Closterium costatum var. westii Cushman, 
abnormality caused by prolonged culture with KCM & Hyponex (?), 
cell body 174 μm long, 31 μm wide, L/W=5.6, 
x 400, x 640, near Imori pond, Myoko-kogen (Myoko highland), Myoko village, Niigata Pref., Japan, November 7, 2004 by Y. Tsukii
 
 31 μm
 63 μm
 94 μm; x 640