OOLITIC GROUP. 415 



The Stonesfield slate of Gloucestershire and Oxfordshire 

 contains the remains of insects belonging to the families 

 Prioniidce, Blcvpsidce, Buprestidce, and others, which are 

 figured and described by the Rev. Mr. Brodie. The remains 

 of Crustacea are rare in the inferior oolite, but the litho- 

 graphic schists of Solenhofen, which belong to the Oxford 

 stage have yielded many genera of this class. 



The fishes formed a numerous section of the fauna of the 

 oolitic period. Their history has disclosed the curious fact 

 that all the JLepido'id said. Sauro'id fishes which lived in the seas 

 before the deposition of the lias, had their vertebral column 

 prolonged into the upper lobe of the tail, and are therefore 

 called heterocercal, whilst all the Lepido'id and Sauro'id 

 fishes of the oolitic group, with one exception, the Coccolepis, 

 found at Solenhofen, have the tail bilobed or homocercal, 

 like the majority of the fishes of the present day. In our 

 palseontological sketch we have cited the families most 

 common in the different stages of the oolitic group. 



The reptiles of the oolites are neither so numerous nor so 

 well preserved as those of the lias. The most remarkable 

 are the Pterodactyles, found in the Stonesfield slate of 

 Oxfordshire and Gloucestershire, of which fig. 204 is a 

 drawing of the skeleton, reduced from Goldfuss. 



The MEGALOSAUBTTS was discovered by Dr. Buckland at 

 Stonesfield ; its teeth have been found in the equivalent bed 

 in Gloucestershire; it was a gigantic carnivorous reptile 

 allied to the crocodile and monitor, and, from the dimensions 

 of its bones, must have attained a colossal size. The long 

 bones of the extremities form hollow cylinders for the lodg- 

 ment of marrow; the same anatomical fact has been observed 

 in the femur of the iguanodon, and of all our terrestrial 

 quadrupeds. The powerful teeth (fig. 200) had serrated 

 edges, and combined in their construction the powers 

 of the knife, the sabre, and the saw. 



One of the most interesting discoveries in the palseon- 

 tological history of the oolitic period is the presence of jaws 

 and teeth in the Stonesfield slate, which have been referred 

 to mammalia, and supposed to belong to extinct genera of 

 the marsupialia, a group now found in the Australian con- 

 tinent. The fig. 216 represents the jaw of ThylacotJierium, 

 from Stonesfield: we have already alluded to the doubts 

 which some entertain of its mammalian character. 



