Birds.—Peculiar forms of birds are hardly to be found here; we only meet with two—Hypocolius, a genus of shrikes in Abyssinia; and Balæniceps, the great boat-billed heron of the Upper Nile. Yet throughout the country birds are abundant, and most of the typical Ethiopian forms are well represented.
Reptiles.—Of reptiles, the only peculiar forms recorded are Xenocalamus, a genus of snakes, belonging to the Calamariidæ; and Pythonodipsas, one of the Dipsadidæ, both from the Zambesi; and among lizards, Pisturus, one of the Geckotidæ, from Abyssinia.
Amphibia and Fishes.—There are no peculiar forms of amphibia or of fresh-water fishes.
Insects.—Insects are almost equally unproductive of peculiar forms. Among butterflies we have Abantis, one of the Hesperidæ, from Mozambique; and in Coleoptera, 2 genera of Cicindelidæ, 8 of Carabidæ, 1 or 2 of Cetoniidæ, and about half-a-dozen of Longicorns: a mere nothing, as we shall see, compared with the hosts of peculiar genera that characterise each of the other sub-regions. Neither do land-shells appear to present any peculiar forms.
The fact that so very few special types characterise the extensive area now under consideration is very noteworthy. It justifies us in uniting this large and widespread tract of country as forming essentially but one sub-division of the great Ethiopian region, and it suggests some curious speculations as to the former history of that region, a subject which must be deferred to the latter part of this chapter. In none of the other great tropical regions does it occur, that the largest portion of their area, although swarming with life, yet possesses hardly any distinctive features except the absence of numerous types characteristic of the other sub-regions.
Plate IV.
CHARACTERISTIC ANIMALS OF EAST AFRICA.
Plate IV.—Illustrating the Zoology of East Africa.—Although this sub-region has so little speciality, it is that which abounds most in large animals, and is, perhaps, the best representative of Africa as regards zoology. Some of the most distinctive of African animals range over the whole of it, and as, from recent explorations, many parts of this wide area have been made known to the reading public, we devote one of our plates to illustrate the especially African forms of life that here abound. The antelopes represented are the koodoo (Tragelaphus strepsiceros) one of the handsomest of the family, which ranges over all the highlands of Africa from Abyssinia to the southern districts. To the left is the aardvark, or earth pig, of North Eastern Africa (Orycteropus æthiopicus) which, to the north of the equator in East Africa, represents the allied species of the Cape of Good Hope. These Edentata are probably remnants of the ancient fauna of Africa, when it was completely isolated from the northern continents and few of the higher types had been introduced. The large bird in the foreground is the secretary-bird, or serpent-killer (Serpentarius reptilivorus), which has affinities both for the birds-of-prey and the waders. It is common over almost all the open country of Africa, destroying and feeding on the most venomous serpents. The bird on the wing is the red-billed promerops (Irrisor erythrorhynchus), a handsome bird with glossy plumage and coral-red bill. It is allied to the hoopoes, and feeds on insects which it hunts for among the branches of trees. This species also ranges over a large part of east and central Africa to near the Cape of Good Hope. Other species are found in the west; and the genus, which forms a distinct family, Irrisoridæ, is one of the best marked Ethiopian types of birds. In the distance is a rhinoceros, now one of the characteristic features of African zoology, though there is reason to believe that it is a comparatively recent intruder into the country.
II. The West-African Sub-region.