Cell body broad ellipsoidal, cylindrical, or inverted ovoid, both ends rounded,
20-32 μm long, 13-27 μm wide; cellwall thick;
covered by two layers of gelatinous sheaths; papilla broad, short, rounded at corners;
length of flagella nearly the same as that of cell body; chloroplast cup-shaped, filling whole cell;
stigma rounded, at equator or slightly anterior; nucleus centrally located; two apical contractile
vacuoles at the base of flagella.
[var. subporosa (Skuja) Ettl 1993]: Cell body larger (26-28 x 25-32 μm); inner cellwall finely porous; sexual reproduction by heterogamy (Süßwasserflora von Mitteleuropa 9, Chlorophyta I, 1983).
cell body 21 μm long, 16 μm wide,
double-layered gelatinous coats about 3 μm in thickness,
x 640, Kawaguchi Natural Park, Sashima, Kawaguchi city, Saitama Pref., Japan, January 29, 2005 by Y. Tsukii