207 



PAGE 



at first enclosing the sorus, ultimately 

 splitting vertically into two lips. Veins 

 free forked, terminating within the 

 margin into clavate (club-shaped) apices. 



Genus IV. Ptrantma Don. 34 



TRIBE III. HYMENOPHYLLE^ 



Sporangia globose or ovate, furnished 

 with 2 transverse ring ; indusium inferior, 

 two-valved or tubular. Filmy ferns, 

 usually epiphytic in habit. 



Sori marginal ; indusium more or less 

 two-valved ; receptacle elongated, colum- 

 nar, protruding beyond the mouth of the 

 indusium or included within it. 



Genus V. Hymenophylium L. 35 



Sori always terminating a vein, more or 

 less sunk in the frond ; indusium tubular 

 or slightly two-lipped ; receptacle elongat- 

 ed, columnar, otten considerably protrud- 

 ing beyond the mouth ot the indusium. 



Genus Vi. -Trichomants Smith 37 



TRIBE IV. DAVALLIE.E 

 Sori rounded or oblong, situated at or 

 near the margin ; indusium adherent at 



