206 WISCONSIN PHYTOPLANKTON 



PLATE 81. 



All figures x 500. 



Page 



Figs. 1-2. Staurastrum aiikyroides v&r.' pentacladum var. nov 114 



Figs. 3-4. Staurastrum OpMura Lund 115 



Figs. 5-8. Staurastrum rotula Nordst 116 



