EXPLANATIONS AND REFERENCES, 



PLATE CLXXXII. 



Figures magnified 250 diameters. 



PAGE. 

 Fig. 1-3. SCYTONEMA MYOCHROUS; three forms, .... 252 



" 4. SCYTONEMA TOL.YPOTRICHOIDES, a normal vegetative condition, 250 



" 5. " an older plant, ..... 251 



Figs. 6, 7. part of filament with secondary branches, . 251 



Fig. 8. " a young form just developed from a Nostoc, (255), 251 



Figs. 9, 10. Nostoc forms developing Scytonema, . (255,) 251 



Fig. 11-13. " less advanced stage of development, . . 251 



