KEY TO THE GENERA 



Cheilanthes. 



Sporangia marginal, indusium 

 formed by the reflexed ends 

 of the roundish lobes, soon 

 pushed back by the enlarg- 

 ing sporangia; fronds us- 

 ually hairy. Lip Ferns. 



Cheilanthes. 122 



Cryptogramma, 



Fruiting pinnules long, pod- 

 like, indusium formed by 

 the reflexed edges reaching 

 to tlie midrib, opening later 

 quite flat; sterile fronds 

 shorter than the fertile with 

 broader divisions. Rock 

 Brakes. 



Cryptogramma. 



66 



Trichomanes. 



C — Fruit dots marginal, ter- 

 minating a vein, sporangia 

 at the base of a long, bris- 

 tle-like receptacle, s u r - 

 rounded by a cut-shaped in- 

 dusium which is two-lipped 

 at the mouth. Filmy Fern. 

 Trichomanes. 



178 



