Examples from the Web for equivalve
The shells are equivalve, and devoid of bright colors or striking sculptural features.
Shell transverse, equivalve, not affixed, the tops decorticated.
A bivalve is said to be equivalve when the two shells composing it are of the same size, inequivalve when they are not.Sea-Weeds, Shells and Fossils|Peter Gray
The shells are porcelanous and translucent, equivalve, with an external ligament, and at least two cardinal teeth in each valve.
Shell bivalve, equivalve, very transversely elongated, open at both ends.