46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 128 



C.I.T. 



No. 

 1244 



Length of lower cheek tooth series, Pi (at alveolus) -M3, inclusive 42.3 



Lower premolar series, Pi (at alveolus) -P4, inclusive 22.8 



Lower molar series, M1-M3, inclusive i97 



Pi, anteroposterior diameter (at alveolus) 3-io 



P2, anteroposterior diameter : greatest transverse diameter 4.2 : 1.8 



P3, anteroposterior diameter : greatest transverse diameter 5-5 : 2.6 



P4, anteroposterior diameter : greatest transverse diameter 5-8 : 3-2 



Ml, anteroposterior diameter : transverse diameter of talonid 5-0: 4-i 



Mj, anteroposterior diameter : transverse diameter of talonid 5-9 '■ 4-7 



Ms, anteroposterior diameter : transverse diameter of trigonid 8.9 : 4.9 



a. Approximate. 



* Measurements of posterior upper premolars are taken anteropostenorly across outer por- 

 tion and transversely perpendicular to outer margin. Those of upper molars are taken 

 anteroposteriorly perpendicular to anterior margin and transversely across anterior portion 

 of tooth. 



Discussion. — Included in the material upon which this species was 

 based is also a lower jaw, C.I.T. No. 1244, with P1-M3, designated as 

 a paratype, and a left maxillary portion exhibiting P^ and P*. In 

 size 5. hudsoni is rather close to Leptotraguliis clarki, even to the 

 length of diastema separating Pi from Pg. The teeth, however, both 

 upper and lower, are fundamentally different in structure. 



SIMIMERYX MINUTUS 20 (Peterson), 1934 



Type. — Portion of right ramus of mandible with P4-M2, CM. 



No. 11913. 



Horizon and locality. — Lapoint member of Duchesne River forma- 

 tion, north side of "Red Narrows," east of Tridell, Uinta County, 

 Utah. 



Discussion. — That Peterson should have referred this form, even 

 questionably to Leptomeryx, is surprising, inasmuch as the P4 is quite 

 unlike that in the Oligocene genus. Correspondence to Simimeryx 

 hudsoni, not known to Peterson at the time of his writing, is rather 

 marked. Apparently, the only differences to be noted between the 

 types are the much smaller size of Simimeryx minutus and the better- 



MEAStJREMZNTS IN MILLrMETERS OF DENTITION IN TYPE SPEaMEN OF 



Simimeryx minutus, cm. no. 11913 



Length of lower cheek tooth series, P4-Mj, inclusive 12.4 



P«, anteroposterior diameter 3-9 



Ml, anteroposterior diameter : transverse diameter of talonid 4.1 : 2.8 



Mj, anteroposterior diameter : transverse diameter of trigonid 4.6 : 3.1a 



a. Approximate. 



20 Illustrated in Peterson, 1934, fig. 6. 



