NO. 1172. THE FOSSIL BISON OF NORTE AMERICA— LUCAS. 761 



Bison bonasus var. priscus Lydekker, Cat. Foss. Mam. Brit. Mus., Pt. II, Contug. 



the Order Ungulata, Suborder Artiodactyla, 1885, pp. 25, 26, London, in part. 

 Bison alaskensis Rhoads, Proc. Acad. Nat. Sci., Phila., 1897, p. 490. 

 Bos priscus Lydekker, Wild Oxen, Sheep, and Goats of All Lands, London, 1898, 



p. 61. 



Type. — In the British Museum, from Eschscholtz Bay, Alaska. 

 Horns long; length of horn core along upper curve very much greater 

 than circumference at base; horn cores slightly flattened on superior 

 face; transverse diameter much greater than vertical; curve of horn 

 regular, the tip not abruptly reflected nor pointing decidedly backward; 

 horn cores raking decidedly backward. 



This species, which has fared so well in the matter of synonyms, is, 

 so far as American species go, perfectly distinct, and its affinities with 

 EuiopeoAsiatic forms remain to be decided, though from the relations 

 between the existing faunas of northeastern Asia and northwestern 

 America it would be (juite natural to find fossil bison in eastern Siberia 

 that were indistinguishable from B. crasstcornis. 



Dr. J. A. Allen, in his Monograph of American Bisons, treats B. 

 crassicornis as a synonym of B. antiquus Leidy, while still more 

 recently Mr. Rhoads^ has divided Richardson's specimens into two 

 species, one of which, including the type, he considers as B. antiquus^ 

 while the other he calls B. alaskensis. The validity of Richardson's 

 Bison crassicornis hinges on the question of the identity of his tyj^e 

 I, A, with Leidy's B. antiquus. Both species are founded on more or 

 less imperfect specimens, but after going over descriptions, figures, 

 and specimens the conclusions reached are as follows: Richardson's 

 I, A, Plate IX, fig. 1, is specifically identical witli his No. 24589, Plate 

 VII, fig. 1, and this in turn with the specimens in the U. S. National 

 Museum and University of Pennsylvania, which do not in any way 

 resemble B, antiquus and do resemble one another. 



The disparity in size between the specimens under discussion amounts 

 to nearly 30 per cent, but the form and proportions of the crania and 

 horn cores are similar, while the specimen shown on Plate VII, fig. 1, is 

 shown by the cast to be young, being what would be termed a spike 

 horn. Owing to this youthfulness the horn cores do not have the proxi 

 mal downward curve found in adults, but the slender nature of the horn 

 cores and their backward inclination distinguish this from B. antiquus 

 at a glance. 



The type of B. crassicornis is Richardson's I, A, figured on Plate IX 

 and described on pages 40-43 of the Voyage of the Herald,^ and while 

 the horn cores are broken off a short distance from the base, enough 



'Proc. Acad. Nat. Sci., Phila., 1897, p. 490. 



2 A very good idea of the type may be obtained from Plate LXXV, taken from No. 

 13753 of the Museum of Archaeology and Pahnontology, University of Pennsylvania. 

 This specimen Mr. Rhoads considers to be identical with B, antiquus, but from the 

 backward rake of its horn cores this is out of the question. 



