﻿394 



ME. L. RICHARDSON ON THE RH^TIC AND [Aug. 1905, 



[Leckwithbridge Section (continued).] 

 Thickness in feet inches. 



Limestone 



Clay, with three bands of lime- 

 stone, totalling 7 inches 



°1 

 i 



0! 



Ostrea irregularis. 



Ostrea irregularis, Lima 

 giganiea, Carclinia 

 ovalis, Schlotheimia 

 angulata (Schloth.). 



( Carclinia ovalis (Stutch- 

 bury) ; Ostrea irregu- 

 laris, Minister ; Lima 

 giganiea (Sowerby) ; 

 Pholadomya fortu- 

 nata, Dumortier ; 

 Liltorina cf. minuta, 

 Terq.&Piette; ossicles 

 oWentacrinus, radioles 

 of Cidaris; Ehyncho- 

 nella aff. calcicosta, 

 Dav. ; Dentalium eta- 



\ lense, Terq. & Piette. 



Concerning the higher beds at Lavernock no details can be given ; 

 they are inaccessible, but limestones predominate. Proceeding 

 farther westward along the coast, the other side of the syncline is 

 entered upon, and the strata are soon passed over in descending 

 order, until at St. Mary's-Well Bay, Sully, the Phgetic reappears. 



( Limestone 



^ Clay and limestones 12 



Clay, • blue ; Cardinia ovalis ] r> 

 I abundant j 



Clay and limestones. Some of 

 I the limestone-bands become \ 22 

 I, nodular seen 



(B) St. Mary's-Well Bay, Sully. 



At this locality the whole of the Rhsetic Series can be studied ; 

 but, since the Lavernock section has been dealt with in such detail, 

 it will be sufficient for our present purpose to describe the basal 

 portion only of the exposure. The beds are very much disturbed, 

 owing to a fault — that which starts at Dinas Powis. The result is 

 that the lihsetic Beds are faulted against the littoral Keuper, and 

 in the downward course that portion of the series which I have 

 denominated the Sully Beds has been prettily contorted. 



The Bone-Bed seen in this section, although consisting of several 

 layers, as at Lavernock, is nevertheless lithically distinct. The main 

 band is a hard grey limestone, seldom pyritic, but usually crowded 

 with fish-remains, although no quartz-pebbles were observed. Below 

 the Bone-Bed are black shales with intermittent hard layers, as 

 noticed in the appended section :— 



Ggrolepis Alherti (teeth ? & 

 scales) ; a lamellibranch 

 (Schizodits or Pullastra) 



not uncommon 



Thickness in feet inches. 



15. A series of sandstone- and lime- 1 



stone-layers, with partings | 1 



of shale J 



16. Shales, black 1 5 



17. Limestone; intermittent 1 



18. Shales, black 5 



19. Limestone, earthy ; intermittent 1 



20. Shales, black 1 4 



21 . Rust-coloured layer 0^ Ggrolepis Alberti ( 



