Foissner and Foissner, 1988
Cytostome apical, round or slit-like, in suborder Didiniina on top of cone-like proboscis; rhabdos made of three microtubular components: transverse ribbons originating from the nonciliated basal bodies of the oral dikinetids, nematodesmal bundles originating exclusively from the same source, and bulge microtubules. Somatic ciliation uniform or limited to dense bands which, however, rest within longitudinally running kineties composed of nonciliated basal bodies; dorsal brush composed of two to many kineties. Toxicysts localized, typically in or near oral area. Free-living.
Suborder Spathidiina
Family Trachelophyllidae
Family Homalozoonidae
Suborder Didiniina
Family Didiniidae