Epicone (or epitheca) consists of 10-16 thecal plates;
hypocone (or hypotheca) of 6-7 thecal plates
(Illustrations of The Japanese Fresh-water Algae, 1977).
(An Illustrated Guide to the Freshwater Zooplankton in Japan, 2000).
Gymnodinium ordinatum Skuya, 1939,
cell body 17 μm long, 13 μm wide,
x 640, Akigase Park, Saitama city, Saitama Pref., Japan, March 2002 by Y. Tsukii
94 μm; x 640