BISON PRISCUS. 493 



orbits, being equal to its breadth ; in the Aurochs, mea- 

 sured at the same place, the breadth greatly exceeds the 

 height, in the proportion of three to two : the horns 

 are attached in the Ox to the extremity of the highest 

 salient line of the head, that which separates the forehead 

 from the occiput ; in the Aurochs this line is two inches 

 behind the root of the horns : the plane of the occiput 

 forms an acute angle with the forehead in the Ox ; the 

 angle is obtuse in the Aurochs : finally, that plane of the 

 occiput is quadrangular in the Ox, but semicircular in 

 the Aurochs."* The ribs never exceed in number thir- 

 teen pairs in any species of Bos proper ; the European 

 Bison or Aurochs has fourteen, and the American Bison 

 fifteen pairs of ribs. 



The fossil cranium with horn-cores, described and figured 

 by Klein in the thirty-seventh volume of the ' Philo- 

 sophical Transactions,' No. ccccxxvi. figs. ], 2, and 3, and 

 which is now in the British Museum, well illustrates the 

 characters which distinguish the Aurochs : the specimen 

 was dug up near the city of Dantzig. 



Faujas,"f* Cuvier,J and H. v. Meyer, have added abund- 

 ant illustrations of the remains of the same species from 

 the superficial deposits of various parts of Europe, some 

 of which carry the antiquity of the Aurochs as far back 

 as the period of the extinct Pachyderms of the uewer 

 pliocene deposits. The remains of the ancient European 

 Bisons attest their larger size, and longer and somewhat 

 less bent horns than are manifested by the individuals 

 of the present race, but no satisfactory specific distinc- 

 tion has been detected in the fossils compared with the 

 bones of the Lithuanian Aurochs. 



* Menagerie du Museum d'Histoire Nat. Art. Zebu. 



t ' Essai de Geologic,' torn. L pi. xvii. f Loc. cit. 



$ ' Uber Fossile Reste von Ochsen,' 4to., 1832, tab. viii. xi. 



