Genus: Highly flattened; pellicle firm; body form constant (Kudo, 1966).
Chloroplasts small, discoid, pyrenoids usually absent; most species flat and leaf-shaped;
often with ridges or fins running helically or longitudinally (Illustrated Guide, 1985).
Species:
Phacus skujae Skvortzov,
cell body 18 μm long, 9 μm wide, L/W=,
x 640, Ashikaga flower park, Tomita, Ashikaga city, Tochigi Pref., Japan, April 22, 2006 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
a pond at Ashikaga flower park, Tomita, Ashikaga city, Tochigi Pref., Japan, April 22, 2006 by Y. Tsukii