No. 10.] 



FRESH-WATER ALG^. 



77 



Odcystis, 33. 

 Ophiocytium, 25, 26. 

 Oscillaria, 19. 

 Oscillatoria, 18, 19, 20. 

 Oscillatoriacese, 10, 17. 



Palmella, 30. 

 Palmellaceae, 28. 

 Palmellese, 29, 30. 

 Palmellococcus, 33, 34. 

 Palmodactylon, 30. 

 Palmodictyon, 29. 

 Pandorina, 40, 42. 

 Pediastrese, 37. 

 Pediastrum, 37. 

 Penium, 58, 60. 

 Petalonema, 22. 

 Phaeophyceae, 9. 

 Phormidium, 18, 19. 

 Phycocyanin, 9. 

 Phycoerythrin, 10. 

 Phycophsein, 9. 

 Phymatodocis, 59. 

 Phythelieae, 31, 36. 

 Pilinia, 45. 

 Pithophora, 53. 

 Placodermae, 56, 58. 

 Plagiospermum, 68. 

 Planogametes, 30. 

 Plectonema, 18, 19. 

 Pleurococcaceae, 28, 38. 

 Pleurococcus, 38. 

 Pleurotaeniopsis, 63. 

 Pleurotaenium, 58, 61. 

 Polycystis, 13. 

 Polyedrium, 32. 

 Prasiola, 44. 

 Protococcaceas, 28, 31. 

 Protococcales, 27. 

 Protococcus, 34, 38. 

 Pseudocilia, 29. 

 Pseudoccenobia, 31. 

 Pseudopleurococcus, 38. 

 Psilonemateae, 14, 17. 



Raphidium, 35. 

 Rhizoclonium, 54. 



Rhodophyceae, 10. 

 Rivularia, 15, 16. 

 Rivulariaceae, 15. 

 Roya, 58, 60. 



Saccodermae, 56. 



Scenodesmus, 34, 35. 



Schizochlamys, 30. 



Schizogoniales, 27, 43. 



Schizogonium, 44. 



Schizophyceae, 9. 



Schizosiphon, 22. 



Schizothrix, 20. 



Schoderia, 35. 



Sciadium, 26. 



Scytonema, 22, 23. 



Scytonemaceae, 17, 22. 



Selenastreae, 31, 34. 



Selenastrum, 34, 35. 



Selenosphaerium, 36. 



Sex union, 9. 



Siphonales, 27, 54. 



Sirogonium, 67. 



Sirosiphon, 23. 



Sorastrum, 36. 



Sphasrella, 42. 



Sphaeroplea, 53. 



Sphserozosma, 59, 64. 



Sphaerozyga, 21. 

 Spirocoleus, 19. 

 Spirogyra, 66, 67. 

 Spirotaania, 57. 

 Spirulina, 18. 

 Spondylomorum, 40, 41. 

 Spondylosium, 59, 65. 

 Spores, 8. 

 Squamariaceas, 71. 

 Staurastrum, 59, 62. 

 Staurogenia, 36. 

 Staurospermum, 68. 

 Stephanosphasra, 40, 41. 

 Stichococcus, 49. 

 Stigeoclonium, 47. 

 Stigonema, 23. 

 Stigonemaceae, 17, 23. 

 Streptonema, 60. 

 Swarm spores; 9. 



