in Scotland and Parts of England. 21 h 



presented, within the last two years, a piece of polished and 

 scratched surface, which, however, has since been quarried. 

 The blocks are of granite, porphyritic traps, mica-slate, 

 greywacke, red sandstone conglomerate, and quartzose rock, 

 all of which are found in the Highlands many miles to the 

 north-west ; besides some less worn coal, sandstone, and car- 

 boniferous limestone, from the immediate neighbourhood of 

 Glasgow. 



In another situation, between Greenock and Port-Glas- 

 gow, Mr Smith of Jordanhill found the following deposits, 

 which, as in the above case, we venture to assign to their 

 relative places by numbers:* — 



Vegetable soil. 



3. Coarse gravel, two feet. 



{Sand, ten feet. 

 A series of thin beds of sand, gravel, and clay, full of 

 sea-shells ; (33 species found at two visits). 



1. Diluvium. 



The same diligent observer has described a deposit of shells 

 found at Airdrie, in digging a coal shaft, at a spot 524 feet 

 above the sea i\ — 

 3. Upper till. 



2. Stratified clay, in connection with which the shells were 



found. 



1. Lower till. 

 It must be admitted that there is some uncertainty in assign- 

 ing these relations, the imperfection of the description making 

 certainty for the present impossible. 



The superficial formations of England have been de- 

 scribed by various local observers, but with such a want of 

 concert and relation, that it is extremely difficult to reduce 

 them to any conformity even amongst themselves, much more 

 to bring them into harmony with those of Scotland. 



The region of Siluria — the south-east-looking slope of the 

 hills of North Wales, and adjacent districts of Herefordshire, 

 Worcestershire, and Salop — is described by Sir Roderick 

 Murchison, as presenting a local drift — that is, a drift com- 



* Memoirs of Wernerian Soc, viii. \ Quar. Jour. Gcol. Soc, vi. 386. 



