Class Conjugatophyceae Engl. (1892) see Class Zygnematophyceae Round ex Guiry (2013) Order Zygnematales - filamentous conjugates and saccoderm desmids Family Zygnemataceae (Meneghini) Kützing (1843) Genus Spirogyra Link (1820), nom. cons. 1 Spirogyra porticalis (O.F.Müll.) Cleve 2 Spirogyra mirabilis (Hassall) Kützing