252 W. K. GREGORY TUPAIIDjE AXD EOCENE LEMURS 



of Tarsi us and the Anthropoidea from the neighborhood of the Anapto- 

 morphidse, as maintained by Schlosser. 



Conclusions 



To recapitulate, present evidence favors the following conclusions : 



(1) That in the Bridger Eocene there already existed primitive 

 Tupaiid Insectivores (Entomolestes) and primitive lemur-like Primates; 

 and these, while less widely separated than their modern representatives, 

 were even at that time referable to distinct orders. 



(2) The fauna of the Wasatch, with its numerous highly modernized 

 types, such as Anaptomorplius, proves that we are witnessing rather the 

 noontime than the dawn of Placental Mammals. The marked struc- 

 tural gap even in the Eocene between Tupaiids and Primates does not, 

 I think, constitute a serious objection to the ultimate derivation of the 

 Primates from Entomolestes-like ancestors of the late Mesozoic. The 

 Primates give evidence of derivation from very small mammals, with a 



dental formula of ' ' ' ' , animals with simple non-carnassial premolars 



3.1.4.3. 

 and tritubercular molars; and such mammals could only have been In- 

 sectivores of some sort. 



(3) It seems quite likely that many of the lemur-like features of 

 Tupaia, such as the large brain-case, ringed orbits, enlarged lumbar 

 parapophyses and the like, may have been developed independently after 

 the separation of the Primates took place. 



(4) That in spite of their very ancient divergence the Primates are 

 more nearly allied to the Tupaiids than to any other existing group. 



