Wilson’s filmy fern. 
325 
WILSON’S FILMY FERN, [natural size). 
Hymenophyllum Wilsoni, Hooker. 
The range of this species in Great Britain appears to be much 
more extensive than that of H. tunhridgense : it also seems 
to be a more northern species, and generally to prefer a 
greater elevation : still, as already stated, the two plants are 
often intermixed, particularly about the waterfalls in the vicinity 
of Killarney. The following are some of the principal English 
and Welch stations. 
Brecknockshire. — Mr. Ralfs informs me it is common 
among the mountains in this county. 
Caernarvonshire. — As far as I am able to decide I should 
say that the habitats at Snowdon, Llanberis, Cwm Idwell, Nant- 
frangon, &c., although generally accompanied by the name of 
tunhridgense., belong exclusively to the present species. I for- 
merly supposed I had found tunhridgense in Caernarvonshire, 
but, on referring to the specimens, can only find the present 
species, which is most abundant on rocks and stones throughout 
the Snowdon district, at Rhaiadr-y-Wenol, Falls of the Lugwy, 
Capel Cerig, Rhaiadr-Mawr near Llanberis, &c. 
Cardiganshire. — Mr. Lees has observed it in some quantity 
on rocks close to Pont Bren, or the Parson’s bridge. 
