Zygobranchia \Zyg`o*bran"chi*a\, n. pl. [NL., from Gr. zygo`n a yoke + ? a gill.] (Zool.) A division of marine gastropods in which the gills are developed on both sides of the body and the renal organs are also paired. The abalone ({Haliotis}) and the keyhole limpet ({Fissurella}) are examples. [1913 Webster]