136 THE STORY OF THE EARTH. 



Kelloway rock. Near its base, about Peter- 

 borough, the Oxford clay abounds in remains of 

 timber trees, apparently coniferous. Its plant 

 remains also include Cycads. It yields the ter- 

 restrial reptiles Cetiosaurus and Omosaurus^ with 

 Teleosaurian crocodiles, Ophthalmosaurus % which 

 is an Ichthyosaur with three bones in the fore- 

 arm instead of two. The big headed IMiosaurus 

 is common; Munenosaurus is a long-necked plio- 

 siosaurian with single headed ribs to the neck, 

 and two bones in the forearm. The common 

 shells in the Oxford clay are the oyster Gryphaa 

 dilatator Belemnites ha status, Ammonites Duncani, 

 and Ammonites eardatus. The Ampthill Clay and 

 Oxford Oolite rest upon the Oxford clay. The 

 Ampthill clay is seen between Ampthill in Bed- 

 fordshire and Acklam Wold in Yorkshire. 



The Coralline Oolite interlaces with the clay 

 in Bedfordshire by a number of thin beds of blue 



Fig. n — Belemnites Oweni, an internal shell of a kind <>f cuttle- 

 fish. The "Guard'' is broken to shew the conical phi 

 cone which penetratea into it. Oxford Clay, 



earthy limestone. Traced southward by Shot- 

 over, it forms two divisions; and at Weymouth 

 there is the sandy lower calcareous grit well de- 

 fined, and an upper grit or sand which passes up 



to the Kimeridge clay. In Yorkshire this Oolite 



extends through the ilowardian Hills by Malton, 



through the Vale of Pickering to Filey. At Up- 

 ware, on the river ('am, a small reef lull of corals 

 appears to result from the Carboniferous lime- 

 stone having furnished calcareous matter to the 



