The Geographical Distribution of Animals/Chapter 11
THE ETHIOPIAN REGION.
This is one of the best defined of the great zoological regions, consisting of tropical and South Africa, to which must be added tropical Arabia, Madagascar, and a few other islands, all popularly known as African. Some naturalists would extend the region northwards to the Atlas Mountains and include the whole of the Sahara; but the animal life of the northern part of that great desert seems more akin to the Palæarctic fauna of North Africa. The Sahara is really a debatable land which has been peopled from both regions; and until we know more of the natural history of the great plateaus which rise like islands in the waste of sand, it will be safer to make the provisional boundary line at or near the tropic, thus giving the northern half to the Palæarctic, the southern to the Ethiopian region. The same line may be continued across Arabia.
With our present imperfect knowledge of the interior of Africa, only three great continental sub-regions can be well defined. The open pasture lands of interior tropical Africa are wonderfully uniform in their productions; a great number of species ranging from Senegal to Abyssinia and thence to the Zambesi, while almost all the commoner African genera extend over the whole of this area. Almost all this extensive tract of country is a moderately elevated plateau, with a hot and dry climate, and characterised by a grassy vegetation interspersed with patches of forest. This forms our first or East African sub-region. The whole of the west coast from the south side of the Gambia River to about 10° or 12° south latitude, is a very different kind of country; being almost wholly dense forests where not cleared by man, and having the hot moist uniform climate, and perennial luxuriance of vegetation, which characterise the great equatorial belt of forest all round the globe. This forest country extends to an unknown distance inland, but it was found, with its features well marked, by Dr. Schweinfurth directly he crossed the south-western watershed of the Nile; and far to the south we find it again unmistakably indicated, in the excessively moist forest country about the head waters of the Congo, where the heroic Livingstone met his death. In this forest district many of the more remarkable African types are alone found, and its productions occasionally present us with curious similarities to those of the far removed South American or Malayan forests. This is our second or West African sub-region.
Extra-tropical South Africa possesses features of its own, quite distinct from those of both the preceding regions (although it has also much in common with the first). Its vegetation is known to be one of the richest, most peculiar, and most remarkable on the globe; and in its zoology it has a speciality, similar in kind but less in degree, which renders it both natural and convenient to separate it as our third, or South African sub-region. Its limits are not very clearly ascertained, but it is probably bounded by the Kalahari desert on the north-west, and by the Limpopo Valley, or the mountain range beyond, on the north-east, although some of its peculiar forms extend to Mozambique. There remains the great Island of Madagascar, one of the most isolated and most interesting on the globe, as regards its animal productions; and to this must be added, the smaller islands of Bourbon, Mauritius and Rodriguez, the Seychelles and the Comoro Islands, forming together the Mascarene Islands,—the whole constituting our fourth sub-region.
Zoological Characteristics of the Ethiopian Region.—We have now to consider briefly, what are the peculiarities and characteristics of the Ethiopian Region as a whole,—those which give it its distinctive features and broadly separate it from the other primary zoological regions.
Mammalia.—This region has 9 peculiar families of mammalia. Chiromyidæ (containing the aye-aye); Potamogalidæ and Chrysochloridæ (Insectivora); Cryptoproctidæ and Protelidae (Carnivora); Hippopotamidæ and Camelopardalidæ (Ungulata); and Orycteropodidæ (Edentata). Besides these it possesses 7 peculiar genera of apes, Troglodytes, Colobus, Myiopithecus, Cercopithecus, Cercocebus, Theropithecus, and Cynocephalus; 2 sub-families of lemurs containing 6 genera, confined to Madagascar, with 3 genera of two other sub-families confined to the continent; of Insectivora a family, Centetidæ, with 5 genera, peculiar to Madagascar, and the genera Petrodromus and Rhynchocyon belonging to the Macroscelididæ, or elephant-shrews, restricted to the continent; numerous peculiar genera or sub-genera of civets; Lycaon and Megalotis, remarkable genera of Canidæ; Ictonyx, the zorilla, a genus allied to the weasels; 13 peculiar genera of Muridæ; Pectinator, a genus of the South American family Octodontidæ; and 2 genera of the South American Echimyidæ or spiny rats. Of abundant and characteristic groups it possesses Macroscelides, Felis, Hyæna, Hyrax, Rhinoceros, and Elephas, as well as several species of zebra and a great variety of antelopes.
The great speciality indicated by these numerous peculiar families and genera, is still farther increased by the absence of certain groups dominant in the Old-World continent, an absence which we can only account for by the persistence, through long epochs, of barriers isolating the greater part of Africa from the rest of the world. These groups are, Ursidæ, the bears; Talpidæ the moles; Camelidæ, the camels; Cervidæ, the deer; Caprinæ, the goats and sheep; and the genera Bos (wild ox); and Sus (wild boar). Combining these striking deficiencies, with the no less striking peculiarities above enumerated, it seems hardly possible to have a region more sharply divided from the rest of the globe than this is, by its whole assemblage of mammalia.
Birds.—In birds the Ethiopian region is by no means so strikingly peculiar, many of these having been able to pass the ancient barriers which so long limited the range of mammalia. It is, however, sufficiently rich, possessing 54 families of land birds, besides a few genera whose position is not well ascertained, and which may constitute distinct families. Of these 6 are peculiar, Musophagidæ (the plantain eaters); Coliidæ (the colies); Leptosomidæ, allied to the cuckoos; Irrisoridæ, allied to the hoopoes; and Serpentaridæ, allied to the hawks. Only one Passerine family is peculiar—Paictidæ, while most of the other tropical regions possess several; but Euryceros and Buphaga, here classed with the Sturnidæ, ought, perhaps, to form two more. It has, however, many peculiar genera, especially among the fruit-thrushes, Pycnonotidæ; flycatchers, Muscicapidæ; shrikes, Lanidæ; crows, Corvidæ; starlings, Sturnidæ; and weaver-birds, Ploceidæ; the latter family being very characteristic of the region. It is also rich in barbets, Megalæmidæ (7 peculiar genera); cuckoos, Cuculidæ; rollers, Coraciidæ; bee-eaters, Meropidæ; hornbills, Bucerotidæ; and goat-suckers, Caprimulgidæ. It is poor in parrots and rather so in pigeons; but it abounds in Pterocles and Francolinus, genera of Gallinæ, and possesses 4 genera of the peculiar group of the guinea-fowls, forming part of the pheasant family. It abounds in vultures, eagles, and other birds of prey, among which is the anomalous genus Serpentarius, the secretary-bird, constituting a distinct family. Many of the most remarkable forms are confined to Madagascar and the adjacent islands, and will be noticed in our account of that sub-region.
