ASPLENIUM. 
143 
point, except size, by which to distinguish the present 
plant from A- lanceolatum. In structural details they 
yery 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 larger 
pinnules some of these veins become divided, so that a 
venule is directed towards each of the serratures 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 
