The Collaborative International Dictionary
paw shell
Tridacna \Tri*dac"na\, n. [L., pl., a kind of oysters, fr. Gr. ? eaten at three bites, ? tri- + ? to bite.] (Zo["o]l.) A genus of very large marine bivalve shells found on the coral reefs of the Indian and Pacific Oceans. One species ( Tridacna gigas) often weighs four or five hundred pounds, and is sometimes used for baptismal fonts. Called also paw shell, and fountain shell.