Kingdom Protoctista Hogg, 1860
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
     Class Bacillariophyceae Haeckel (1878) - pennates
       Subclass Bacillariophycidae D.G.Mann (1990) - raphid diatoms
         Order Cymbellales D.G.Mann (1990)
           Family Gomphonemataceae Kütz. (1844)
             1 Genus Gomphonema Ehrenb. (1832)
             2 Genus Gomphoneis Cleve (1894)
             3 Genus Didymosphenia Mart. Schmidt (1899)