The corallite is the part of the skeleton deposited by one polyp. The skeletal wall around each polyp is called the theca. The coral anatomy also includes calcareous plate-like structure known as septa. The septa radiate from the wall to the center of the corallite. Perforate corals have porous skeletons with connections between the polyps through the skeleton.
Imperforate corals have solid skeletons.
Many corals have different growth forms. Other growth forms include cocoid, spherical shaped and phalecoid, as in Eusmilia fastigiata .