58 



GEOLOGY. 



or semi-erect position,* after the manner of a bird, to which its long 

 neck, slight head, and small anterior limbs must have given it an 

 extraordinary resemblance " (Huxley). 



" Mantell's Iguanodon" — The slab in the centre of Case 3 contains 

 a great portion of the skeleton of a young individual of Iguanodon 

 Mantelli from Bensted's Kentish Kag quarry at Maidstone. This is 

 one of the largest of the great extinct land-reptiles, some of which 

 certainly rivalled the elephant in bulk.f 



The femur (thigh bone) alone measured 4 to 5 feet in length. The 

 fore-limbs were very short, so that it is almost certain that it did not 

 make use of them for progression on the ground, but supported itself 

 habitually in an upright position by the aid of its long and powerful 

 tail, after the manner of a kangaroo. 



This great reptile was a vegetarian in its diet, as is proved by its 



"Fig. 27.— a, Front view ; b, Side view of Tooth of Iguanodon (natural size), Wealden, 

 Isle of Wight. 



teeth, which correspond with those of the living and vegetable-feeding 

 Iguana of S. America. 



Their fossil teeth are not unfrequently found worn down at the 

 crown, like the grinders of an elephant. They were implanted in 

 distinct sockets, and a succession of teeth always growing up from 

 beneath, replaced the worn -down stumps. The teeth are curved and 

 leaf-shaped in form, and the edges are elegantly serrated, a character 

 peculiar to all the vegetable-feeding Dinosaurs, such as Acanthopholis, 

 Scelidosaurus, and the South African genera, Anthodon and NytJio- 

 saurus. (See Woodcut, Fig. 27.) 



In the centre of Wall-case No. 4 is placed the great block of 



* Or like a Jerboa 



t As many as twenty-four of these huge reptilia were recently obtained from 

 the Wealden of Belgium, and an almost complete skeleton has been put together 

 in the Brussels Museum, proving it to have been more than 30 feet in length. 



