456 HYMENOPHYLLUM UNII.ATERALE. 



Brecknock, Cardigan, Carmarthen, Montgomery, Merioneth, 

 Carnarvon, Dumfries, Kircudbright, Ayr, Renfrew, Peebles, 

 Stirling, Forfar, Clackmannan, Perth, Argyle, Dumbarton, Ross, 

 Sutherland, Tyrone, Antrim, Londonderry, Donegal, Down, 

 Fermanagh, Galway, Mayo, Dublin, Wicklow, Tipperary, Kerry, 

 Islands of Mull, Arran, Shetland, Orkney, Langa, and Harris. 



Found also in the Faroe Islands, Norway, Bourbon, Tierra 

 del Fuego, Cape Horn, Falkland Islands, Tasmania, New 

 Zealand, Cape of Good Hope, Chiloe, and Hermite Island. 



Fronds pellucid-membranaceous, smooth, length from one to 

 six inches, colour dark olive brown, elongate-oblong, and jjinnate. 

 Pinnse distinct below, and decurrent and narrowly-winged above, 

 curved backwards, sub-unilateral, and several times dichotomously 

 forked; the fronds sometimes branched. 



Segments linear, obtuse, and spinulosely serrated. 



Stipes slender, one third the length of the frond. Rachis 

 narrowly-winged above. 



Veins several times dichotomously branched. 



Fructification extra-marginal. Receptacles free, central, oblong 

 club-shaped, and shorter than the valves of the involucre. 

 Involucres stalked, two-valved, convex, and quite even and entire 

 on the margins. 



The fronds endure for several years and renew their growth 

 annually, a circumstance pointed out by Mr. F. Clowes, of 

 Windermere. 



There are no varieties. 



