SOME AMERICAN MONSTERS. 155 



matrix that the brain-cavity and the openings leading from it 

 could be worked out without difficulty. In removing the skull 

 from the rock, on the high and almost inaccessible cliff where it 

 was found, two or three important fragments were lost ; but 

 Professor Marsh, after a laborious search,^:ecovered them from 

 the bottom of a deep ravine, where they had been washed down 

 and covered up. 



It is about twenty-two years since the wonderful forms of life 

 sealed up within these Eocene lake-deposits first became known 

 to science. Long before then, however, the wandering Indian 

 had been accustomed to seeing strange-looking skulls and 

 skeletons that peeped out upon him from the sides of canons and 

 hills, as the rocks that enclosed them crumbled away under the 

 influence of atmospheric agents of change the ceaseless working 

 of wind, rain, heat, and cold. To his untrained mind no other 

 explanation suggested itself than the idea that these were the 

 bones of his ancestors, which it would be highly impious to 

 disturb. Requiescant in pace ! So he left them in peace. 

 Perhaps he believed in a former race of human giants ; if so, 

 these would be their bones. Long before Professor Marsh's 

 expeditions, the earliest squatters, trappers, and others used to 

 bring back news of marvellous monsters grinning from the ledges 

 of rock beneath which they camped. At last these tales attracted 

 the notice of some enthusiastic naturalists in the eastern States. 

 Professor Leidy obtained a number of bones, from which he was 

 able to bring to light an extinct creature at that time unknown 

 to science, namely, the Uintatherium. Professor Cope also 

 described some extinct animals disinterred by himself from the 

 same region. 



But our knowledge of the Dinocerata is chiefly due to 

 Professor Marsh, who has despatched one expedition after 

 another, and who, after many years of laborious research both in 

 the western deserts and in his wonderful collection at Yale 

 College, has published a splendid monograph on the subject. 



