PLATE XCIX. 



FIGS. PAGE 



12. Cosmarium conspersum Ralfs. 1, x 400 (after 



Ralfs) ; 2, x 520 . . 13 



3. C. conspersum var. rotundatum Wittr. x 400 



(after Wittrock) . . .16 



4. C. conspersum var. subrotun datum West, a, x 



600; b, x 400 . . . .17 



5-6. C. conspersum var. latum (Breb.) W. & Gr. S. West. 



5, x 400 (after Roy & Bissett) ; 6, x 500 . 15 

 7. C. Logiense Biss. forma expatisa W. & Gr. S. West. 



x 400 (after Roy & Bissett) . .16 



8. C. margar 'datum (Lund.) Roy & Biss. x 600 . 18 



9. C. margar 'datum forma minor Boldt. x 520 . 19 



10. C. mnryaritafum. x 520 . . .18 



