Athenaria with flattened base. Sphincter mesogloeal. Mesenteries divisible into macro- and microcnemes. Retractors of macrocnemes very strong, circumscribed. Acontia present containing only basitrichs.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1