288 On a fossil Ox from the Mississippi. 



mal of this genus found in Siberia, within, or rather under the 

 arctic circle. He perceived at once, that it must be referred 

 to one of the two living species with flat horns just mentioned, 

 or, according to the notions prevalent at that day, it must 

 have belonged to a third species, which would one day be 

 discovered in the interior of Asia. He afterwards had an 

 opportunity of examining a skull of the musk ox, and his 

 friend Sparrman communicated to him, from the Cape of Good 

 Hope, his observations on the Bos coffer. 



With these facts before him, he was finally induced to con- 

 sider his two mutilated crania, as having belonged to the 

 Bos moschatus. Probably, as Cuvier suggests, he was influ- 

 enced in his opinion, by the supposition that these skulls 

 might have been brought to Siberia from America, the native 

 country of the musk ox, by the currents of the Icy Sea. 



The following are some of the more remarkable peculiari- 

 ties observed by Pallas, in the more perfect of the two Sibe- 

 rian fossil skulls. I am indebted for them to the great work 

 of Cuvier, the original paper not being in any library in this 

 city. 



The cranium was excessively thick. The front flat. The 

 bases of the cores (noyaux) of the horns, occupying all the 

 space from the orbits to the occipital crest, approaching each 

 other in a straight line, and leaving between them a space 

 hardly large enough to lodge the little finger. Their inter- 

 nal part is hollowed out into many cells. The horns turn 

 almost vertically down along the temples. The cerebral 

 cavity was six inches long, and two and a half inches in 

 breadth. The occipital hole, and all the arterial canals, were 

 smaller in proportion than among others of this family. 



With the single exception of the great proportional length 

 of the cerebral cavity, Cuvier thinks it would be difficult to 

 distinguish this from the skull of the musk ox. It will be 

 perceived that this description also coincides with that of the 

 New-Madrid specimen. 



