no. 2086. SOME MAMMALS OF THE PLEISTOCENE— HAY. 517 



squamosal suture. This course is quite different from that followed 

 in the existing American bison. In this bison the suture continues for- 

 ward to opposite the middle of the pedestal or hardly so far, and then 

 descends toward the parieto-squamosal suture; and the point where 

 the suture turns downward seems not to be affected by the size of the 

 horn-core. The anterior end of the parietal in the fossa of the fossil 

 bison is narrow and somewhat prolonged. The horizontal part of the 

 parieto- frontal suture has the same length as in the jersey cow; but, 

 since in the latter the horn is situated farther backward, the point 

 where the suture turns downward is much farther in front of the 

 horn than in the fossil bison. It is noted, too, that in the latter the 

 roof of the temporal fossa extends out on the base of the pedestal, but 

 it does not do so in the jersey skull. 



That part of the parietal of the fossil which enters into the occiput 

 is 23 mm. wide and rather rough, and it appears to have formed a 

 part of the occipital crest. 



The larger fragment (pi. 30, fig. 2) presents a part of the base of 

 the skull, including the left occipital condyle and a part of the right ; 

 most of the basioccipital and the basisphenoid ; that part of the left 

 squamosal which enters into the glenoid fossa and the zygomatic arch ; 

 and a part of the auditory apparatus. For our understanding of the 

 skull it would have been better if the two fragments had belonged to 

 the same side, for both reach the suture between the parietal and the 

 squamosal, in the temporal fossa. 



The distance from the median point on the lower lip of the fora- 

 men magnum to the front of the basisphenoid is 85 mm., as in the 

 jersey cow. In the skull of a cow buffalo (No. 15690, National Mu- 

 seum), whose basilar length is 423 mm. and whose upper tooth line is 

 148 mm. and whose width of skull at the zygomatic arches is 205 

 mm., the distance forward to the front of the basisphenoid is 98 mm. 

 The width across the occipital condyles can not be exactly deter- 

 mined, but it was about 96 mm.; that of the jersey being 93 mm.; 

 that of the small buffalo cow just mentioned, 110 mm. The width 

 across the tuberosities on the basioccipital was close to 56 mm.; in 

 the jersey 45 mm. ; in a large bison 62 mm. ; in another bison 57 mm. 

 In the jersey cow and in the American bison there are tuberosities 

 on the basisphenoid which sometimes are hardly more than rough 

 surfaces, but which may form considerable processes. In the fossil 

 under consideration, these form two platelike processes of bone. 

 These are about 25 mm. long at their bases, extend downward about 

 12 mm. from the lower surface of the basisphenoid, and are 4 mm. 

 or 5 mm. thick. They diverge from each other and leave a channel 

 between them into which one may lay one's little finger. When en- 

 larged, in the bison, these tuberosities are quite thick and are prob- 

 ably never so high. How much variation in this respect there was in 

 the new species one can not yet know. 



