1873.] SHARP OOLITES OP NORTHAMPTONSHIRE. 269 



the beds between the Upper Lias and the Lincolnshire Limestone, 

 in regular sequence, crop out upon the face of the escarpment. 



Pilsgate. 



In ascending Pilsgate Hill, half-a-mile further east, are passed 

 over, in strange succession at this level (little above the river Wel- 

 land) — the narrow outcrop of the Upper Estuarine beds, the Great 

 Oolite Limestone (from a quarry in which many years ago I ob- 

 tained fossils), the Great Oolite Clay, and further on in the village 

 Cornbrash ; with which the fault has brought into lateral contact 

 the Lincolnshire Limestone. 



Barnack. 



South of the road near Barnack, is Mr. Shelton's quarry, present- 

 ing a section in the marly beds of the Lincolnshire Limestone of 

 about 17 feet. At a little distance to the north of this quarry, and 

 at a lower level, is a wide flat of Oxford Clay, which in Barnack, 

 for a considerable distance, is brought into lateral contact with the 

 Upper Lias Clay ; and again, on the other side of the Welland, at 

 Uffington, about half-a-mile to the north, the Cornbrash occurs 

 nearly upon the same level. 



Fossils from the Cornbrash at Uffington. 



Avicula echinata, Sow. 

 Lima duplicata, Sow. 

 Ostrea Marshii, Sow. (large). 

 Peeten, sp. 

 Rhynehonella concinna, Sow. 



varians, Schloth. sp. 



Terebratula intermedia, Sow. 



lagenalis, Schloth. 



sub-lagenalis, Dav. 



obovata, Sow. 



Terebratula ornitbocephala, Sow. 

 Chemnitzia vittata, Phil. sp. 

 Ammonites macrocepbalus, Schloth. 

 Serpula tetragona, Sow. 

 Cidaris Bradfordensis, Wright. 

 Ecbinobrissus clunicularis, Lhwyd. 



orbicularis, Phil. sp. 



quadratus, Wright. 



Holectypus depressus, Leske (a var.?). 



Immediately south of Barnack, the road to Ufford passes through 

 the site of the widely spread quarries whence was obtained the 

 ancient and famous "Barnack Bag". Boman works are known to 

 have been executed in this stone, and Boman coins bestrew the neigh- 

 bourhood. Several Cathedrals and Abbeys, and most of the early 

 churches throughout a very wide extent of country, are built of this 

 time-enduring stone. A carved fragment from Crowland Abbey, of 

 the 12th century, shows few symptoms of decay. These quarries 

 have been exhausted for more than 400 years, and no section of the 

 ancient beds exists. They may be equivalent to the worthless 

 "Bag" beds of Weldon, Wakerley, and Little Casterton, or to the 

 shelly beds of Ponton : from the stone of the last, the Barnack Bag 

 lithogically is certainly frequently undistinguishable. Mr. Judd in- 

 forms me, however, that the Barnack Bag immediately overlies the 

 Northampton Sand, and I have found a corresponding shelly bed 

 elsewhere occupying the same position ; so that the Barnack Bag 

 is possibly situated quite low down in the general section of the 

 Lincolnshire Limestone, its peculiar character being attributable 



