Body elongate, aboral end physa-like or forming a physa sometimes broadly adherent in Mesacmaea. Column either smooth or with hollow or solid papillae or suckers rarely with cinclides, rarely divisible into physa, scapus and scapulus. No sphincter or rarely a weak or moderately developed diffuse one (in Mesacmaea and Oractis). Tentacles short, sometimes capitate, usually simple, never numerous, the inner shorter or of same length as the outer ones. A single, ventral, usually very strong siphonoglyph, which is occasionally more or less completely separated from the other part of the actinopharynx, and sometimes drawn out at its oral end into a more or less folded conchula. Perfect pairs of mesenteries varying in number, usually they are all macrocnemes, in Oractis only 8 mesenteries are perfect. Retractors usually strong.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1