PLATE LXXXVL 



FIGS. PAGE 



1-4. Cosmarium Blyttii. 1, x 480 (after Wille) ; 2, 

 x 570 (after Nordstedt) ; 3, x 500 ; 4, x 

 -600 . . . . .225 



5-6. C. Blyttii var. Novse-Sylvx West & G. S. West. 



x 520 . . . . 227 



7. C. sexnotatum Gutw. a, x 430 ; a, x 810 



(after Gkitwinski) . . .227 



8-9. C. sexnotatum var. tristriatum (Liitkem.) 



Sclimidle. 8, x 500 ; 9, larger form, x 520 228 

 10-14. C. subcrenatum Hantzsch. 10 and 11, x 570 

 (after Nordstedt) 12 and 13, x 500; 14, 

 x 840 . . . . 228 



15. C. subcrenatum forma. x 1000 . . 230 



16-18. C. subcrenatum var. divaricatum Wille. 16, x 



400 (after Wille) ; 17 and 18, x 520 . 230 



19-21. C. suhprotumidum Nordst. 19, x 570 (after 



Nordstedt); 20, x 400; 21, x 840 . 231 



22. C. subprotumidum forma. x 625 . . 232 



23-25. C. subprotumidum var. G-regorii (Roy & Biss.) 

 West & G. S. West. 23, x 600 (after Koy & 

 Bissett) ; 24, x 1000 ; 25, a form described 

 by Gutwinski as " C. G-regorii var. papilli- 

 ferum Gutw.," x 1030 (after Gutwinski) . 232 

 26-32. C. Boeckii Wille. 26, x 480 (after Wille); 

 27 and 28, x 500 ; 29-31, three variations of 

 the central granules of the semi cell (the line 

 under each represents the position of the 

 isthmus), after Schmidle; 32, a form from the 

 United States, x 520 . . 234 



