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, 25 μm in diam., axopodia up to 32 μm wide,
x 640, near Kumagaya oh-hashi (large bridge), Ara-kawa (river), Kumagaya city, Saitama Pref., Japan, February 29, 2004 by Y. Tsukii
94 μm; x 640