Rhizamoeba polyura Page, 1972

Diagnosis: Length of limax form approximately 25—135 (mean 72) µm; L/B ratio c. 4.3; nucleus rounded, spindle- or comet-shaped, greatest dimension on fixed preparation 4.9—13.7 (mean 7.5) µm; majority uninucleate, many with two nuclei, rarely 16 or more.

Ecology: Marin.

Geographical distribution: Western North Atlantic.