Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919)
Count: [*] 3c;39o
   Subdivision Bacillariophytina Medlin & Kaczmarska (2004) see Subphylum Bacillariophytina Medlin & Kaczmarska (2004)
  Count: [*] 2c;26o
     Class Mediophyceae Medlin & Kaczmarska (2004) - bipolar centrics
    Count: [*] 9o
       1 Order Chaetocerotales Round & R.M. Crawford (1990)
      Count: -
       2 Order Biddulphiales Willi Krieg. (1954)
      Count: -
       3 Order Cymatosirales Round & R.M. Crawford (1990)
      Count: -
       4 Order Thalassiosirales Glezer & I.V. Makarova (1986)
      Count: -
       5 Order Triceratiales Round & R.M. Crawford (1990)
      Count: -
       6 Order Hemiaulales Round & R.M. Crawford (1990)
      Count: -
       7 Order Lithodesmiales Round & R.M. Crawford (1990)
      Count: -
       8 Order Toxariales Round (1990)
      Count: -
       9 ?Order Ardissoneales Round (1990)
      Count: -