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greater part, is replaced by a yellow sandy limestone. The freestone 

 beds, which are not to be lithologically distinguished from those of the 

 great oolite, gradually increase in number and thickness, from the 

 neighbourhood of Bath to the Cotteswolds, east of Cheltenham, where 

 they constitute the whole of the escarpment. This vertical importance 

 is retained through the north of the country examined ; but to the 

 eastward of the valley ranging from Stow-on-the-Wold to Barrington, 

 near Burford, a change takes place, both in the structure and thick- 

 ness of the formation. The freestone beds are there replaced by 

 strata of nodular coarse oolite, containing numerous specimens of 

 Clypeus sinuatus : the sandy portion consists of only a thin bed, and 

 the thickness of the whole formation is diminished from 150 feet to 

 about 50. The most characteristic fossils which were noticed by the 

 author, are Clypeus sinuatus, Terebratula fimbria, Modiola plicata, 

 Pholadomya fidicula, Trigonia costata, Gryphcea columba (Sowerby), 

 Lima proboscidea, and Ammonites corrugatus. ' 



The formation occupies, in Gloucestershire, a much greater super- 

 ficial importance than has been hitherto assigned to it. Besides form- 

 ing the upper part of the escarpment, it constitutes, to the south of 

 Cheltenham, the inclined plane which ranges between the crest of the 

 hills and the ridge of Fuller's earth and great oolite, and, to the north 

 of that town, the summit of the whole of the hills, with the exception 

 of an occasional capping of great oolite. 



Fuller's earth. — This argillaceous deposit is of much less importance 

 in the district surveyed than in the neighbourhood of Bath. The 

 mineral to which it owes its designation is wanting, or is represented 

 by only an occasional bed of impure, useless Fuller's earth. Its greatest 

 thickness in Gloucestershire is estimated not to exceed fifty feet : in 

 the Cotteswolds it was found to be not more than twenty-five ; and 

 the deposit was ascertained to thin out to the north-east of a line 

 passing from the neighbourhood of Winchomb to Burford. 



Great oolite. — The threefold arrangement of upper rags, fine free- 

 stone, and lower rags, into which this formation was divided near 

 Bath, does not prevail through the whole of the district examined. 

 The upper rags, consisting of soft freestone and hard shelly oolite, 

 were traced to Cirencester ; but to the north-east of that town they 

 are replaced by a rubbly white argillaceous limestone. In the middle 

 division, fine workable freestone is of partial occurrence ; and the 

 greater number of the beds are composed of hard oolitic limestone. 

 The lower rags, consisting of coarse shelly oolites, resting upon 

 closely-grained or crystalline limestone, extend from Bath to Wotton 

 Underedge ; but in the neighbourhood of that town a change occurs, 

 and their position is occupied by beds of fissile calcareous limestone. 

 These strata were traced through the whole of the north-east of Glou- 

 cestershire, and to the neighbourhood of Burford. They are exten- 

 sively worked as a tile-stone ; possess the lithological character of 

 the Stonesfield slate ; have their fissile property developed by exposure 

 to atmospheric agency ; contain Trigonia impressa, the characteristic 

 fossil of Stonesfield ; and, on comparing the strata of Burford with 

 those which rest at Stonesfield on the slaty beds, it was found that 



