148 



(a) Rhizome wide-creeping. Only one 

 pair of veins anastomosing, rarely two in 

 unitum. 



(i) Venation and sori anomalous. 



i. N. subpectinatum. 



(ii) A swamp fern ; no auricles on 

 the pinnae. 



2. A 7 , unitum. 



(Hi) Sori confined to the lobes. 



3. N. pteroides. 



(iv) Venation often as in Lastrea, 

 when anastomosing the angle 

 acute at the apex. 



4. N. extensum. 



(b) Rhizome erect, sub-erect, or occa- 

 sionally somewhat creeping in molle and 

 pennigerwn Two or more pair of veins 

 anastomosing occasionally, only one in molle. 



(i) Herbaceous, more or less hairy, 

 auricles present or absent, 1-2 

 pair of veins anastomose. 



5. N. molle. 



