12 



during the drift period. Cases still more striking as regards eleva- 

 tion have been lately noticed by Professor Ramsay. He finds drift 

 with shells on the mountains of Snowdonia at heights of 1,800 to 

 2,300 feet.* 



The shores of Loch Lomond present many isolated boulders of 

 granite, but few are of such enormous size as above stated. These 

 phenomena, however, come under a large class, belonging to general 

 geology, and need not be further referred to. It may merely be 

 remarked with reference to the remains of the extinct quadrupeds 

 (Art. 8), that they seem to point to the existence of a warmer climate 

 than the present, and to present evidence of a kind opposite to that 

 afforded by the Arctic testacea. The state of the remains of the ex- 

 tinct quadrupeds shows that, though associated with rounded gravel 

 and far transported blocks, they belong to animals which must have 

 lived not far from the places where the remains are found ; and that 

 their destruction may have been caused by a sudden submergence, 

 and a sweeping of the surface by diluvial currents. But that the 

 climate was warmer does not necessarily follow ; since elephantoid 

 remains occur abundantly in North Siberia and Arctic America, in 

 such a perfect state of preservation as to show that the creatures 

 were fitted for a cold climate, and as everywhere in the British isles 

 these remains occur in association with existing quadrupeds and tes- 

 taceous species. 



Striated Hocks Roches Houtonnees. 



12. Local examples of scratched and polished rocks may be 

 noticed here in connection with the scratched boulders of the 

 Till. Perhaps the finest instance to be seen within a short dis- 

 tance from Glasgow is the summit level of the pass between the 

 Gare Loch and Loch Long, 600 feet high, and about two miles 

 from the village of Gareloch-head, fully described by Mr. M'Laren ; 

 Ed. Phil. Jour., xl. to xlii. Mica slate rocks are here finely striated 

 in a direction nearly from N.W. to S.E. The rocks on the road- 

 side in several places, from this point to Gareloch-head, exhibit the 

 same markings. They may be seen also at the landing-place at 

 Row, and at several points on both shores of the Loch, where they 

 extend under the sea. But at none of these points are there any 

 striking examples of polishing, nor of that peculiar " Moutonnee" 

 (rounded and bossy) character which is elsewhere exhibited, as at 

 Parson's Green, near Edinburgh, described by Mr. R. Chambers, 

 and Jacob's Wood, near Stavely, Westmoreland, described by the 



* Jour. Geol. Soc., vol. viii. 



