Genus Pessonella Pussard, 1973
Diagnosis: Locomotive form flattened and broadly lingulate or fan-shaped. Anterior margin clear with many cone-like bosses on hyaloplasm. Floating form with blunt, cylindrical, and frequently bent pseudopodia. No posterior uroid. Cytoplasm finely granular without crystals. Nucleus spherical with 3 to 5 parietal nucleolar pieces. Reported from freshwater and compost.
Monospecific.
Type species: Pessonella marginata Pussard, 1973