Family PLEURONEMATIDAE Kent, 1881

For	Aphthoniidae

With characters of suborder s.s. (above); dominating feature is the paroral membrane, sometimes present as a stiff velum and distinctly curling around the subequatorial cystome; multifragmented paroral (segment "b") in one species; long, stiff caudal cilia; some species possibly have trichocysts?; in fresh-water and (especially) marine habitats, occasionally associated with some invertebrate as an ectocommensal (e.g., Pleurocoptes on hydractinian coelenterates).

Pleurocoptes Wallengren 1896. Single species.
Pleuronema Dujardin, 1836. Many species.
Schizocalyptra Dragesco, 1968. Single species.
Incertae sedis:
Hippocomos Czapik & Jordan, 1977. Single species.