NO. 2021. EXTINCT BISONS OF NORTH AMERICA— HAT. 165 



that found in California in having slenderer horns. This may be 

 explained on the supposition of a difference of sex. There seem to 

 be some differences in the proportions of the cranium likewise. In 

 the Indiana specimen the distance from the occiput to a line joining 

 the hinder borders of the orbits is about 73 per cent of the width at 

 the rear of the orbits; m the California specimen the corresponding 

 estimate is about 69 per cent. However, in four skulls of the Ameri- 

 can bison a range is found which is equally great. It seems to the 

 writer that we must believe that the California specmien and that 

 found in Indiana belong to the same species. The characters that 

 distmguish this bison are found, as pomted out by Lucas, in the 

 horns, which are about as long as the skull is wide, rapidly tapermg, 

 somewhat sagging, at the base, recurved at the tip, and directed out- 

 ward in a plane at right angles with the midline of the skull. In all 



Fig. 1.— Bison antiquus. Type. Part of skull. Horn-core restored to show form. 



the other species of North American and apparently also of European 

 bisons the axis of the base of the horn-core is directed more or less 

 toward the orbit of the opposite side. 



In his work The American Bisons, Living and Extinct, page 21, 

 published in 1876, J. A. Allen accepted this species as being distinct 

 from the European Bison priscus; but, he included in it Bison crassi- 

 cornis, of Alaska; as well as remains which have since been recog- 

 nized by Lucas as B. occidentalis. He was therefore entirely con- 

 sistent when he gave his judgment as follows: 



The types here recognized as distinct forms under the names B. priscus and B. 

 antiquus, it should be remarked, differ but slightly from each other — not more so, 

 probably, than do B. bonasus and B. americanus, if indeed so much — and constitute, 

 as it were, a common circumpolar form from which B. bonasus and B. americanus 

 have probably been differentiated. 



Richard Lydekker, in his Wild Oxen, Sheep, and Goats, etc., pub- 

 lished in 1898, on page 61, regarded B. antiquus and B. crassicornis 



