40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 128 



MEASUREMENTS IN MILLIMETERS OF DENTITION IN TYPE SPECIMEN OF 



Achaenodon robushis, p.u. no. 10033 



Length of upper cheek tooth series, C-M^ inclusive 185.0 



Length of upper cheek tooth series, anterior margin of alveolus for 



P'' to posterior margin of M^ 147.0 



Upper molar series, M*-M^, inclusive 70.0 



C, anteroposterior diameter (at alveolus) : greatest transverse diame- 

 ter 31.5 : 26.5 



P^ anteroposterior diameter : greatest transverse diameter 29.0 : 16.5 



P*, anteroposterior diameter : transverse diameter 23.0 : 27.5 



M*, anteroposterior diameter : transverse diameter 21.8 : 25.8 



M^, anteroposterior diameter : transverse diameter 24.5 : 31.8 



M^ anteroposterior diameter : transverse diameter 26.7 : 30.0 



Length of lower cheek tooth series, C-M3, inclusive 210.0 



Length of lower cheek tooth series, anterior margin of alveolus for 



P2 to posterior margin of Ms 172.0 



Ps, anteroposterior diameter : greatest transverse diameter 24.4 : 14.3 



P4, anteroposterior diameter : greatest transverse diameter 30.0: 17.5 



Ml, anteroposterior diameter : transverse diameter of talonid 22.5 : 17.5 



M2, anteroposterior diameter : transverse diameter of talonid 24.2 : 19.5 



Ms, anteroposterior diameter : transverse diameter of trigonid 36.8 : 23.0 



ACHAENODON TJINTENSIS is Osborn, 1895 



Type.—SknW with shattered teeth, A.M. No. 1822. 



Horizon and locality. — Uinta B, eastern portion of Uinta Basin, 

 Utah. 



Discussion. — Achaenodon uintensis was originally described by Os- 

 born as Elotherium uintense and provisionally given the new generic 

 name Protelotherium. Peterson, in his monograph on the entelodonts, 

 placed this genus in synonomy with Achaenodon and in 1919 outlined 

 his reasons. There appears to be little doubt but that Protelotherium 

 is a synonym, and Peterson's critical examination of the distortions 

 afifecting the A. robustus skull resulted in leaving little of significance 

 to distinguish the species A. uintensis other than somewhat greater 

 size. Peterson has also noted the somewhat broader premolars in 

 A. uintensis and the presence of an accessory cuspule on M^, Much 

 of Peterson's study of this form was based on two referred skulls in 

 the Carnegie Museum stated to be from the same horizon and locality 

 as the type. In reexamining these specimens, as well as material in 

 the American Museum referred to this species, I find differences in 

 proportions between them, particularly in the measurements of 

 teeth, fully as great as there is between the smaller of these and 

 the A. robustus type. I am much inclined to regard the species A. 



IS Illustrated in Osborn, 1895, figs. 16-17; and Peterson, 1919, pi. 47, figs. 1-4. 