Reptiles.—Of the reptiles there are 4 peculiar Ethiopian families;—3 of snakes, Rachiodontidæ, Dendraspidæ, and Atractaspidæ and 1 of lizards, Chamæsauridæ.
Psammophidæ (desert snakes) are abundant, as are Lycodontidæ (fanged ground-snakes), and Viperidæ (vipers). The following genera of snakes are peculiar or highly characteristic:—Leptorhynchus, Rhamnophis, Herpetethiops and Grayia (Colubridæ); Hopsidrophis and Bucephalus (Dendrophidæ); Langalia (Dryophidæ); Pythonodipsas (Dipsadidæ); Boædon, Lycophidion, Holuropholis, Simocephalus and Lamprophis (Lycodontidæ); Hortulia and Sanzinia (Pythonidæ); Cyrtophis, Elapsoidea and Pœcilophis (Elapidæ); and Atheris (Viperidæ). The following genera of lizards are the most characteristic:—Monotrophis (Lepidosternidæ); Cordylus, Pseudocordylus, Platysaurus, Cordylosaurus, Pleurostrichus, Saurophis and Zonurus (Zonuridæ); Sphænops, Scelotes, Sphænocephalus and Sepsina (Sepidæ); Pachydactylus (Geckotidæ); Agama (Agamidæ); and Chamæleon (Chamæleonidæ). Of tortoises, Cinyxis, Pyxis and Chersina (Testudinidæ), and Cycloderma (Trionychidæ) are the most characteristic.
Amphibia.—Of the 9 families of amphibia there is only 1 peculiar, the Dactylethridæ, a group of toads; but the Alytidæ, a family of frogs, are abundant.
Fresh-water Fish.—Of the 14 families of fresh-water fishes 3 are peculiar: Mormyridæ and Gymnarchidæ, small groups not far removed from the pikes; and Polypteridæ, a small group of ganoid fishes allied to the gar-pikes (Lepidosteidæ) of North America.
Summary of Ethiopian Vertebrates.—Combining the results here indicated and set forth in greater detail in the tables of distribution, we find that the Ethiopian region possesses examples of 44 families of mammalia, 72 of birds, 35 of reptiles, 9 of amphibia, and 15 of fresh-water fishes. It has 23 (or perhaps 25) families of Vertebrata altogether peculiar to it out of a total of 175 families, or almost exactly one-eighth of the whole. Out of 142 genera of mammalia found within the region, 90 are peculiar to it; a proportion not much short of two-thirds. Of land birds there are 294 genera, of which 179 are peculiar; giving a proportion of a little less than three-fifths.
Compared with the Oriental region this shows a considerably larger amount of speciality under all the heads; but the superiority is mainly due to the wonderful and isolated fauna of Madagascar, to which the Oriental region has nothing comparable. Without this the regions would be nearly equal.
Insects: Lepidoptera.—11 out of the 16 families of butterflies have representatives in Africa, but none are peculiar. Acræidæ is one of the most characteristic families, and there are many interesting forms of Nymphalidæ, Lycænidæ, and Papilionidæ. The peculiar or characteristic forms are Amauris (Danaidæ); Gnophodes, Leptoneura, Bicyclus, Heteropsis and Cœnyra (Satyridæ); Acræa (Acræidæ); Lachnoptera, Precis, Salamis, Crenis, Godartia, Amphidema, Pseudacræa, Catuna, Euryphene, Romalæosoma, Hamanumida, Aterica, Harma, Meneris, Charaxes, and Philognoma (Nymphalidæ); Pentila, Liptena, Durbania, Zeritis, Capys, Phytala, Epitola, Hewitsonia and Deloneura (Lycænidæ); Pseudopontia, Idmais, Teracolus, Callosune (Pieridæ); Abantis, Ceratrichia and Caprona (Hesperidæ). The total number of species known is about 750; which is very poor for an extensive tropical region, but this is not to be wondered at when the nature of much of the country is considered. It is also, no doubt, partly due to our comparative ignorance of the great equatorial forest district, which is the only part likely to be very productive in this order of insects.
Coleoptera.—In our first representative family, Cicindelidæ or tiger-beetles, the Ethiopian region is rather rich, having 13 genera, 11 of which are peculiar to it; and among these are such remarkable forms as Manticora, Myrmecoptera and Dromica; with Megacephala, a genus only found elsewhere in Australia and South America.
In Carabidæ or carnivorous ground beetles, there are about 75 peculiar genera. Among the most characteristic are Anthia, Polyrhina, Graphipterus and Piezia, which are almost all peculiar; while Orthogonius, Hexagonia, Macrochilus, Thyreopterus, Eudema, and Abacetus are common to this and the Oriental region; and Hypolithus to the Neotropical.
Out of 27 genera of Buprestidæ, or metallic beetles, only 6 are peculiar to the region, one of the most remarkable being Polybothris, confined to Madagascar. Sternocera and Chrysochroa are characteristic of this region and the Oriental; it has Julodis in common with the Mediterranean sub-region, and Belionota with the Malayan.
