Actinomonas vernalis A. C. Stokes

Cells subspherical, the frontal border slightly emarginate, somewhat changeable in shape, free-swimming or temporarily attached by a short pedicel; flagellum active throughout its length. The flagellum equals or somewhat exceeds the diameter of the body in length; cytoplasm transparent, slightly granular; pseudopodia few in number, radiating from any part of the periphery, simple or variously branched, often capitate, sometimes curved, their length exceeding the diameter of the body; several small contractile vacuoles distributed near the periphery; nucleus spherical, subcentral. Diameter of body 16.9-21.2 microns.