Genus: Small, oval, compressed, anterior end obliquely truncate; without chloroplasts; with two equal or subequal anterior flagella; colorless; contractile vacuole anterior (Kudo, 1966). Species: Cell body 15-25 μm long, 10-15 μm wide (Kudo, 1966). 15-30 μm long; body nearly oval; no chloroplasts; reservoir-pocket distinct, surrounded by ring of bright-appearing granules; stored carbohydrates stain red with iodine; stagnant water or infusion (How to know the protozoa, 1979).