The region is not rich in Lucanidæ, or stag-beetles, possessing only 10 genera, 7 of which are peculiar, but most of them consist of single species. The other three genera, Cladognathus, Nigidius, and Figulus, are the most characteristic, though all have a tolerably wide range in the Old World.
In the elegant Cetoniidæ, or rose-chafers, this region stands preeminent, possessing 76 genera, 64 of which are peculiar to it. The others are chiefly Oriental, except Oxythræa which is European, and Stethodesma which is Neotropical. Preeminent in size and beauty is Goliathus, comprising perhaps the most bulky of all highly-coloured beetles. Other large and characteristic genera are Ceratorhina, Ischnostoma, Anochilia, Diplognatha, Agenius, and many others of less extent.
In the enormous tribe of Longicorns, or long-horned beetles, the Ethiopian is not so rich as the other three tropical regions; but this may be, in great part, owing to its more productive districts having never been explored by any competent entomologists. It nevertheless possesses 262 genera, 216 of which are peculiar, the others being mostly groups of very wide range. Out of such a large number it is difficult to select a few as most characteristic, but some of the peculiarities of distribution as regards other regions may be named. Among Prionidæ, Tithoes is a characteristic Ethiopian genus. A few species of the American genera Parandra and Mallodon occur here, while the North Temperate genus Prionus is only found in Madagascar. Among Cerambycidæ, Promeces is the most characteristic. The American genera Oeme and Cyrtomerus occur; while Homalachnus and Philagathes are Malayan, and Leptocera occurs only in Madagascar, Ceylon, Austro-Malaya, and Australia. The Lamiidæ are very fine; Sternotomis, Tragocephala, Ceroplesis, Phryncta, Volumnia, and Nitocris, being very abundant and characteristic. Most of the non-peculiar genera of this family are Oriental, but Spalacopsis and Acanthoderes are American, while Tetraglenes and Schœnionta have been found only in East and South Africa and in Malaya.
Terrestrial Mollusca.—In the extensive family of the Helicidæ or snails, 13 genera are represented, only one of which, Columna, is peculiar. This region is however the metropolis of Achatina, some of the species being the largest land-shells known. Buliminus, Stenogyra, and Pupa are characteristic genera. Bulimus is absent, though one species inhabits St. Helena. The operculated shells are not very well represented, the great family of Cyclostomidæ having here only nine genera, with but one peculiar, Lithidion, found in Madagascar, Socotra, and Arabia. None of the genera appear to be well represented throughout the region, and they are almost or quite absent from West Africa.
According to Woodward's Manual (1868) West Africa has about 200 species of land-shells, South Africa about 100, Madagascar nearly 100, Mauritius about 50. All the islands have their peculiar species; and are, in proportion to their extent, much richer than the continent; as is usually the case.
The Ethiopian Sub-regions.
It has been already explained that these are to some extent provisional; yet it is believed that they represent generally the primary natural divisions of the region, however they may be subdivided when our knowledge of their productions becomes more accurate.
I. The East African Sub-region, or Central and East Africa.
This division includes all the open country of tropical Africa south of the Sahara, as well as an undefined southern margin of that great desert. With the exception of a narrow strip along the east coast and the valleys of the Niger and Nile, it is a vast elevated plateau from 1,000 to 4,000 feet high, hilly rather than mountainous, except the lofty table land of Abyssinia, with mountains rising to 16,000 feet and extending south to the equator, where it terminates in the peaks of Kenia and Kilimandjaro, 18,000 and 20,000 feet high. The northern portion of this sub-region is a belt about 300 miles wide between the Sahara on the north and the great equatorial forest on the south, extending from Cape Verd, the extreme western point of Africa, across the northern bend of the Niger and Lake Tchad to the mountains of Abyssinia. The greater part of this tract has a moderate elevation. The eastern portion reaches from about the second cataract of the Nile, or perhaps from about the parallel of 20° N. Latitude, down to about 20° S. Latitude, and from the east coast to where the great forest region commences, or to Lake Tanganyika and about the meridian of 28° to 30° E. Longitude. The greater part of this tract is a lofty plateau.
The surface of all this sub-region is generally open, covered with a vegetation of high grasses or thorny shrubs, with scattered trees and isolated patches of forest in favourable situations. The only parts where extensive continuous forests occur, are on the eastern and western slopes of the great Abyssinian plateau, and on the Mozambique coast from Zanzibar to Sofala. The whole of this great district has one general zoological character. Many species range from Senegal to Abyssinia, others from Abyssinia to the Zambesi, and a few, as Mungos fasciatus and Phacochœrus æthiopicus, range over the entire sub-region. Fennecus, Ictonyx, and several genera of antelopes, characterise every part of it, as do many genera of birds. Coracias nævia, Corythornis cyanostigma, Tockus nasutus, T. erythrorhynchus, Parus leucopterus, Buphaga africana, Vidua paradisea, are examples of species, which are found in the Gambia, Abyssinia and South East Africa, but not in the West African sub-region; and considering how very little is known of the natural history of the country immediately south of the Sahara, it may well be supposed that these are only a small portion of the species really common to the whole area in question, and which prove its fundamental unity.
Although this sub-region is so extensive and so generally uniform in physical features, it is by far the least peculiar part of Africa. It possesses, of course, all those wide-spread Ethiopian types which inhabit every part of the region, but it has hardly any special features of its own. The few genera which are peculiar to it have generally a limited range, and for the most part belong, either to the isolated mountain-plateau of Abyssinia which is almost as much Palæarctic as Ethiopian, or to the woody districts of Mozambique where the fauna has more of a West or South African character.
