Family ARCHIASTOMATIDAE Foissner, 1976

Mouthless, medium large, ovoid, with holotrichous ciliation, mucocysts, lengthy macronucleus, multiple micronuclei, and scattered contractile vacuoles; but no endoskeleton, no thigmotactic cilia, and found entirely free-living; special feature: prominent, centrally located, regularly pulsating ("contractile"?) central vacuole; taken from a eutrophic pool in the Austrian Alps.

[See Foissner (1976b); the family is provisionally accepted and placed here, but the organism remains a most puzzling one in need of further and more intensive study.]

Archiastomata Foissner, 1976. Single species.