Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919) Class Bacillariophyceae Haeckel (1878) - pennates Subclass Bacillariophycidae D.G.Mann (1990) - raphid diatoms Order Achnanthales P.C.Silva (1962) Family Achnanthaceae Kütz. (1844) Genus Achnanthesᵀ Bory (1822)