101 FEENS OP THE LAKE COUNTRY 



Trichomanes are entire, and those of Hymenopliyllum 

 split lengthwise into two valves. 



The Tunbridge Film Fern (named from its being 

 first found near Tunbridge, in Kent) grows in matted 

 tufts upon rocks in moist warm places, usually carpet- 

 ing the damp surfaces of the rocks themselves, but 

 sometimes choosing the mossy ground, or living moss- 

 like on the trunks of trees the black wiry rhizomes 

 or creeping caudices interlacing themselves among their 

 neighbour plants. The fronds are very short, from an 

 inch to three or at most six inches long, membranous 

 and half-transparent, almost erect, and of a dull dead- 

 locking brownish-green even when at their freshest ; 

 lanceolate or slightly ovate, pinnate, with pinnse pin- 

 natifid or bipinnatifid, and having their branches 

 mostly on the upper side, though sometimes alternately 

 on each side of the pinna. The fronds are virtually a 

 branched series of rigid veins, winged throughout, ex- 

 cept on the lower part of the short stipes, by a narrow 

 membranous leafy margin. The sori are produced 

 around the axis of a vein, which, as before said, is con- 

 tinued beyond the frond-margins, and enclosed in an 

 urn-shaped indusium, involucre, or cover, consisting of 

 two almost perfectly round (orbicular) compressed 

 valves, spinosely serrate on the upper margin. It will 

 grow well in pots in equal parts of peat and silver sand, 

 scarcely caring for any other mould, but requires a 

 glass, and constant but not stagnant moisture. 



HABITATS. Coniston, Buzzard Hough Crag near 

 Wrynose (JRay), Hawl Ghyll near Wastwater (Hobson), 

 Ennerdale (7. Dickinson). 



