Family: Usually polypodial, pseudopods granular, cylindroid.
Genus (Linnaeus, 1858), emend King & Jahn, 1948: Pseudopods ridged; multinucleate (Illustrated Guide, 1985).
Species: Polypodal, 1000-2000 μm; monopodal, 1000-5000 μm long; pseudopods, cylindroid, ridged, clear caps; uroid, morulate; ectoplasm clear, distinct; endoplasm granular; nuclei, multinucleate, 1000 or more, each a circular or ellipsoid disc, 18-30 μm diam., 11-12 μm thick; cysts rare, round, 300-600 μm; division by plasmotomy; synchronous mitosis of nuclei; Paramedium caudatum adequate food (Illustrated Guide, 1985).