252 PROCEEDINGS OJ? THE GEOLOGICAL SOCIETY. [Mar. 8, 



cordially agree. I never could see any sound stratigraphical reason 

 why the strata in the Elgin country that have yielded Hyperodapedon, 

 Telerpeton, and Stagonolepis should be separated from the Old Eed 

 Sandstone. The piece of Lias (or Oolite as it used to be called) at 

 Linksfield, to my mind, does not alter the question. Mr. Geikie, in 

 a letter lately received, has no doubt that it is a large erratic ice- 

 borne mass. In Northamptonshire Professor Morris has described a 

 larger erratic mass of Oolite, 380 yards in length, exposed in a cutting 

 in Boulder-clay on the Great Northern railway *. I have seen it, 

 and can vouch for his accuracy. Mr. Judd has since discovered 

 several such masses of erratic Marlstone, some of them even of 

 larger size, in the same county, associated with Boulder-clay, and 

 resting indiscriminately on Oxford Clay, Inferior OoHte, and all 

 the formations between. These I have also seenf. The whole 

 mass near Elgin, which has been largely quarried, seems to me to 

 be of the same nature as the great Marlstone and Oolitic erratics 

 observed by Professor Morris and Mr. Judd. If the Hyperodapedon 

 of the Trias is nearly allied to a living lizard, it may very well be 

 equally allied to a lizard of the Old-Red-Sandstone period. In 

 like manner Teleosaurian Crocodilia go down from our times to 

 Liassie or even to Permian times. There can surely, then, be no 

 difficulty in carrying the former two stages lower, to the strata in 

 which Stagonolepis and Telerpeton occur, and which I still believe 

 to be true Old Red Sandstone ; for, as Professor Huxley has well 

 remarked, there is no " necessary relation between the fauna of a 

 given land and that of the seas on its shores " %. This applies 

 to geological time as well as to geographical space. 



In conclusion, so vast a continental period as that between the 

 close of the Silurian and the end of the Triassic epochs must have 

 witnessed many disturbances of strata, and changes of physical geo- 

 graphy, though the actual identity of the continent was not ob- 

 literated thereby. I will only give one comparatively modern instance 

 to show how a continent may become changed, but stiU remain the 

 same continent, notwithstanding great physical alterations involving 

 upheaval of mountains and the formation of great lakes. From 

 Upper-Eocene times to the present day it is certain that a great part 

 of what is now Europe has existed as a continent ; and yet the Alps 

 and the Pyrenees have to a great extent been raised since that 

 time ; and many vast Miocene fresh lakes in various countries, 

 with a marine interstratification in Switzerland, have been spread 

 across the plains. These also have disappeared, because their con- 

 solidated sediments have since been raised in places into mountains. 



Finally let me rapidly pass in review what I think we know of 

 terrestrial as opposed to marine epochs in the British and neigh- 

 bouring areas of Europe. 



* Quart. Journ. Geol. Soc. vol. xix. p. 317. 



+ See Brickenden on the Boulder-clay near Elgin (Q,uart. Journ. Geol. Soo. 

 1851, p. 291), C. Moore on the so-called Wealden Beds at Linksfield, &c. 

 {ibid. 1860, p. 445), and A. Geikie on the phenomena of the Glacial Drifts of Scot- 

 land (extracted from the Transactions of the Geol. Soc. Glasgow, 1863, p. 48). 



% On Hyperodapedon (Quart. Journ. Geol. Soc. 1869, vol. xxt. p. 149). 



