holobranchia

Century Dictionary and Cyclopedia

1. A group of fishes.
2. In J. E. Gray's classification (1821), one of three orders of Saccophora or ascidians, distinguished from Tomobranchia and from Diphyllobranchia.
3. A subclass of the Bryozoa, characterized by having the lophophore unbroken and either circular or horseshoe-shaped.