280 peoceedings of the geological society. [feb. 5, 



Sotjtheen Escarpment of the Neke Valley. 



"West of "Wansford Tunnel, near Elton, the Lincolnshire Lime- 

 stone, in like manner, has disappeared from the southern escarp- 

 ment of the Nene Valley ; but this has received the addition of the 

 Oxford Clay (based by the Kelloway Rock) as the summit bed, and 

 continues unaltered as to its constituent beds (represented in the 

 diagram of vertical sections *) as far as Higham Ferrers (18 miles) ; 

 near to which town, its upper portion, consisting of the Oxford Clay, 

 Kelloway Eock, and Cornbrash, trends southward, by Rushden and 

 Wymmington, into Bedfordshire, and, crossing the valley of the 

 Ouse, passes on into Buckinghamshire, and away. 



OtTKDLE. 



At Oundle (the eastern extremity of my horizontal section f), the 

 escarpment upon either side of the Nene valley is precisely the same. 

 No trace of the Lincolnshire Limestone is found, although at 

 Weldon, only six miles distant due west, it has a thickness exceeding 

 thirty feet ; so that the thinning away of that formation in the 

 short intervening space must have been very rapid. 



The Oxford Clay caps the high ground of that intervening space, 

 and extends over a considerable tract west and south-west of the 

 same ; while at Benefield, three miles west of Oundle, and also on 

 the line of my horizontal section, the Cornbrash and great Oolite 

 beds are also accessible. 



Fossils from Benefield. 

 Cornbrash. 



Khynchonella Morieri, Dav. I Terebratula lagenalis, Schloth. 



I obovata, Sow. 



Great Oolite. 



Terebratula intermedia, Sow. 



maxillata, Sow. 



Clypeus Mulleri, Wright. 



Cyprina Loweana, Mor. cf Lye. 

 Isocardia tenera, Sow. 

 Modiola imbricata, Sow. 

 Pinna ampla, Sow. 



In a quarry in the Great Oolite Limestone near Oundle, long 

 since closed, were formerly obtained specimens of a beautiful little 

 Ophiurella, named by Dr. Wright, 0. OriesbacMi, in compliment to 

 the late well-known veteran Northamptonshire geologist of that 

 name. 



Section in Great Oolite Limestone, Oundle. 



ft. in. ft. in. 



1. " Lime Earth " — a cream-coloured calcareous argillaceous 



material, sometimes used for mortar without burning. . . 2 



2. " Pendle " — very hard and gbstening, splits into thin 



flags or slates (Modiola imbricata, Sow.) 6 



3. BhieClay 9tol 



4. Calcareo-argillaceous bed, full of Ostrea Sowerbyi, Mor. 



& Lye, burnt for lime...., 1 Oto 1 3 



5. Very shelly hard limestone, in thin layers 9 



* See fig. 4, II., page 283. t Plate X. fig. 2. 



