Plate IX ; Figures 6i to 71 ; Fig. 68 Magnified 500 Diam- 

 eters ; ALL OTHERS IOOO DlAMETERS. 



Figs. 61-63. Pediastriim Ehrenbergii A. Br. . page 38 

 Fig. 64. " " var. 



truncatiim Braun .... " " 



Fig. 65. Pcdiastrum sp. ( ?) . . . . " " 



Fig. 66. pcrtusum Kiitz. . . " " 

 Fig. 67. Boryanum (Turp.) Meneg. 



var. granulatum Kiitz. . . " " 



Fig. 68. Pediastrum pcrtusum Kiitz. . . " 



Fig. 69. " tetras Ehrb. ... " " 



Figs. 70, 71. " pcrtusum Kiitz. . . " 



