GEOGRAPHICAL DISTRIBUTION 421 



therium). Deer and wild Oxen are absent. Gnawers (Rodentia) 

 are represented by a number of peculiar forms, of which may be 

 mentioned the Cape Jumping- Hare (Pedetes) and the African 

 " Flying "-Squirrels (Anomalurus). The archaic order of Mam- 

 mals Poor in Teeth (Edentata) is represented by the Cape Ant- 

 Eater or Aard-Vark (Orycteropus], and Pangolins (Manis), though 

 the latter are shared with the Oriental region. 



Ethiopian Birds (Aves). Among the many peculiar forms 

 it may suffice to mention Plantain- Eaters (Musophagd), Colies 

 (Colius], Whydah Finches (Vidua), Ox-Peckers (Buphaga), many 

 of the beautiful little Sun- Birds (Nectariniidte), the Secretary- 

 Bird (Serpentarius), and the African Ostrich (Struthio). 



Ethiopian Reptiles (Reptilia). Crocodiles are abundant but 

 not peculiar, while among Lizards (Lacertilia) the large majority 

 of the Chameleons are limited to the region. Among the in- 

 numerable Serpents (Ophidia) the Egg-eating Snake (Dasypeltis) 

 and deadly Puff-Adders (Bitis) are purely Ethiopian. 



Ethiopian Amphibians (Amphibia). The Clawed Toads 

 (Xenopus) are limited to Africa, while, on the other hand, not 

 only are Tailed Amphibians (Urodela) entirely absent, but also 

 several families of Tailless Amphibians (Anurd), e.g. the Tree- 

 Frogs (Hylidtz). 



Ethiopian Freshwater Fishes (Pisces). Some of the most 

 archaic types are limited to the region, e.g. one of the Lung- 

 Fishes (Protopterus), the Bichir (Polypterus\ and the Reed- 

 Fish (Calamoichthys), the last two being Ganoids. 



Ethiopian Land and Freshwater Molluscs (Mollusca). One 

 of the large Land- Snails (Achatina) is very characteristic, though 

 not limited to Africa, while Land-Slugs are comparatively scarce, 

 and freshwater molluscs are less abundant than in some other 

 regions. The fauna of Lake Tanganyika presents some re- 

 markable features. As we have seen elsewhere (see p. 313) 

 the Caspian Sea and Lake Baikal were once continuous with 

 the Arctic Ocean, the fact that each is inhabited by a peculiar 

 species of Seal being accounted for in this way. It appears 

 that in remote geological times Tanganyika was also part of a 

 sea area, and was converted into a lake as one of the results of 

 a series of land-upheavals. Some of the marine molluscs and 

 other animals living in the sea of which it formed a part proved 

 able to accommodate themselves to the altered conditions, and 



VOL. IV. 122 



