Endocoelantheae with elongate, not lobed body. Column with little groups of nematocysts. Tentacles rather few, up to about 70 in more than two cycles, without basal swellings on their aboral side, their arrangement curious differring [sic] from the common type. A single siphonoglyph. Mesenteries divisible into macro- and microcnemes, 6 or 10 pairs of macrocnemes. Some of the microcnemes, however, perfect. Retractors of the macrocnemes rather strong, restricted.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1