80 



OOLITE. 



named, from twenty-five to thirty feet long, with an enormous 

 muzzle furnished with strong teeth, must have been by far the 

 most formidable land creature of its age. The Iguanodon was 

 an equally huge herbivorous reptile, which Dr. Mantell has 

 shown, by a curious process of reasoning, to have possessed a 



FIG. 60. 



Portion of lower jaw and teeth of Iguanodon. 



tongue of prehensile character, like certain 

 ruminant mammalia of our day. From the 

 scapula or blade-bone of the remaining genus, 

 the Hylceosaurus, the approximation of the 

 whole of the dinosaurs to the mammalian type 

 of structure has been inferred. 

 The imagination eagerly aspires to picture the world of the 

 Oolitic Era, when there were scarcely any living creatures of 

 more exalted character than reptiles. There were then vast 

 tracts of dry land, as now ; their surface bore a luxuriant 

 vegetation of no mean kind. The meteoric agencies, the rise 

 and fall of tides, were common phenomena of that time, as of 

 the present. Day after day, through long-drawn ages, the 

 sun passed on his course. Night after night, the sparkling 

 garniture of the sky looked down on this green world. But a 

 being of superhuman intelligence, coming to examine our 

 globe, would have seen all this existing only for fishes and still 

 humbler creatures in the sea, and for reptiles, insects, and 

 perhaps a few birds, and still fewer opossums, upon land. 

 He would have beheld the tyrant sauria pursuing their carni- 

 vorous instincts upon the wave, upon the shore, and even in 

 the air ; huge turtles creeping along the muddy coasts ; still 

 more huge megalosaurs traversing the plain j and with all 

 this, the air filled with multitudes of insects. But no flocks 

 would have met his eye upon the mountains, no herds quietly 



