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 Borzinemataceae L. Geitler (1942) see Family Borzinemataceae Geitler 1942
         Form genus Seguenzaea Borzì (1907) see Genus Seguenzaea Borzì 1907