1210 
Wisconsin Academy of Sciences, Arts and Letters . 
EXPLANATION OF PLATE LXXXYI. 
Pediastrum Boryanum 
Figs. 20, 23-26, 31-35, are magnified 750 X; Figs. 21, 37 and 38, 1650 X; 
Figs. 18, 19, and 22, 2000 X. 
Figs. 18, 19, 21, 22, 31-38. Colonies one month old, from cultures 
grown in 0.1% Knop’s solution. 
Figs. 20, 23-26. Colonies two months old, from cultures grown on 
agar slants containing 0.1% Knop’s solution. 
Pediastrum tetras 
Figs. 27-30. Colonies as occurring in nature. The magnification in 
Fig. 27 is 750 X, the rest 2000 X. 
