Plate XV; Figures 90 to 95; Magnified iooo Diameters, 



except Fig. 91. 



Fig-. 90. Ulothrix. Young stage . . . page 49 



(low power) 

 Microspore! Stagnorum ( Kiitz.) Lag. 50 



Ulothrix tenerrima Kiitz. . . 49 



zonata (Web. and Mohr) 



Kiitz " 



Fig. 95. Ulothrix sp. ( ?) 



