Kingdom Protoctista Hogg, 1860 Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844) Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Subclass Rhizosoleniophycidae Round & R.M. Crawford (1990) Order Rhizosoleniales P.C.Silva (1962) Family Rhizosoleniaceae De Toni (1890) Genus Rhizosolenia Brightw. (1858)