420 ME. L. BICHAEESON ON THE INFEBIOE OOLITE [ISToV. I907, 



IV. CoBEELATION OF THE STRATA OF THE BaTH-D0ULTIJS t G DlSTEICT 

 WITH THOSE OF DuNDET HlLL, J5TEAE BEISTOL. 



The Inferior Oolite of Dundry Hill, together with the underlying 

 deposits dating from Dumortierice to spinati, has been very thoroughly 

 investigated by Mr. S. S. Buckman and the late Edward Wilson. 

 At the conclusion of their work the only matter of importance to 

 the stratigraphist about which they felt in doubt was the precise age 

 of certain beds at the western end of the hill. They were not able 

 to settle whether the beds were on the same horizon as the Dundry 

 Freestone (but much thicker), or came above the ' Coralline Beds ' or 

 Upper Coral-Bed. I think there can be little doubt that the beds 

 under consideration are of later date than the Upper Coral-Bed, and 

 equivalent to the Doulting Stone and the Anabatici-Limestones. 

 Before discussing this matter in full, the stratigraphical relations 

 of that end of Dundry Hill to the nearest portion of the Bath- 

 Doulting district may be pointed out. 



The Timsbury-Sleight section is the nearest to the easternmost 

 section on Dundry Hill described by Buckman & Wilson — that made 

 by excavating on the eastern flank of Maes Knoll. 



In the Timsbury-Sleight section specimens of Shynchonella 

 Moorei were very abundant along a line near the top of the brown, 

 richly-ironshot marl of about Struckmanni hemera. There can be 

 little or no doubt that this Rhync7ionella-~Be& corresponds to the 

 Upper Rhynchonella-Bed of Buckman & Wilson's section on the 

 eastern flank of Maes Knoll. 



At Timsbury Sleight the Midford Sands are h\ feet thick, and 

 immediately overlie the Struckmanni-Beds ; but at Maes Knoll 

 the succeeding deposit is a clay-deposit, with occasional sandstone- 

 and limestone-bands, measuring over 62 feet in thickness. The 

 ' Maes-Knoll Conglomerate-Bed ' succeeds the clay-beds, and a 

 similar deposit follows — as we have seen — the Midford Sands at 

 Timsbury Sleight. So the deposit which intervenes between those 

 of Garantiance and Struckmanni hemerae, as regards lithological 

 structure, is strikingly dissimilar at the two localities. 



Above the equivalent of the Upper* Triyonia-Gcrit at Maes Knoll 

 there has certainly been some representative of the Dundry Free- 

 stone ; but how thick it was, or whether it rests directly upon the 

 ' grit,' or was separated therefrom by the Upper Coral-Beds, were 

 questions which it was not found possible to answer. Probably both 

 the Upper Coral- Bed and the upper portion of the Dundry Freestone 

 have been removed by a Bathonian erosion. 



In the large quarry near the church at Dundry, however, the 

 Upper Coral-Bed is well-displayed, resting upon a good development 



Montlivaltia from Stantonbury Hill, at which place the Inferior Oolite contains 

 Rhynchonella hampenensis, Acanthothyris spinosa, Aulacothyris carinata, etc., 

 these beds resting directly upon the Midford Sands as at Midford. Hence the 

 identification of the Terebratula perovalis must be wrong, and the position of 

 the bed in our paper must be emended.' The blocks of limestone from the 

 shafts regarded as portions of two beds, the Triyonia-Gvit and Montlivaltia- 

 Bed, are, there is little doubt, fragments of one and the same bed — the Upper 

 Triyonia-Grit. 



