Pterobrancllia, a group of animals closely allied to the Bryozoa (q.v.), but the exact systematic value of which is uncertain. It is, however, probably most closely associated with the Entoprocta (q.v.). Only two genera are known, and these are very different in structure and habit. The better known is Rhabdopleura, which has been dredged off the coasts of Norway and Scotland, and Cephalodiscus, which lives in the seas of Patagonia. The former occurs as branching colonies, but the latter is simple. Their affinities to the Bryozoa are shown by the possession of an epistome and the flexure of the intestine.