Dr. Wheelton Hind— The Yoredale Series. 165 



where the beds, with from five to eight thick beds of limestone, to 

 which the name Yoredale Series was given, are typically developed ; and 

 they extend to about 1500 feet in thickness, but the Great Scar Lime- 

 stone below this series is ouly estimated to be 600 feet. In the south 

 of Yorkshire the massif of limestone itself is probably about 2000 feet 

 thick, but its base has nowhere been seen. This diminution in deposit 

 is not in any way due to denudation, for no evidences of unconformity 

 are to be observed. The Carboniferous Series as developed in 

 Wensleydale can be fairly well traced northwards into Swaledale 

 and Teesdale, but still north of this there is a tendency to subdivision 

 and variation, and the Great Scar Limestone becomes the Melmerby 

 Scar Series. 



In the neighbourhood of Ash Fell and Eoman Fell an interesting 

 series of sandstones with plant-remains, limestones of tolerable 

 thickness, conglomerates, and shales, is developed below the Great 

 Scar Limestone, the most southern trace of the Calciferous Sand- 

 stone Series so much more fully developed in Northumberland and 

 Scotland, and which would appear to be stratigraphically below the 

 Carboniferous Limestone mass of Central England. 



In certain districts of England the Carboniferous Limestone is 

 immediately overlain by the Millstone Grit (Coalbrookdale and Clee 

 Hill). This is generally said to be the case in Flintshire also, if 

 the beds classed as Millstone Grit really belong to that formation, 

 which I doubt on palseontological grounds. In the Forest of Dean the 

 intervening beds are estimated at 116 feet (Wethered). At Clifton 

 about 300 feet of shales, sandstones, and limestones occur between tlie 

 grits and the main mass of limestone, and here the limestone fauna 

 is largely present. In South Wales the Carboniferous Limestone is 

 succeeded by the Gower Series of about 1600 feet of black shales and 

 sandstones. At Tenby they are only represented by a few feet, with 

 beds of limestone, and contain Goniatites. Mr. H. B. Woodward 

 ("GeoL Eng. and Wales," p. 167) says they remind one of the 

 Black Limestones of North Devon that occur at the base of the 

 Culm-measures. 



In Europe and North America the intermediate beds between 

 the calcareous beds of the Carboniferous period and the Coal- 

 measures seem to be to a large extent wanting, and the 

 ■ misfortune is, that an attempt has been universally made to correlate 

 these beds with those of a series in Great Britain which have been 

 chosen as a type, and to identify certain well-marked beds with others 

 which have a purely local character. A fuller and more accurate 

 knowledge of Carboniferous palaeontology will, however, in time 

 establish a better basis for comparison. 



In the Carboniferous Series ot North Wales, Mr. Morton has shown 

 (Proc. Liverpool Geol. Soc. 1881-2) that the following series 

 obtains : — 



Cefn y Fedw Sandstone. 



Upper Black Limestone. 



Arenaceous Limestone. 



Upper Grey Limestone. 



Middle White Limestone. 



Lower Brown Limestone. 