Mammalia.—The only forms of Mammalia peculiar to this sub-region are Theropithecus, one of the Cynopithecidæ confined to Abyssinia; Petrodromus and Rhynchocyon, belonging to the insectivorous Macroscelididæ, have only been found in Mozambique; the Antelopine genus Neotragus, from Abyssinia southward; Saccostomus and Pelomys genera of Muridæ inhabiting Mozambique; Heterocephalus from Abyssinia, and Heliophobius from Mozambique, belonging to the Spalacidæ; and Pectinator from Abyssinia, belonging to the Octodontidæ. Cynocephalus, Rhinoceros, Camelopardalis, and antelopes of the genera Oryx, Cervicapra, Kobus, Nanotragus, Cephalophus, Hippotragus, Alcephalus, and Catoblepas, are characteristic; as well as Felis, Hyæna, and numerous civets and ichneumons.
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.
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.
This may be defined as the equatorial-forest sub-region, since it comprises all that portion of Africa, from the west coast inland, over which the great equatorial forests prevail more or less uninterruptedly. These commence to the south of the Gambia River, and extend eastwards in a line roughly parallel to the southern margin of the great desert, as far as the sources of the upper Nile and the mountains forming the western boundary of the basin of the great lakes; and southward to that high but marshy forest-country in which Livingstone was travelling at the time of his death. Its southern limits are undetermined, but are probably somewhere about the parallel of 11° S. Latitude.
This extensive and luxuriant district has only been explored zoologically in the neighbourhood of the West coast. Much, no doubt, remains to be done in the interior, yet its main features are sufficiently well known, and most of its characteristic types of animal life have, no doubt, been discovered.
Mammalia.—Several very important groups of mammals are peculiar to this sub-region. Most prominent are the great anthropoid apes—the gorilla and the chimpanzee—forming the genus Troglodytes; and monkeys of the genera Myiopithecus and Cercocebus. Two remarkable forms of lemurs, Perodicticus and Arctocebus, are also peculiar to West Africa. Among the Insectivora is Potamogale, a semi-aquatic animal, forming a distinct family; and three peculiar genera of civets (Viverridæ) have been described. Hyomoschus, a small, deer-like animal, belongs to the Tragulidæ, or chevrotains, a family otherwise confined to the Oriental region; and in the squirrel family is a curious genus, Anomalurus, which resembles the flying squirrels of other parts of the world, without being directly allied to them.
Birds.—In this class we find a larger proportionate number of peculiar forms. Hypergerus and Alethe, belonging to the Timaliidæ, or babblers, are perhaps allied to Malayan groups; Parinia, a peculiar form of tit, is found only in Prince's Island; Ixonotus is an abundant and characteristic form of Pycnonotidæ; Fraseria, Hypodes, Cuphopterus, and Chaunonotus, are peculiar genera of shrikes; Picathartes is one of the many strange forms of the crow family; Cinnyricinclus is a peculiar genus of sun-birds; Pholidornis is supposed to belong to the Oriental Dicæidæ, or flower-peckers; Waldenia is a recently-described new form of swallow; Ligurnus, a finch, Spermospiza, a weaver bird, and Onychognathus a starling, are also peculiar West African genera. Coming to the Picariæ we have Verreauxia, a peculiar woodpecker; three peculiar genera of barbets (Megalæmidæ); the typical plantain-eaters (Musophaga); Myioceyx, a peculiar genus of kingfishers; while Berenicornis is a genus of crested hornbills, only found elsewhere in Malaya. The grey parrots, of the genus Psittacus, are confined to this sub-region, as are two peculiar genera of partridges, and three of guinea-fowl. We have also here a species of Pitta, one of the Oriental family of ground-thrushes; and the Oriental paroquets, Palæornis, are found here as well as in Abyssinia and the Mascarene Islands.
We thus find, both in the Mammalia and birds of West Africa, a special Oriental or even Malayan element not present in the other parts of tropical Africa, although appearing again in Madagascar. In the Mammalia it is represented by the anthropoid apes; by Colobus allied to Semnopithecus, and by Cercocebus allied to Macacus; and especially by a form of the Malayan family of chevrotains (Tragulidæ). The Malayan genus of otters, Aonyx, is also said to occur in West and South Africa. In birds we have special Oriental and Malayan affinities in Alethe, Pholidornis, Berenicornis, Pitta, and Palæornis; while the Oriental genus Treron has a wide range in Africa. We shall endeavour to ascertain the meaning of this special relation at a subsequent stage of our inquiries.
Plate V.—River Scene in West Africa, with Characteristic Animals.—Our artist has here well represented the luxuriance and beauty of a tropical forest; and the whole scene is such as might be witnessed on the banks of one of the rivers of equatorial West Africa. On the right we see a red river-hog (Potamochœrus penicillatus), one of the handsomest of the swine family, and highly characteristic of the West African sub-region. In a tree overhead is the potto (Perodicticus potto), one of the curious forms of lemur confined to West Africa. On the left is the remarkable Potamogale velox, first discovered by Du Chaillu,—an Insectivorous animal, with the form and habits of an otter. On the other side of the river are seen a pair of gorillas (Troglodytes gorilla), the largest of the anthropoid apes.
The bird on the wing is the Whydah finch (Vidua paradisea), remarkable for the enormous plumes with which the tail of the male bird is decorated during the breeding season. The crested bird overhead is one of the beautiful green touracos (Turacus macrorhynchus), belonging to the Musophagidæ, or plantain-eaters, a family wholly African, and most abundant in the western sub-region.
Reptiles.—In this class we find a large number of peculiar forms; 13 genera of snakes, 3 of lizards, and 2 of tortoises being confined to the sub-region. The snakes are Pariaspis, Elapops, and Prosymna (Calamariidæ), Rhamnophis, Herpetethiops, and Grayia (Colubridæ), Neusterophis and Limnophis (Homalopsidæ), Simocephalus and Holuropholis (Lycodontidæ); Pelophilus (Pythonidæ); Elapsoidea (Elapidæ); and Atheris (Viperidæ). The lizards are Dalophia (Lepidosternidæ); Otosaurus (Scincidæ); Psilodactylus (Geckotidæ). The tortoises, Cinyxis (Testudinidæ) and Tetrathyra (Trionychidæ).
