8 Woodsia . 



, 20 



9 Peranema . 



. 22 



IO ClBOTIUM . 



. 24 



I I Dennstvedtia 



. 24 



viii Table of the Genera of Ferns. 



Genus. Page. 



TRIBE II.— DICKSONIEiE. 



Sori globose, indusium inferior, subglobose, free, 

 sometimes covering the whole sorus, closed, at length 

 bursting irregularly, more frequently cup-shaped 

 entire or with two lips. 



Fertile fronds contracted with revolute margins, 

 indusium hemispherical, very fugacious or wanting, 

 veins free 7 Struthiopteris 20 



Indusium thin, subglobose, open at the top and 

 laciniate ........ 



Indusium medial on a vein, thick globose pedicellate, 

 bursting into two lips ...... 



Indusium apical on a vein, two-valved 



Indusium apical on a vein, cup-shaped . 



TRIBE III.— HYMENOPHYLLE.E. 



Filmy ferns, indusium inferior, apical on a vein, 

 two-lipped or tubular. 



Indusium more or less two-lipped . . . .12 Hymenophyllum 28 



Indusium tubular, the mouth truncate or slightly two- 

 lipped 13 Trichomanes . 36 



TRIBE IV.— DAVALLIE.E. 



Indusium squamiform, suborbicular or tubular, 

 open at the apex, fastened broadly at the base, and 

 sometimes at the sides. 



Indusium apical on a vein, suborbicular coriaceous, 



attached by a broad base, the sides free . . . 14 Humata . . 46 



Indusium as in Humata, but thin and smaller and 



narrower 15 Leucostegia . 48 



Indusium a subcylindric cyst formed of the substance 



of the frond, apical on the veins . . . .16 Prosaptia . . 56 



Indusium apical, tubular, attached by the base and 



sides 17 Davallia . . 58 



Indusium apical, half cup-shaped, attached by the 



base and sides 18 Microlepia 



