coralligenaIn some systems of classification, one of the primary divisions of the Actinozoa, the other being the Cenophora. The mouth always has one or more circlets of tentacles, slender and conical, or short, broad, and fimbriated. The enterocœle is divided into 6, 8, or more intermesenteric chambers communicating with cavities in the tentacles; the mesenteries are thin and membranous, each ending aborally in a free edge, often thickened and folded, looking toward the center of the axial chamber; and the outer wall of the body has no large paddle-like cilia. Most Coralligena are fixed and may give rise by gemmation to zoanthodemes of various shapes. The great majority have a hard skeleton, composed chiefly of carbonate of lime, in some of its forms known as coral, which may be deposited in spicula in the body, or form dense networks or plates of calcareous substance. The chief divisions of the Coralligena are the Hexacoralla and the Octocoralla (or Alcyonaria). The Coralligena include all the Actinozoa which form coral, and many which do not, as the sea-anemones, dead-men's-fingers, etc. Nearly all “corals” of ordinary language are hexacoralline; not, however, the red coral, with which the name is most popularly associated.
Webster's Revised Unabridged Dictionary
NL., fr. L. corallum, coral + root of gignere, to produce