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Gamophyceae: Zygnematales: Desmidiaceae

Cosmarium westii
Bernard
= Actinotaenium westii Bernard

Cosmarium westii Genus: Unicellular; variable in shape; a constriction at the center of the cell body; mostly longer than wide; flattened; each semicell hemispherical, spherical, ellipsoidal, rectangular, pyramidal or kidney-shaped; no apical indentation.
Subgenus [ Dysphinctium ]: Cell body cylindrical or dumbbell-shaped, dorso-ventrally not compressed, transverse section circular .
Section [ Actinotaenium ]: Cell body cylindrical, slightly constricted at the center, cell surface smooth or dotted or punctated (Illustrations of The Japanese Fresh-water Algae, 1977).

Species: Cell body cylindrical ellipsoid, slightly constricted at the center, 60-(68-76)-79 μm long, 40-(43-54) μ wide, isthmus 38-(41-52) μm wide; semicells semi-elliptical, slightly flattened at the apex, with 2 pyrenoids (Illustrations of The Japanese Fresh-water Algae, 1977).


Cosmarium westii Bernard ?, cell body 71 μm long, 40 μm wide, isthmus 35 μm wide, semicells with a single pyrenoid (or side view ?), x 640, Hasukawara-shinmachi, Tsuchiura city, Ibaraki Pref., Japan, July 2003 by Y. Tsukii
scale 31 μm scale 63 μm scale 94 μm; x 640
Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium


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