212 WISCONSIN PHYTOPLANKTON 



PLATE 84. 

 All figures x 500. 



Page 



rigs. 1-2. Staurastrum Arctiscon (Ehr.) Lund 124 



Figs. 3-5. Staurastrum Arctiscon var. glabrum W. & G. S. West 125 



Fig. 6. Arthrodesmus convergens Ehr 126 



Figs. 7-8. Arthrodesmus Bulnheimii Eacib 127 



Figs. 9-10. Arthrodesmus suhulatus Ktz 127 



