482 PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. [May 9, 



side of tlie Pennine escarpment, overlies the fossiliferous flaggy strata, 

 is succeeded by a limestone which is the equivalent of the Bala 

 Limestone of Wales, and of the Coniston Limestone of the Lake- 

 country. The Coniston Limestone of the Lake-country is well seen 

 in the valley of Long Sleddale, having been worked on both the east 

 and the west sides of the valley. To the north-west of this lime- 

 stone, and supporting it, is a porphyry agreeing in all respects 

 with that immediately beneath the Coniston Limestone of Keisley, 

 near Dufton, which separates the limestone from the fossiliferous 

 zone. In Long Sleddale, north-west of this porphyry are ash-beds 

 which have been worked for slates ; but the quarries are now aban- 

 doned. The old slate-quarry is known as iStyle End Grassing Quarry, 

 and forms a portion of the southern skirts of Harterfell. Among 

 the debris of the quarrj^ a few fossils may be obtained, which 

 make their appearance in consequence of some of the slaty rocks 

 weathering along the planes of bedding. 



At Sunney Brow, a short distance west of Windermere Lake, the 

 same fossiliferous rocks occur, and under nearly the same circum- 

 stances as at Style End Grassing. A mass of porphyry here also 

 separates the ash-beds from the Coniston Limestone ; and the ash- 

 beds have been worked for slates at Pull Scar, on the side of a hill 

 immediately north-west of Sunney Brow. The fossils are rare in 

 the slaty rocks, but they are by no means uncommon in the green 

 sandstones which interstratify the slaty beds of Pull Scar ; and as 

 the coarser rocks have been used for diking, the fossils can be ob- 

 tained from the walls near the quarry, where they weather out 

 rapidly. 



The fossils of Style End Grassing and Pull Scar are nearly iden- 

 tical. They consist of Stenopora fibrosa, Petraia subduplicata, Orthis 

 vespertilio, 0. fiahellulum, Strojoliomena tenuistriata, and crinoid 

 stems. The fossils of Pull Scar are less distorted by cleavage than 

 those of Style End Grassing, and in both localities the forms are 

 those which are most abundant in the fossiliferous flags of Dufton. 

 The coarser strata of Pull Scar resemble the fossiliferous ash-beds of 

 Snowdon ; the finer beds of Style End Grassing are nearly allied to 

 the ash-beds of Grange Hill, which underlie the Bala Limestone of 

 the Chair of Kildare, in both of which deposits fossils similar to those 

 of the ash-beds of the north of England occur. 



The fossiliferous flags of Dufton, and the fossiliferous ash-beds of 

 the Lake-country, appertain to the Bala or Caradoc age. There 

 is,- in the north of England, beneath these a great thickness of 

 igneous rocks, which separate them from the Skiddaw Slates, and 

 which probably represent the Upper Llandeilo group. 



Although the evidence of the occurrence of the Upper Llandeilo 

 in the Lake-country is not satisfactory, the Bala or Caradoc forma- 

 tion is well marked, and is capable of being divided into three dis- 

 tinct groups. The lower is made up of igneous rocks and ash-beds, 

 but has no well-defined base ; the middle consists of a mass of highly 

 fossiliferous limestone, with associated black shales, and has been 

 described by Professor Sedgwick under the name of Coniston Lime- 



