458 ON THE PLEISTOCENE DEPOSITS OF DEVON. 



climate of Devon ; therefore the maximum intensity of glacial con- 

 ditions mnst have produced a corresponding effect on Devon. 



Ignoring the hypothesis of glaciation put forward in the above 

 Table, a great snowfall and very penetrating frosts may at least be 

 invoked. From such agents and from the liberation of large quan- 

 tities of surface-water during fluctuations of climate, a much greater 

 surface-waste than that of the Head-period would result. The re- 

 distributed relics of such a period would be undistinguishable ; but 

 the fracture of flints to considerable depths from the surface and the 

 intrusion of earthy matter might be referred to it, though other dif- 

 ficulties presented by the clay with flint and chert are not so easily 

 solved. 



Discussion. 



Mr. Belt thought that sufficient reason had not been shown for 

 ascribing a Tertiary age to any of the surface deposits. At Bovey 

 Tracey lignites of Miocene age occupy the bottom of the valley, and 

 have been proved to extend to at least 50 feet below the present 

 level of the sea. The valley had therefore been excavated to more 

 than its present depth in Miocene or Premiocene times. The 

 Miocene deposits were covered with drift-gravels, boulder-beds, and 

 clays. In the latter the remains of Arctic plants had been found. 

 The drift-gravels mantled the slopes of the valley, as had been 

 shown by Mr. H. B. Woodward, and they reach at least up to a 

 height of 500 feet above the sea. The tops of many of the hills are 

 also covered with a drift-deposit containing far-transported boulders, 

 as had been described by De La Beche, Mackintosh, and others. In 

 Somerset, Mr. H. B. Woodward had recorded the discovery of a 

 tooth of a Rhinoceros in these drift-beds on the Oolitic summit of 

 King's Down; and in Dorsetshire, Prof. Prestwich had described 

 the occurrence of bones of Elephas antiquus, E. primigenius, and 

 other mammals in the drift-gravels on the hill at Portland Bill, 

 400 feet above the sea. All these drift-beds, whether in the bottom 

 of the valleys or on the slopes or tops of the hills, were thus clearly 

 shown to be of Posttertiary age ; and it remained for those who 

 held that the gravels had been deposited as the valleys were being 

 excavated to explain their presence up the slopes and on the tops of 

 the hills bounding the Bovey-Tracey and Teign valleys, when it was 

 evident that these valleys were in existence in Miocene times. To 

 him it appeared certain that the hills in the Glacial period had been 

 covered with water, over which the far-tran sported stones had been 

 carried on floating ice. 



Mr. Wmtaker said that he had been requested by Mr. U ss her to 

 state that his views were theoretical as to the earliest conditions of 

 these Pleistocene formations. With regard to the clay with flints, 

 every conceivable theory had been broached by French writers, one 

 of whom has lately brought forward a theory similar to his own. The 

 author's reasons for his notions of the period intervening between that 

 of the raised beaches and that of the sunken forests were derived 

 from investigations carried out, not only in Devonshire, but also in 

 Cornwall. He inquired whether Mr. Belt maintained that the gravel 

 went up the hillsides continuously, or only in patches. 



