Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013)
   Order Zygnematales - filamentous conjugates and saccoderm desmids
     Family Mesotaeniaceae
       01 Genus Ancylonema Berggr. (1871) [monotypic]
       02 Genus Cylindrocystis Meneghini ex de Bary (1858)
       03 Genus Geniculus Prescott (1967) [monotypic]
       04 Genus Mesotaenium Nägeli (1849)
       05 Genus Netrium (Nägeli) Itzigs. & Rothe (1856)
       06 Genus Nucleotaenium A.A. Gontcharov & M. Melkonian (2010)
       07 Genus Planotaenium (Ohtani) Petlovany & Palamar-Mordvintseva (2009)
       08 Genus Roya West & G.S.West (1896)
       09 Genus Spirotaenia Bréb. ex Ralfs (1848)
       10 Genus Tortitaenia (Brook) Brook