equivalve

A shell described by De Blainville as an equivalve, terebrating species of Anatina.

Thus a bivalve-shell, the valves of which are nearly alike, would be described as sub-equivalve.

In the former, all the shells are inequivalve; in the latter equivalve.

Shell transverse, equivalve, not affixed, the tops decorticated.

Shell bivalve, equivalve, very transversely elongated, open at both ends.