592 



CYiii. POLTPODiACE^. \_Hymenophyllum. 



Of 



Wet rocks in mountainous countries, rare. Near Bingley, York- 

 shire. Powerscourt, and near the cascade at the foot of Turk Moun- 

 tain, Killarney; Hermitage Glen, Wieklow This rare and beau- 

 tiful Fern, together with the species of the following genus, have a 

 habit very different from the rest of our ferns, and belong to a 

 group which abounds in the tropics. Their froyids are membranous 

 and elegantly reticulated, and their depressed sessile ca/JswZes have a 

 jointed ring which completely surrounds them transversely, and 

 they are fixed at a distance from the ring to the receptacle. For 

 the numerous synonyms of this species, see Hoolu Sp. Fil, i. p. 125 

 A narrower and elongated form, with very copious fructifications, and 

 generally longer receptacles, is found by W. Andrews, Esq., at Inve- 

 ragh, Ireland ; the var. Andrewsii of Newm.' Brit. Ferns, ed. 3., p. 292. 



tf __ . . * _ , __ _ 



14. HyME>^oPHYLLUM Sm, Filmy-fern. (Tab. XI. f. ] 



(Tab. XI. f. 1.) 



Capsules upon a narrow receptacle, within a 

 2-valved involucre Avhich is of the same texture as the frond. 



Sori marginal. 



forh 

 leaf 



ISTamed from vjli]v^ v[.u]vqc^ a 



opening above. 



membrane 



pellation. 



1. IT. Tunhridgense Sm. {Timhridge F^ ; fronds tender pin- 

 nate, pinnte distichous vertical pinnatifid the segments linear 

 undivided or bifid and as well as the axillary solitary suborbi- 

 cular compressed involucre spinulose-serrate, rachis strongly 

 winged. E. B. t. 162. 



Moist rocks among moss, in mountainous countries. First found 



at Tunbridge. 



Abundant in the north-west of England and in Wales 



and many parts of Ireland. Banks of the Clyde ; Luss ; Arran, 

 Habit tender and delicate. P2//?2te pointing in two opposite directions, 

 flat and vertical, on the same plane with the winged rachis. In- 

 volucres nearly orbicular, slightly swollen at the base, where the cluster 

 ofcapstiles is lodged, the rest compressed, especially at the margin of 

 the valves. When dry there is a degree of elasticity in the plant. 



2. H. Wilsoni Hook. (Scottish F.) ; fronds rigid pinnate, pin- 

 nse recurved subunilateral wedge-shaped and 4 — G-lobed, the 

 segments linear undivided or bifid spinuIose-sex*rate, involucres 

 axillary solitary ovate inflated entire, rachis only slightly mar- 

 gined towards the extremity, Wils. in E. B. S. t. 2686. 



Wet rocks. North of Enj^land and Wales. 



High granite rock. 

 Abundant in the Highlands, especially in 

 the west of Scotland, and in many parts of Ireland 



near Bodmin, Cornwall, 



. _ More rigid, 



and with larger reticulations than the last : quite distinct in its mode 

 of growth, for all the pinnce are strongly curved backwards, in a di- 

 rection contrary to that of the fructification : the involucre is totally 

 different, larger, browner, of a more rigid texture, trulv ovate, each 

 valve remarkably convex for its whnh 



f. 



only 



the 



valves being applied to each other, and they are quite entire. — This 

 is probably the H. unilaterale of Willd. Sp. PL 5. p. 521., a native 



of Bourbon ; but we have seen no authentic specimen to confirm the 

 opinion. - 



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