1865.] 



TAWNEY RHiETIC BEDS AND SUTTON STONE. 



79 



Sir H. De la Beche*. I have no doubt that these beds are also 

 Rhaetic ; they are conglomeratic in places, enclosing Carboniferous - 

 limestone fossils ; and they are precisely similar to the Sutton con- 

 glomerate. I have found in them Plicatula intusstriata, a Cardinia 

 like the one at Stormy (page 77 supra), and an Aixa abundantly as 

 casts. Except Ostrea Uassica (?) and Modiola minima (?), the Lias 

 fossils seem absent. 



I am greatly indebted to my friend Mr. W. Saunders, F.R.S., of 

 Bristol, for the inspection of his collection from the curious white 

 and siliceous modifications of Lias (spoken of by Buckland and 

 Conybearet) at Chewton Mendip, East Harptree, Shepton Mallet, &c. 



An examination of these fossils leaves no doubt on my mind 

 that they are for the most part E-hsetic ; some of them vrere — 



From Shepton f Pecten Sutton ensis, 

 Mallet. \ Lima tuberculata. 



From Chewton, f Ostrea multicostata, 

 Mendip, and \ Monotis decussata, 

 East Harptree. [ Axinus elongatus. 



9. Middle Lias. — As it is not expressed on the map, I may remark 

 that the upper part of the Bridgend Eailway-section is Middle and 

 not Lower Lias. This is shown by the presence of Ammonites spi- 

 natus, Gryphcea cymhium, Avicula inoequivalvis, Pecten suhlcevis, and 

 P. dentatus, Belemnites, &c. 



10. Table showing the range of the Fossils of the Bhcetic Beds of 

 South Wales. 



Species. 



Sutton series. 



Southern- 

 down 

 series. 



Avicula- 



contorta 



series. 



3 



O 

 1 



a 



1 



1 



t 

 ft 



1 





1 

 1 



i 



ft 







1 



a 



O 



o 



i 



o 



i 

 1 



if 

 * 

 * 

 if 



* 

 if 

 * 



if 

 if 



6 



if 



it 

 if 



if 

 if 

 if 



Equisetites ... 













































* 



Axinus elonffatus Moore ... 

















































cloacinus, Moore ... 

























* 



* 







* 











































Anatina praecursor, Qu 





















■ 





Natica Pylensis, Tawn 

























Monotis decussata 







if 



















Mr 



* 



Pecten Valoniensis, Peril. 

















































* These beds were coloured as Ehatic by Mr. Bristow on the map of the 

 Geological Survey laid before the Bath Meeting of the British Association by 

 Sir R. I. Murchison in 1864. . 



t " Buckland and Conybeare on the South-west district of England," Trans. 

 Geol. Soc. 2nd series, vol. i. p. 294. 



