WISCONSIN PHTTOPLANKTON 227 



PLATE 42. 



Page 



Fig. 1. Coelastrum microporum (x 825) 160 



Figs. 2-3. Coelastrum cambricum (x 825) 161 



Figs. 4-6. Ooelastrum reticulatum (x 825) 161 



Figs. 7-8. Coelastrum proboscideum (x 825) 162 



