Order: No kinetidal specializations at oral region.
Family (Kahl 1926): Cytostome terminal; ciliation uniform; usually encased in a pseudochitinous lorica (Kudo, 1966).
Genus: Ovoid with caudal cilia; lorica flask-shape, ringed; cytostome with four rows of long cilia; body surface with shorter cilia; macronucleus round (Kudo, 1966). Large protruding vacuole absent (Carey, 1992).