Plate 91 



Figs. 1-4. Peridinium cinctum (Muell. ) Ehienberg, x 600 



Figs. 5, 6. Cystodinium cornifax ( Schill. ) Klebs, x 300 



Figs. 7-12. Peridinium cinctum var. tuberosum (Meunier) Linde- 

 man: 7, x 600; 8-10 (after Meunier, ex Schiller), x 

 about 188; 11 and 12, x 600 



Figs. 13-15. Peridinium wisconsinense Eddy: 13 and 15, x 500; 14, 

 x250 



Figs. 16-18. Peridinium limbatum (Stokes) Lemmermann, x 750 



Figs. 19-21. Cystodinium iners Geitler: 19, x 750; 20 and 21, x 325 

 ( 21 redrawn from Geitler ) 



Figs. 22-25. Peridinium Willei Huitf eld-Kaas : 22, x 600; 23 and 

 24, X 440; 25, x 600 



842 



