FERNS OF GREAT BRITAIN AND IRELAND. 89 
is also met with in the Hebrides and Orkneys, Shetland, and the Isle of 
Man. In Ireland it is rare, occurring principally in the northern and 
eastern provinces: In elevation it extends from the coast level in the 
west of England to upwards of 3000 feet in the Western Highlands. 
Geographical Distribution—This fern is scattered nearly throughout 
Europe, extending from Iceland and the Scandinavian countries south- 
wards through the British Isles and continental Europe to Spain and 
Italy. In Asia it is recorded from Unalaschka and Kamtchatka, and also 
along the chain of the Altai (Hb. Hooker). Algeria, in Africa, is also 
mentioned as producing it; whilst in America, where it is sometimes 
known under the name of P. connectile, it is met with from Greenland and 
Labrador on the eastern side, to Prince William’s Sound on the western, 
extending southwards to the Rocky Mountains, to Canada, and to the 
Northern United States (Hb. Hooker). 
Rhizome.—Creeping extensively, branched, tough, slender, about the 
thickness of a straw, dark brown, pilose and slightly scaly while young, 
the older portions denuded both of scales and hairs. 
Scales.—Lanceolate, golden brown, intermixed with other cobwebby 
hair-like ones. 
Fibres.—Numerous, much branched, dark brown, invested with golden- 
brown cobwebby deciduous pubescence. ; 
Stipes.—As long as, or more frequently longer, and often much longer, 
than the frond, erect, brittle, pale green, furnished near the base with a 
few scattered subulate scales; the whole length clothed with minute re- 
versed hairs; distant and lateral on the rhizome. 
Vernation.—Circinate; the pinne rolled up separately towards the 
rachis, which is then rolled from the point downwards. 
Fronds.—From four to eighteen or twenty inches in length, including 
the stipes, adherent to the rhizome, membranaceous, of a dull pale green, 
hairy, ovate-triangular, much acuminate, pinnate below, the apex of the 
frond pinnatifid. Pimne deeply pinnatifid, linear acuminate, nearly or 
quite opposite, the lower pair lanceolate, deflexed, sessile, but attached by 
their midrib ; distant from the upper pinne, which are sessile and broadly 
attached, and, except occasionally the second pair, confluent, so that the 
united bases of the opposite pairs form by the direction of their two basal 
lobules a cruciform figure ; all the upper pinnz have their points directed 
towards the apex of the frond. Lobules oblong, obtuse, entire or slightly 
crenato-dentate, directed towards the apex of the pinne. 
Venation of the lobules—consisting of a flexuous mdvein, from which 
proceed alternate or sometimes opposite veins; these veins extend to the 
margin of the lobule, and are either simple or become once forked about 
halfway their length (the simple veins ?), or when divided, the anterior of 
the venules, bearing a sorus at a short distance from the edge of the lobule 
N.S. VOLju- N 
