KEY TO THE GENERA 



Sporangia borne on the under side of the ordinary 

 fronds, sori in dots or lines. 



Indusium wanting, A. 

 Indusium present, formed by 



the reflexed margins of the 



pinnules, B. 

 Indusium present, not formed 



by the reflexed margins of 



the pinnules, C. 



A — Fruit dots large, round- 

 ish ; evergreen, rock species. 

 Polypody. 



POLYPODIUM. 130 



Fruit dots roundish, small, 

 fronds triangular. Beech 

 Ferns. 



Phegopteris. 72 



Polypodium. 



Phegopteris. 



Notholaena. 



Fruit dots roundish or oblong, 

 soon forming an irregular 

 marginal band; under sur- 

 face of pinnules covered 

 with a whitish powder. 

 Cloak Fern. 



Notholaena. 160 



