176 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 46. 



the catalogue number 5513, and was found 12 miles above the mouth 

 of Pelly River, Yukon Territory. The finder was Charles Sheldon, 

 who in 1905 presented the skull to the United States National 

 Museum, through W. H. Osgood. It lacks the lower jaws, the max- 

 illae, premaxillae, and the nasals. It is remarkable on account of the 

 shortness of the horn-cores. The following measurements have been 

 taken : 



Measurements of No. 5513, United States National Museum. 



Distance from lower lip of foramen magnum to fronto-nasal suture 270 



Width at mastoid region 290 



Width at hinder ends of temporal fossae 194 



Width at constriction between orbits and horn-cores 288 



Width at rear of orbits 355 



Height of occipital crest above lower lip of foramen magnum 150 



Width between bases of horn-cores 290 



Diameter of base of horn-cores, fore and aft 102 



Diameter of base of horn-cores, vertical 93 



Length of horn-core on upper curve 220 



Length of horn-core on lower curve 295 



Circumference of horn-core at base 280 



Distance between tips of horn-cores 650 



Distance from occipital protuberance to middle of line joining rear of orbits 215 



Distance between base of horn-core at the tip 208 



It will be seen that the dimensions of the horn-cores are greatly 

 like those of B. 'bison. In this respect the specimen resembles that 

 figured by Allen on plate 4 of his work already cited. Both these 

 skulls differ, however, from those of B. hison in having the bases of 

 the horn-cores pass outward from the skull without drooping, as they 

 do probably always in the species last mentioned. Such skulls might 

 be looked upon as illustrating the transition from B. occidentalis to 

 the existing American buffalo. 



A few words may be said regarding the specimen, consisting of the 

 horn-cores and the rear of the skull, more or less damaged, but 

 appearing in front to come forward to the notch for the nasals, 

 which was described by Sir John Richardson * as doubtfully Bison 

 priscus. Lucas ^ regarded this skull as specifically identicaWith the 

 type of B. crassicornis. There is in the United States National 

 Museum a cast of this skull and there is here presented (pi. 13, figs. 

 2, 3) figures showing it from above and from the rear. It will be 

 seen that the horn-cores are not as long as in other specimens of B. 

 crassicornis, and that they do not sag as much. The measurements 

 show that the individual must have had nearly or wholly the adult 

 size. It appears more probable that the skull is that of B. occiden- 

 talis. The horn-cores are less curved than is most specimens of this 

 species, but its index of curvature is not the lowest one (p. 178). 



J Zool. Voyage Herald, p. 34, pi. 7, fig. 1. 2 Proc. U. S. Nat. Mus., vol. 21, p. 761. 



