Plate 47 



Fig. 1. Hydrodictyon reticulatum (L. ) Lagerheim, x 75 



Fig. 2. Euastropsis Richteri (Schmidle) Lagerheim, x 1000 



( after Smith ) 



Fig. 3. Pediastrum araneosum var. rugulosum (G. S. West) G. 



M. Smith, X 590 



Fig. 4. Pediastrum araneosum ( Racib. ) G. M. Smith, x 590 

 (Reticulations on walls not shown.) 



Figs. 5, 6. Pediastrum biradiatum Meyen: 5, x 600; 6, x 300 



Figs. 7, 8. Pediastrum biradiatum var. emarginatum fa. convexum 

 Prescott, X 750 



Fig. 9. Pediastrum boryanum (Turp. ) Meneghini, x 750 



Fig. 10. Pediastrum boryanum var. longicorne Raciborski, x 590 



[754 



