Family: Oral area subapical, ovoid, flattened, along ventral margin of laterally compressed body; both side ciliated (Illustrated Guide, 1985).
Genus: Ventral side with a hyaline border, reaching posterior end and bearing trichocysts; dorsal side with either similar trichocyst-border or with trichocyst-warts (Kudo, 1966).
Species: a very common species; elongate; 160 μm long; with a neck region and rounded tail; highly contractile; two ovoid macronuclei; a single contractile vacuole (Carey, 1992).