8 4 



THE NEOG^EIC REALM. 



[CHAP. 



sodactyle type than do their more specialised descendants the 

 Toxodons, although there are no forms known from other parts of 

 the world to which they present any direct relationship or show any 

 marked resemblance. 



A second family ( Typotheriidce) of the sub-order is represented 

 in the Pampean by the typical genus Typotherium and in the 

 Santa Cruz, or Patagonian, beds by the allied Trachytherus. Both 

 these have a dentition still more like that of the rodents ; the 

 front, or incisor teeth being reduced to a single chisel -like pair in 



FlG. 17. IMPERFECT PALATE OF Typotht 



Reduced. 



each jaw, while the molars are narrow, rootless, and of compara- 

 tively simple structure and relatively small size. Moreover, in- 

 stead of hoofs, these highly modified ungulates appear, like many 



