NO. I LOWER EOCENE MAMMALIAN FAUNAS — GAZIN 59 



in Ma of the New Fork specimen. Measurements of teeth in the two 

 Wasatch specimens are given below, together with those for the type 

 of L''. massetericus. 



MEASUREMENTS IN MILLIMETERS OF LOWER TEETH IN 



SPECIMENS OF Uintacyoti 



U. massetericus U. asodes 



A.M. U.S.N.M. U.S.N.M. 



No. No. No. 



4250 19351 32468 



Type Type 



P*, anteroposterior diameter: 



transverse diameter 6.0 : 2.9 6.1 : 3.3 5.8 : 3.5 



Ml, anteroposterior diameter : 



transverse diameter 6.9 : 4.8 7.5 : 5.5 7.9 : 5.9 



M2, anteroposterior diameter : 



transverse diameter 4.2 : 3.6 6.0 : 5.1 



MIACIS, near M. EXIGTTUS Matthew 



Included among the more recent collections made from the New 

 Fork tongue is a lower jaw fragment with Mg and most of Mi 

 (U.S.N.M. No. 22469), clearly of Miacis but representing a species 

 distinctly smaller than M. latidens. In size it cannot be distinguished 

 from Miacis exigims, although all the heretofore described materials 

 of this species have been recorded only from Gray Bull levels. The 

 only feature seen in the two teeth that might be regarded as distinc- 

 tive is a more forward position of the paraconid of Mj. This was 

 noted in comparison with La Barge materials of M., cf. latidens as 

 well as with Gray Bull specimens of M. exiguus. 



An isolated lower carnassial in the La Barge collection, too small 

 to be included in Miacis latidens, may represent the same species as 

 that present in the New Fork fauna. The form of its talonid, however, 

 more closely resembles that of the other, much larger La Barge 

 specimens. 



MIACIS, cf. LATIDENS Matthew 



(Plate 8, figure i) 



The miacid jaws (U.S.N.M. No. 19335) described in 1952 and ten- 

 tatively referred to Matthew's Lost Cabin species Miacis, cf . latidens, 

 exhibit a well-preserved and nearly complete cheek tooth series on 

 the left side, illustration of which is included in this report. No 

 further materials that may represent this species have been encoun- 

 tered. 



