8 A, 9 A), but in many Cheilostomes the frontal surface is protected by a calcareous shield, which grows from near the free edges of the vertical walls and commonly increases in thickness as the zooecium grows older by the activity of the "epitheca," a layer of living tissue outside it.
The "epitheca" noticed above is in this case the persistent frontal membrane.
(6) Epitheca, an offset of the basal plate which surrounds the base of the theca in a ring-like manner, and in some corals may take the place of a true theca.
Septa radial; dissepiments present; an epitheca surrounds the base of massive or maeandroid forms, but only surrounds individual corallites in simple or branching forms. Typical genera - Goniastraea, M.