FAUNA OF THE ETHIOPIAN REALM. 89 



sixty of these are siluroids (cat-fishes), fifty cyprinoids (carps), and 

 about an equal number members of the family Mormyridse. Owing 

 to the broad distribution of the different types, which are spread 

 throughout the greater extent of the continent, a division of the 

 region into ichthyic sub-regions is rendered impossible. Of some 

 fifty-six species found in the waters of the Upper Nile, no less than 

 twenty-five are absolutely identical with forms belonging to the 

 West African rivers, and doubtless most of these also occur in the 

 waters of the unexplored tracts of the interior. Greater dissimi- 

 larity exists between the northern and western faunas and those of 

 the south, where the relationship has been rendered generic instead 

 of specific. Thus, the fishes of Lake Nyassa and the Zambesi River 

 are specifically distinct from those of the great equatorial lakes, 

 and their outflowing northern and western waters. Africa has rep- 

 resentatives of two genera of ganoid proper, Polypterus and Cala- 

 nioichthys, and one genus of lung-fishes, Protopterus (P. annectens), 

 the last closely related to the Lepidosiren of South America. With 

 the fish-fauna of this region the Ethiopian agrees in the partial 

 possession of the characinids (about thirty-five species) and the 

 chromids, and the genus Pimelodus among the cat-fishes. How 

 the transference of similar or identical types was effected to such 

 widely remote areas, whether through the intermedium of the 

 waters of a continental tract now submerged beneath the Atlantic, 

 or by way of the northern streams, it is impossible to say. 



The Ethiopian faunas, taken collectively, exhibit a remarkable 

 homogeneousness throughout, so that the delimitation of even the 

 three greater faunal sub-regions becomes difficult. The East Central 

 African sub-region is, strictly speaking, representative of the entire 

 tract, where the vast majority of all the distinctive types are found. 

 The West African sub-region is more properly the home of the 

 anthropoid apes, the chimpanzee and gorilla, and of the numerous 

 species of Cercopithecus and Colobus. The antelopes are much 

 less abundantly represented than in the plateau districts, although 

 they comprise a number of peculiar types, especially of the bush- 

 boks (Cephalophus). Other characteristic ungulates are the za- 

 moose, a species of buffalo (Bubalus brachyceros possibly also found 

 in Abyssinia), the Hyeemoschus aquaticus, and the Chreropsis Li- 

 beriensis (hippopotamus). The insectivores present as a distinctive 

 type the otter-like Potamogale velox ; the rodents the singular 



