Division Bacillariophyta Engl. & Gilg (1919) see Phylum Bacillariophyta Engl. & Gilg (1919)
   Subdivision Coscinodiscophytina Medlin & Kaczmarska (2004) [monotypic] see Subphylum Coscinodiscophytina Medlin & Kaczmarska (2004)
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
       01 Order Coscinodiscales Round & R.M. Crawford (1990)
       02 Order Corethrales Round & R.M. Crawford (1990)
       03 Order Rhizosoleniales P.C.Silva (1962)
       04 Order Melosirales R.M. Crawford (1990)
       05 Order Orthoseirales R.M. Crawford (1990)
       06 Order Aulacoseirales R.M. Crawford (1990)
       07 Order Chrysanthemodiscales Round (1990)
       08 Order Stictocyclales Round (1990)
       09 Order Asterolamprales Round & R.M. Crawford (1990)
       10 Order Arachnoidiscales Round (1990)
       11 Order Stictodiscales Round & R.M. Crawford (1990)
       12 Order Ethmodiscales Round (1990)
       13 Order Leptocylindrales Round & R.M. Crawford (1990)