62 baker's north YORKSHIRE. 



are much pitted and channelled by the influence of time and 

 weather. There are numerous lichens upon the rocks and walls, 

 Endocarpon smaragdulutn, Biatora polytropa, thin-crusted black- 

 fruited LecidecB, Parmelia saxatilis, P.physodes and other foliaceous 

 species, ix\ngQ.X\k.t\Mi\.%oi Everjiiajubata 2cadiE.furfuracea; and 

 in the shaded sandy ground beneath the rocks and in the trenches 

 by the wall-sides abundance of DicraneUa heteroinalla ^nd/im- 

 germannia albicans. The peaty rills gradually converge to the 

 head of a little grassy gill, and the streamlet which they form, not 

 as -in the limestone sinking through the surface of the hill to ap- 

 pear as a fuU-gro'ftm rivulet at the foot of its slope, makes its way 

 down the hill-side with Jiiuch animation, at first forcing a road 

 down a narrow channel where it is almost hidden by overhanging 

 grasses and rushes, and gathering as it goes, fed by the numerous 

 tiny watercourses edged by Stellaria uliginosa and Montia 

 fontaua, now leaping with foam and bubbles over a moss- 

 fringed rock, that would interpose to bar its progress and ever 

 and anon- spreading out into a more open channel and rippling 

 noisily.over the scattered pebbles. The principal mosses of 

 the stream are Racomitrium adculare, Hyoco7nim?i flagellare and 

 a form of Hypmtm palustre : and the swamps upon the hill-sides 

 yield abundance of Sphagna, Bartramia fontana, Bryum veti- 

 tricosian, Auhicomnion paltistre, Hypnumflmians, If. cuspidatum, 

 and H. strainineum : and of the less frequent species the bogs yield 

 Hypnuin exannidatiini and Mnmm subglobosum and the walls 

 and rocks Dicranum fuscescens, Weissia cirrhata, and Ptychomi 

 trium polyphylhun. The natural woods of the hill-side are 

 principally Oak, with more Rowan and Birch, and less Hazel 

 and Ash than in the limestone dales, with more of swamp (with 

 Chrysosplenzu?n, Caltha, Cardamine sylvatica, Crepis paludosa, 

 Equisetum Telmateia, Spircea Uhnaria) and less of underwood 

 and entirely without the characteristically Xerophilous species.' 

 Amongst the higher moorlands Of the west there is a difference 

 in vegetation which is conspicuously connected with the differ- 

 ence between the hills of the two types in respect of humidity of 



