402 



PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 29, 



K) 



No. 

 13. 



14. 



LlTHOLOGY. 



Bluish limestone . . 



Dark shales, containing 

 indurated imperfect 



limestone 1 



Bluish limestone 



Dark indurated clay 1 



Grey limestone, with the 

 plant-bed at the top ... 



18. Dark-bluish limestone ... 1 6 



19. 

 20. 



21. 

 22. 



h'. 

 24. 



Dark shale 



Dark-greyish limestone . 



Dark shale 



Grey limestone 



Dark shale 1 



Dark-greyish limestone . 1 



1(1 



Hard shale, forming 



"Quick Ledge" 1 



Blue limestone 



25. 

 26. 

 27. Dark shale 8 



28. 



29. 

 30. 

 31. 



32. 



Concretionary limestone 

 (surface mammillated) 



Dark-grey shale 



Greyish limestone 



Dark indurated shale .... 



Hard grey limestone 



The shingle of the shore covers the lower beds 



Organic Remains. 



Gryphcea incurva, Ehynchonella vari- 

 abilis, and Lima antiquata. 



Ichthyosaurus communis, I. platyodon, 

 Pentacrinus tuberculatus, Mill., and 

 Lima gigantea, Sow. 



Gryphcea incurva and fragments of 

 Pentacrinus tuberculatus. 



Otopteris obtusa, L. & H., and Arau- 

 carites peregrinus, Sternb., in the 

 plant-bed. 



Ammonites Conybeari and Ehyncho- 

 nella variabilis. 



Gryphcea incurva, Sow. 



Ammonites Bucklandi, Sow., and Am. 

 rotiformis, Sow. 



Ichthyosaurus tenuirostris, Conyb. 



Ichthyosaurus communis, skulls and 

 bones of other species, and Ehyn- 

 chonella variabilis. 



Ichthyosaurus communis and I. inter- 

 medins. 



Ammonites BucJclandi and Lima gi- 

 gantea. 



Gryphcea incurva and Ehynchonella 

 variabilis. 



Ammonites angulatus, Schl. 

 Lima gigantea and L. antiquata. 

 Ammonites BucMandi (large speci- 

 mens on the shore). 

 Lima gigantea and L. antiquata. 



Coast of Glamorganshire. — In Glamorganshire there is an exten- 

 sive exposition of the Am. BucMandi and Lima series for the distance 

 of sixteen miles along the coast, from Penarth Head b y Barry Island, 

 Aberthaw, and Dunraven Castle to the mouth of the River Ogmore, 

 where the Lower Lias rests on upturned beds of Carboniferous Lime- 

 stone. The strata chiefly laid bare by the sea are those containing 

 Lima gigantea and Gryphcea incurva. At Cowbridge the same litho- 

 logical relations are observed ; the Lower Lias here rests on Carbo- 

 niferous Limestone. 



At Penarth Head, however, the relation of the Am. BucMandi series 

 to the Am. planorbis and Avicula contorta beds below is much better 

 seen than at any other part of the Glamorganshire coast. 



Fossils of the zone of Ammonites Bucklandi. — The fossils of the 

 zone of Ammonites BucMandi are numerous, and in general in a good 

 state of preservation. 



Ichthyosaurus communis, 



intermedius, Conyb. 



platyodon, Conyb. 



tenuirostris, Conyb. 



Conyb. 



Ichthyodorulites of Hybodus. 

 Ammonites Bucklandi, Sow. 



Conybeari, Sow. 



rotiformis, Sow. 



