1897.] NATURAL SCIENCES OF PHILADELPHIA. 499 



the line of the base;" nearly semicircular in exterior outline, but 

 more abruptly incurved along terminal third. Horn-cores of de- 

 tached skull strongly curved, directed at base " slightly downward " 

 below frontal plane, " then outward and upward, the tips slightly 

 incurved, the general direction of core being slightly backward; a 

 Hue drawn from middle of orbit to tip of core intersecting base of 

 core higher than in Bison bison." Horn-cores nearly circular in 

 section at base, becoming slightly flattened above, medially, " with 

 an obscure ridge below." 



Measurements. — (Sent by collector with skin to Prof. Frank A. 

 Ward). " Height at shoulders, 1,703 millimeters ; height [to rump] 

 justin front of hind legs, 1,602 mm.; total length [of head and 

 body, without tail ?] 2,846 mm." 11 



Skull: (measurements sent by Mr. J. F. Whiteaves, zoologist of 

 Canadian Geological Survey). — Frontal width, between bases of 

 horn-cores, 343 mm. ; length of horn-core measured along superior 

 curve, 293 mm.; greatest depression of superior arc of horn-core 

 below a line connecting the tip and superior base of core, 102 mm. ; 

 horns (on mounted specimen) measured along the inferior curve, 

 533 mm. ; shortest distance from tip of horn to its superior base, 

 229 mm. 



Habitat. — Wooded uplands of the Northwest Territories, formerly 

 from the east slope of the Rocky Mountains to the 95th meridian, 

 and from latitude 63° to latitude 55° ; probably ranging south 

 along the Rocky Mountains to the United States. 



Remarks. — The great size, darkness of color, and character of horn 

 and horn-core in the type of Bison bison athabascoz, granting that it 

 is typical of the form known as the Wood Bison, are quite sufficient 

 to distinguish it from the plains animal and fully justify the opin- 

 ions of many huuters and travellers as to its separability from the 

 latter. The characters of the skull alone are sufficient to warrant 

 the distinction. In the type the frontal breadth between the bases 

 of horn-cores is equal to that of the old male specimen of fossil 

 bison (PI. XII, fig. 2) from California, which Leidy figured as " B. 

 latifrons" in the Geological Survey of the Territories; and in this 

 respect is more than 50 mm. wider than the largest old male skull of 

 B. bison in the museum of the Academy of Natural Sciences of 



"Prof. Macoun sends the following measurements from the mou'nted speci- 

 men : — " Height at shoulder, 1,779 mm. ; length without the tail, 2,821 mm. ; 

 length of horn 458 mm. ; circumference of horn at base 318 mm." 