Amphibia.—Of Amphibia, there are 2 peculiar genera of tree-frogs, Hylambates and Hemimantis, belonging to the Polypedatidæ.
SCENE IN WEST AFRICA, WITH CHARACTERISTIC ANIMALS.
Here, too, we find some interesting relations with the Oriental region on the one side, and the Neotropical on the other. The snakes of the family Homalopsidæ have a wide range, in America, Europe, and all over the Oriental region, but are confined to West Africa in the Ethiopian region. Dryiophis (Dryiophidæ) and Dipsadoboa (Dipsadidæ) on the other hand, are genera of tropical America which occur also in West Africa. The family of lizards, Acontiadæ, are found in West and South Africa, Ceylon, and the Moluccas. The family of toads, Engystomidæ, in West and South Africa and the whole Oriental region; while the Phryniscidæ inhabit tropical Africa and Java.
Insects.—We have here a large number of peculiar genera. There are 10 of butterflies, Lachnoptera, Amphidema, and Catuna belonging to the Nymphalidæ, while four others are Lycænidæ. The genus Euxanthe is common to West Africa and Madagascar.
Of Coleoptera there are 53 peculiar genera; 20 are Carabidæ, 2 Lucanidæ, 12 Cetoniidæ, 3 Prionidæ, 16 Cerambycidæ, and 34 Lamiidæ. Besides these there are 4 or 5 genera confined to West Africa and Madagascar.
Land Shells.—West Africa is very rich in land shells, but it does not appear to possess any well-marked genera, although several of the smaller groups or sub-genera are confined to it. Helicidæ of the genera Nanina, Buliminus and Achatina are abundant and characteristic.
Islands of the West African Sub-region.—The islands in the Gulf of Guinea are, Fernando Po, very near the main land, with Prince's Island and St. Thomas, considerably further away to the south-west. Fernando Po was once thought to be a remarkable instance of an island possessing a very peculiar fauna, although close to the main land and not divided from it by a deep sea. This, however, was due to our having obtained considerable collections from Fernando Po, while the opposite coast was almost unknown. One after another the species supposed to be peculiar have been found on the continent, till it becomes probable, that, as in the case of other islands similarly situated, it contains no peculiar species whatever. The presence of numerous mammalia, among which are baboons, lemurs, Hyrax, and Anomalurus, shows that this island has probably once been united to the continent.
Prince's Island, situated about 100 miles from the coast, has no mammals, but between 30 and 40 species of birds. Of these 7 are peculiar species, viz., Zosterops ficedulina, Cuphopterus dohrni (a peculiar genus of Sylviidæ), Symplectes princeps, Crithagra rufilata, Columba chlorophæa, Peristera principalis, and Strix thomensis.
In the Island of St. Thomas, situated on the equator about 150 miles from the coast, there are 6 peculiar species out of 30 known birds, viz., Scops leucopsis, Zosterops lugubris, Turdus olivaceofuscus, Oriolus crassirostris, Symplectes sancti-thomæ and Aplopelia simplex; also Strix thomensis in common with Prince's Island. The remainder are all found on the adjacent coasts. It is remarkable that in Prince's Island there are no birds of prey, any that appear being driven off by the parrots (Psittacus erithacus) that abound there; whereas in St. Thomas and Fernando Po they are plentiful.
III. South-African Sub-region.
This is the most peculiar and interesting part of Africa, but owing to the absence of existing barriers its limits cannot be well defined. The typical portion of it hardly contains more than the narrow strip of territory limited by the mountain range which forms the boundary of the Cape Colony and Natal, while in a wider sense it may be extended to include Mozambique. It may perhaps be best characterised as bounded by the Kalahari desert and the Limpopo river. It is in the more limited district of the extreme south, that the wonderful Cape flora alone exists. Here are more genera and species, and more peculiar types of plants congregated together, than in any other part of the globe of equal extent. There are indications of a somewhat similar richness and specialization in the zoology of this country; but animals are so much less closely dependent on soil and climate, that much of the original peculiarity has been obliterated, by long continued interchange of species with so vast an area as that of Africa south of the equator. The extreme peculiarity and isolation of the flora must not, however, be lost sight of, if we would correctly interpret the phenomena afforded by the distribution of animal life on the African continent.
Mammalia.—A much larger number of peculiar forms of mammals are found here than in any of the other sub-regions, although it is far less in extent than either of the three divisions of the continent. Among Insectivora we have the Chrysochloridæ, or golden moles, consisting of two genera confined to South Africa; while the Macroscelididæ, or elephant shrews, are also characteristically South African, although ranging as far as Mozambique and the Zambezi, with one outlying species in North Africa. The Viverridæ are represented by three peculiar genera, Ariela, Cynictis, and Suricata. The Carnivora present some remarkable forms: Proteles, forming a distinct family allied to the hyænas and weasels; and two curious forms of Canidæ—Megalotis (the long-eared fox) and Lycaon (the hyæna-dog), the latter found also in parts of East Africa. Hydrogale is a peculiar form of Mustelidæ; Pelea one of the antelopes; Dendromys, Malacothrix, and Mystromys are peculiar genera of the mouse family (Muridæ); Bathyerges one of the mole-rats (Spalacidæ); Pedetes, the Cape-hare, a remarkable form of jerboa; and Petromys, one of the spiny-rats (Echimyidæ). The remarkable Orycteropus, or earth-pig, has one species in South and one in North East Africa. We have thus eighteen genera of mammalia almost or quite peculiar to South Africa.
