CARBONIFEROUS LIMESTONE SERIES. 1 53 



The upper beds of limestone (equivalent to the Yoredale Series) 

 have yielded many fossils at Lowick and other places. They 

 include Spirifera lineata, S. sy7Ji?7ietrica, Prodiicius giganteus. Pinna 

 flexicostata, Edmondia sulcata, Sangiiinoliies iridinoidcs, Solenomya 

 pri?ncrva, Dentalium denialoidcum, etc. 



The Budle Shales (or Budle Schists of G. Tate, 1853), which 

 consist of red shales, are exposed at Budle Bay on the coast of 

 Northumberland, between Holy Island and Bamburgh. They 

 belong probably to the upper part of the Bernician Series, and 

 contain, besides Plant-remains, Lingida mytiloidcs, Spirifera hisidcata, 

 Orthis Michel ini, Posidonomya Becheri, and Eiiomphalus pe^itangulatus} 



The Ridsdale ironstone-beds, which correspond to the Scar 

 Limestone Series, yield Lithostrotion irregulare, Rhynchonella ptignus, 

 Strophomena atialoga, Chonetcs Hardrensis, Conularia qiiadrisulcata, 

 Goniatites obiusiis, etc.^ 



Among grits, there are the Inghoe, Simonside and Harbottle Grits — the last- 

 named belonging perhaps to the Tuedian Series. The Annstead Rocks are formed 

 of brown false-bedded sandstone. The Rothbury Grits, so named by Mr. W. 

 Topley, comprise thick beds of sandstone in the Bernician Series. 



CARBONIFEROUS LIMESTONE SERIES. 

 Lower Limestone Shales. 



This term is applied in South Wales, Gloucestershire, Somerset- 

 shire, and, locally, in the north-west of England, to the beds 

 between the Carboniferous Limestone and the Upper Old Red 

 Sandstone. They are sometimes known as the Lower Carboniferous 

 Shales. They consist of clays and shales, sometimes mottled, sandy 

 and micaceous, of various tints, blue, greenish-grey, and brown ; 

 with occasional beds of tough bluish limestone, like Carboniferous 

 Limestone, in the upper part, and alternating with beds of sand- 

 stone in the lower. In fact, they form a passage between the Upper 

 Old Red Sandstone and the Carboniferous Limestone, and Sedgwick 

 observed that they might be probably here and there replaced by 

 the conglomerates at the top of the Old Red Sandstone.* Some- 

 times the shale is very feebly represented, occurring in thin beds 

 rapidly alternating with limestone. 



In the gorge of the Avon the aggregate thickness of the beds is 

 stated to be 500 feet; in the Forest of Dean 250 feet; at Caldy 

 Island 400; and on the Mendip Hills 500 feet. In the north-west 

 of England the beds vary from a few feet to nearly 300 feet. 



1 G. A. Lebour, G. Mag. 1885, p. 73. 



^ G. A. Lebour, Geology of Northumberland, pp. 60, 66 ; Trans. N. ot 

 England Inst. Mining Engineers, xxii. 



2 Proc. G. S. iv. 223. 



