XIV. A SKULL OF BISON CRASSICORNIS. 



By W. J. Holland. 



(Plate XLIII.) 



In the spring of the year 1907 the Carnegie Museum acquired by 

 purchase from Mr. Frank Caldwell of Indianapolis, Indiana, the 

 cranium and horns of a specimen of Bison crassicornis Richardson, 

 which had been obtained by the vendor from an excavation made 

 near Dawson, Yukon Territory, in gold-bearing gravel. It was found 

 at a depth of forty-four feet below the surface associated with the 

 remains of a mastodon. 



The specimen is remarkable because of the preservation on the 

 horn-cores of the horns themselves, which for rather more than three- 

 quarters of their length are present, as is shown in the accompanying 

 plate. Unfortunately the dentition of the upper jaw and the 

 lower jaw were not recovered. Whether present when the excavation 

 was made and lost in the process of digging the remains from the 

 soil is not now known. The maxilla is broken ofT just in front of the 

 infra-orbital foramen and the premaxillaries are not present. 



The dimensions of the skull and horns, so far as they can be ascer- 

 tained, are as follows: 



Mm. 



Length of skull from occiput to infra-orbital foramen 465 



Height of skull from occipital condyle to median portion of frontals 268 



Transverse diameter of skull at superior border of orbits 372 



Transverse diameter of skull at inferior border of orbit 295 



Transverse diameter of skull above the orbits and between the horns 317 



Transverse diameter of skull below orbits 212 



Antero-posterior diameter of orbits 80 



Vertical diameter of orbits 77 



Distance from upper margin of orbit to point of union with frontal. 55 



Circumfeience of orbit 280 



Distance between horns at base of cores 325 



Circumference of cores at origin 365 



Greatest length of horns measured along poscerior curve 770 



Greatest distance between tips of horns i.iSS 



As our illustration shows, the tubular orbits characteristic of the 

 genus Bison are remarkably well developed. 



The skull of which the foregoing is a description is believed by the 



writer to be one of the most perfect specimens of the species which has 



thus far been recovered. 



22.5 



