Body outline elliptical, left margin sometimes slightly concave, caved in region of caudal cirri. Usually 2 macronuclei, 2-4 micronuclei. Contractile vacuole in posterior 1/3 on right. Five to six frontal, 2 pretransverse, 4-5 transverse, 1-3 left marginal cirri. Five to six dorsal kineties often composed of about 6-10 cilia each, in some populations interrupted in mid-body; 3 strong caudal cirri. Adoral zone of membranelles extending over about 1/2 of body length, composed of 30-37 membranelles. Movement moderately rapid. Size 50-120 x 30-70 µm.
Ref.: Kahl (1932), Curds and Wu (1983), Dragesco and Dragesco-Kernéis (1986), Hill and Borror (1992), Petz et al. (1995a), Song and Packroff (1997).