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 spherical, 30 μm in diam., axopodia up to μm long,
x 640, Iruma river, Sayama city, Saitama Pref., Japan, January 25, 2004 by Y. Tsukii
94 μm; x 640