geology of the bristol coal-field. 53 



Section on Bedminster Down. 



Ft. In. 

 Rubble ... ... ... ... 5 o 



Four rubbly Limestone beds, with Am. 



Flanorlis, Ostrea, &c. ... ... 2 4 



Ostrea bed ... ... ... ... i 2 



Limestone and Shale ... ... ...16 



Four Nodular Limestone beds ... ... i 7 



Shaly Limestone, with Naiaditea, Insects, 



jEstheria, Fish Scales y Coleia,^c. ... o 7 



Shaly Clay with Ostrea... ... ... o 5 



Bluish Limestone with Insects ... ... 8 7 



Limestone ... ... ... ...16 



Limestone with Modiola ... ... i 3 



C\2cys vj'iih. Modiola ... ... ... i 4 



Above the Gotham marble are ten or twenty feet of beautifully 

 smooth, cream coloured, argillaceous beds of limestone. So close 

 grained and homogeneous in their structure are they, that they have 

 been very successfully used in Lithography. They resemble in 

 outward appearance some of the true lias beds, but differ in being 

 white throughout 3 whereas the latter, on being broken, are bluish 

 internally. Many of the beds are perforated with tubular markings 

 and bormgs of Annelida and Mollusca. Good typical specimens 

 may be collected at Whitchurch and Curry Rivel. 



The Rhaetic beds of this neighbourhood are covered up by a 

 peculiar hard limestone, termed by^the quarrymen in the south of 

 Somersetshire "Jew Stone,'' but by the inhabitants of Paulton, 

 Street, Radstock, and Bristol *' Sun Stone." 



During the deposition of the Rhaetic formation, the ancient 

 country seems to have had a remarkable resemblance to that now 

 seen in many parts of equatorial Africa. The same damp, muddy 

 marshes exhaling the same pestiferous miasmata. This observation 

 is rendered still more probable by the fossil fauna. Sun cracks, 

 pseudomorphs of crystals of salt are very common ; and small 

 fishes must have abounded in low creeks and muddy estuaries, that 



