PLATE XVII. 



Figures magnified 500 diameters. 



I 1 M.I.. 



Figs. 1, 2. COSMARIUM CONSPERSUM ; two forms, . . . .82 



Fig. 3. COSMARIUM OCHTHODE8, ..... 84 



" 4. empty cell of smaller form, . . 84 



Figs. 5, 6. COSMARIUM AMOSNUM, ..... 85 



Fig. 7. " " Var. tumidum, . . . . 85 . 



Figs. 8, 9 COSMARIUM ELEGANTISSIMUM, .... 86 



Fig. 10. COSMARIUM RENIFORME, . . . . . .84 



" 11. " " smaller form, empty cell, . . 84 



" 12. COSMARIUM PORTIANUM, . . . . . .84 



" 13. " " cell dividing, . . 84 



" 14. zygospore and emptied semi-cells, . 8t 



" 15. COSMARIUM BROOMEI, Var. (Compare Plate XX, figs. 6-9), 93 



Figs 16, 17. COSMARIUM PYRAMIDATUM, two forms, one cell empty, . 74 

 " 18, 19. " Var. stenonotuni, . . 74 



" 20, 21. COSMARIUM ORBICULATUM, . . . . .85 



