1 80 Bulletin American Museum of Natural History. [Vol. XVI, 



(29) Hyopsodus miniiscidiis Leidy Bridger. 



(32) " (Microsyops) vicarius Cope " 



(34) " {Esthonyx) miticiilus Cope Wasatch. 



(36) " {Lemiiraviis) distans Marsh Bridger. 



(48) " lemoinianus Cope Wasatch. 



(50) ? " {Phenacodus,Diacodexis) laiicuneus Cope.. . " 



(53) " powellianus Cope " 



(55) " wortinani Osbom Wind River. 



(56) " marshi Osbom Bridger. 



(57) " uiniensis Osbom Uinta. 



Species of Sarcoleniur. 



(11) SarcoJemur {Hyopsodus) pygmcBus Cope Bridger. 



{31) " (Antiacodon) furcatus Cope " 



(41) " (Antiacodon) crassus Cope 



(5) ? " (Hyopsodus) gracilis, Marsh " 



(24) ? " (Entomodon) comptus Marsh 



This family embraces a great variety of middle-sized Pri- 

 mates extending from the Wasatch (Suessonien) to the Uinta 

 (Ligurien) divided into two readily distinguishable genera, 

 Hyopsodus Leidy and Sarcoleniur Cope. 



Hyopsodus. Sarcoleimir. 



Paraconid t3^pically wanting. Paraconid persistent, close to 



nietaconid. 



A single specimen (Am. Mus. No. 4192) of Hyopsodus exhibits a 

 vestigial paraconid and bridges the gap between these genera. 



Genus HYOPSODUS Leidy. 



Microstis Leidy, Lemuravus Marsh, ? Sienacodon Marsh. Compare 

 also Diacodexis laticuneus Cope. 



Hyopsodus is one of the most abundant and persistent of the 

 Mesodonta, extending from the Wasatch to the Bridger and 

 even into the Uinta. It was first described by Leidy in 

 1870 from a lower jaw found near Fort Bridger; the types 

 of Microsus Leidy and Lemuravus Marsh, also from 

 the Bridger, appear to be generically identical with it. 

 Lemuravus was mistakenly separated by the formula i |, 

 a character which is common to all the known species of 

 Hyopsodus. This is the only Primate with the complete 

 eutherian dentition known, namely : |, \, -|, | = 44. The 



