Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919) Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Subclass Chaetocerotophycidae Round & R.M. Crawford (1990) see Class Mediophyceae Medlin & Kaczmarska (2004) ?Order Leptocylindrales Round & R.M. Crawford (1990) Family Leptocylindraceae M. Lebour (1930) Genus Leptocylindrus Cleve (1889)