366 Antediluvian Zoology. 



vertebrae, and is also furnished with paddles, intermediate 

 between feet and fins. " This genus exhibits the snout of a 

 dolphin, the teeth of a crocodile, the head and sternum of a 

 lizard, the swimmers of a whale, and the vertebrae of a fish." 

 Found in the lias, Stonesfield slate, Oxford clay, Kimmeridge 

 clay, coral rag or Malton oolite, and probably in other form- 

 ations. 



Restoration of Ichthyosaurus communis, by the Reii||i|/. D. Coneylieare, Geol. Trans., vol. i. 



The Megalosaurus, or gigantic lizard of Stonesfield and 

 Tilgate Forest, is computed by Dr. Buckland to be 40 ft. 

 long. It possesses resemblances both to the monitors and 

 the crocodiles. 



Mr. Mantell estimates the Iguanodon, the great herbivorous 

 reptile of the Tilgate stone, to have far exceeded the last in 

 magnitude, and to have attained the extraordinary length of 

 60 ft. This appears to have been an inhabitant of fresh-water 

 lakes, and rivers. 



Vertebrae of another saurian animal have lately been dis- 

 t^overed in the Portland series at Thame, near Oxford, of still 

 more extraordinary dimensions. They are twice as large as 

 those of the Iguanodon, and four times the size of the ver- 

 tebrae of the Mastodon. 



The Stonesfield slate contains perhaps one of the most 

 remarkable assemblages of organic remains that are known to 

 geologists. Here are marine, amphibious, and terrestrial 

 animals, associated with terrestrial, fluviatile or lacustrine, and 

 marine plants, and with birds and insects ; all collected in a 

 hed, *t!ohose greatest thickness does not exceed 6ft, 



This deposit has a singular parallel in the ferruginous sand- 

 stone of Tilgate Forest, where a similar series occurs, notwith- 

 standing the formations are of different periods. Here occurs, 

 blended with the bones of a gigantic species of crocodile, of 

 the Megalosaurus and the Plesiosaurus, the Leptorjnchus, the 

 Pterodactylus, and the remains of turtles, birds, shells, and 

 tropical vegetation, that extinct herbivorous reptile to which 

 Mr. Mantell, at the suggestion of Mr. Coneybeare, has given 

 the name of Iguanodon, from its close affinity to the recent 

 Igiuhia of the West Indies. The great difference appears to be 



