EXPLANATIONS AND REFERENCES, 

 PLATE CLXXVI. 



PAGE. 

 Fig. 1. MASTIGONEMA AEROGINEUM; a form parasitic on Lyngbya 



Wollei, and probably a young 

 development of it, . . 242 



" 2-4, " u another form indicating the 



same mode of branching as 

 PlateCLXXI, fig. 8-10, . 241 



" 5. LSACTIS CAESPITOSA, small section of a thallus, . . . 245 



Figs. 6, 7. MASTIGONEMA VELUTINA, young condition of Lyngbya aestuarii. 242 

 Fig. 8. " " early development of the last, . 242 



" 9-11. " " differing principally in having inter- 



stitial heterocysts, , . . 242 



