Cell body cylindroid or spindle in shape; spiral ribbon-like chloroplasts or laminae of
the chloroplast arranged spirally around central rod
(Illustrations of The Japanese Fresh-water Algae, 1977).
Spirotaenia diplohelica Coesel,
cell body 58 μm long, 11 μm wide, L/W=5.3,
x 640, Imou bog, Toyohashi city, Aichi Pref., Japan, September 11, 2004 by Y. Tsukii
94 μm; x 640