VI. POLYPODIACEAE. § 11. ACROSTICHEAE. 135 



h.h. Pinnae free or joining at the base, articulate to the rachis, 

 dimorphous, the fertile ones linear. 



No. 84. Phoiinoptei'is. 

 a.u.a. Fertile region not restricted as in a. or a.u. Fronds di- 

 morphous, bai'ren and fertile ones separate. 

 $. Barren fronds simple or more commonly 2-fid, the lobes 

 divaricating, sometimes 2-fid again. Each segment with 2 

 or more, stout, longitudinal ribs springing from the base 

 of the frond. No. 85. Cheiropleuria. 



$.$. Barren fronds simple or pinnate. Each segment with a 

 single costa. 

 ;|c. Spores oblong, ovate or 2-lateral. 



No. 86a. licptocbilus. 

 *.*. Spores globoso-tetrahedral. No. 866. Platytaenia. 



