108 PALAEOZOIC TIME. [CHAP. VII. 



but a West-European continent, which presented a con- 

 tinuous front to the Atlantic, considerably to the west of 

 what are now the shores of France and Ireland. 



It is now time to seek for the boundaries of the seas 

 and lakes in which the Dyassic sediments were deposited. 

 The open Mediterranean sea of the Carboniferous period 

 appears to have been converted into a large inland sea, 

 like the Caspian of the present day, surrounded by a 

 rocky and hilly continent, on which grew trees and plants 

 of various kinds. Many of these plants are closely allied 

 to those of the Carboniferous, but species belonging to the 

 Yew and Fir tribes, which nourish on dry ground, pre- 

 ponderate over the reeds, ferns, and gigantic lycopodia 

 which flourished in the Coal-measure swamps. 



The western part of this inland sea stretched across the 

 centre of what is now the North Sea, and covered a portion 

 of north-eastern England, and its actual margin seems to 

 have lain only a little to the west of the outcrop which now 

 runs through the counties of York and Nottingham, curv- 

 ing round to the eastward beneath the south of Lincoln- 

 shire. If the Pennine range formed a continuous barrier 

 in Dyassic times, its eastern slope must naturally have 

 been the shore-line of the Magnesian Limestone sea, and 

 such is now the prevalent opinion ; but it is only fair to 

 state that the geologist who first studied the uplifts of the 

 Pennine range l came to the conclusion that they were post- 

 Dyassic. Strong arguments were, however, subsequently 

 adduced by other writers to show that he was mistaken, 

 and it is perhaps desirable that the reasons for the view 

 here adopted should be stated seriatim? 



1. The flexures of the South Yorkshire and Derby coal- 

 fields are certainly pre-Dyassic, and as their major axes 



1 Hull, in " Quart. Journ. Geol. Soc.," vol. xxv. p. 171. 



2 See Wilson, " Geol. Mag.," ser. 2, vol. vi. p. 500, and Teall, vol. 

 vii. p. 349. 



