THE BRITTLE BLADDER FERN. 95 



lochen, on Craig Maid, in Glen Isla, in Glen Dole, and 

 in Glen Fiadh ; in the county of Inverness, amongst the 

 mountains and rocks near Loch Erricht ; in the county 

 of Perth, on Ben Chonzie, near Crieff, on Ben Lawers, 

 on Ben Voirlich, on Craig Challiach, and in Glen Lyon. 

 In the county of Ross, near Castle Leod, on the Raven 

 Rock ; and in the county of Sutherland, at Assynt and 

 on Ben Hope. In Ireland, in the counties of Donegal, 

 Kerry, Leitrim, Meath, and Sligo ; and in the following 

 places : to the east of Lough Eske, in a glen on the 

 Rosses, and in the Thanet mountain passes. In Kerry, 

 on Brandon Hill ; in Leitrim, on the Glenade Moun- 

 tains ; in Meath, at Navan, and in Sligo, on the Ben 

 Bulben Mountains. The Holly Fern is found at 

 heights ranging from a thousand feet above the sea- 

 level to three thousand two hundred feet above it. 



XXV. THE BRITTLE BLADDER FERN. 



Cystopteris frag His. 

 (Plate X., Fig. 2, page 67.) 



LENGTH OF FROND. Six to fourteen inches, depend- 

 ing on the character of its habitats. 



GENERAL DESCRIPTION. Roots black, fibrous, wiry, 

 numerous. Rootstock, a small, tufted cormus, which 

 spreads laterally, forming several adjacent crowns. 

 Fronds in numerous tufts from each crown, delicate- 

 green, brittle, herbaceous ; stipes of varying lengths, very 

 brittle ; leafy part broadly lance-shaped, bipinnate, the 

 ovate pinnae alternate or in pairs along the rachis, and 

 divided into irregularly-alternate, ovate pinnules, which 

 are again divided into rounded, oblong, much-indented 



