PLATE 10.— Desmidiacea. 



Figure 



1. Hyalotheca dissiliens, front view. 



2. Hyalotheca dissiliens, side or end view. 



/ > Hyalotheca dissiliens, conjugating cells, with sporangia. 



5. Didymoprium Grevillii, front view. 



6. Didymoprium Grevillii, side view. 



7. Desmidiiim Sivartzii, front view. 



8. Des?7iidiiim Swart zii, side view. 



9. Sphcei'ozosma vertebratum, front view. 



10. Sphcerozosma vertebratum, side view. 



11. Micrasterias denticulata, cell dividing. 



12. Micrasterias denticulata, sporangium. 



13. Micrasterias rotata. 14. Euastriim verrucosum. 

 15. JEuastrum oblongum. 16. Euastrum Didelta. 



17. Euastrum didelta, cell free from contents. 



18. Cosmarium pyramidatum. 19. Cosmarium pyramidatum, em^ty cq][. 

 20. Cosmarium crenatum. 21. Cosmarium margaritiferum, 



22. Cosmarium tetraophthalmum. 



23. Xanthidium armatum. 24. Xanthidium armatum, empty cell. 



25. Xanthidium fasciculatum. 



26. Staurastrum dejectum. 27. Arthrodesmus convergens. 



28. Staurastrum margaritaceum, front view. 



29. Staurastrum margaritaceum, side view. 



30. Staurastrnim gracile, ho\^tV\evi. 31. Staurastrum gracile, side yiew. 



32. Didymocladon furcigerus, front view (fig. 56, side view). 



33. Tetmemorus granulatus. 



34. Tetmemorus granulatus, empty cell. 



35. Tetmemorus Icevis, in conjugation. 



36. Penium Brebissonii. 



37. Penium margaritaceum, empty cell. 



38. Docidium truncatum. 



39. Docidium baculum. 



40. Closterium lunula. 



41. Closterium acerosum. 



42. Closterium acerosum, in conjugation. ^jif. • 



43. Closterium moniliferum. 



44. Closte?'ium didymotocum. 



45. Closteriu?n setaceum. 



46. Closterium setaceum, in conjugation. 

 47>. Ankistrodesmus falcatus. 



48. Pediastrum Boryanum. 



49. Pediastrmn granulatum, empty cell. 



50. Scenede^mus cpxadricauda. 



51. Scenedesmus obliquus, 



52. Aptogonum desmidium, side view (fig. 55, front view). 



53. Scenedesmus obtusus, just after division. 



54. Scenedesmus obtusus, ordinary state. 



55. Aptogonum desmidium, front view (fig. 52, side view). 



56. Didymocladon furcigerus a,, side view (fig. 32, front view). 



57. Closterium Griffithii. 

 58. 



>j 



