Explanation of Plate XX. 

 i 



Acrostichum osmundaceum (H. B. K.) Hook. p. 186. 

 Fig. i. A sterile pinnule. X i. 



Acrostichum canaliculatum (Klotzsch) Hook. p. 187. 

 Fig. 2. A sterile pinnule. X 1. 



Gymnogramma incisa M. et L. p. 191. 

 Fig. 3. One-half of a fertile frond. The base of the stipe, and the root- 

 stock should be represented as decidedly scaly. X 1. 

 Fig. 4. The basal pinna of the broadest form. X I. 



Fig. 5. The tip of a pinnule, showing margin, apex, venation and sori. 

 The surface should be represented as more hairy. Magnified- 



Polypodium macbridense Shimek. p. 199. 

 Fig. 6. Scale from rachis. It was attached at the dark area. Magnified. 

 Fig. 7. Tip of a frond, lower surface. X i« 



Fig. 8. Two pairs of pinnae of the broadestfrond in the collection. X I- 

 Fig. 9. One-half of a fertile frond. X 1. 



Polypodium hvvigatum Cav. p. 201. 

 Fig. 10. Part of frond between two main veins. X 2. 



Polypodium repens L. p. 201. 

 Fig. 11. Part of frond between two main veins. X 2. 



Polypodium phyllitidis L. p. 202. 

 Fig. 12. Part of frond between two main veins, from the narrow form. 



The venation is typical. X 2. 

 Fig. 13. Similar portion of the broad form from Castillo. The venation 

 is peculiar, there being three rows of areolae between the main 

 veins. X 2. 



Polypodium sororium H. B. K. p. 196. 

 Fig. 14. A pinna. The figure is inverted. X i« 



Polypodium loriceum L. p. 197. 

 Fig 15. A pinna of the smooth blunt form from X I. 

 Fig 16. A pinna of the hairy acute form from X i- 



Dancea crispa E. et R. p. 206. 



Fig. 17. Two pairs of pinnae and part of the winged rachis of a sterile 

 ond. X 1. 



