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 Hapalosiphonaceae Elenkin (1917), nom. cons. see Family Hapalosiphonaceae Elenkin 1917
         Form genus Matteia A. Borzì (1907) see Genus Matteia Borzì 1907