294 CONCERNING NOMENCLATURE. 



OPHIOGLOSSAO. 



Sporangia without a ring formed 

 of the interior tissues of the leaf, 

 borne in spikes or panicles and 

 discharging their spores through a 

 transverse slit ; fronds erect or in- 

 clined in vernation ; roots usually 

 fleshy ; prothallia subterranean. 



GENERA Ophzoglossum, Botrychium. 



OSMUNDACEyE. 



Sporangia spherical on altered portions 

 of the fronds, opening longitudinally; 

 ring rudimentary; rootstock very large ; 

 fronds in circular crowns. 



GENUS Osmunda. 



, 



Sporangia egg-shaped, borne usually on a 

 contracted portion of the frond, opening long- 

 itudinally ; ring apical ; rootstock short 

 or creeping; rachis often twining. 

 GENERA Schz'zcea, Lygodz'um. 



HYMENOPHYLLACE^E. 



Sporangia sessile along a bristle like 

 receptacle and surrounded by an urn- 

 shaped or funnel-form, two-lipped in- *""" 

 volucre ; ring transverse, opening verti- *&**&** 

 cally; rootstock creeping; fronds very delicate often but 

 one cell thick. 



GENUS Trzchomanes. 



