Genus : Corals have a range of different forms including those that are massive, meandering, columnar, leaf-like, and plate-like. A single species may vary in form according to the current, wave action, lighting conditions, and depth of its location. having no walls to the corallites, but having clearly delineated septocostae that connect each corallite to its neighbours, giving a flower-like pattern on the surface of the coral. The corallites themselves are shallow depressions with central columella and may be separated by ridges. The polyps are only extended at night. The foliose and plate-like forms tend to be two-sided