||Zyg`o*bran"chi*a (?), n. pl. [NL.,
from Gr. zygo`n a yoke + ? a gill.] (Zoöl.)
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.