I go 



2.] 



O shorn, American Eocene Primates. 



177 



B 



positively determine the relationships of some of these forms 

 to the existing Anthropoidea or Lemuroidea; but it will 

 require detailed investigation, which I am not able to under- 

 take at present.' 



Three suppositions are possible: First, that these Primates 

 represent an ancient 

 and generalized 

 group (Mesodonta, 

 Cope) ancestral to 

 both Lemuroidea 

 and Anthropoidea ; 

 second, that they 

 include representa- 

 ti ves of both 

 Lemuroidea and An- 

 thropoidea, contem- 

 poraneous and in- 

 termingled ; third, 

 that they belong 

 exclusively to one 

 or the other order. 

 There are certain 

 advantages in the 

 revival of the term 

 Mesodonta Cope, a 

 suborder (antieipat- 

 ing the terms 

 Pseudolemuroidea 

 and Tarsii) which 

 would bear some- 

 what the same re- ^. ,. , „ , , „ , ^ 



Fig. 4. Jaw outlines. All natural size. A, Felycodus 

 lationship to the tutus : B,Hyopsodus/>atelus .■ C^Anaptomoiphus cemulus .■ 

 D, Microsyops. 



modern specialized 



Monkeys and Lemurs that the Condylarthra bear to the 

 Ungulata and the Creodonta to the Carnivora. The serious 

 ■difficulty with this view is the very considerable separation 

 of these families. 



' Dr. J. L. Wortman is now taking up these problems with the rich materials afforded 

 by the Yale Museum Collections. I therefore omit phylogenetic questions here. 

 iJune, igos.l 12 



p.3P:'f'm.ll'";2m.3 



P-? P-f m.l „,2- m,3 



