EXPLANATIONS AND REFERENCES, 

 PLATE CXC. 



Figures magnified 250 diameters. 



PAGE. 

 Fig. 1-3. SIROSIPHON PULVINATUS, luacrogonidia, (Gloeocapsa cells), . 269 



" 4-8. early development from macrogonidia, 269 



Figs. 9, 10. two elongated filaments with a single 



series of cells, . . . 269 



" 11,12. " " older forms with 2-6-8 series of cells. 269 



