The Carboniferous Succession heloio the Coal-Measures. 505 



The number of specimens found in various localities is remarkable 

 when the marine character of the deposit is considered. The 

 presence of drifted plants at any place must be purely due to 

 currents and the proximity of land. 



There can be no doubt, then, that the palteontological evidence 

 definitely correlates the Teilia Beds with the lower part of the 

 Pendleside Series of the Midlands and the Posirloiioniyn Becheri beds 

 of the Culm. Between Holywell and Bagillt the shaley division 

 of the series is well developed and reaches a normal thickness. 

 The beds are difficult to examine in detail, but we know that the 

 peculiar mutation of Productus Cora which characterises beds of this 

 horizon elsewhere is present in abundance {vide ante, p. 454). 



From Holywell south the black shale series are only occasionally 

 exposed, as they occupy the flat country east of the limestone 

 escarpment. 



In the ravine of Nant Figillt Wood, shales with Lingida and 

 obscure fish - remains appear to succeed limestones containing 

 Amplexi-zaplirentis and Cyatliaxonia, and the brick-pits near Hendre 

 gave a dark earthy limestone crowded with Posidoniella Icevis, 

 Glyphioceras reticidatnm, and Dimorphoceras Gilhertsoni, so that here 

 we get evidence of a zone of the Pendleside Series much higher in 

 the succession than the Posidonomya Becheri beds, which corresponds 

 to the black fossiliferous limestones of Horsebridge Clough, High 

 Green Wood, near Hebden Bridge. South of Hendre exposures 

 of the shale series are very few. The Survey mentions the 

 occurrence of Posidonomya and Goniatites in shale with cement 

 stones in the River Terrig, some miles further south. It is to be 

 regretted that the species were not determined. 



All through the Midlands and North Wales the southern limit of 

 the Pendleside Series is marked by a very rapid thinning-out, and it 

 is rather singular that this practically coincides with a latitude of 

 53° N. The following table illustrates the remarkable variation of 

 thickness in these beds that takes place within about ten minutes 

 of latitude : — 



Locality. 



Holywell, Co. Flint 



Near Buxton, Co. Derby 



Morridge, Co. Stafford 



Llangollen, Co. Denbigh 



Liileshall, Co. Salop 



TicknaH and Grace Dieu, Co. Leicester .. 



It is interesting, therefore, to note in this particular also the 

 intimate relation of the North Wales development of the Pendleside 

 Series with the larger Pennine area. 



7. Notes on the Paleontology. 



Daviesiella (Productus) LlangoUensis, Davidson, sp. Waagen 

 (Mem. Geol. Surv. India : Palseontologica Indica, sei*. xiir, vol. i, 

 No. iv, p. 613) says : "I create this genus for the reception of such 

 forms as Productus LlangoUensis and Chonetes comoides, Sow., which 



