Vol. 50.] ON THE PURISECK BEDS OF THE VALE OF WARDOUR. 45 



induced Mr. Erodie to revisit the Vale of Wardour, and in 1854 l 

 he published a short account (but more connected than his previous 

 one) of the Wiltshire Purbccks. He stated that the Upper division 

 is wanting, but that the Middle and Lower groups are tolerably 

 well-developed ; he gave a descending section drawn up by the 

 Eev. 0. Eisher, in which the demarcation between Middle and Lower 

 Purbeck was fixed at a certain dark clay overlying a limestone 

 which contains Cypris purbeclcensis. Mr. Eisher also for the first 

 time recognized the ' Cinder-bed ' in the Vale of Wardour ; but the 

 Wockley section was not mentioned, and no attempt was made to 

 estimate the total thickness of the Wiltshire Eurbecks. 



The district was mapped by the Geological Survey during the 

 years 1852, '53, and '54, the map (sheet 15) being issued in 1850; 

 but no explanatory memoir has ever been published, nor did the 

 surveyor ever publish any account of his observations. 



A detailed account of the Middle Eurbeck Beds exposed in the 

 railway-cutting south of Teffont was written by one of us in 1881, 

 to accompany Mr. Etheridge's description of a new species of 

 Trigonia from the ' Cinder-bed ' of that locality. 2 The four 

 lowest beds of that section were grouped as Lower Eurbeck, but it 

 was subsequently found that they really belonged to the Middle 

 Eurbeck, the base of that division not being exposed in the 

 cutting. 



A general account of the geology of the Vale of Wardour was 

 compiled by the same writer, and printed in the Eroceedings of the 

 Dorset Nat. Hist. & Antiq. Field Club for 1883, vol. v. pp. 57-68. 



In 1890, while one of us was engaged in examining the Creta- 

 ceous rocks of Wiltshire, we jointly surveyed the eastern end of 

 the Vale of Wardour, with the special object of separating the 

 Eurbeck from the Wealden, and of ascertaining whether any 

 Vectian Sand intervened between the latter and the Gault. The 

 work was done on the six-inch Ordnance maps, and the result of 

 our survey was to convince us that not only were all these formations 

 present, but that a considerable thickness of strata lay between the 

 recognized Middle Eurbeck and the beds regarded as Wealden. 

 These strata seemed to be so clearly an upward continuation of the 

 Eurbeck series that we felt justified in referring the greater part of 

 them to the Upper Eurbeck group, a division which had not pre- 

 viously been recognized in the district. The existence of these Upper 

 Eurbeck Beds was announced in the Geol. Mag. for 1891, p. 292, 

 and in that note we expressed our intention of preparing a more 

 detailed account of the Eurbeck series. The present communica- 

 tion is the fulfilment of that intention. 



The correlation of the beds exposed in the various quarries and 

 cuttings in the central part of the Vale is by no means an easy 

 task, for though easterly dips are prevalent, and higher beds come 

 in gradually towards the east, yet this general inclination is so 



1 Quart. Journ. Geol. Soc. vol. x. p. 475. 

 a Ibid. vol. xxxvii. p. 246. 



