LITHOLOGY. 63 



surface. ' Into the Upper zone three of the limestone hills ascend, 

 Mickle Fell, Cam Fell, and Widdale Fell : and within its limits the 

 surfaces of these are covered in some places with a short grassy 

 turf which yields several of the species which are common in 

 grassy places throughout the low country, and in the crevices of 

 the limestone rock a few ferns and shade-loving plants occur, 

 and a few of the characteristically Montane species are also to 

 be met with, as for instance Draba incana, Viola lutea, Saxifraga 

 hypnoides, and Arenaria verna. To those portions of these three 

 hills where the limestone rock is at or near the surface fully 

 two-thirds of the Flowering Plants and Ferns which ascend into 

 the Upper zone are restricted. Which these species are can be 

 ascertained so readily by a glance through the list in the 

 Botanical portion of these notes that it does not appear needful 

 to recapitulate them here. But the far more numerous arena- 

 ceous peaks and ridges which ascend into the Upper zone 

 present everywhere what a botanist on the outlook for rarities is 

 apt to consider a monotonous repetition of the common gregari- 

 ous plants of a swampy heatherland, so that the following florula, 

 which is a list of all the species observed within the limits of the 

 Upper zone upon Raven's Seat moor and Nine Standards might, 

 with little variation, stand for any of the other hill-summits of 

 the eugeogenous type. 



FLORULA OF THE UPPER ZONE ON A EUGEOGENOUS HILL. 



Drosera rolundifolia 

 Cerastium triviale 

 KuIjus Chama'morus 

 Galium saxatile 

 Erica Tctralix 

 Calluna vulgaris 



Vaccinium Myrtillus 

 Juncus eflu.su.s 



,, squarrosus 

 Empetrum nigrum 

 Scirpus caispitosus 

 Eriophorum vaginatum 



Eriophorum 



angustifolium 

 Agrostis vulgaris 

 Aira flexuosa 

 Festuca ovina 

 Nardus stricta. 



Throughout the moorlands both upon the east and west of 

 the Central Valley this swamp-heatherland vegetation attains its 

 greatest perfection and covers without intermission the widest 

 tracts of surface over the Millstone Grit and the Lower Oolite : 



April 1888, 



