Plate 107 



Fig. 1. Dinobryon cylindricum Imhof, x 400 



Fig. 2. Tetradinium simplex Prescott, x 400 



Fig. 3. Gymnodinium palustre Schilling, x 500 (redrawn from 



Holl) 



Figs. 4-6. Phacus triqiieter (Ehrenb.) Dujardin, x 600 (redrawn 

 from Skuja ) 



Figs. 7-9. Peridiniiim pusillum (Penard) Lemmermann, x about 

 1000 (redrawn from Schilling) 



Figs. 10, 11. Holopedium irregulare Lagerheim, x 500 (drawn from 

 material collected in Louisiana ) 



Fig. 12. Marssoniella elegans Lemmermann, x 500 



Fig. 13. Gloeocapsa rupestris Kuetzing, x 250 



Fig. 14. Dinobryon Vanhoeffcnii ( Krieg. ) Bachmann, x 500 



Fig. 15. Phormidium inundatuni Kuetzing, x 1000 



Fig. 16. Phormidium subfuscum Kuetzing, x 625 



Fig. 17. Spiridina laxissima G. S. West, x 2000 



Fig. 18. Phormidium uncinatum ( C. A. Ag. ) Gomont, x 625 



Figs. 19, 20. Phormidium autumnale (C. A. Ag. ) Gomont: 19, x 

 925; 10, X 800 



Fig. 21, Oscillatoria rubescens De Candolle, x 625 



Fig. 22. Oscillatoria articulata Gardner, x about 1400 (redrawn 



from Gardner ) 



Fig. 23. Oscillatoria subbrevis Schmidle, x 580 



Fig. 24. Oscillatoria minima Gicklhorn, x 1000 



Figs. 25, 26. Oscillatoria terebriformis C. A. Agardh, x 625 



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