LITHOLOGY. 6 1 



and narrower, and the dales open out, and the towns grow larger 

 and busier and smokier, far away to westward where the dales 

 grow narrower and steeper, and the ridges higher and the sum- 

 mits rise, hundreds and hundreds of square miles in area over 

 the higher ground, one broad surface of treeless, houseless, un- 

 cultivated moor. Of the Ericaceous shrubs Calluna vulgaris is 

 much the most abundant, and there are also Erica cinerea and 

 E. Tetralix, Empetrum nigrum and Vaccinium Myrtillus, thick- 

 swelling in the hollows and over the turfy undulations, stunted 

 and rough where the ground is drier and the rock nearer the 

 surface. \w\\\q.^x\q.x ^zjc&%Juncus squarrosus^ Galiinn saxatile, 

 Nardus stricta and Aira flexuosa are the most prominent plants, 

 and of the ferns Blech7ium boreale and the Common Brake. 

 Amongst the heather Hyloconmnn splendens is the commonest 

 moss and of the Lichens Cetraria aculeata and Cladonia rangi- 

 ferina and C. cocci/era and in the spaces between the tufts are 

 Polytrichtun commune and Dicranum scopariu7n. In the 

 swamps grow Scirpus ccespitosjis, Eriophoi'um vaginaUwi and 

 sometimes Drosera rotundifolia and Narthecium, and in pools 

 and peaty rills abundance of Hypnutn fluitans, Leucobryuvi 

 glaucion and various species of Sphagnum. Where the turf has 

 been bared away for fuel are Polytrichum piliferum and P. jutii- 

 perinum and wide-spreading patches of Ceratodon purpureus. 

 Vaccinium Viiis-idcea is not plentiful here, and V. Oxycoccus I 

 know in this neighbourhood in one swamp only, where Corydalis 

 claviculata grows upon the rock below. 



The crest of the hill is marked by an irregular line of scar- 

 like ' edges ' of gritstone, huge boulders of which are piled about 

 in picturesque confusion immediately beneath the edge and scat- 

 tered more sparingly far down below towards the bottom of the 

 slope ; and the walls along the hill-side and over the moor-top 

 are built of loosely-piled blocks of this same gritstone, which is 

 a sandstone of coarse grain and moderate firmness of texture, 

 with large crystals of quartz thickly imbedded amongst it. As 

 in all the gritstones the blocks are rough and unshapely and 



April 1888, 



