What is "dimya"

Dimya \Dim"y*a\, Dimyaria \Dim`y*a"ri*a\, n. pl. [NL., fr. Gr. ? = ? + ? to close.] (Zo["o]l.) An order of lamellibranchiate mollusks having an anterior and posterior adductor muscle, as the common clam. See Bivalve.

Dimya is a genus of very small clams, marine bivalve molluscs in the family Dimyidae.