Birds.—These do not present so many peculiar forms, yet some are very remarkable. Chætops is an isolated genus of thrushes (Turdidæ). Lioptilus, one of the fruit-thrushes (Pycnonotidæ). Pogonocichla, one of the fly-catchers; Urolestes, a shrike; Promerops, a sun-bird; Philetærus and Chera, weaver-birds; and three peculiar genera of larks—Spizocorys, Heterocorys, and Tephrocorys, complete the list of peculiar types of Passeres. A wood-pecker, Geocolaptes, is nearly allied to a South American genus. The Cape-dove, Œna, is confined to South and East Africa and Madagascar; and Thalassornis is a peculiar form of duck. Several genera are also confined to West and South Africa;—as Phyllastrephus (Pycnonotidæ), Smithornis (Muscicapidæ), Corvinella (Laniidæ); Barbatula and Xylobucco (Megalæmidæ); Ceuthmochares, also in Madagascar, (Cuculidæ); Tympanistria (Columbidæ). Other remarkable forms, though widely spread over Africa, appear to have their metropolis here, as Colius and Indicator. Others seem to be confined to South Africa and Abyssinia, as the curious Buphaga (Sturnidæ); and Apaloderma (Trogonidæ). Machærhamphus (Falconidæ) is found only in South-West Africa, Madagascar, and the Malay Peninsula.
Reptiles.—There are 4 peculiar genera of snakes,—Typhline, belonging to the blind burrowing snakes, Typhlopidæ; Lamprophis (Lycodontidæ); Cyrtophis and Pœcilophis (Elapidæ), a family which is chiefly Oriental and Australian. Of Lizards there are 10 peculiar genera; Monotrophis (Lepidosternidæ), but with an allied form in Angola; Cordylus, Pseudocordylus, Platysaurus, Cordylosaurus, Pleurostrichus, and Saurophis, all peculiar genera of Zonuridæ; Chamæsaura, forming the peculiar family Chamæsauridæ; Colopus and Rhopitropus (Geckotidæ).
Amphibia.—Of Amphibia there are 4 peculiar genera: Schismaderma (Bufonidæ); Brachymerus (Engystomidæ); Phrynobatrachus and Stenorhynchus (Ranidæ). These last are allied to Oriental genera, and the only other Engystomidæ are Oriental and Neotropical.
Fresh-water Fish.—Of fresh-water fishes there is 1 genus—Abrostomus—belonging to the carp family, peculiar to South Africa.
Insects.—South Africa is excessively rich in insects, and the number of peculiar types surpasses that of any other part of the region. We can only here summarize the results.
Lepidoptera.—Of butterflies there are 7 peculiar genera; 2 belonging to the Satyridæ, 1 to Acræidæ, 3 to Lycænidæ, and 1 to Hesperidæ. Zeritis (Lycænidæ) is also characteristic of this sub-region, although 1 species occurs in West Africa.
Coleoptera.—These are very remarkable. In the family of Cicindelidæ, or tiger-beetles, we have the extraordinary Manticora and Platychile, forming a sub-family, whose nearest allies are in North America; as well as Ophryodera and Dromica, the latter an extensive genus, which ranges as far north as Mozambique and Lake Ngami. Another genus of this family, Jansenia, is common to South Africa and South India.
In the large family of Carabidæ, or ground-beetles, there are 17 peculiar South African genera, the most important being Crepidogaster, Hystrichopus, Arsinoë, and Piezia. Three others—Eunostus, Glyphodactyla, and Megalonychus—are common to South Africa and Madagascar only. There is also a genus in common with Java, and one with Australia.
Of Lucanidæ, or stag-beetles, there are 3 peculiar genera; of Cetoniidæ, or rose-chafers, 14; and of Buprestidæ, 2.
In the great family of Longicorns there are no less than 67 peculiar genera—an immense number when we consider that the generally open character of the country, is such as is not usually well suited to this group of insects. They consist of 5 peculiar genera of Prionidæ, 25 of Cerambycidæ, and 37 of Lamiidæ.
Summary of South-African Zoology.—Summarizing these results, we find that South Africa possesses 18 peculiar genera of Mammalia, 12 of Birds, 18 of Reptiles, 1 of Fishes, 7 of Butterflies, and 107 of the six typical families of Coleoptera. Besides this large amount of speciality it contains many other groups, which extend either to West Africa, to Abyssinia, or to Madagascar only, a number of which are no doubt to be referred as originating here. We also find many cases of direct affinity with the Oriental region, and especially with the Malay districts, and others with Australia; and there are also less marked indications of a relation to America.
Atlantic Islands of the Ethiopian Region. St. Helena.—The position of St. Helena, about 1,000 miles west of Africa and 16° south of the equator, renders it difficult to place it in either of the sub-regions; and its scanty fauna has a general rather than any special resemblance to that of Africa. The entire destruction of its luxuriant native forests by the introduction of goats which killed all the young trees (a destruction which was nearly completed two centuries ago) must have led to the extermination of most of the indigenous birds and insects. At present there is no land bird that is believed to be really indigenous, and but one wader, a small plover (Ægialitis sanctæ-helenæ) which is peculiar to the island, but closely allied to African species. Numerous imported birds, such as canaries, Java sparrows, some African finches, guinea-fowls, and partridges, are now wild. There are no native butterflies, but a few introduced species of almost world-wide range. The only important remnant of the original fauna consists of beetles and land shells. The beetles are the more numerous and have been critically examined and described by Mr. T. V. Wollaston, whose researches in the other Atlantic islands are so well known.
