Suborder: Paroral dikinetid shorter than other oral structures;
no ribbed wall from paroral dikinetids towards cytostome (Illustrated Guide, 1985).
Family: Ovoid to ellipsoid, usually flattened; dense ventral cilia; oral area relatively large; ~ midventral; long,
prominent cytoproct.
Genus: Preoral suture prominent; anterior suture extends to right immediately forward of oral area
(Illustrated Guide, 1985).
Ovo-cylindroid body, dark colored; no anterior cilia; transverse ring of long cilia near
anterior end; cytostome small, near anterior ring of cilia; a long caudal cilium;
common in decaying vegetation (How to know the protozoa, 1979).
Ovoid to cylindrical; crescentic cytostome on slightly flattened area near anterior end;
a zone of cilia around body; one (or more) long caudal cilium;
cytoplasm yellowish to dark brown; macronucleus ovoid; a single contractile vacuole;
fresh or brackish water (Kudo, 1966).