Boloceroidaria, the column of which has longitudinal muscles at least in its upper part, but is devoid of spirocysts. Margin tentaculate. No sphincter. Tentacles not deciduous, atypically arranged, without sphincters at their bases. Longitudinal muscles of tentacles and radial muscles of oral disc ectodermal. Weak siphonoglyphs. More than 6 pairs of perfect mesenteries. No differentiation into macro- and microcnemes. 6 first pairs of mesenteries usually sterile. Muscles of mesenteries weak. Origin of the youngest mesenteries and tentacles diverging from the usual type.
Definitions and contained taxa are those of Oscar Carlgren
as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series
4, Volume 1, Number 1