Frontal wall extensive, calcified, rugose and perforate by pseudopores which serve as opesiules. Operculum calcified and thick. Heterozooidal gynozooids may be present. Ovicell subimmersed usually recumbent, the zooid it overlies being restricted, in many cases having no room to develop either a polypide, or orifice and operculum and thus is a kenozooid. Avicularia may exist, similar in size and aspect to an autozooid, but differing in their orifices that are roughly square or rectangular in shape, usually with external denticles in their distal edge and acute teeth directed downwards, not visible when the orifice is closed.
Oral spines present either in the avicularia, the autozooids, or both.
If both zooidal types have oral spines, those of the avicularia are usually longer and thicker. Avicularia with oral spines have always one spine more than the mandibles have denticles. A cryptocystal operculum and a new method of lophophore protrusion in the cheilostome bryozoan Macropora levinseni .