Expedition to the Bad Lands 77 



animals during our stay on Dog Creek, but near the 

 summit of the Bad Lands, under beds of yellowish 

 sandstone, we came upon localities literally filled 

 with the scattered bones and teeth of dinosaurs, 

 those terrible lizards whose tread once shook the 

 earth. They are represented now by the little 

 horned toad of central Kansas. Among the frag- 

 ments were pieces of the finely-sculptured shells of 

 the sea turtles, Trionyx and Adocus, and remains of 

 that strange dinosaur Trachodon (Fig. I3a), whose 

 teeth were arranged as in a magazine, one below 

 another, so that when the old teeth wore out, others 

 were ever ready to take their place. 



The specimen in the illustration is from Drs. 

 Osborn and Lambe's Contribution to Canadian 

 Paleontology, on the Vertebrata of the Mid-Cre- 

 taceous of the Northwest Territory (1902). The 

 splendid Cretaceous dinosaur here illustrated is from 

 Wyoming (Fig. 14). This last form was restored 

 by the late Professor Marsh, and is now mounted in 

 the museum of Yale University. What a strange 

 picture it presents, this great plant-eater, as, stand- 

 ing on its hind limbs, its powerful tail acting as the 

 third leg of a tripod, it grasps the branches of a 

 tree with its weak hands and arms, while its teeth 

 scrape off the tender leaves ! 



In one of these localities we found teeth belong- 

 ing to some extinct ray-like fish that were arranged 



