f SOILS AND SPECIES. 13 
Convallaria majalis L. 
*Scirpus Caricis Retz. 
*Carex digitata L. 
*C. ornithopoda Willd. 
Avena pratensis L. 
Keeleria cristata Pers. 
Melica nutans L. 
Bromus erectus Huds. 
Brachypodium pinnatum Beauv. 
*Asplenium viride Huds. 
Ceterach officinarum Wvil/d. 
*Phegopteris calcarea Wée. 
The Yoredale Rocks comprise two groups—soft black earthy 
shales with thin layers of limestone interspersed, and lighter 
coloured harder shales with layers of sandstone. The former, 
which are the older, are found immediately adjoining the lime- 
stone, and in the valleys along the course of streams, ¢.g., the 
Noe, the upper part of the Dove, Nun’s Brook near Buxton, the 
Wye between Bakewell and the Derwent, the Henmoor Brook, 
and at Ticknall and Calke Abbey in the south. The latter, 
which are more recent, occur at higher levels, as in the Edale 
Valley up to the summit of Mam Tor. Being impervious to 
water, the shales, especially the lower group, tend to produce a 
wet marshy surface with coarse grass rushes and bog plants as 
characteristic vegetation. 
G.—MILLSTONE GRIT.—Lying over the limestone shales 
on the east and north is the Millstone Grit, consisting mostly of 
massive coarse, hard sandstones, of which there are four or five 
beds, their outcrop running generally north and south. The 
shales on which they rest have worn away to a large extent, 
producing valleys lying along the outcrop, topped by continuous 
and lofty escarpments of grit on their eastern side. The grit 
constitutes a considerable part of the extensive and high table- 
land of the Peak, and also of Axe Edge, extending southwards 
1For an account of these see Dale’s ‘‘Scenery and Geology of the Peak 
of Derbyshire,” pp. 61-64. 
