Genus Amoeba Bory de St. Vincent, 1822
Diagnosis: locomotive cells commonly polypodial, with several tubular pseudopodia with hemispherical tips and usually hyaline caps; one pseudopodium dominant at one time, often with ectoplasmic ridges; monopodial in rapid locomotion; nucleus single, granular in most described species; resting cells irregularly rounded, floating form with long radiating pseudopodia; cytoplasm often with truncated bipyramidal crystals; posterior uroid morulate.
Ecology: Freshwater. In all kind of water types.
Key to the species:
|1||Nucleus large, mean 40 µm, discoid, often biconcave||A. proteus|
|–||Nucleus smaller, spherical, ovoid or compressed||2|
|2||Nucleus compressed spherical, ovoid or lens-shaped, mean 29 µm; crystals mainly squared||A. borokensis|
|–||Nucleus spherical, often slightly compressed; numerous bipyramidal crystals|