28o GFOLOGY OF THE BRISTOL COALFIELD. 



are found only near the mainland. This no doubt was the case 

 when Dundry Hill was so situated with regard to the Cotswolds, 

 and thus both the fossils and physiography bear witness to the 

 insular idea. 



On leaving Bristol by the Knowle road, the summit of the beds 

 of the Triassic marls are reached at an altitude of about 150 feet 

 above the sea level, jast under the Bedminster reservoir of the 

 Bristol Water Company. These marls are unfossiliferous, and 

 form a good and distinct base for Dundry Hill. 



On an examination of the accompanying section it will be seen 

 that this hill consists of the following divisions, viz., 

 Rhcetic Strata, about 65 feet. 

 Liassic Strata, about 376 feet. 

 Inferior Oolitic Strata, about 43 feet. 



Part of the upper portion of the lias is covered by cultivated land 

 and cannot therefore be examined. 



Immediately on leaving Bedminster we notice, on the left-hand 

 side of the road and just under the reservoir, a small well, on the 

 top of which is a thin bed of light cream-coloured limestone full of 

 remains from the bottom of a fresh- water pond or river. Among 

 them is an exquisite little ^hnt {Naiadites peiiolaf a) shewing the 

 leaves with their venation beautifully preserved, with the stems 

 crowded with the entomostracous valves of Estherice and Cytheridoe. 

 Near, and behind a public house, is a small quarry, which is a 

 whitish cream-coloured bed containing the valves of Cytheridoe in 

 such abundance, that a great resemblance reminds one of the 

 Eocene beds in the Isle of Wight. Eighteen inches above this is 

 the well-known Cotham marble bed, from which good specimens 

 of the nodular landscape stone may be collected. The following 

 section shews the strata of this spot. 



Ft. In. 



1. Light-coloured Limestone ... ... 6 



2. Two beds of ditto with Modiola ... 10 



3. Conchoidal bed with Insects and Entomostraca 4 