Coleoptera of St. Helena.—Omitting those beetles which get introduced everywhere through man's agency, there are 59 species of Coleoptera known from St. Helena; and even of these there are a few widely distributed species that may have been introduced by man. It will be well, therefore, to confine ourselves almost wholly to the species peculiar to the island, and, therefore, almost certainly forming part of the endemic or original fauna. Of these we find that 10 belong to genera which have a very wide range, and thus afford no indication of geographical affinity; 2 belong to genera which are characteristic of the Palæarctic fauna (Bembidium, Longitarsus); 3 to African genera (Adoretus, Sciobius, Aspidomorpha); and two species of Calosoma are most allied to African species. There are also 4 African species, which may be indigenous in St. Helena. The peculiar genera, 7 in number, are, however, the most interesting. We have first Haplothorax, a large beetle allied to Carabus and Calosoma, though of a peculiar type. This may be held to indicate a remote Palæarctic affinity. Melissius, one of the Dynastidæ, is allied to South African forms. Microxylobius, one of the Cossonides (a sub-family of Curculionidæ) is the most important genus, comprising as it does 13 species. It is, according to Mr. Wollaston, an altogether peculiar type, most allied to Pentarthrum, a genus found in St. Helena, Ascension, and the south of England, and itself very isolated. Nesiotes, another genus of Curculionidæ, belongs to a small group, the allied genera forming which inhabit Europe, Madeira, and Australia. A third peculiar and isolated genus is Trachyphlæosoma. The Anthribidæ are represented by 2 genera, Notioxenus and Homœodera, which are altogether peculiar and isolated, and contain 9 species. Thus no less than 27 species, or more than half of the undoubtedly indigenous beetles, belong to 5 peculiar and very remarkable genera of Rhynchophora.
It appears from this enumeration, that the peculiar species as a whole, exhibit most affinity to the Ethiopian fauna; next to the South European fauna; and lastly to that of the islands of the North Atlantic; while there is such a large amount of peculiarity in the most characteristic forms, that no special geographical affinity can be pointed out.
Land Shells.—These consist of about a dozen living species, and about as many extinct found in the surface soil, and probably exterminated by the destruction of the forests. The genera are Succinea, Zonites, Helix, Bulimus, Pupa, and Achatina. The Bulimi (all now extinct but one) comprise one large, and several small species, of a peculiar type, most resembling forms now inhabiting South America and the islands of the Pacific. Zonites is chiefly South European, but the other genera are of wide range, and none are peculiar to the island.
The marine shells are mostly Mediterranean, or West Indian species, with some found in the Indian Ocean; only 4 or 5 species being peculiar to the island.
Tristan d'Acunha.—This small island is situated nearly midway between the Cape of Good Hope and the mouth of the La Plata, but it is rather nearer Africa than America, and a little nearer still to St. Helena. An island so truly oceanic and of whose productions so little is known, cannot be placed in any region, and is only noticed here because it comes naturally after St. Helena. It is known to possess three peculiar land birds. One is a thrush (Nesocichla eremita) whose exact affinities are not determined; the other a small water-hen (Gallinula nesiotis) allied to our native species, but with shorter and softer wings, which the bird does not use for flight. A finch of the genus Crithagra shows African affinities; while another recently described as Nesospiza acunhæ (Journ. für Orn. 1873, p. 154) forms a new genus said to resemble more nearly some American forms.
The only known land-shells are 2 peculiar species of Balea, a genus only found elsewhere in Europe and Brazil.
IV. Madagascar and the Mascarene Islands, or the Malagasy Sub-region.
This insular sub-region is one of the most remarkable zoological districts on the globe, bearing a similar relation to Africa as the Antilles to tropical America, or New Zealand to Australia, but possessing a much richer fauna than either of these, and in some respects a more remarkable one even than New Zealand. It comprises, besides Madagascar, the islands of Mauritius, Bourbon, and Rodriguez, the Seychelles and Comoro islands. Madagascar itself is an island of the first class, being a thousand miles long and about 250 miles in average width. It lies parallel to the coast of Africa, near the southern tropic, and is separated by 230 miles of sea from the nearest part of the continent, although a bank of soundings projecting from its western coast reduces this distance to about 160 miles. Madagascar is a mountainous island, and the greater part of the interior consists of open elevated plateaus; but between these and the coast there intervene broad belts of luxuriant tropical forests. It is this forest-district which has yielded most of those remarkable types of animal life which we shall have to enumerate; and it is probable that many more remain to be discovered. As all the main features of this sub-region are developed in Madagascar, we shall first endeavour to give a complete outline of the fauna of that country, and afterwards show how far the surrounding islands partake of its peculiarities.
Mammalia.—The fauna of Madagascar is tolerably rich in genera and species of mammalia, although these belong to a very limited number of families and orders. It is especially characterized by its abundance of Lemuridæ and Insectivora; it also possesses a few peculiar Carnivora of small size; but most of the other groups in which Africa is especially rich—apes and monkeys, lions, leopards and hyænas, zebras, giraffes, antelopes, elephants and rhinoceroses, and even porcupines and squirrels, are wholly wanting. No less than 40 distinct families of land mammals are represented on the continent of Africa, only 11 of which occur in Madagascar, which also possesses 3 families peculiar to itself. The following is a list of all the genera of Mammalia as yet known to inhabit the island:—
We have here a total of 12 families, 27 genera, and 65 species of Mammals; 3 of the families and 20 of the genera (indicated by italics) being peculiar. All the species are peculiar, except perhaps one or two of the wandering bats. Remains of a Hippopotamus have been found in a sub-fossil condition, showing that this animal probably inhabited the island at a not very remote epoch.
The assemblage of animals above noted is remarkable, and seems to indicate a very ancient connection with the southern portion of Africa, before the apes, ungulates, and felines had entered it. The lemurs, which are here so largely developed, are represented by a single group in Africa, with two peculiar forms on the West coast. They also re-appear under peculiar and isolated forms in Southern India and Malaya, and are evidently but the remains of a once wide-spread group, since in Eocene times they inhabited North America and Europe, and very probably the whole northern hemisphere. The Insectivora are another group of high antiquity, widely scattered over the globe under a number of peculiar forms; but in no equally limited area represented by so many peculiar types as in Madagascar. South and West Africa are also rich in this order.
The Carnivora of Madagascar are mostly peculiar forms of Viverridæ, or civets, a family now almost confined to the Ethiopian and Oriental regions, but which was abundant in Europe during the Miocene period.
