Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919) Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Subclass Biddulphiophycidae Round & R.M. Crawford (1990) see Class Mediophyceae Medlin & Kaczmarska (2004) Order Hemiaulales Round & R.M. Crawford (1990) Family Bellerocheaceae R.M. Crawford (1990) 1 Genus Bellerocheaᵀ Van Heurck (1885) 2 Genus Subsilicea Stosch & Reimann (1970)