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 Naviculales Bessey (1907) Suborder Naviculineae (Bessey) Hendey (1937) Family Naviculaceae Kütz. (1844) Genus Seminavis D.G.Mann (1990) 1 Seminavis gracilenta (Grunow ex A.Schmidt) D.G.Mann (1990) 2 ?Seminavis cymbelloides (Grunow) D.G.Mann (1990)