354 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. 



two former not equally open to the Western Province, The Eastern and 

 Southern Provinces further resemble each other in consisting largely of 

 grassy plains, and in being, par excellence, the land of Antelopes. On 

 the other hand, the Western Province, in consequence of its moist climate 

 and dense forests, is the metropolis of the African Quadrumanes, to 

 which region no less than six genera are restricted, and where all but one 

 are rei>resented, while only four occur in the Eastern, and merely a few 

 outlying species reach the Southern. Hence the Eastern and Southern 

 Provinces are far more closely allied than is either with the Western. 



Eastern Province. — The East African Province or "Subregiou'^ 

 includes, as claimed by Mr. Wallace, not only East Africa proper, but 

 also a considerable portion of the Great Sahara and the whole of the 

 northern portion of Tropical South Africa, thus bounding the Western 

 Province on three sides. In other words, it not only includes East Africa 

 and Southern Arabia, but all of Tropical Africa, except the western 

 portion, situated (speaking generally) between latitude 15° north and 

 latitude about 22° south. As is well known, it consists mainly of a 

 moderately elevated plateau, rising, in Abyssinia, into lofty mountains. 

 It is generally an open region, " covered with a vegetation of high grasses 

 or thorny shrubs, with scattered trees and isolated patches of forest 

 in favorable situations. The only parts where extensive continuous 

 forests occur are on the eastern and western slopes of the great Abys- 

 sinian plateau, and on the Mozambique coast from Zanzibar to Sofala."* 

 It is worthy of note that the species peculiar to the province occur 

 almost exclusively in Mozambique, or in Abyssinia and adjoining por- 

 tions of Northeast Africa, a few extending into the Arabian Peninsula. 



Of the ninety genera occurring in this province, ten, which are almost 

 cosmopolite, may be considered as having too wide a range to possess 

 any special significance. Of the remaining eighty, about one-fourth are 

 found also in the Indian Region, leaving three-fourths (thirty-nine) as 

 peculiarly African. Of these, twelve only are restricted to the Eastern 

 Province, sixteen being common to the Southern Province, and ten to 

 the Western. The subjoined tabular list indicates approximately the 

 distribution of the genera of the Eastern Province. 



* Wallace, Geogr. Dist. Anim., vol. i, p. 2.'i0. 



