56 Oxen 



ot bone surmounting the crest ot that surface is, as already said, visible. 

 The whole occipital aspect of" the skull takes the form of an inverted V. 

 the summit of which is formed by the aforesaid boss. The presence of 

 fourteen pairs ot ribs is an essentially bisontine character ; and it seems 

 highly probable that the mass of long hair on the tianks, as well as the 

 uniform coloration, are also indicative of atiinitv with that group. The 

 premaxillary bones of the skull differ from those of the taurine group and 

 resemble the bibovine group and the bisons in not extending upwards to 

 join the nasals ; but the interval between these two bones is, as in the gaur, 

 considerably shorter than in the bisons. 



On the whole, it seems preferable to regard the yak as an aberrant 

 member ot the bisontine group, rather than the representative of a group 

 by itself. This view is supported by the occurrence of the under- 

 mentioned extinct species, which on distributional grounds appears to 

 connect the yak with tiie livinir bisons. 



Distrihiitir/n. — The plateau of Tibet, extending eastwards as far as the 

 province of Kansu in Cliina, and nurthwards probably as far as the Kuen 

 Lun. The south-western range embraces the north-eastern portions ot Ladak 

 in the neighbourhood of the Changchenmo valley and the Pangkong lake. 

 In summer yak are found at elevations from about 14,000 or 15,000 to 

 20,000 feet above the sea-level. 



Habits. — In Ladak the regions inhabited by the wilii yak are of the 

 most dreary and desolate description, where the pasturage even in summer 

 consists only ot patches ot a coarse, wiry grass apparently ill-fitted tor tlie 

 nutriment ot herds ot such large animals. Nevertheless, both yak and 

 argali thrive upon it ; and although in Ladak itself yak are now com- 

 paratively tew, in Chinese territory they exist in great munbers, and are 

 tound in herds numbering from ten to a hundred liead or more. The old 

 bulls are, however, for the most part solitary, or go about in small hands of 

 three or four. 



