Species: Cell body spherical, 20-30 μm diam.;
cellwall thin; papilla absent; a single cup-shaped chloroplast with many (5-12-20) pyrenoids; a nucleus central;
a sitgma located anteriorly near center; two contractile vacoule at the base of flagella
(An illustrated guide to freshwater zooplankton in Japan, 2000).
Cell body ellipsoidal, posterior half slightly wider than anterior, sometimes laterally asymmetrical, 16-27 μm long, 6-23 μm wide; conical papilla present; chloroplast with several pyrenoids; stigma small, located near anterior end; (Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).