1 82 Bulletin American Museicm of Natural History. [Vol. XVI, 



feebly developed; fourth superior premolar only with a well 

 developed internal cusp or deuterocone, third superior pre- 

 niolar with a small deuterocone, no trace of paraconid on 



Pa S? 



Fig. 5. Hyopsodus pauliis. Am. Mus. No. 2301. Lateral, 

 palatal, and superior views of skull. See page 186. Natural size. 



lower molars except as an occasional vestige on mj ; this is 

 a remarkably early specialization of these Primates towards 

 a quadritubercular type and readily distinguishes them from 

 the contemporary Notharctidae, and Anaptomorphidae. The 



