190 WISCONSIN PHYTOPLANKTON 



PLATE 73. 



All figures x 500. 



Page 



Figs. 1-2. Staurastrum paradoxum Meyen 85 



Figs. 3-6. Staurastrum paradoxum var. longipes Nordst 86 



Figs. 7-15. Staurastrum, paradoxum var. parvum W. West 87 



Figs. 16-18. Staurastrum gracile Ralfs 88 



