Some with suctorial tentacles. Usually ectoparasites of marine crustaceans. Foettingeria, Traumatiophyra, Cyrtocaryum, Hyalophysa, Phtorophysa. Parasites or commensals of oligochaetes. Reproduction by terminal budding.
Daughter cells can remain connected to mother cell and form a chain.
Anoplophrya, Kofoidella, Herpetophrya, Butschliella, Haptophrya, Steinella, Sieboldiella, Intoshellina, Mesnilella, Opalinopsis, Chromidina. Myonemes involved in stalk contraction. Reproduction by longitudinal fission. This class has 2 orders. Vorticella, Charchesium, Zoothamnium, Epistylis, Scyphidia, Ophrydium, Astylozoon, Vaginocola, Lagenophrys.