Bryoza means "moss animals" and there are two distinct phyla, the Entoprocta consisting of about 150 species and the Ectoprocta with about 4000. Some are solitary and some colonial and the individual animals superficially resemble corals, though their body structure is quite different. Some colonies are branched and resemble seaweed but others are encrusting, forming mats on the surface of seaweeds or stones.