Plate I : Figures i to 6; Au. Magnified i.ooo Diameters 

 Fig - , i 



Oscillatoria subtilissima Kutz. . 



oerugineo-ccerulea kutz. 

 Merismopedia glauca Nag. 



" convoluta I'>reb. . 



Oscillatoria limosa Ag. 



" percursa Kiitz. 



page 19 



12 



!9 



