Genus: Outer envelop made of two kinds of siliceous element; tangential scales or pearls and radial
spicules (Illustrated Guide, 1985).
Similar genus ->> Nuclearia; Rabdiophrys sp. ?,
cell body 19 μm in diam., axoneme μm long,
x 640, riverside at Tokachi river (Tokachi-gawa park), Obihiro city, Hokkaido, Japan, October 13, 2005 by Y. Tsukii
94 μm; x 640