Plate XXIV ; Figures 160 to 165 ; Magnified iooo Diam- 

 eters, Except Fig. 161. 



Fig. 160. Closterium Jenneri Ralfs. . . page 61 

 Fig. 161. areolatum Wood (500 



diameters) ..... 



Fig. 162. Closterium Diaiuc Ehrb. . 

 Figs. 163, 164. Closterium parvulum Nag. 

 Fig. 165. Closterium moniliferum (Bory) Ehrb 



. . .. 



