67 



the skin as it were of the globe. We have not yet got to the flesh, yet these beds 

 have an aggregate thickness of several thousand feet, and are each of them sub- 

 divided into a number of minor divisions, each containing a different set of fossils. 



But now we come to the next great division or Secondary rocks, in which 

 no traces of existing forms of life are found. This division contains the great 

 Chalk formation, which many of you may have seen in the South and East of 

 England, and which is of very great thickness in this country, and still thicker 

 abroad, since many beds are found there which were either not deposited here, or 

 were afterwards denuded. Below this comes the Oolite formation, which you see 

 wen developed round Bath and Cheltenham, and which is also of very great 

 thickness. Below this is the Lias, and below that again the Trias, or New Red 

 Sandstone, which is found of very great thickness in Shropshire and Cheshire. 



We now come to the Primary Strata, which I may call the Rock masses 

 "par excellence," as they are many of them very hard, and all but the first are of 

 very great thickness. They are divided into seven great formations, the most 

 recent of which is the Permian, which was formerly classed with the Trias, but 

 was afterwards found to contain a distinct set of fossils. York Cathedral and the 

 Houses of Parliament are buUt of this. Then comes the great coal or carboniferous 

 series, on which the wealth of England depends. We know this formation, to a 

 very small extent, in our own neighbourhood on the Clee Hills ; but in some parts 

 of the world it attains a thickness of many thousand feet. It contains in its lower 

 beds the Mountain Limestone, which forms the romantic hills of Derbyshire, the 

 cliffs of the Orm's Head, and also the quarries at Oreton, near Cleobury Mortimer. 



Below this, again, we arrive at the Devonian or Old Red Sandstone, which 

 we see at Whitbach and Hayton's Bent, and forming the base of the Clee HiU.", 

 but which is much more largely developed in South Wales, where it forms the fans 

 of Brecon and Carmarthen, the Skyrrid, and the Black Mountain. The higher 

 beds of this series are found largely in the North-West of Scotland, though, I 

 believe, they have never been found in England, and they abound in a great 

 variety of fish, quite different from those found in our lower beds in this neigh- 

 bourhood. Indeed, this, together with the coal series seem to have been the great 

 fish formations, as their remains, though scantily found in the top of the next 

 lower formation, occur in shoals in some parts of those. 



We next come to the rocks among which we now stand — the vast Silurian 

 Formation, — more than 20,000 feet thick, which at one time was fancied to be 

 destitute, or nearly so, of fossil remains, but was elevated to its proper dignity by 

 Sir Roderick Murchison, who has the credit of having worked it out, and rendered 

 it intelligible to anyone who studies it under his guidance. The Upper Silurian 

 is the most recent series of this formation, and is subdivided into Upper Ludlow, 

 having at its top the Downton Sandstone (named from this locality); the Lower 

 Ludlow, containing at its top, in some places, the Aymestry Limestone, which we 

 see here above Bow Bridge ; and the Wenlock Limestone and Shales, which are 

 seen a little higher up, about Burrington. 



