PLATE III. 



Figures magnified 500 diameters. 



PAGE. 

 Fig. 1. DESMIDIUM CYLINDBICUM, (Didymoprium Grevilli), part of a 



vegetative filament, . . .25 



" 2. " " end view of a cell, . . 25 



' 3. two cells copulated ; chlorophyllous 



contents parsing through a gelatinous 

 tube, from one cell to the other, . 25 

 " 4. Two developed zygospores ; the two 



empty cells still connected, . . 25 



" 5. MESOTAENIUM BRAUNII, D. By. (Palmoglcea nuicrococca, Kg.), 



a group of three vegetative cells, . 32 



Figs. 6-9. advancing stages of copulation and 



spore formation to the fully developed 

 zygospore, . . , .32 



Fig 10. MESOTAENIPM MICROCOCCUM, a group of seven cells, . 32 



" 11. MESOTAENIUM ENDLICHERIANUM, a group of four cells, . 32 



" 12. MESOTAENIUM CLEPSYDRA, three vegetative cells, . . 32 



Figs. 13-15. " " two cells copulating and two devel- 



oped spores, husks remaining at- 

 tached, . . . .33 



" 16-19. SPIROTAENIA OBSCURA, ..... 33 



' 16, 17. " young stages of development in gela- 



tinous envelopes, . . .33 



" 18, 19. " " more matured forms, . . 33 



Fig. 20. SPIROTAENIA BRYOPHILA, (S. muscicola), a group of four, . 34 

 Figs. 21, 22. SPIROTAENIA CONDENSATA, ..... 33 



