178 The Eeptilia of the Arundel Formation 



The character of these dinosaurs, and of the crocodile as well, cor- 

 relates the beds wherein they are found absolutely with the Morrison 

 (Como) of the West. An accurate comparison with European forma- 

 tions is more difficult, as the faunas have fewer forms in common. 

 'Pl&urocoelus is reported from the Kimmeridgian as well as from the 

 Wealden, but that from the former horizon may readily have been an- 

 cestral to the Arundel type, although the European material is too frag- 

 mentary to admit of a just comparison. Of the other dinosaurs, the 

 affinities seem to be entirely with Wealden forms, Ccelurus being found 

 therein, while Allosaurus compares in point of size and dentition with the 

 Wealden Megalosaurus. Dryosaurus has its nearest European ally in 

 Hypsilophodon, again a Wealden type, and the crocodile, Goniopliolis, 

 is reported from the Wealden and its marine equivalent the Purbeckian, 

 not from the older Jurassic levels. 



The weight of this evidence would seem to place this fauna beyond the 

 Jurassic into the beginning of Cretaceous times. 



