An animal phylum synonymous with Ectoprocta that contains approximately 5,000 living species. They are all sessile colonial forms composed of zooids. Zooids are tubular, oval or box-like structures that contain a lophophore, which is a circular or horseshoe-shaped fold of the body wall that encircles the mouth and bears numerous ciliated tentacles. Most species form erect or encrusting colonies. They occur in many different habitats, including coral reefs.