285 GEOLOGY OF THE BRISTOL COALFIELD. 



analysis of the fine light coloured stone from the summit of the 

 hill gives as its composition : — 



Carbonate of Lime ... 94.5 



Carbonate of Magnesia ... 1.5 



Peroxide of Iron ... i.S 



Silica... .... ... T.6 



Alumina and loss ... .6 



lOO.O 



On account of the excessive porosity of the stone, the Bramah 

 press method is better adapted for ascertaining the cohesive povv'er 

 than the French one of Brard. 



The Dundry stone is generally worked by means of saws and 

 wedges, and reached by tunnelling -, and on account of the relative 

 val^e of the shape and size of the blocks, gunpowder is never used. 

 Notwithstanding so many microscopic observations having been 

 made, none of the oolitic grannies have been seen to have had 

 foraminiferous nuclei, all being siliceous and inorganic. The 

 following is a list of the fossils that have been collected from 

 Dundry Hill, inclusive of those both from the liassic and oolitic 

 beds : — 



PLANTS. 



ZooiDhycos scopariiis, (Heer.) 

 Otopteris obtusa, (Lindl.) 

 Equisetites Brodiaji, (Buckm.) 

 Araucarites 

 Naiadites petiolata 



FORAMINIFERA. 



Involutina liassica 

 Nodosaria radicula 

 Spiroloculina carinata 

 Marginulina 



