Cylindrical Halcampidae with the body divisible into physa, scapus and capitulum. Scapus long, with tenaculi to which grains of sand are often attached. Capitulum in the sphincter region, with spirocysts and longitudinal muscles. A single very small mesogloeal sphincter extending into the bases of tentacles. Tentacles short, 8-12. No distinct siphonoglyphs. 8-12 perfect mesenteries, 2 pairs of directives. A second more or less complete cycle of imperfect mesenteries present. Perfect mesenteries fertile with filaments and strong, restricted, more or less reniform retractors. More mesenteries than tentacles. Cnidom: spirocysts, basitrichs, microbasic p-mastigophors.
Actinia crysanthellum Peach in Johnston 1847
Edwardsia duodecimcirrata Sars 1851
H. arctica Carlgren 1893
?H. vegae Carlgren 1921
H. octocirrata Carlgren 1927
H. capensis Carlgren 1938
Definitions and contained taxa are those of Oscar Carlgren
as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series
4, Volume 1, Number 1