INDEX TO THE GENERA. 13 



INDUSIATE; 



OR WITH A DISTINCT INDUSIUM BELONGING 

 THERETO. 



Sori on the back, in round masses. Indusiuin 

 round like a shield, and fixed in the centre 

 only, as in the family of Lonchitis; or 

 appearing somewhat like a kidney, from 

 having a deep connecting indentation from 

 the centre to the extremity, as in the rest. 



ASPIDIUM. 



Sori on the back, in round masses. Indusium 

 bladder-shaped, attached under the sori at 

 the part farthest from, and opposite to, the 

 points of the pinnule ; eventually retorted, or 

 thrown off entirely. 



CISTOPTERIS. 



Sori on the back, in round masses. Indusium 

 attached under them, and splitting above into 

 hair-like divisions or fine threads. 



WOODSIA. 



