Plate 4 



Figs. 1, 2. Elakatothrix viridis (Snow) Printz: 1, x about 620 (re- 

 drawn from Smith ) ; 2, x 440 



Figs. 3, 4. Palmodictyon varium ( Naeg. ) Lemmermann, x 500 



Figs. 5, 6. Palmodictyon viride Kuetzing, x 500 



Figs. 7-9. Stylosphaeridium stipitatum ( Bachm. ) Geitler & Gi- 

 mesi: 7, x 500; 8 and 9, single cells, x 1000 



Fig. 10. Asterococcus superbus ( Cienk. ) Scherffel, x 440 



Fig. 11. Asterococcus limneticus G. M. Smith, x 500 



Figs. 12-14. Schizochlaniys compacta Prescott, x 500 



Fig. 15. Schizochlaniys gelatinosa A. Braun, x 500 



[ 668 



