Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013) Order Zygnematales - filamentous conjugates and saccoderm desmids Family Mesotaeniaceae Genus Planotaenium (Ohtani) Petlovany & Palamar-Mordvintseva (2009) Planotaenium interruptum (Bréb. ex Ralfs) Petlovany & Palamar-Mordvintseva