Mastigamoeba aspera Schulze: Locomotive 150-200 μm long, 50 μm wide; during locomotin elongate and narrowed anteriorly, posterior end rounded or lobed; pseudopods slender, straight; two contractile vacuoles (Kudo, 1966).
* Mastigamoeba longifilum Stokes: 28 μm long when extended; elongate, tranparent; flagellum twice body length; pseudopods few short; contractile vacuole anterior (Kudo, 1966).
Mastigamoeba setosa (Goldschmidt): Up to 140 μm long (Kudo, 1966).
Mastigamoeba hylae (Frenzel): In the hind-gut of the tadpoles of frogs and toads; 80-135 μm long, 21-31 μm wide; flagellum about 10 μm (Kuod, 1966).