2tZ 



Yorkshire Naturalists at Askrigg. 



amara), White Milkwort, Wood Stitchwort, Shining- Geranium, 

 Cat-leaved Saxifrage (Saxifraga hypnoides)^ Saxifraga granulata, 

 Wood Sanicle, Sweet Cicely, Butterwort, Early Purple Orchis, 

 Spotted Orchis, Tway-blade, Orchis latifolia, Hahenaria albida, 

 Bladder Fern, Green Spleenwort, Wall Spleenwort {Asplenium 

 Ruta-imiraria). The Rev. J. R. Wynne-Edwards found Thlaspi 

 alpestre growing on lead waste above Ellerbeck. 



We are indebted to Mr. H. E. Wroot for the photographs 

 accompanying these notes (Plate XV.). 



APPENDIX 1. 



GEOLOGICAL NOTES ON THE DISTRICT AROUND ASKRIGG. 



COSMO JOHNS, F.G.S. 



Dealing with a district so well known, it was hardly to be 

 expected that, in a classic region like that of the Yoredales, 

 any new data could be collected in so short a time or any fresh 

 light thrown on the special development of its Lower Car- 

 boniferous rocks. The visit did, however, suggest that the 

 time had come when a new effort should be made to do some- 

 thing towards discovering the exact conditions under which the 

 Carboniferous rocks of Yorkshire were deposited, and to attempt 

 to unravel the somewhat complex problem of their later history. 



Before discussing this it would perhaps be best to briefly 

 describe some of the g^eological features noticed during the 

 visit. Whitfield Gill is, of course, too well known as Phillips' 

 typical example of the Yoredales to require more than the 

 intimation that it could not fail to arouse interest even among 

 geologists who had visited it before. The third day found an 

 enthusiastic band of geologists tramping round fair Semmer- 

 water. One of the very few survivals of the vast number of 

 lakes and morasses that dotted the county at the close of the 

 glacial period, it will soon be but a name. For what with man's 

 persistent efforts to win, for his own benefit, the land from the 

 water, and nature's never-ending work of denuding the hill 

 sides and depositing her spoils at the bottom of the lake, the 

 delta at the mouth of the stream that feeds it is rapidly growing 

 and the area of the little lake is diminishing. At the time of the 

 visit the water was lower than has been the case during the last 

 ■fifty years. An effort was made to discover indications of the 

 old strand lines, but the drift that now covers the hill sides is 



Naturalist, 



