BISON PRISCUS. 515 



slender proportions, compared with those of the Ox, which 

 distinguish the fossils. There are fourteen pairs of ribs. 

 The skull shows the same expanse, convexity, and short- 

 ness of the frontal region, and the same angle between 

 this and the occipital region, as does the fossil skull of the 

 Bison priscus ; the horn-cores have the same advanced 

 origin, and the same direction : these, however, are rela- 

 tively shorter than in most of the fossil skulls, and the 

 general size of the existing Aurochs is less than that of 

 the ancient or fossil specimens. Admitting with Cuvier, 

 that such characters are neither constant nor proper for 

 the distinction of species, we may recognise in the con- 

 fined sphere of existence to which the Aurochs has been 

 progressively reduced, precisely the conditions calculated 

 to produce a general loss of size and strength, and a special 

 diminution of the weapons of offence and defence. I can- 

 not perceive, therefore, any adequate ground for aban- 

 dqning the conclusion to which I had arrived from a study 

 of the less perfect materials available to that end, before 

 the arrival of the entire skeleton of the Lithuanian Au- 

 rochs, viz. that this species was contemporary with the 

 Mammoth, the Tichorhine Rhinoceros, and other extinct 

 Mammals of the pliocene period. , 



Fig. 212 



Side view of cranium of Bos longifrons, Bog, Ireland. 



L L 2 



