292 WISCONSIN PHYTOPLANKTON 



PLATE 74. 



All figures x 500. 



Page 



Figs. 1-4. Staurastrum protectum var. planctonicum G. M. Smith 87 



Figs. 5-11. Staurastrum longiradiatum W. & G. S. West 90 



Figs. 12-18. Staurastrum floriferum W. & G. S. West 91 



Figs. 19-23. Staurastrum Bullardii sp. nov 91 



