Dr. Bright on the Strata in the Neighbourhood of Bristol. 205 



green colour is contrasted with the dark foliage of the elm, which is 

 the prevailing tree of the county, very few oaks of considerable size 

 being now found. 



The limestone district has as yet produced little but heath and 

 fern, the rock in general approaching too near the surface to be 

 favourable to vegetation. Much of it however has been lately en- 

 closed on the southern side of the river, and a part of that is of good 

 promise. Within the limits of the sandstone and of the breccia there 

 is very fertile grazing land. 



Note on Magnesian Breccia* 

 By HENRY WARBURTON. Esq. 



VICE PRESIDENT OF THE GEOLOGICAL SOCIETY. 

 [Read 21st June, 1816.] 



THE great stratum of magnesian limestone which passes from 

 Sunderland in the north of England through the centre of the 

 midland counties, suddenly terminates, as is well known, in the 

 vicinity of Nottingham ; and I am not aware of its reappearance 

 in the south of England having been noticed except perhaps on the 

 north-eastern border of the Ashby de la Zouch coal-field, where it is 

 said to occur in great insulated masses. 



The geological relations of this rock to other strata appear to have 

 been well ascertained in the northern and midland counties, v/here 

 it is described as forming horizontal beds, and as lying under and 

 parallel to the red marl, or occasionally as alternating with it. It has 

 been ascertained by numerous sinkings in the same counties that the 



Vol. iv. 2 d 



