Species [ var. pseudoexiguum ]: Cell body small, L/W=2 or more, with deep constriction;
semicells nearly rectangle in shape; apex and lateral margins slightly convexed;
18-25 μm long, 10-13.6 μm wide, isthmus 2-4 μm wide.
[ var. retusum Hirano ] Semicells trapezoid in shape; lateral margins nearly straight, narrowed toward apex; anterior half of the margins slanted and slightly concaved; 22-23 μm long, 12-13 μm wide, isthmus 3.4 μm wide. [ var. hexagonum Grönblad ] Semicells hexagonal in shape, broadened toward apex; 18-19.6 μm long, 10.7-12.6 μm wide, isthmus 3-4.3 μm wide. |
31 μm
63 μm
94 μm; x 640
Images of collecting locality:
a pond near the entrance of climbing route to Omine mountain, Minakami town, Gunma Pref., Japan, October 21, 2007 by Y. Tsukii
