Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919)
   Class Fragilariophyceae Round (1990) - araphid, pennate diatoms see Class Bacillariophyceae Haeckel (1878)
     Subclass Fragilariophycidae Round (1990) - core araphid diatoms
       Order Fragilariales P.C.Silva (1962)
         Family Fragilariaceae Grev. (1833)
           Genus Podocystis Bailey (1854)