284 WISCONSIN PHYTOPLANKTON 



PLATE 70. 



All figures x 500. 



Page 



Figs. 1-2. Staurastrum megacanthum var. scoticum W. & G. S. West 76 



Figs. 3-5. Staurastrum BicMei var. maximum W. & G. S. West 76 



Figs. 6-7. Staurastrum connatum var. rectangulum Roy & Biss 77 



Figs. 8-9. Staurastrum quadrangulare Be Breb. forma 78 



Figs. 10-15. Staurastrum hreviaculeatum sp. nov 78 



Figs. 16-18. Staurastrum hreviaculeatum forma 79 



Figs. 19-25. Staurastrum setigerum Cleve 79 



