370 PALAEONTOLOGY 



with cloven feet and ruminating stomach, appears at a later 

 period in the tertiary series. 



The modification of the upper molars of the existing Rumi- 

 nant quadrupeds consists in the lower and less pointed lobes of 



the crown, the unworn summits of 

 which are at first rather trenchant, 

 like curved blades, than piercing. 

 They are soon abraded by mastica- 

 tion, and present the crescentic lobes 

 of dentine (ct,b,c,d) shown in fig. 124. 

 The transverse double-crescentic 

 Fig. 124. valley (</, i) contains a thicker layer 



Upper molar of Megaceros. f cem ent, and forms two detached 

 crescents in worn teeth. The premolars resemble in structure 

 one half of the true molars. 



Family I. — Bovid^e. 



Fossil molars of the ruminant type and bovine character 

 have hitherto been found, with unequivocal evidence, to the 

 writer's knowledge, only in beds or breccias of pliocene and 

 pleistocene age. At those periods in Britain there existed a 

 very large species of bison [Bison priseus), and a larger species 

 of ox [Bos antiquus), from pliocene fresh-water beds ; whilst a 

 somewhat smaller but still stupendous wild ox {B.prwiige- 

 nius\ has left its remains in pleistocene marls of England and 

 Scotland. With this was associated an aboriginal British ox 

 of much smaller stature and with short horns (B. longifrons), 

 which continued to exist until the historical period, and was 

 probably the source of the domesticated cattle of the Celtic 

 races before the Roman invasion. A buffalo, not distinguish- 

 able from the musk kind (Bubalus moschatusj, now confined to 

 the northern latitudes of North America, roamed over similar 

 latitudes of Europe and Asia in company with the hair-clad 

 elephants and rhinoceroses. 



