480 AN INTRODUCTION TO ZOOLOGY 



back was a row of great upstanding plates, and on the tail four pairs 



FIG. 174. Restoration of Iguanodon. Cretaceous of Belgium and the 

 Isle of Wight. After Heilmann. 



of powerful spines 2 feet or more in length. It is also noteworthy 



FIG. 175. Restoration of the armoured dinosaur, Stegosaurus, based upon the 

 mounted skeleton in the Yale University Museum. Length, about 20 feet. 

 Comanchian, Wyoming and Colorado. After Lull, from Schnchert's 

 "Historical Geology." 



in that its brain was extremely small, and it had a big swelling in 



