244 PKOCEEDINGS OF THE GEOLOGICAL SOCIETX, [Feb. 22, 



Stone has a great affinity to the contents of the Bala limestone, but it 

 is even more nearly related to the Coniston limestone, the northern 

 equivalent of the Bala calcareous rocks : when the strike of the 

 Keisley limestone is looked at, and this strike connected with the 

 range of the Coniston limestone in the north-west of England, the 

 relation of the Keisley area with the limestone of the Lake-country 

 is seen to be still more intimate. We can trace the Coniston lime- 

 stone (as shown by Professor Sedgwick) extending from Broughton 

 in Furness, by Monk Coniston, Low Wood, at the north-east end of 

 Windermere, Applethwaite, Kentmere, and Longsleddle, to Shap 

 Wells, where it is overlain by the Upper Old Red Sandstone and 

 the Carboniferous Eocks of the centre of Westmoreland. Thence 

 extending E.N.E., it passes under the Permian Rock of the. Vale of 

 the Eden, and reappears at Keisley on the same line of strike as 

 at Shap Wells, where it passes underneath the newer Palseozoic 

 Rocks. 



With reference to the fossiliferous flaggy shales which underlie 

 the ash-beds of Keisley and the porphyritic rocks of Gregory, but 

 which succeed the thick porphyritic masses of Dufton and Knock 

 Pikes, these as yet have no recognized analogues in the Lake- 

 country. They have, however, their equivalents in North Wales. 

 The black slates which are superposed on the igneous rocks of the 

 Arens and Arenigs are their representatives in this country, since 

 they afford similar fossils. 



The fossiliferous rocks of the Snowdon series, occuriing between 

 felspathic traps and ash-beds, also exhibit the same fossil contents, 

 and occur likewise Tinder nearly the same conditions as the flaggy 

 shales occupying the gently undulating area south-east of Dufton 

 Pike. 



If we take collectively the group of rocks from the N.N.W. limit 

 of the Lower Silurian area of the south-east of Cumberland, and of 

 the north-east of Westmoreland, we have the following sequence : — 

 namely, first and lowest, Skiddaw slates, or Lower Llandeilo, with 

 characteristic fossils. Second, a thick mass of porphyries, including 

 green and purple slates, and having ash-beds in their higher por- 

 tions. As yet these have afforded no fossils, and they represent the 

 Upper Llandeilo. Upon these Upper Llandeilo fossiliferous thick 

 black shales, felspar-porphyries, ashes, and limestones occur, which, 

 both in mineral nature and fossil contents, represent the Caradoc or 

 Bala group*. 



A short distance to the south-east of the Keisley lime-quarries a 

 mass of rocks presents itself having a nature altogether different 

 from the calcareous strata, and with a dip directly opposite to that 

 of the Keisley limestones. It is well seen in a hill called Whinskill, 



* In the determination of the fossils, I have been assisted by Professor T. Ru- 

 pert Jones, who examined the Entomostraca for me, and Mr. W. H. Bailey, pa- 

 laeontologist to the Irish Gl-eological Siu-vey, who has gone over a portion of the 

 remains from the Keisley limestone with me, and who recognized the affinity of 

 this limestone with that of the Chair of Kildare both in fossils and mineral 

 character. 



