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 obolus Pochmann,
cell body 45 μm long (including tail), 23.5 μm wide, L/W=1.9,
x 640, damp area at Kitamoto nature observation park, Kitamoto city, Saitama Pref., January 29, 2006 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
damp area at Kitamoto nature observation park, Kitamoto city, Saitama Pref., January 29, 2006 by Y. Tsukii