Kingdom Protoctista Hogg, 1860
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
       Subclass Chaetocerophycidae see Subclass Chaetocerotophycidae Round & R.M. Crawford (1990)
         ?Order Leptocylindrales Round & R.M. Crawford (1990)
           1 Family Leptocylindraceae M. Lebour (1930)