve or lid. Hippurites are found only in the Cretaceous rocks.