TUNBRIDGE FILMY FERN. 
323 
Dumfriesshire. — Mr. Cruickshank has found it on rocks at 
Drumlanrigg bridge. 
In Ireland this fern is not generally distributed, being con- 
fined to those romantic parts of a few counties which have for 
many years attracted the notice of tourists. 
Kerry. — In the vicinity of Killarney it attains a degree of 
luxuriance and profusion that I have never observed elsewhere : 
it is almost invariably intermixed with Wilsoni, and sometimes 
also with Trichomanes speciosum : it not only covers the rocks, 
but even clings to the bark of trees, ascending them to a height 
of two or three feet, and presenting a very beautiful appearance. 
Wicklow. — Mr. Mackay informs me it occurs at Powerscourt 
waterfall, Glencree, and several other places in this county. 
A species of Hymenophyllum occurs under the name of tun- 
hridgense in the Floras of Germany, France, Italy and Sweden. 
From the ‘ Flore Frangaise ’ we learn that in France it grows 
amongst moss on the trunks of trees ; and a closely-allied spe- 
cies, often indeed bearing the same name, has been received 
from New Holland, South Africa, and South America. 
The figure of this fern in Sowerby’s ^English Botany ’ ^ is 
sufficiently exact, and that in Hooker’s ‘ Flora Londinensis ’ f 
is still better. The figure in Bolton’s ^ Filices ’ X appears to be 
drawn from the next species. 
This plant is the Trichomanes tunhridgense of Linneus,§ 
Hudson, II and many of our earlier authors : it was separated by 
Smith as a genus in the fifth volume of the Turin Transactions,^! 
and the name has been adopted by nearly all subsequent bota- 
nists, a strong proof of the weight of Smith’s authority, for even 
now, when generic subdivision has extended to so great a length, 
we have no new genera founded on such imaginary differen- 
ces as those which separate Hymenophyllum from Trichomanes, 
In my endeavours to draw a line between these genera I have 
been totally unsuccessful : if we regard the exserted receptacle 
of the one, or the bivalved involucre of the other, the only con- 
clusion at which we can arrive is this — that those species with 
* Eng. Bot. 162. f Flor. bond, 71. | Bolt. Fil. tab. 31. 
§ Sp. PI. 1.561, II Flora Anglica, ii. 461. ^ Act. Taiir. v. 418. 
y2 
