194 WISCONSIN PHYTOPLANKTON 



PLATE 9. 



Page 

 Figs. 1-3. Anabaena spiroides var. crassa (Fig. 1, x 825, figs. 2-3, x 400) 59 



Figs. 4-5. Anabaena circinalis (Fig. 4, x 825, fig. 5, x 400) 59 



Fig. 6. Anabaena circinalis var. macrospora (x825) 60 



