EXTINCT BISONS OP NORTH AMERICA— HAY. 181 



obtained at "26 claims below Carmack's," a few miles southeast of 

 Dawson, Yukon Territory. The great value of this specimen lies 

 in the fact that the horn-sheaths are yet preserved. The photograph 

 from which the figure was engraved was kindly sent to the writer by 

 W. G. Blunt, of the Memorial Museum. This gentleman informs 

 me that the distance between the horns is 14 inches (350 mm.) ; the 

 circumference of the horns at the base, 16-i mches (414 mm.); the 

 extent from tip to tip, 5 feet 5-^ inches (1,665 mm.). 



This species, with its long, heavy, saggmg horns, appears to be 

 very distinct from any other mentioned in this paper. That the 

 skulls here figured belong to the same species as those recorded under 

 B. antiquus and B. occidentalis, the writer does not for a moment 

 concede. 



It seems to the author that F. A. Lucas was right when he identified 

 Kichardson's type of B. crassicornis with No. 1584 of the United 

 States Museum and concluded that it was a species distinct from 

 Leidy's B. antiquus. 



Tscherski described' under the name Bison priscus various 

 remams wliich had been discovered, some in the basin of the Jana 

 River, some on Liakhof Island, some at the delta of the Lena. He 

 figured one skull which had been found in the basin of the Jana River 

 and wliich lacked some of the bones of the muzzle, but which still 

 retamed the horn-sheaths. Tscherski's figures are here reproduced 

 (pi. 15, figs. 1, 2) on a somewhat smaller scale than the originals. 

 A comparison of these illustrations with those here presented of 

 Alaskan specimens seems to make it higlily probable that the Siberian 

 skull belonged to Bison crassicornis. In the fifth column, on page 1 79, 

 are measurements which are in part those given by Tscherski, in 

 part are determined from his data or from the illustrations. It is 

 evident that the animal was a larger one than either of the others 

 whose measurements are here given except No. 6834 of the Field 

 Museum of Natural History, Chicago; and the horn-cores are 

 apparently longer than even in this. Nevertheless, the space between 

 the horn-cores is less than in the others. The dimensions of the 

 bases of the horn-cores are those given by Tscherski for the bases of 

 the horn-sheaths, but there can be little difference. The length of 

 the horn-cores on the upper border has been taken from the Russian 

 author's statements, on his page 85; the lower curve is estimated 

 from his figure and indices. According to Tscherski's computations 

 the length of the horn-core is to that of the horn-sheath as 100 to 144,3. 

 The author just named gives as the index of the curvature of the 

 horn-sheath 178.9. This figure is obtained by measuring the chord, 

 the shortest distance between the upper border of the base of the 

 horn and its tip, regarding this as 100 and comparing it with the 



1 M§m. Acad. Imp. Sci. St. Petersb., ser.7,vol.40, pp. 75-152. 



