Alcyonaria

Alcyonaria, or Octocoralla, that division of the Anthozoa (q.v.) characterised by the possession of fringed tentacles and by having the Mesenteries or Septa arranged in multiples of eight. An account of the structure of a typical member of this order is given under Alcyonium. The Alcyonaria are always colonial, though simple ones have been described. The principal families are the Alcyonidae, Tubiporidae, Axifeea, and Pennatulidae, including the "dead men's fingers," the organ-pipe corals, the gorgonias, and the "red coral" (Corallium).