IV.] 



FILICES. 



347 



Niphoboliis {adnascens). — Sterile and fertile fronds distinct 

 The upper part of the linear fertile frond crowded with 

 pedicellate sporanges between the midrib and margins, 

 mixed with stellate, peltate scales. 



Fig. 228. Pinnules and sori of Polypodium. Fig. 229. Pinnule of Adtatihiin. 



Adiantum {Capillus- Veneris^ or caiidatum). — Sori on the 

 margins of the pinnules, covered by the indusium, which is 

 attached by its outer edge, opening (free) within. 



Pteris, — Sori in a continuous line upon the margin of the 

 pinnules. Indusium continuous, attached, as in Adiantum^ 

 by its outer edge. 



Blechium {prientali). — Sori in continuous lines on each 

 side of, and parallel with, the midrib of the frond or pinnule. 

 Indusium opening along its inner edge. 



Asplenium. — Sori scattered on the under surface ; not 

 marginal, and generally oblique to the midrib of the frond 

 or pinnule. Indusium membranous. 



Aspidium (molie). — Sori nearly or quite globose on the 

 under surface of the frond. Indusium peltate (in § Aspidiwn 

 proper), or reniform and attached by a point at the side (in 

 § Nephrodium, to which belongs our Type-species). 



