Kingdom Protoctista Hogg, 1860
Count: [p] 36p;91c;87o;183f;507g;35s;2v
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
  Count: [f] 4c;41o;83f;204g
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
    Count: 20o;33f;85g
       Subclass Biddulphiophycidae Round & R.M. Crawford (1990) see Class Mediophyceae Medlin & Kaczmarska (2004)
      Count: [f] 4o;4f;23g
         Order Hemiaulales Round & R.M. Crawford (1990)
        Count: [f] 1f;8g
           Family Hemiaulaceae Heib. (1863)
          Count: 8g
             1 Genus Eucampia Ehrenb. (1839)
            Count: -
             2 Genus Hemiaulus Heib. (1863)
            Count: -
             3 Genus Climacodium Grunow (1868)
            Count: -
             4 Genus Trinacria Heib. (1863)
            Count: -
             5 Genus Riedelta see Genus Riedelia Jousé & Shesh.-Por. (1971), nom. illeg.
            Count: -
             6 Genus Cerataulina H. Perag. ex F. Schütt (1896)
            Count: -
             7 Genus Pseudorutilaria Grove & Sturt (1886)
            Count: -
             8 Genus Baxteriopsis G. Karst. (1928)
            Count: -