Family: Oral area subapical, ovoid, flattened, anlong ventral margin of laterally compressed body; both side ciliated (Illustrated Guide, 1985).
Genus: Flask-shaped; elongate, flattened; anterior region neck-like; cilia only on right side; without trichocyst-borders; cytostome with trichocysts; two macronuclei (Kudo, 1966).
Species: Long, thin and contractile; cell body is 200 μm long with a very long and thin neck region and pointed tail; laterally compressed; two macronuclei; a large contractile vacuole with small satellites (Carey, 1992).