Zoology. An American name of a bivalve mollusc, Lutraria elliptica, the oval otter-shell.

Any of several large saltwater clams, esp. the Atlantic surf clam, Spisula solidissima, and (formerly) †the Pismo clam, Tivela stultorum (obsolete)…

any of various burrowing marine bivalve molluscs of the genus Lutraria (family Lutrariidae), with relatively thin elliptical shells.

a mollusc of the family Mactridæ.

any of several marine bivalve molluscs constituting the genus Spisula (family Mactridae) (also called triangle shell); esp. the large and edible S.…