Acrostiduim. 
Capules irregularly spread over under surface of frond) 
or pinna j"' 
„ large, on under surface of lower segments only ... Todea. 
,, few, 2 to 10 in each sorus, medial, frond rigid, opaque Oleichenia. 
,, few, concrete, intramarginal 
... Marattia. 
II. 
Barren frond ovate, vernation straight 
,, „ linear „ circinate 
Ophioglosstum. 
■ Schizaa. 
III. 
Fronds bipinnate, apex fertile 
, f pinnate, barren and fertile different 
... Osmundu. 
Anemia. 
