Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919)
   Class Bacillariophyceae Haeckel (1878) - pennates
     Subclass Bacillariophycidae D.G.Mann (1990) - raphid diatoms
       Order Naviculales Bessey (1907)
         Suborder Neidiineae D.G.Mann (1990)
           Family Diadesmidaceae D.G.Mann (1990)
             Genus Diadesmisᵀ Kütz. (1844)
               1 Diadesmis aerophila (Krasske) D.G.Mann (1990)
               2 Diadesmis brekkaensis (J.B. Petersen) D.G.Mann (1990)
               3 Diadesmis contenta (Grunow ex Van Heurck) D.G.Mann (1990)
               4 Diadesmis laevissima (Cleve) D.G.Mann (1990)
               5 Diadesmis perpusilla (Grunow) D.G.Mann (1990)
               6 [Diadesmis confervacea] Kütz. (1844)
               7 Diadesmis gallica W.Sm. (1857)