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at first enclosing the sorus, ultimately 
splitting vertically into two lips. Veins 
free forked, terminating within the 
margin into clavate (club-shaped) apices. 
Genus LV.—Peranema Don. 
Tripe I]].—HymENnopHyLte& 
Sporangia globose or ovate, furnished 
with a 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. 
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 of the indusium. 
Genus VI.--Trichomaues Smith 
Tripe 1V.—DavaLLira& 
Sori rounded or oblong, situated at or 
near the margin; indusium adherent at 
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