Thenaria (Mesomyaria) with well developed mesogloeal sphincter. Mesenteries divisible into macro- and microcnemes. No acontia. Retractors of mesenteries very strong, strongly restricted (reniform) to almost circumscribed.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1