EXTi?fCT BTSO^S OF" NORTH AMERICA— HAY. 



171 



at hand, see table on page 168. In the lower jaw of another i?isori 

 hison, No. 172689, U.S.N.M., from northern Alberta, the length of 

 the last lower molar is 46 mm.; the width across the front lobe, 21 

 mm.; across the middle lobe, 20 mm.; across the hinder, 11 mm. It 

 will be seen that at least this tooth in the fossil species is longer and 

 especially much wider than in the existmg bison. The dimensions 

 of the upper teeth of this Kansas specimen differ somewhat from those 

 of the specimen in the American Museum of Natural History. 



As regards the direction taken by the horn-cores it may be said 

 that a straight line joinmg the tips has its middle point 90 mm. above 

 the occipital crest and at a somewhat shorter distance behmd it. 

 Near the bases the horn-cores are directed outward, somewhat back- 



FiG. 5.— Bison occidentalis. Skvll at Kansas Universitt. Lateral view. 



ward, and slightly downward, but soon beginnmg to rise. At the 

 base the horn-cores are only slightly flattened. 



Measurements of the other parts of the skeleton have been pub- 

 lished by Stewart and McClung. A drawing of the whole skeleton is 

 here presented (fig. 6), prepared from a photograph furnished by the 

 University of Kansas. The atlas is wholly artificial. The centrum 

 of the axis has a length of 110 mm.; its spine rises 170 mm. above the 

 lower surface of the centrum. The spine of the seventh cervical is 

 510 mm. high, but it is partly restored. The spine of the first dorsal 

 is 540 mm. high; of the second, 600 mm. high. The centrum of the 

 fifth dorsal is 72 mm. long; that of the tenth dorsal, 61 mm. long; 

 that of the first lumbar, 70 mm. long. The sacrum has a length of 



