vn. CARBONIFEROUS LIMESTONE. 81 



erinoids, brachiopods, at intervals throughout the mass. 



400 feet. 

 I. Scar limestones ; grey, reddish, mottled, brown or black ; 



partially divided by shales ; compact or oolitic, shelly, and 



crinoidal. 1438 feet. 

 a. Alternations of limestones and shales, of black, brown, or 



yellowish tints; the limestones usually very fossiliferous, 



and toward the base full of remains of fishes, cyprides, 



&c., constituting a fish- bed. 500 feet. 

 Yellow and grey sandstones below. 



The presence of red oxide of iron through a great part of this 

 series of limestones is a feature of Gloucestershire and Somerset- 

 shire, which is in some degree extended to the Forest of Dean 

 and South Wales, but is rarely found in the same manner in the 

 north of England. The red haematite of Lancashire and Cumber- 

 land is of a later date than the rock in whose hollows and fissures 

 it is collected. Iron ore of similar quality lies in hollows and veins 

 of the limestones of Mendip and other tracts near Bristol. 



The mountain limestone and millstone grit are totally absent 

 from the whole tract of the old red sandstone west of May hill, 

 Malvern, and Abberley. Whether this entire absence is to be 

 explained by the continued separation of the Malvernian sea from 

 that further to the south, is not to be so confidently inferred as 

 in the case of the Devonian rocks. For in the Forest of Dean, 

 on the south, the limestone and millstone grit are well developed, 

 round an insulated basin of coal strata ; and it may be conjectured 

 that as that is now insulated by denudation, other portions on 

 the west of Malvern may have been wholly removed by that cause. 

 On the other hand, it is observed that coal occurs on the western 

 side of the Abberley Hills, resting on the old red, and so excluding 

 the limestone; and a similar fact occurs in the small poor coal- 

 field of Wire Forest on the north, and at Newent on the south 

 of the Malvern tract. If the limestone were removed by denuda- 

 tion in a north and south direction, it must have happened before 

 the sera of the coal formation. 



The Table of the genera of fossils in the mountain limestone 

 of Bristol is taken from a full and exact Catalogue of the species 

 compiled for me by Mr. Stoddart, F.G.S., whose knowledge of 

 that rock and of the rich geology round the city where he resides 



G 



