Thenaria (Endomyaria) with well developed pedal disc. Column usually with verrucae. Sphincter diffuse to circumscribed, usually not very strong. Tentacles short, wart-like or longer, never very long. From all or some of the endocoels the tentacles arise in radial series; sometimes there is more than one row per endocoel, sometimes only one; rarely the radial arrangement is indistinct or absent. Only one tentacle communicates with each exocoel. Longitudinal muscles of tentacles and radial muscles of oral disc ectodermal. Pairs of perfect mesenteries numerous, all the stronger ones, with or without the directives, fertile. Retractors weaker or stronger, always diffuse. Cnidom: spirocysts, basitrichs, microbasic p-mastigophors.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1