Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919) Class Fragilariophyceae Round (1990) - araphid, pennate diatoms see Class Bacillariophyceae Haeckel (1878) Subclass Fragilariophycidae Round (1990) - core araphid diatoms Order Rhaphoneidales Round (1990) Family Psammodiscaceae Round & D.G.Mann (1990) 1 Genus Psammodiscusᵀ Round & D.G.Mann (1980)