84 GEOGRAPHICAL DISTEIBUTIOST. 



comprises the common hog or wild-boar of Eurasia, but its place 

 is taken by the so-called "water-hogs" and "wart-hogs," of the 

 genera Potamochoerus and Phacochosrus. Of the Rhinocerotidas, a 

 family which this region shares with the Oriental or Indian, there 

 are four or five species or varieties, all of them two-horned. Bj' far 

 the most important of all the African ungulates are the ruminants. 

 We have here an extraordinary development of the antelopes, which 

 in the number of their species far surpass those of all the other 

 regions put together. No less than from eighty to ninety distinct 

 species have already been described, and doubtless many more re- 

 main in the districts that have not yet been explored. Among the 

 numerous genera of these animals, which comprise forms ranging in 

 size from the dimensions of a large ox (eland) to those of a rabbit 

 (m'doqua, guevi), there are none that are found in any other faunal 

 region, excepting Gazella, the gazelle, and Oryx, to which the gems- 

 bok belongs, the former represented by a limited number of species 

 in the desert regions of Western and Southwestern Asia (Arabia, 

 Persia), and the latter, by a single species, also from the Arabian 

 desert. The antelopes may be conveniently divided by their habits 

 into four groups: 1. The desert antelopes, or such as frequent the 

 desert regions, like the gazelle; 2. The hush antelopes, or those 

 which habitually frequent the forest recesses, like the koodoos, 

 water-bucks, and bushboks ; 3. The rock antelopes, which, like the 

 klipspringer, recalling in aspect and habits the European chamois, 

 frequent the mountain-fastnesses ; and, 4. The antelopes of the 

 open plains — gemsbok, blessbok, hartebeest, gnu, springbok — 

 which comprise the greater number of species, and which, as the 

 springbok, not unfrequently congregate in herds of several hundreds 

 or even thousands. The more familiar forms of ruminants, such as the 

 deer, sheep, and goats, are, with the exception of an ibex found in the 

 Abyssinian highlands, completely absent. The only deer- like animal 

 found on the African continent south of the Sahara is the chevrotain 

 (Hyaemosehus aquaticus), from the region lying between the Senegal 

 and the Gaboon, a small animal closely allied to the Oriental musk- 

 deer, whose nearest representatives, the Traguli, inhabit the south- 

 eastern extremity of the continent of Asia, and the adjacent islands of 

 the East Indian Archipelago. The wild-ox (Bos) is also absent, but 

 its place is occupied by the Cape buiialo (Bubalus Caffer), whose 

 domaifl extends throughout the greater portion of South, Central, 



