Astrocoeniidae Koby, 1890: small corallites; simple trabeculae; reduced coenosteum; beaded septal margins.
Pocilloporidae Gray, 1842: small corallites; simple trabeculae; nonporous coenosteum.
Acroporidae Verrill, 1902: small corallites; simple trabeculae; extensive porous, reticulate coenosteum. Agariciidae Gray, 1847: corals with confluent septa comprised of closely packed simple trabeculae and united by synapticulae. Siderastreidae Vaughan and Wells, 1943: fenestrate septa; synapticulothecal. Poritidae Gray, 1842: porous septa; well-defined calices; reduced coenosteum. Faviidae Gregory, 1900: strongly dentate margins and rare synapticulae. Trachyphylliidae Verrill, 1901: dentate septa; inner fan of trabeculae forming prominent lobes. Meandrinidae Gray, 1847: fine septal dentations; lamellar columella; solid coenosteum; invariably intramural budding. Oculinidae Gray, 1847: fine septal dentations; vesicular or solid coenosteum; extramural budding (only massive, exclusively hermatypic taxa included). Mussidae Ortmann, 1890: solitary or colonial with large coarse septal dentition. Caryophylliidae Gray, 1847: costae covered by epitheca; exsert, subequal septa.