Athenaria (Abasilaria) with elongate body and rounded or rarely flattened aboral end. Column smooth or provided with suckers, or warts forming nematocyst batteries, without tenaculi. No distinct sphincter. 6 pairs of fertile, filamented macrocnemes which have strong restricted to circumscribed retractors. A variable number of microcnemes which are sterile and devoid of filaments but that those of the second cycle are occasionally fertile and filamented. Acontia present.
I prefer to use Haliactiidae instead of Halcampactiidae as the genus Halcampactis is imperfectly known.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1