[Division] Thallophyta Endl. (1836)
   [Subdivision] Schizophyta
     1 [Class] Schizomycetes Nägeli (1857) see Class Schizomycetes Nägeli 1857 nom. inval.
     2 [Class] Cyanophyceæ Hauck (1885) see Class Chroococcophyceae Hollerbach et al. 1953