HYMENOPHYLLUM AND TRICHOMANES. 
21 
THE TUNBRIDGE FILM FERN. 
Hymenophyllum Tunbridgense. — Smith. 
A somewhat similar fern, with broader 
fronds and having more divisions in the 
pinnae, sometimes being split into 8 or io 
lobes. Less common than H. unilaterale. 
Found in Cornwall, Devon, Somerset, 
Kent, Sussex, Lancashire, Cheshire, York- 
shire, Cumberland, Westmoreland, Gla- 
morgan, Brecknock, Merioneth, Carnar- 
von. In 5 Scotch and 6 Irish counties. 
Valentia, Mull, Bute, and Arran. 
A native of Norway, Sweden, France, 
Germany, Italy, Belgium, India, Madeira, 
Azores, Mauritius, Chili, Brazil, New 
Holland, New Zealand, Tasmania, Valdi- 
via, and the Cape of Good Hope. 
The fronds paler in colour than those of H. unilaterale. The 
involucres without stalk and the upper margin not serrated. 
Variety. 
latifolium, Praeger. Found in 1882 at Narrowwater, county 
Armagh, by Mr. R. L. Praeger. 5x13- inches (in widest part), 
lower half depauperate and very narrow, above broad and plumose. 
Fig. 4. — Hymenophyllum 
Tunbridgense (showing 
fructification). 
The Film Fern succeeds well when fastened to a large stone 
with wires, provided the stone is kept wet. 
Both the Film Ferns are often found growing together, though 
H. unilaterale is the commoner of the two. In Hooker’s “ Synopsis 
Filicum,” the one-sided Film Fern is considered as a variety of the 
Tunbridge Film Fern. 
THE BRISTLE FERN. 
T RICHOMANES RADICANS. — Swartz . 
ONE of the Filmy ferns, and the only Trichomanes that is a native 
of Great Britain ; a genus that abounds in the Tropics. It grows 
on wet rocks in mountainous districts, delighting in the spray of a 
waterfall. The fronds vary in length from six to sixteen inches, 
are membranaceous, pellucid, smooth, and olive-green. The fronds, 
if uninjured, remain on the plant for several years. It is ovate- 
triangular in form, and feathery in appearance. Cannot be con- 
fused with any other fern. 
Bolton saw it in 1758 growing in abundance near Bingley in 
Yorkshire, but in 17S2 could only find one plant. The late Mr. 
Backhouse found it about thirty years ago tolerably abundant and 
flourishing luxuriantly in several places, extending over several 
miles in Wales, but the locality has been kept secret from a dread 
of its extermination by collectors. Mr. Backhouse gave me a 
