Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919) Subdivision Coscinodiscophytina Medlin & Kaczmarska (2004) [monotypic] see Subphylum Coscinodiscophytina Medlin & Kaczmarska (2004) Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Order Melosirales R.M. Crawford (1990)