Family: Colonies consisting of a fixed number of cells (Illustrations of The Japanese Fresh-water Algae, 1977).
Genus: Colonies composed of 16, 32, 64 or 128 (mostly 32) cells; 2-layered gelatinous envelope; mamillations anterior or posterior; cells spherical to ovoid with 2 equal-length apical flagella; eyespot present; anisogamy (Illustrated Guide, 1985).

E. elegans or E. cylindrica ? 2 clips Japan, 1999	E. elegans or E. cylindrica ? 3 clips Japan, 1999	E. elegans or E. cylindrica ? 1 clip Japan, 1999
E. elegans 3 clips Saitama, 1999