Athenaria (Abasilaria) with elongate, cylindrical body, divisible into physa, scapus and capitulum. Physa rounded but may be flattened. Scapus sometimes with cinclides. Sphincter mesogloeal, long, usually very strong. Mesenteries more or less distinctly divisible into macro- and microcnemes. Not more than 6 pairs of perfect mesenteries, which are fertile and have well developed filaments, strong retractors and acontia. Acontia with basitrichs and microbasic amastigophors.
Definitions and contained taxa are those of Oscar Carlgren as published in 1949 : Kungl Svenska Vetenskapsakadamiens Handlingar, Series 4, Volume 1, Number 1
Electronic version made possible by NSF grant DEB95-21819 in the PEET program to D. G. Fautin.