UNGULATA. 439 



the Cavicornia. The anterior horns, as shown by the shape 

 of the horn-cores, were simple; and if the posterior horns had 

 been of a similar form, then Sivatherium might have been 

 fairly regarded as merely a gigantic four -horned Antelope, 

 similar to the living Antilope (Tetraceros) quadricornis of 

 India. The posterior horns, however, are not only much 

 larger than the anterior, but they possess two snags or 

 branches a peculiarity not to be paralleled amongst existing 

 Cavicornia, except in the Prong-buck. Dr Murie, however, in 

 an admirable paper on the affinities of Sivatherium, has drawn 

 attention to the fact that the Prong-buck sheds the sheath of 

 its horns annually, and has suggested that this may have also 

 been the case with the extinct form. This hypothesis is ren- 

 dered probable, amongst other reasons, by the fact that no 

 sheath has as yet been discovered surrounding the horn-cores 

 of either pair of horns in the Sivatherium. Upon the whole, 

 therefore, the above-mentioned zoologist would refer Siva- 

 therium to a distinct group which he terms Sivatherida, and 

 regards as being most nearly related to the Antilocaprida. 



Bramatherium has been found in deposits of the same age as 

 Sivatherium, with which it agrees in its colossal dimensions 

 and its possession of two pairs of hollow horns. It differs from 

 Sivatherium, however, in certain details of minor importance. 



The Sheep and Goats (Ovida) have mostly horns in both 

 sexes, and the horns are generally curved, compressed, and 

 turned more or less backwards. The body is heavier, and the 

 legs shorter and stouter, than in the true Antelopes. In the 

 true Goats (Capra) both sexes have horns, and there are no 

 lachrymal sinuses. The true Sheep (Ovis) are destitute of a 

 beard, and the horns are generally twisted into a spiral. Horns 

 may be present in both sexes, or in the males only. 



The Sheep and Goats are of no importance as fossils, unless, 

 indeed, as believed by high authorities, the Musk-ox should be 

 referred to the Ovidcz. Here, however, it will be considered 

 as belonging to the Bovidce. Remains of both Sheep and Goats 

 have been discovered in various Post-Tertiary deposits in 

 Europe, but they present nothing of special interest. 



The true Oxen (Bovida) are distinguished by having simple 

 horns, of a rounded shape, not twisted into a spiral. A few 

 remains of Bovidcz have been found in deposits of Pliocene 

 age, but the Oxen are essentially Post-Pliocene and Recent. 

 The most important Fossil Oxen are the Urus, the Aurochs, 

 the Bos longifrons of Owen, and the Musk-ox. 



The Aurochs or Lithuanian Bison (Bos bison] can hardly be 

 considered as a fossil form, as it occurs in a living state in 



