EXPLANATIONS AND REFERENCES, 

 PLATE CLXXXIV. 



Figures magnified 250 diameters. 



PAGE. 

 Figs. 1. 3. SCYTONEMA NOTARISII, normally developed plants, . 254 



" 4, 5. younger growths, . . . 255 



Fig. 6-9. " more juvenile forms, . . . 255 



Figs. 10, 11. gonidia developing, . . 255 



" 12, 13. " " large cysts containing gonidia, . . 255 



Fig. 14. " " young forms, . . . 255 



Fig. 16-19. SCYTONEMA CASTELLII, parts of matured plants, . . 255 



" 20-21. " " parts of two older filaments, the articu- 



lations, short - discs, sliding out of the 

 sheaths, scattering microgonidia, which 

 in turn increase in size from (21) (23) 

 - (24), then redivide ejecting macro- 

 gonidia and producing a new cyst, Micro- 

 cystis, Gloeothece, and other forms, . 255 



" 24-29. " cysts developing young plants, . 255 



" 30-33. " " young plants, . . . .255 



" 34-40. " " Nostoc and Scytonema forms, . 255 



