Genus: Pseudostome lacks lobed collar; test round or oval in cross-section; pseudostome relatively large, with or lacking a collar (Illustrated Guide, 1985). Species: Test ovoid to subspherical; aperture terminal; with three to six lobes; diameter 80-120 μm (Kudo, 1966). 90-170 μm long; 70-160 μm diam.; test, ovoid, round in cross-section; pseudostome terminal, usually quadrilobate, 30-50 μm diam. (Illustrated Guide, 1985). QuickTime Movies http://protist.i.hosei.ac.jp/

50 μm 100 μm 150 μm; x 400