Hormathiidae with well developed base often elongated in the transversal axis, often attached to gorgonians, sponges or worm-tubes. Column rather low, smooth or with longitudinal rows of mesogloeal papillae in its distal part. Cinclides, if present, few, occurring only over the directive chambers. Sphincter well developed, mesogloeal. Tentacles possibly more numerous than the mesenteries at the base, or of the same number; fairly short, with or without mesogloeal thickenings at the base on their outer sides. Longitudinal muscles of tentacles ectodermal. Radial muscles of oral disc ectodermal to ecto-mesogloeal. 2 distinct siphonoglyphs. Perfect pairs of mesenteries 6-12. Retractors and parietobasilar muscles weak. Gonads on all stronger mesenteries except possibly the directives. Acontia few or perhaps sometimes absent. Cnidom: spirocysts, basitrichs, microbasic p-mastigophors.
Actinauge nexilis Verrill 1883
Sagartia acanellae Verrill 1883
Sagartia spongicola Verrill 1883
S. bulbosa Carlgren 1928
Stephanactis tuberculata Hertwig 1882
S. annularis Carlgren 1936
?Stephanactis hyalonematis Mc Murrich [sic] 1893
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1