'J2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 128 



PROTYLOPUS PETERSONI 3^ Wortman, 1898 



Type. — Anterior portion of skull, right ramus of mandible, ulna 

 and radius, A.M. No. 2076. 



Horizon and locality. — Uinta C (according to Amer. Mus. labels, 

 but probably low in C, or possibly Uinta B to judge by other collec- 

 tions), Uinta Basin, Utah. 



Discussion. — In size Protylopus petersoni is only slightly smaller 

 than Oromeryx plicatus, to judge by the limited amount of material 

 known of each. P^ is three rooted in the type, as appears to be true 

 also in O. plicatus; however, the deuterocone is very weak and com- 



MEASUREMENTS IN MILLIMETERS OF DENTITION IN SPECIMENS OF 



Protylopus petersoni 



A.M. 



No. P.U. 



2076 No. 



Type 14647 



Length of upper cheek tooth series, C (at alveolus) -M", in- 

 clusive 45.0a 47.0a 



Length of upper cheek tooth series, P*-M', inclusive 41.00 43.1a 



Upper premolar series, P'-P*, inclusive 22.00 21.7 



Upper molar series, M*-M^ inclusive 21.0a 22.0a 



C , anteroposterior diameter : greatest transverse diameter . . 2.7 : . . . 2.9a : . . . 



P*, anteroposterior diameter : greatest transverse diameter. . 4.6 : . . . 5.1 : 1.7 



P', anteroposterior diameter : greatest transverse diameter . . 6.0 : . . . 6.00 : . . . 



P', anteroposterior diameter : transverse diameter* 5.8 : 3.8 6.5 : 2.7 



P*, anteroposterior diameter : transverse diameter 5.6a : 5.7a 5.6 : 5.5 



M\ anteroposterior diameter : transverse diameter* 6.50 : . . . 6.6a : 7.0a 



M*, anteroposterior diameter : transverse diameter 7.2 : 8.5 7.8 : 8.8 



M^ anteroposterior diameter : transverse diameter 8.3a : 9.0 8.8 : 9.4 



Length of low^er cheek tooth series, C (at alveolus) -Ma, in- 

 clusive 50.50 49.1a 



Length of lower cheek tooth series, P1-M3, inclusive 46.2 



Lower premolar series, P1-P4, inclusive 21.9 



Lower molar series, Mt-Ms, inclusive 24.3 25.3 



C, anteroposterior diameter : greatest transverse diameter. . Z-yC' '•• • • 3-7 '■ 2-0 



Pi, anteroposterior diameter : greatest transverse diameter 2.7a : 2.0 



Pj, anteroposterior diameter : greatest transverse diameter 5.9: 2.0 



P3, anteroposterior diameter : greatest transverse diameter 6.2 : 2.3 



P4, anteroposterior diameter : greatest transverse diameter 6.7 : 2.8 



Ml, anteroposterior diameter : transverse diameter of talonid 6.0a : . . . 5.9 : 4.6 



Ms, anteroposterior diameter : transverse diameter of talonid 7.2 : . . . 7.0 : 5.8 

 M3, anteroposterior diameter : transverse diameter of trig- 



onid 1 1.8 : 5.8 12.5 : 6.0 



a. Approximate. 



* Measurements of posterior upper premolars are taken anteroposteriorly 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. 



3'^ Illustrated in Wortman, 1898, figs. 3-6; and Scott, 1899, pi. 2, figs. 5, 8, 9. 



