260 PROF, J. C. EWART ON 



maxillary bones doubtless increases the strength of the front 

 part of the jaw which supports the horny pad against which the 

 lower incisors bite. As the Anoa is partial to the neighbourhood 

 of water, it probably feeds on coarse grasses like its ally the 

 Tamarau of the island of Mindoro, which is said to browse on 

 sugar-cane. 



The Indian Buffalo lives in the neighboui-hood of swamps and 

 jungles, and probably also feeds on reeds and coarse grasses — • 

 food which necessitates long, firmly secured premaxillse. 



In the Catalogue of the Ungulata in the British Museum 

 Dr. Gray says that in the tiaie Oxen "the pi-emaxillee are large 

 and always extend upwards into the triangular space between the 

 maxillge and the nasals and consequently articulate with both 

 these bones as in Buhalus ; in the genus Bihos, on the other hand, 

 the premaxillse are small and are attached only to the distal 

 extremity of the maxilla and are separated by a considerable 

 interval from the nasals." As will appear below, the premaxillse, 

 instead of being always long enough in true Oxen to extend 

 upwards between the maxillfe and nasals as in the Buffalo, are 

 sometimes so short that they fail to reach the nasals as in the 

 Bison (text-fig. 67, p. 253). 



In Bos 2^rimigenius the premaxillse, in all the skulls I have 

 examined, reach the nasals. In some cases the connection with 

 the nasals is only 5 mm., but in a Urus skull in the British 

 Museiim the premaxillee extend nearly as far upwards between 

 the nasals and the maxillae as in the Buffalo (text-fig. 64). The 

 extent of the connection between the premaxilla and the nasal 

 in a Urus skull in the Anatomical Museiim of the Univei-sity of 

 Edinburgh is shown in text-figs. 65 & 66. 



The premaxilla is shorter and further removed from the nasal 

 in the Bison than in aiiy other member of the Bos genus (text- 

 fig. 67). According to Major Heber Percy, the European Bison 

 " are fond of grazing on a coarse aromatic kind of grass known as 

 Zubr gi^ass." Others state that " they are equally fond of browsing 

 on the leaves, young shoots, bark, and twigs of trees," and that 

 " in winter they are driven to subsist entirely on buds, twigs, bark, 

 and such patches of dry grass and fern as remain " *. 



The prairie Bison of America apparently fed chiefly on grass, 

 hence doubtless the necessity for the extensive migrations, but the 

 American woodland Bison seem to " subsist chiefly on the leaves 

 and twigs of the birch and willow " t. It is conceivable that 

 owing to the softer nature of the food of the Bison the necessity of 

 having the premaxillse firmly wedged in between the nasal and 

 maxillary bones no longer exists. 



In a very young Domestic Ox skull (breed unknown) the pre- 

 maxilla (text-fig. 68) bears the same relation to the nasal as in 

 the Urus represented in text-fig. 66 ; in an older skull it occupies 



* Lj'deklver, ' Wild Oxen, Sheep, and Cattle,' p. 77. 

 f Lj'dekker, op. cit. p. 91. 



