PLATE LXIX. 



FIGS. PAGE 



1. Cosmarium rectanyulum Reinsch. x about 720 



(after Reinsch) . . .41 



2. C. arctoum Nordst. x 570 (after Nordstedt) . 41 

 3. C. arctoum forma minor. 4-, x 400 . . 42 



4. C. arctoum var. tatricum Racib. x 520 . 42 



5. C. decedens (Reinsch) Racib. var. sinuosum 



(Lund.) Racib. x 400 (after Ralfs) . 44 



6-8. C. decedens (Reinsch) Racib. 6, x 400 (after 

 Nordstedt) ; 7, x 400 ; 8, form with more 

 prominent punctulations, x 500 . . 43 



9. C. decedens forma . . .44 



10. C. tafricitm Racib. x about 1300 (after Raci- 



borski) . . . .45 



11-12. C. tatricum var. novizelandicum Nordst. Ha, 

 x 1080; life, x 400 (after Nordstedt); 12, 

 x 520 . . . . 46 



13. C. tatricum var. sphssruliferum West, x 400 . 47 

 14-17. C. anceps Lund. "14, x 400 (after Lundell) ; 



15 and 16, x 500; 17, x 520 . 47 



18 21. C. obliquum Nordst. 18 and 19, x 400 (after 

 Nordstedt) ; 18, four cells forming a short 

 filament, enveloped in mucus, and seen from 

 the side view; 20 and 21, x 400 . . 49 



22-23. C. obliquum forma minima West. x 520 . 51 

 24. C. obliquum var. trigonum West. x 400 . 51 

 25-27. C. Norimbergense Reinsch. 25 and 26, x about 



1500 (after Reinsch) ; 27, x 520 . 52 



28-29. C. Norimbergense forma depressa West & G. S. 



West, x 520. . . 53 



30. C. repandum Nordst. x 570 (after Nordstedt) 53 

 31-32. C. repandum forma minor West & G-. S. West. 



x 600 (after Roy & Bissett) ; 32, zygospore . 54 



