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 Stigonemataceae Borzì (1892), nom. cons. see Family Stigonemataceae corrig. (Agardh ex Bornet and Flahault 1886) Borzì 1892 nom. cons.
         Form genus Homoeoptyche H. Skuja (1944) see Genus Homoeoptyche Skuja 1944