WISCONSIN PHYTOPLANETON 



PLATE 26. 



Page 



Figs. 1-5. Tetracdron gracile (x 1000) 122 



Figs. 6-7. Tetraedron lobulatum (x 1000) 122 



Fig. 8. Tetraedron lo~bulatum var. polyfurcatum (x 1000) 123 



