Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013)
   Order Zygnematales - filamentous conjugates and saccoderm desmids
     Family Mesotaeniaceae
       Genus Roya West & G.S.West (1896)
         1 Roya obtusa (Bréb.) W.West & G.S.West
         2 Roya pseudoclosterium (Roy) W.West & G.S.West