EXPLANATIONS AND REFERENCES, 

 PLATE CCI. 



Figures magnified 250 diameters. 



PAGE. 



Figs. 1, 2. LYNC4BYA NAVEANUM, Pennsylvania specimens, . 298 



'' 3, 4. " " Florida specimens, . . . 298 



Fig. 5-10. LYNGBYA OBSCURA. Kg., specimens from Canada, Vermont, and 



Pennsylvania, .... 298 



" 11-13. LYNGBYA MEMBRANACEA, specimens from Charlotte, Vermont, 300 

 " 14-20. LYNGBYA VULGARIS, frequent from Maine to Florida, 300 



" 21. LYNGBYA PHORMIDIUM, Var. rivularis, . 299 



" 22-26. LYNGBYA PHORMIDIUM, variable in diameter, . 299 



" 27-29. LYNGBYA ARENARIUM, specimens from vicinity of Atlantic 



City, New Jersey, . , , 299 



