56 WAYSIDE AND WOODLAND FERNS. 



deeply cut into blunt lobes, and the back scaly as well as hairy. 

 The pinnae are more nearly opposite (Plates 49, 59). 



It grows in similar situations to the last, but has a larger 

 number of stations, some at a lower elevation than 2000 feet. 

 At Llyn-y-cwn, on Glyder-vawr near Snowdon, is a well-known 

 station for it, where several lives have been lost in the attempt 

 to gather specimens from the precipitous rocks. It has also 

 been found at Clogwyn-y-Garnedd on the other side of 

 the Pass of Llanberis ; in Westmoreland, Cumberland, and 

 Durham. In Scotland it is recorded from near Loch Skene, 

 Moffat ; the hills between Dumfries-shire and Peebles-shire, 

 Ben Chonzie, Perthshire, and the Clova Mountains, Forfarshire. 

 Its world range includes Arctic and Northern Europe, and 

 the mountainous countries generally. In Asia it occurs in 

 Siberia, and Dahuria ; also in Japan, Canada, and the United 

 States. 



The specific name ilvensis is the Latin form of Elba, in which 

 island was found the first specimen identified as distinct. 



The Bladder Ferns (Cystopteris}. 



Though presenting something of a likeness to the Lady Fern 

 in their fragility of stipes and rachis, and the delicate texture 

 of their pinnae, a glance at the back of the newly expanded 

 frond reveals a great difference in the indusia of the Bladder 

 Ferns as compared with the Lady Fern. In Cystopteris the 

 small globular sori are at first covered by a long tapering and 

 inflated indusium, which is attached by its broad end to the 

 vein underneath the sorus. The bulging centre of this cover 

 has the appearance of a blister or bladder, and this has suggested 

 the name Cystopteris, derived from the Greek Kystis, a bladder, 

 and pteris, a fern. When the spores are ripe, however, the 

 indusium turns back with its long point as far from the sorus 

 as possible (Plate 4). 



