PLATE X. 

 [Proc. Wash. Acad. Sci., Vol. Ill, PI. XLIII.i] 



Fig. I. Cosmarium conspersum Ralfs. 



2. " ccelatum Ralfs. 



3. '* ornattim Ralfs. 



4. Euasirum crassum (Breb.) Kuetz. 



5. Costnarium fseudotaxichondrum Nordst. 



6. " farvtilutn Br^b. 



7. " /rnwwe/-/' Reinsch. 



8. " granatum Br^b. 



9. Euasirum verrucosum Ehrenb. 



10. Cosmarium ochtodes Nordst. 



11. •' bo try its Menegh. 



12. " portianum nephrotdeum Wittr. Front view. 



13. " " " " End view. 



14. Closterium parvulum Naeg. 



15. " venus Kuetz. 



16. Staurasirum echinatum Pecten (Perty) Rab. 



17. Cosmarium depressum (Naeg.) Lund. 



18. " fulcherrimum Nordst. 



19. " " " From Kukak Bay. 



20. " subcrenatum Hantzsch. 



21. " pseudo granatum Nordst. 



22. " quadrifaritim Lund. 



23. Staurastrum polymorphum Breb. End view. 



24. " " " Front view. 



25. Micrasterias roiata (Grev.) Ralfs. 



26. Costnarium brootneiYax. Thwaites. 



27. Closterium accrosum (Schrank), Ehrenb. 



28. Cosmarium bioculatum Breb. 



29. Mesotcenium braunii De Bary. 



30. Disphinctium connatum (Br^b.) De Bary. 



31. Staurastrum calyxoides WoUe. 



32. Euastrum affine Ralfs. 



33. Cosmarium constrictum Delp. Side view. 



34. " " •' Front view. 



35. " broo7nei ThyfaXi&s. End view. 



36. " " " Front view. 



37. Euastrum oblongum (Grev.) Ralfs. 



38. Xanthidium antilopcEum C&rih.) Kuetz. 



39. Cosmarium sexangulare Lund. 



40. " pyramidatum Br^b. 



1 Plates xliii-lxii are from drawings by Eva M. Saunders, except for plate 

 xlvi, figs. 1 and 2, which were drawn by Edna L. Hyatt. 



[448] (312) 



