344 BRITISH MAMMALS 



there is no trace of the metacarpal bone of the second toe. The 

 oxen have this outer metacarpal splint of the musk ox merely 

 represented by a small knob of bone. In this point, therefore, 

 Ovibos is more primitive than the oxen. 1 



In the anatomy of its soft parts the musk ox is somewhat 

 isolated, but perhaps conforms most nearly to the capricorns. 

 In the direction of this group, indeed, its nearest affinities seem 

 to lie. It branched off, no doubt, from a primitive type of 

 hollow-horned ruminant, which was the stock which gave rise 

 to the oxen on the one hand and the capricorns on the other, 

 while the capricorns are the parent forms of the sheep and goats. 

 These mountain antelopes, as they are usually termed, are repre- 

 sented at the present day by Budorcas, a heavily built animal 

 living in Tibet, with a strong superficial resemblance to the 

 musk ox ; by the serows of the Chinese, Indian, Sumatran, and 

 Japanese mountains 2 ; by the chamois of the Alps and the 

 Caucasus ; and, lastly, by another strange-looking creature, the 

 rocky mountain goat (Haploceros) of North-west America. 



The horns of the musk ox are, perhaps, its most peculiar 

 feature. Those of the male are enormously expanded and 

 flattened at the base, and the bases almost touch in the middle 

 of the forehead. They are curved abruptly downwards and then 

 upwards, and resemble very strongly those of the white-tailed 



1 See illustration on p. 281. The vestiges of the second and fifth 

 metacarpal and metatarsal bones in the skeletons of the Bovidce have been 

 very insufficiently illustrated and considered by zoologists. Metatarsal 

 vestiges are very rare perhaps only to be met with in some Tragelaphs 

 and Cephalophines. All the Bovids are " plesiometacarpalian," like the 

 True Deer. It is only the upper portions of the side metacarpals which 

 survive, though there are also nodules of bone (in the sheep, for example) 

 which support the side hoofs. In the TragelaphincK (elands, kudus, 

 bongos, bushbucks) the side metacarpals are well developed, and metatarsals 

 also. They are present in the Cephalophines, but absent from most other 

 antelopes. Their traces in sheep and goats are fleeting. In the oxen, the 

 musk ox, and the capricorns they are only developed on one side the outer. 



2 Urotragus caudatus, the long-tailed goral of North China, is a remarkable 

 form, retaining the primitive long tail which has disappeared in so many 

 bovids. 



