ILLUSTRATIONS 



Plates 



Plat€ Page 



I. Reproductive Structures of Zygnemataceae 246 



II. Zygnema 248 



III. Zygnema 250 



IV. Zygnema 252 



V. Zygnema 254 



VI. Zygnema 256 



VII. Zygnema 258 



VIII. Zygnemopsis 260 



IX. Zygnemopsis 262 



X. Hallasia and Zygogonium 264 



XI. Zygogonium 266 



XII. Zygogonium, Pleurodiscus, Mougeotiopsis, and Debarya. . 268 



XIII. Mougeotia 270 



XIV. Mougeotia 272 



XV. Mougeotia 274 



XVI. Mougeotia 276 



XVII. Mougeotia 278 



XVIII. Mougeotia 280 



XIX. Mougeotia 282 



XX. Temnogametum, Sirocladium, and Entransia 284 



XXI. Spirogyra 286 



XXII. Spirogyra 288 



XXIII. Spirogyra 290 



xiii 



