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 Triceratiales Round & R.M. Crawford (1990)
         Family Plagiogrammaceae De Toni (1890)
           1 Genus Plagiogramma Grev. (1859)
           2 Genus Glyphodesmis Grev. (1862)
           3 Genus Dimeregramma Ralfs (1861)
           4 Genus Dimeregrammopsis Ricard