Genus: Free-living; skeleton with or without coat; cuirass made of scales and of the basal part of the spicules; coat indistinguishable (Illustrated Guide, 1985). Siliceous scales arranged tangentially and radiating siliceous spines with pointed or bifurcated ends; (Kudo, 1966). Species:

50 μm 100 μm 150 μm; x 400

Images of collecting locality: No.8, Karakemi marsh, Yasaka, Omachi city (formerly Yasaka village), Nagano Pref., Japan, June 1, 2008 by Y. Tsukii