DEFINITIONS OF TERMS. 



a frond, a spore-case enormously enlarged, much enlarged 

 spores, and enlarged pinnae, exhibiting, in one case, the 

 veins, and, in the other, enlarged, non-indusiate sori. 



The manner of the fronds unrolling a character which 

 characterises the group is circinate or scroll-like, and 

 is shown in another genus belonging to the group, a 



