Class Cyanoprokaryota Komárek & Golubić 1990 nom. nud. - cyanoprokaryotes
   Subclass Nostocophycidae Hoffmann, Komárek & Kaštovský (2005), nom. inval. [monotypic]
     Order Nostocales Borzì (1914) see Order Nostocales corrig. Borzì 1914
       Family Microchaetaceae Lemmermann (1907) see Family Rivulariaceae Frank (1886)
         Form genus Fortiea G. De Toni (1936) see Genus Fortiea De Toni 1936