140 Annals of the Carnegie Museum. 



more prominent. The general construction of the molars in the two 

 genera is, however, strikingly similar. On comparing the present 

 specimen with other European genera, it may be said that Eomoropus 

 annectens and Macrotherinni grande Lartet resemble each other, 

 more especially in the proportions of the molars. It thus appears 

 that if Eomoropus is in the ancestral line leading directly to Moropus 

 the molar series underwent a considerable lengthening during the 

 Oligocene period. On the other hand, if the postglenoid process, as 

 found, is in its correct position in the type of E. annectens, which seems 

 quite likely, then this region of the skull had already taken on the 

 characters found in Aloropiis to a greater degree than seems to be the 

 case in E. amarorum. More perfect remains must be found and con- 

 sulted before anything final in regard to the true phylogeny of these 

 Eocene Chalicotheres of America can be stated. 



Measurements. 



Length of skull P- to postglenoid process 129 mm. 



Length of skull from AT- to postglenoid process 58 " 



Transverse diameter from internal face of M- to inferior border of jugal 



opposite the orbit 31 " 



Length of the cheek-dentition 73 ' " 



Length of the premolars 29 



" " molars 47 



Antero-posterior diameter of P— 10 " 



Transverse diameter of P- 9.5 " 



Antero-posterior diameter of P- 11 " 



Transverse " " " 12.5 " 



Antero-posterior diameter of P* 10 " 



Transverse 



Antero-posterior 



Transverse 



Antero-posterior 



Transverse 



Antero-posterior 



Transverse 



Carnegie Museum, 

 May 29, 1916. 



13 



Ml 14 



" 13-5 



M^ 17.5 



" 18 



M-3 17.5 



" 19.8 



SYNOPSLS OF CONTENTS OF PAPER. 



Introduction 40 



Pisces 40 



Reptilia 41 



Mammalia, Mesonychida; 41 



Miacidae 48 



