52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 28 



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



No. No. 



i8i8 20352 



Upper molar series, M^-M^ inclusive 36.0a 34-5a 



C, anteroposterior diameter (at alveolus) : greatest trans- 

 verse diameter 8.5a : 7.1a 5.0 : 4.7 



P*, anteroposterior diameter : greatest transverse diame- 

 ter 7.7 : 37 



P', anteroposterior diameter : transverse diameter* lO.o : 5.1 9.4 : 5.0 



P', anteroposterior diameter : transverse diameter 9.5:10.3 9.7:8.5 



P*, anteroposterior diameter : transverse diameter 8.0 : 10.5 8.2 : ii.oa 



M\ anteroposterior diameter : transverse diameter* 10.7a : . . . 



M', anteroposterior diameter : transverse diameter 13.3 : 15.8 13.0 : 14.2 



M', anteroposterior diameter : transverse diameter 13.4 : 17.4 13.7 : 16.0 



Y.P.M. 



No. U.S.N.M. 



ii8go No. 



Type 20352 



Length of low^er cheek tooth series, Pi (at alveolus) -M3, 



inclusive 71.0a 



Lower premolar series. Pi (at alveolus )-P4, inclusive 32.4 



Lower molar series, M1-M3, inclusive 39.0 



Pi, anteroposterior diameter (at alveolus) : greatest 



transverse diameter 5.9 : 4.1 



Pj, anteroposterior diameter : greatest transverse diame- 

 ter 8.0 : 3.8 



Ps, anteroposterior diameter : greatest transverse diame- 

 ter 99: 4-9 



P4, anteroposterior diameter : greatest transverse diame- 

 ter lo.o : 6.9 



Ml, anteroposterior diameter : transverse diameter of tal- 



onid 95 : 7.1 9-7 : 7-5 



Ml, anteroposterior diameter : transverse diameter of tal- 



onid 10.0:7.8 11.4:8.1 



M3, anteroposterior diameter : transverse diameter of trig- 



onid 17.8 : 7-8 



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. 



PROTOREODON PARVUS 25 Scott and Osbom, 1887 



Synonym. — Hy ornery x breviceps Marsh, 1894. 



Type. — Portions of skull and left ramus of mandible, P.U. No. 

 10398. 



Horizon and locality. — Uinta B (according to Thorpe), Uinta 

 County, Utah. 



Discussion. — Protoreodon parvus is distinguished from Protoreodon 



25 Illustrated in Scott and Osborn, 1887, p. 257; Scott, 1889, pi. 7, figs. 1-2; 

 Marsh, 1894, figs. 18, 19, and 22; and Thorpe, 1937, figs. 12-17; pl- i. fig- 3- 



