116 NEOZOIC TIME. [CHAP. VIII. 



The manner in which the Trias, with the succeeding 

 Jurassic and Cretaceous strata, rests upon a floor of Palaeo- 

 zoic rocks is shown in fig. 3. This is a section from the 

 valley of the Severn near Gloucester, through the counties 

 of Gloucester, Oxford, Buckingham, and Hertford, to the 

 valley of the Lea at Ware. It does not pretend to be an 

 accurate representation of the subterranean structure of 

 the country in respect to details, for the Palaeozoic rocks 

 have only been touched at two places along the line of 

 traverse, viz., at Burford and Ware. At the former place 

 Coal-measures were found at a depth of 1,080 feet from 

 the surface, the Trias being here only 424 feet thick, and 

 belonging wholly to the Upper, or Keuper division ; at 

 Ware, Silurian rocks were found below the G-ault, so that it 

 is clear that the Trias and all the Jurassic strata must thin 

 out against the slope of Palaeozoic rocks indicated in the 

 diagram, though how far eastward each division extends is 

 not yet known. It should also be stated that the flexuring 

 and faulting of the Palaeozoic rocks represented in the dia- 

 gram is quite theoretical, and is only intended to convey a 

 general idea of the way in which these rocks are supposed 

 to lie. 



In Ireland the Trias occupies a similar position, resting 

 on an uneven floor of Ordovician and Carboniferous rocks, 

 and being covered conformably by Jurassic and Cretaceous 

 strata. In Scotland also its stratigraphical relations are 

 similar. 



The British Trias is divisible into two series, the 

 lower being usually called the Bunter, and the upper the 

 Keuper, from their German correlatives. There is no re- 

 presentative of the marine member of the German Trias, 

 and the British Trias is certainly not a marine formation. 



The Bunter Beds occupy three distinct areas of deposi- 

 tion : one in Devonshire, which probably extends some way 

 beneath Dorset and the English Channel ; a larger one in 



