450 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



IV. Abnormal Secondary deposits on 



the Carboniferous Limestone. 



1. Marston Eoad Section. 



2. Holwell Carboniferous Lime- 



stone and Liassic Dykes. 



3. The Microlestes Quarry. 



4. Sections in the Vallis. 



5. Gurney Slade Liassic Dykes. 



6. Charter-House Liassic Lead- 



mine. 



7. Terrestrial and Freshwater 



Fauna. 



V. The Bath District. 



1. Pinch's Well. 



2. The Ammonites-Bucklandi 



Beds. 



3. Willsbridge Section of Lower 



Lias, Keuper, Ehastic, and 

 Coal-measures. 



4. Sections near Bristol. 



5. Sections at Keynsham and 



Stout's Hill. 



6. Ehaetic White Lias and Car- 



boniferous Limestone at 

 Broadfield Down. 



7. Sections near Shepton Mallet. 



IX. List 



8. Value of Zones of Zoological 

 Life. 



VI. The South Wales District. 



1. Penarth Ehaetic and Liassic 



Section. 



2. Bridgend Liassic Sections. 



3. Cowbridge Section. 



4. Llanbethian Quarries. 

 6. Laleston Quarry. 



6. Stormy Quarry. 



7. Section at Ewenney. 



8. Section at Brocastle. 



9. The Sutton Stone and the 



Southerndown series. 



a. Local Deposition of the Sut- 



ton Stone. 



b. Organic remains from the 



Sutton Stone. 



c. The Ammonites-Bucklandi 



Beds. 



10. Langan Lead-mine. 



11. Inadmissibility of the term 



" Infralias." 



VII. Conclusion. 



VIII. Description of Organic re- 



mains, 

 of Fossils. 



I. Introditction. 



My attention has for some time been directed to the peculiar physi- 

 cal conditions under which many of the Secondary rocks have been 

 deposited on the southern edge and in the interior of the Somerset- 

 shire Coal- basin, and to the remarkable evidences of nnconform- 

 ability everywhere present. My observations have also been ex- 

 tended into South Wales, where to a considerable extent the same 

 phenomena prevail. Within the last two years I have on several 

 occasions accompanied friends to the interesting coast-sections of 

 Sutton and Southerndown, which have lately been the subject of a 

 paper by Mr. Tawney, when I have pointed out that, instead of re- 

 presenting, as they are supposed by him to do, beds older than the 

 Rhsetic and probably on the horizon of the St. Cassian or Muschel- 

 kalk deposits, they are only abnormal conditions of the Liassic rocks 

 which are so familiar to us in many parts of England and on the 

 continent. 



Elaborate physical descriptions of some parts of the districts I 

 shall have to notice have already been given by Messrs. Buckland 

 and Conybeare, in the Geological Transactions *, under the title of 

 '* Observations on the South-western Coal-district of England," and 

 more recently by the late Sir Henry De la Beche, in a paper con- 

 tained in the Memoirs of the Geological Survey, " On the Formation 

 of the Eocks of South Wales and the South-west of England." I 

 yhall hereafter have to refer to some interesting points not discussed 

 in these Memoirs. 



* 2nd series, vol. i. part 2. 



