Stones/kid Slate. 1 7 7 



The local development called the Stonesfield Slate 

 consists of beds of laminated shelly and oolitic limestone 

 and sandy flags, with much false bedding, and contain- 

 ing ferns, Cyclopteris, Glossopteris, Pecopteris, &c. ; 

 Cycads, Bucklandia squamosa, Zamias, Palceozamia 

 of various species, and Coniferae. Elytra of beetles 

 and wings of insects (Libellula Westwoodii, &c.) ; 

 bones of Plesiosaurus, Crocodile, &c. ; also Ostrea, 

 Terebratida, Rhynchonella, Lima, Pecten, Trigonia, 

 Patella, Nerincea, Belemnites, Ammonites, &c., are 

 all found in these thin shallow water deposits. The 

 reptiles include Ichthyosaurus advena, Plesiosaurus 

 erraticus, and crocodiles of the genus Teleosaurus, 

 allied to the Gravial of the Granges (T. brevidens 

 and T. subulidens), together with a great carnivorous 

 lizard, Megalosaurus Bucklandi, that walked on the 

 neighbouring land, and was probably about 30 feet in 

 length. A flying reptile, Ramphorhynchus Bucklandi, 

 allied to the Pterodactyle, is found in this subformation, 

 which has long been especially celebrated as containing 

 the remains of mammals, viz. the lower jawbones of 

 species of small insectivorous marsupials, Amphitherium 

 Broderipii, A. Prevostii, Phascolotherium Bucklandi, 

 and Stereognathus Ooliticus. 



I call the Stonesfield Slate a local development 

 because it is by no means of universal occurrence at the 

 base of the Great Oolite, and is chiefly known in those 

 parts of Gloucestershire that lie eastward of Cheltenham 

 on the broad Oolitic plateau, and in Oxfordshire at and 

 near the town of Stonesfield, where it perhaps attains 

 its greatest thickness. There it is largely manufactured 

 into what are called slates, but in reality are small slabs, 

 the coarse fissile character of which has no relation to 

 jwhat is known as slaty cleavage. From these areas 



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