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 21 μm long, 10 μm wide, L/W=2.1,
x 640, a small pond near Yoshino park, Mitsukaido city, Ibaraki Pref., Japan, January 24, 2006 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
a small pond near Yoshino park, Mitsukaido city, Ibaraki Pref., Japan, January 24, 2006 by Y. Tsukii