Bryozoans in this family form encrusting, unilaminar to multilaminar colonies, typically domed, mamillate or nodular; or erect, branching, often massive colonies. Frontal shield of autozooid cryptocystidean, typically smoothly calcified, often thick, with marginal pores and occasionally also with central pseudopores. Primary orifice proximally concave, or with a well marked sinus; condyles distinct; oral spines present or absent. Peristome absent to well developed, usually with one or more columnar, suboral or lateral suboral avicularia. Polymorphic adventitious and vicarious avicularia typical. Ovicell formed by maternal zooid or distal autozooid, with imperforate entooecium, forming a frontal tabula if exposed, ectooecium incompletely calcified; not closed by autozooid operculum. Small basal pore chambers present.