Genus: 
 
(Illustrations of The Japanese Fresh-water Algae, 1977). 
Species: (Illustrations of The Japanese Fresh-water Algae, 1977).  | 
Sorastrum spinulosum Nägeli var. spinulosum, 
colony 25 μm wide, 
cell body 8 μm long, 12 μm wide (including spines), spines about 2 μm long, 
x 640, Ikenokochi (or Ikenokouchi) marsh, Tsuruga city, Fukui Pref., Japan, September 11, 2004 by Y. Tsukii