EXPLANATIONS AND REFERENCES, 



PLATE CXCIX. 



Figures magnified 250 diameters. 



PAGE. 

 Fig. 1. SPHAEROZYCIA SACCATA, a cluster of saccate tha Hi, . . 290 



" 2. " " older detached floating forms, . 290 



" 3-5. specimens of filaments contained in the 



saccate thalli, . . . 290 



" 6-8. CYLINDROSPERMUM MACROSPERMUM, normal appearance of the 



filaments, . . 292 



" 9-10. CYLINDROSPERMUM LIMNICOLA, after specimens from a ditch 



almost dried up. Some of 

 the filaments appear to be 

 veritable Oscillaria, . 292 



" 11. cells of filaments indistinct; 



not constricted at joints; 

 Oscillaria-Yike, . . 292 



" 12. " Wood's figure of C. minutum, . . 292 



'13. " Wood's figure of C. flexwsum, . . 293 



" 14. " Wood's figure of C. mocrosperraww, . 292 



" 15. ANAByENA, FLOS-AQUyE, ..... 286 



" 1 6. CYLINDROSPERMUM COMATUM, Wood's figure, . . 293 



" 17. SPHAEROZYGA SMITHII ; Hilsia, Kirch., . . . 290 



Figs. 18, 19. " " typical filaments, . . .290 



Fig. 20-22. " filaments with two or three trichomes 



in a sheath, .... 290 

 Figs. 23, 24. more advanced conditions of older 



filaments, . . ... 290 



