EXPLANATIONS AND REFERENCES, 







PLATE CXLIII. 



Figures magnified 300 diameters. 



PAGE. 

 Fig. 1-3. . ZYGNEMA LEIOSPERMUM, . . . 222 



" 4-6. ZYGNEMA INSIGNE, . . . 223 



Figs. 7, 8. ZYGNEMA STELLIUM, ...... 223 



" 9, 11. " " forma Vaucheria, . . . 223 



" 12, 13. " " " tenue, . . . .223 



" 14, 15. " " subtile, . . . .223 



" 16, 17. < ll " stagnate, . . . .223 



