186 



PR0CEBDIN08 OP TEW NATIONAL MUSEUM. 



VOL. 46. 



Tho upper premolars of No. 7706 are missing, but the molars 

 (fig. 8) are present and in excellent condition. The lower incisors 

 are gone, as well as the anterior two premolars of the right side. 

 The other premolars and molars are present (fig. 9). The follow- 

 ing measurements have been taken, as shown in the first column 

 of the table. In the second column are given the measurements of 

 the teeth of the existing American bison. The upper molars are those 

 of No. 22374, U.S.N .M, in which the premolars are missmg, as they are 

 m the fossil. The measurements of the lower teeth are from No. 38302, 

 U.S.N .M. Both of these specimens were of approximately the same 



FiQ. 8.— Bison alleni. Left upper molars of No. 7706, United States 

 National Museum. M.^ at right. X J- 



age as was the specimen of B. alleni. It must be understood that 

 the length of the tooth as here given is that of the grmding surface 

 from front to rear, and that this diminishes as the tooth is worn. 

 The width is taken at the base of the crown, and this width is indi- 

 cated by the outermost Ime in the illustrations. The double lines 

 indicate the arrangement of the enamel on the worn surface of the 

 tooth. As the tooth is worn down the bands of enamel, other than 

 those surrounding the lakes, approach nearer and nearer the narrow 

 outer lines. 



Measurements of teeth. 



Teeth measured. 



Length of the upper premolar-molar series 



Length of the upper premolar series (estimated from the sockets). . 



Length of the upper molai- series 



M.",leagth 



width 



M.s,length 



width 



M.s,length 



width 



Length of the lower premolar-molar series 



Length of the lower premolar series 



Length of the lower molar series 



Pm.2, length 



width 



Pm.j.length 



width 



Pm.4, length 



width 



M.i, length 



width 



M.2,length 



width 



M.i,length 



width 



