pterobranchia

from The Century Dictionary.

• In J. E. Gray's classification (1821), one of two orders of pteropods (the other being Dactyliobranchia): Same as Gymnosomata.
• In Lankester's classification of molluscoids, the second section of the third class of a phylum Podaxonia, composed of two genera, Rhabdopleura and Cephalodiscus: called by others Podostomata and Aspidophora.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) An order of marine Bryozoa, having a bilobed lophophore and an axial cord. The genus Rhabdopleura is the type. Called also Podostomata. See rhabdopleura.