Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013) Order Zygnematales - filamentous conjugates and saccoderm desmids Family Mesotaeniaceae Genus Cylindrocystis Meneghini ex de Bary (1858) 1 Cylindrocystis brebissonii (Meneghini ex Ralfs) de Bary 2 Cylindrocystis crassa de Bary