532 



CENOZOIC ERA— AGE OF MAMMALS. 



hoofed toes on the hind-feet, and four functional toes, a fifth meta- 

 carpal, and a corresponding rudimentary fifth toe on the fore-feet. 



As already said, generalized Carnivores, Insectivores, and lemurine 

 monkeys, Pro-Si?nm, are found on this and the previous horizon. 



6. Green River Basin — Bridger Beds — Middle Eocene. — From this 

 wonderful fresh-water deposit there have been described by Marsh, 

 Cope, and Leidy, 150 species of vertebrates, of which the larger number 

 are mammals. This shows a marvelous abundance of mammalian life 

 in this early Tertiary time. The most numerous of these are tapir-like 

 animals, such as Hyracliyus, Limnoliyus (Palwosyops — Fig. 913), etc. ; 

 but the most formidable are the Dinocerata, an order established by 

 Marsh and including the genera Dinoceras (Marsh), Uintatlierium 

 (Leidy), and Tinoceras (Marsh), or Loxolojrfiocloti (Cope). The re- 



ft IT 



Fig. 911.— Dinoceras mirabile, x § (after Marsh): A, Skull; B, Hind-foot, x £; C, Fore-foot, x £. 



mains of thirty species and more than one hundred and fifty distinct 

 individuals of this order have been obtained from the Middle Eocene 



