41 



very common on the Alps and Pyrenees, and most of the growing 

 plants in our collections are of continental origin. Mr. Moore, 

 however, observes that he has received specimens from Mr. Shep- 

 herd, of Liverpool, gathered in Derbyshire and Yorkshire, but 

 without any particular habitat being assigned. The species is very 

 distinct in character, when closely compared with any form of C. 

 fragilis or C. dentata : the fronds are, strictly speaking, bipinnate, 

 but the pinnules are so deeply lobed or pinnatifid, that, although 

 always confluent, they give them at first sight the appearance of 

 being again pinnate : the lobes are linear, very obtuse, and gene- 

 rally divided on the margin with two or three blunt teeth pointing 

 upwards. The venation is more or less compound, according with 

 the division and toothing of the pinnules, and the small roiindish 

 sori are sub marginal. The fronds are variable in height, from 

 two to six or eight inches in foreign plants, but I have never seen 

 any British specimens from the wall at Low Leyton above three or 

 four inches long. 



It is not at all difficult to cultivate and multiply when once 

 established ; but is more susceptible of injury from the accumula- 

 tion of moisture about the roots than C. fragilis; good drainage is 

 therefore more imperative, but otherwise it may be similarly treated. 

 A sheltered situation in the out-door fernery is better than confine- 

 ment under glass. 



CYSTOPTERIS MONTANA. Mountain Bladder-Fern. TAB. XXIV. 



Fronds triangular bipinnate : pinnules of lower pinnae pinnate ; 

 ultimate pinnules and lobes deeply pinnatifid, their segments 

 toothed at the apex. 



Cystopteris montana, Link. Hooker and Arnott. Babington. Moore. 

 Cystopteris Myrrhidifolium, Villars. Newman, Hist. Brit. 

 Ferns, 97. Polypodium montanum, Allioni. Aspidium mon- 

 tanum, Swartz. 



First found as a British species in 1836, by Mr. W. Wilson, on 

 Ben Lawers, one of the Breadalbane mountains, and since by others 

 in several localities on the mountains of Perthshire and Forfarshire, 

 but so sparingly distributed that it maybe considered as one of our 

 rarest ferns. The rhizoma is filiform, branching and creeping, like 

 that of Polypodiwn Dryopteris, or P. calcareum,ihe latter of which, 

 especially, this species nearly resembles in habit and general appear- 

 ance. The fronds might almost correctly be regarded as ternate, 

 the two lower pinnae, which are opposite, being so much larger than 

 the others as often to be nearly equal to them in the aggregate ; it 

 is in this pair only that the pinnules are pinnate, all those of the 

 upper pinna3 being only deeply lobed : the lower inferior pinnule of 



