Genus: Postoral kineties usually to left of oral poykinetids (Illustrated Guide, 1985).
Left edge is more curved than right edge; cytopharynx with numerous strong fibrils; ectoplasm with
numerous fusiform trichocysts; macronucleus oval; one to several micronulei (Kudo, 1966).
Species: 150-600 μm long; ventrally flattened; dark colored; buccal cavity close to anterior end (How to know the protozoa, 1979). Elongate 150-600 μm long; anterior is not wider than posterior; cytostome small with well defined pre- and postoral suture; a large macronucleus with three micronuclei; single contractile vacuole with 12 radiating canals; many trichocysts (Carey, 1992). Cell body 150-600 μm long (Kahl, 1930).
Frontonia leucas, stock Cos-2, stained with Azure C,
cell body μm long, μm wide,
x 640, Omachi-shizen-koen (park), Ichikawa, Chiba, 2001 by Y. Tsukii
16 μm 32 μm 63 μm; x 640