Genus: Elongate, ovoid; anterior apex often curves over the peristome; non contractile (Carey, 1992). In front of cytostome a two-layered undulating membrane on right edge; contractile vacuole and cytopyge terminal; rose-colored; many species (Kudo, 1966).
Species: Pink, 115-220 μm long; peristome nearly 1/2 cell length with conspicuous undulating membrane; macronucleus multinodal with 3-7 nodes (moniliform); 6-20 micronuclei (Giese, 1973). 150-300 μm long (How to know the protozoa, 1979).