Genus: Colonial; cells arranged pyramidately, each bearing spiny projections.
Species:
Errerella sp. (or Micractinium ),
cell body μm long, μm wide, each bearing two spiny projections ?,
x 640, Kanokawa-numa (pond), Iwajuku, Kasakake town, Gunma Pref., Japan, October 2001 by Y. Tsukii
31 μm
63 μm
94 μm; x 640