Genus (Aragoa): Cell body ovoid or pyriform with conical or pointed posterior end; 4 equal-length flagella inserted at the base of a papilla; cells colorless; eyspot present or absent; 1-layered cysts common; 2 anterior contractile vacuoles; cell division by longitudinal fission; sexual reproduction isogamous to form a 4-flagellate zygote (Illustrated Guide, 1985). Species: Cell body narrowly egg-shaped; a small papilla present; no eyespot (John et al. 2002).

50 μm 100 μm 150 μm; x 400

* Polytomella caeca Pringsheim, 1937: Cell body conical or elongated ovoid, tapered at posterior; four anterior flagella; cell wall not contain cellulose; 2 contractile vacuole at the base of flagella; no chloroplasts; no stigma; 17-20 x 9-12 μm; fresh water (Inoki ed., 1981).

Polytomella agilis Doflein: 8-18 μm long; cell body ovoid, not tapered at posterior; with stigma; fresh water (How to know the protozoa, 1979).