506 PEOCEEDIls^GS OP THE GEOLOGICAL SOCIETY. 



ft. in. 



7. Blue clay, with nodular stone and Pentacrinites 1 



8. Yellowstone 6 



9. Eubblystone 6 



10. Clay, with Lima gigantea, abundant 3 



11. Stone 3 



12. Clay 4 



13. Stone, with Ammonites angulatus 5 



14. Yellow marl, with Pentacrinites 9 



15. Stone 4 



16. Eubbly beds, Ammonites BucJdandi, &c. &c 6 



The succession from the Xeuper through the lihsetic clays and 

 ^' White Lias " is admirably shown on the line of railway, the 

 Rhaetic series being crowded with its characteristic fossils. We need 

 only refer to the discovery, for the first time, of two metacarpal 

 bones of a large land reptile, allied to Scelidosaurus, from the Avi- 

 cida-contorta shales, a genus which has hitherto been recognized 

 only in the upper portion of the Lower Lias. 



On comparing the Liassic beds with the Camel section, it wiU be 

 at once apparent that the lower members are absent, and the upper 

 at this point but feebly represented. Close down upon the Rhsetic 

 beds we find Ammonites planorhis, with Fecten Folluce, and Lima 

 tuherculata of the Sutton stone, associated with Brachiopoda hitherto 

 found only in the Ammonites- BucMandi beds. As we pass along 

 the section towards Shepton, the group of beds No. 16 comes in. 

 These beds are composed of a greyish, sandy, irregularly bedded 

 limestone, and are full of organic remains, amongst which are 

 Ammonites BucJdandi, A. Conyheari, A. angidatiis, Nautilus stna- 

 tus, and Bpirifera Walcottii, the fauna at once indicating that they 

 belong to the A.- BucMandi series. The railway continues upon 

 them until the Shepton station is reached, where the beds can be 

 again seen ; and as the stone has been used throughout for the bal- 

 last of the line the organic remains of this stage can be well 

 studied. On this horizon we have unquestionably many of the 

 Sutton-stone and Southerndown fossils. Amongst these we find the 

 large Cerithium so abundant at Southerndown, which at Shepton 

 retains its shell, and which I propose to name O. nodidosum. A 

 small flat Montlivaltia is remarkably plentiful on the line of rail- 

 way, as many as a dozen examples occurring in a hand specimen. 

 Independently of the general fauna, several curious coincidences con- 

 nect the Ammonites-Buclclandi beds of Shepton with the Southern- 

 down series. Washed into the Sutton and Southerndown beds are 

 many blocks of dark sihceous stone, to which are frequently attached 

 Ostrea intusstriata ; and the same occurs, though more rarely, at 

 Shepton. Again, on the inside of a Nautilus striatus, and in the 

 chamber of a Ceritliium nodidosum, Moore, from the Shepton rail- 

 way-cutting, small individuals of Discina Davidsoni, Moore, attached 

 themselves, which are not unlike D. JSandersi, Moore, of the Upper 

 Lias. In the hollow chamber of the phragmocone of a very large 

 Belemnite, from Southerndown, the same little Discina occurs ! 



A close examination of the matrix of the Ammonites- BucMandi 



