Explanation of Plate XVIII. 



Hypoderris seemanni Prent. p. 169. 

 Fig. 1. Two lobes from the terminal division of a fertile frond. X 1. 

 Fig. 2. An involucre, with sporangia removed, showing the ciliated 

 lobes. The upper, or open, part of the involucre is next to the 

 margin of the frond in both figs. 2 and 3. Magnified. 

 Fig. 3. An involucre of one large scale. Magnified. 



Nephrodium conterminum (Willd.) Desv. p. 172. 

 Fig. 4. An indusium, with a few sporangia adhering to the margin. 

 Magnified. 



Nephrodium mexicanum Presl. p. 173. 

 Fig. 5. A sterile pinna. The broader side uppermost. X 1. 



Nephrodium sphcerocarpum (Fee) Hook. p. 174. 

 Fig. 6. A fertile pinna. The broader side uppermost. X 1. 



Nephrodium karxvinskyanum (Mett.) Bak. p. 174. 

 Fig. 7. A pinnule. The largest lobe at base is uppermost. X l- 

 Fig. 8. An indusium, with slightly ciliated margin. Magnified. 



Nephrodium effusum (Swz.) Bak. p. 175. 

 Fig. 9. A segment. The largest lobe at base is uppermost. Compare 

 with fig. 7. X i- 



Nephrodium parasiticum (L.) Shimek. p. 176. 

 Fig 10. Indusium with long-ciliated margin. Magnified. 



Nephrodium endresi Bak. p. 177. 

 Fig. 11. Frond with rootstock. X i- 

 Fig. 12. Part of frond between two main ribs. X 2. 



