Domain Bacteria Woese et al. 1990 Phylum Cyanobacteria (ex Stanier 1974) Cavalier-Smith 2002 - cyanobacteria Class "Cyanobacteria" Cavalier-Smith, 2002 Subsection IV Subgroup II see Family II Form genus Calothrix C.Agardh ex É. Bornet & C. Flahault 1886 [ICBN] Form genus Rivularia C.Agardh ex É. Bornet & C. Flahault (1886) Form genus Tolypothrix F.T. Kützing ex É. Bornet & C. Flahault 1886-1888[1887] [ICBN]