50 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



Several isolated sciuravid teeth from the Cathedral Bluffs (in a 

 vial accompanying a Notharctus jaw, P.U. No. 16109) are tentatively 

 referred to 5". wilsoni. These are a part of the evidence cited by 

 Morris (1954, p. 199) as indicative of a Bridgerian age. Some of the 

 lower teeth are a Uttle larger than in the New Fork jaw, and in cer- 

 tain of them there is noted a little better evidence for a metastylid. 

 Nevertheless, they resemble those in S. wilsoni in having a somewhat 

 less progressive appearance than in 5". nitidus. An upper molar in 

 this assortment of teeth from the Cathedral Bluffs is about the size 

 of those in the New Fork maxilla but is much less worn, and it is 

 observed that the metaloph is not so deflected anteriorly, resulting in 

 a relatively smaller basin between the metaloph and posterior cingulum 

 than in S. nitidus. There is, of course, no certainty that the teeth are 

 all of the same sciuravid. 



MEASUREMENTS IN MILLIMETERS OF UPPER AND LOWER TEETH IN 

 WASATCHIAN SCIURAVIDS * 



Length, M*-M^ inclusive 



M\ anteroposterior diameter ; transverse diameter 



M^ anteroposterior diameter : transverse diameter. . . 

 M', anteroposterior diameter : transverse diameter 



"Sciuravus" Dawsonomys Sciuravus 



depressus woodi zuilsoni 



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



No. No. No. 



458 19309 22425 



"Cotype" Type Type 



Length, P4-M2, inclusive 5.7 



P«, anteroposterior diameter: 



transverse diameter i-9:i-5 1.9:1.6 



Ml, anteroposterior diameter : 



transverse diameter 1.9 : 1.7 2.0 : 1.8 2.0 : 1.8 



Ms, anteroposterior diameter : 



transverse diameter 2.1 : 1.9 



* Measurements of the type of Knightomys senior were given in 1952 (p. 49). 



CARNIVORA 



ARCTOCYONIDAE 



THRYPTACODON, near T. ANTIQUUS Matthew 



No additional material of Thryptacodon, beyond that from the 



La Barge horizon described in 1952, has been encountered in any of 



the Knight horizons. 





