ASPLENIUM. 143 



point, except size, by which to distinguish the present 

 plant from A. lanceolatum. In structural details they 

 very much resemble each other ; so that, although quite 

 distinct, their descriptions appear very similar. 



The fronds being rigid and opaque, the venation is often 

 less evident than is usual in Ferns. It consists, in each 

 pinnule, of a central vein, or midrib, which throws off a 

 vein towards each lobe or serrature, and in the laro^er 

 pinnules some of these veins become divided, so that a 

 venule is directed towards each of the serraturcs into 

 which the margin is divided. On two or more of these 

 veins a sorus is produced ; these in form are short compared 

 with those produced by most of the genus, being oblong, 

 rather flat on the side by which they are attached ; and 

 they are covered by an indusium of similar form* which is 

 waved and indented on the free margin. Sometimes the 

 sori keep quite distinct, but it is not uncommon for them 

 to become confluent, so as to cover nearly all the under- 

 surface of the whole of the little pinnules. 



There are some who doubt this species being really a 

 native of Britain, on the ground that it is not now to be 

 found in the places where it is said to have been originally 

 met with. The most recently recorded stations are a very 



