CONTENTS 



Chapter Page 

 I. General Taxonomic Characteristics — The Order Zygnematales 



G, M. Smith 1933 3 



II. The Genus Zygnema C. A. Agardh 1824 13 



III. The Genus Zygnemopsis (Skuja) Transeau 1934 49 



IV. The Genus Hallasia Rosenvinge 1924 61 



V. The Genus Zygogonium Kiitzing 1843 63 



VI. The Genus Pleurodisciis Lagerheim 1895 71 



VII. The Genus Mougeotiopsis Palla 1894 73 



VIII. The Genus Debarya Wittrock 1872 75 



IX. The Genus Motigeotia C. A. Agardh 1824 79 



X. The Genus Temnogametum W. & G. S. West 1897 117 



XI. The Genus Sirocladium Randhawa 1941 119 



XII. The Genus Entransia Elwyn Hughes 1943 121 



XIII. The Genus Spirogyra Link 1 820 123 



XIV. The Genus Sirogonium Kiitzing 1843 231 



Index 239 



Plates 247 



