Polychaos Schaeffer 1926

This genus includes large amoebae (up to 400 microns) with many pseudopodia that point in the direction of locomotion; cytoplasmic streaming frequently involves several pseudopodia at the same time. In his original description, Schaeffer commented that amoebae resemble a human hand with fingers spread out. Posterior often with a fascicle of pseudopodial remnants. Cytoplasm commonly with numerous bipyramidal and/or plate like crystals, some as paired bodies or clusters. Single nucleus, flexible and easily distorted but generally ovoid or cup-shaped. Nucleolar granules dispersed in nucleus or as large, lobed parietal band. Some species form cysts. Type species: P. dubium (Schaeffer, 1916).

Polychaos is an amoeboid genus in the Amoebozoa group. Several characters unite the species in this genus. The pseudopods meld at their bases when the organism is moving, and have dorsal, longitudinal ridges. The nucleus is oval or ellipsoid.