LATER TERTIARIES. 



163 



America, whose forms bear a wonderful parallelism to those 

 of Europe; while in South America a similar gradation 

 will yet be determined upward to those Pampean flats, 

 whose pliocene clays and gravels have yielded those won- 

 derful megatheres, mylodons, toxodons, glyptodons, mac- 



Glyptodou, Megatherium (gigantic ground-sloth) HAWKINS. 



rauchenes, and other mammals, whose congeneric forms now 

 people, in diminutive scale, the plains and forests and up- 

 lands of that exuberant continent. As with the larger 