The Potamochœrus is a peculiar species only, which may be perhaps explained by the unusual swimming powers of swine, and the semi-aquatic habits of this genus, leading to an immigration at a later period than in the case of the other Mammalia. The same remark will apply to the small Hippopotamus, which was coeval with the great Struthious bird Æpiornis.
Rodents are only represented by three peculiar forms of Muridæ, but it is probable that others remain to be discovered.
Birds.—Madagascar is exceedingly rich in birds, and especially in remarkable forms of Passeres. No less than 88 genera and 111 species of land-birds have been discovered, and every year some additions are being made to the list. The African families of Passeres are almost all represented, only two being absent—Paridæ and Fringillidæ, both very poorly represented in Africa itself. Among the Picariæ, however, the case is very different, no less than 7 families being absent, viz.—Picidæ, or woodpeckers; Indicatoridæ, or honey-guides; Megalæmidæ, or barbets; Musophagidæ, or plantain-eaters; Coliidæ, or colies; Bucerotidæ, or hornbills; and Irrisoridæ, or mockers. Three of these are peculiar to Africa, and all are well represented there, so that their absence from Madagascar is a very remarkable fact. The number of peculiar genera in Madagascar constitutes one of the main features of its ornithology, and many of these are so isolated that it is very difficult to classify them, and they remain to this day a puzzle to ornithologists. In order to exhibit clearly the striking characteristics of the bird-fauna of this island, we shall first give a list of all the peculiar genera; another, of the genera of which the species only are peculiar; and, lastly, a list of the species which Madagascar possesses in common with the African continent.
|Genera of Birds peculiar to Madagascar, or found elsewhere only in the Mascarene Islands.|
|Ethiopian or Oriental Genera which are represented in Madagascar by peculiar species.|
Species of Birds common to Madagascar and Africa or Asia.
|1. Cisticola cursitans.||7. Aplopelia tympanistria.|
|2. Corvus scapulatus.||8. Falco minor.|
|3. Crithagra canicollis.||9. Falco concolor.|
|4. Merops superciliosus.||10. Milvus ægyptius.|
|5. Collocalia fuciphaga.||11. Milvus migrans.|
|6. Œna capensis.||12. Strix flammea.|
These three tables show us an amount of speciality hardly to be found in the birds of any other part of the globe. Out of 111 land-birds in Madagascar, only 12 are identical with species inhabiting the adjacent continents, and most of these belong to powerful-winged, or wide-ranging forms, which probably now often pass from one country to the other. The peculiar species—49 land-birds and 7 waders, or aquatics—are mostly well-marked forms of African genera. There are, however, several genera (marked by italics) which have Oriental or Palæarctic affinities, but not African, viz.—Copsychus, Hypsipetes, Hypherpes, Alectrœnas, and Margaroperdix. These indicate a closer approximation to the Malay countries than now exists.
The table of 33 peculiar genera is of great interest. Most of these are well-marked forms, belonging to families which are fully developed in Africa; though it is singular that not one of the exclusively African families is represented in any way in Madagascar. Others, however, are of remote or altogether doubtful affinities. Sittidæ is Oriental and Palæarctic, but not Ethiopian. Oxylabes and Mystacornis are of doubtful affinities. Artamia and Cyanolanius still more so, and it is quite undecided what family they belong to. Calicalicus is almost equally obscure. Neodrepanis, one of the most recent discoveries, seems to connect the Nectariniidæ with the Pacific Drepanididæ. Euryceros is a complete puzzle, having been placed with the hornbills, the starlings, or as a distinct family. Falculia is an exceedingly aberrant form of starling, long thought to be allied to Irrisor. Philepitta, forming a distinct family, (Paictidæ), is most remarkable and isolated, perhaps with remote South American affinities. Leptosoma is another extraordinary form, connecting the cuckoos with the rollers. Atelornis, Brachypteracias, and Geobiastes, are terrestrial rollers, with the form and colouring of Pitta. So many perfectly isolated and remarkable groups are certainly nowhere else to be found; and they fitly associate with the wonderful aye-aye (Chiromys), the insectivorous Centetidæ, and carnivorous Cryptoprocta among the Mammalia. They speak to us plainly of enormous antiquity, of long-continued isolation; and not less plainly of a lost continent or continental island, in which so many, and various, and peculiarly organized creatures, could have been gradually developed in a connected fauna, of which we have here but the fragmentary remains.
Plate VI.—Illustrating the characteristic features of the Zoology of Madagascar.—The lemurs, which form the most prominent feature in the zoology of Madagascar, being comparatively well-known from the numerous specimens in our zoological gardens; and good figures of the Insectivorous genera not being available, we have represented the nocturnal and extraordinary aye-aye (Chiromys madagascariensis) to illustrate its peculiar and probably very ancient mammalian fauna; while the river-hogs in the distance (Potamochœrus edwardsii) allied to African species, indicate a later immigration from the mainland than in the case of most of the other Mammalia. The peculiar birds being far less generally known, we have figured three of them. The largest is the Euryceros prevosti, here classed with the starlings, although its remarkable bill and other peculiarities render it probable that it should form a distinct family. Its colours are velvety black and rich brown with the bill of a pearly grey. The bird beneath (Vanga curvirostris) is one of the peculiar Madagascar shrikes whose plumage, variegated with green-black and pure white is very conspicuous; while that in the right hand corner is the Leptosoma discolor, a bird which appears to be intermediate between such very distinct families as the cuckoos and the rollers, and is therefore considered to form a family by itself. It is a coppery-green above and nearly white beneath, with a black bill and red feet. The fan-shaped plant on the left is the traveller's tree (Urania speciosa), one of the peculiar forms of vegetation in this marvellous island.
SCENE IN MADAGASCAR, WITH CHARACTERISTIC ANIMALS.
Reptiles.—These present some very curious features, comparatively few of the African groups being represented, while there are a considerable number of Eastern and even of American forms. Beginning with the snakes, we find, in the enormous family of Colubridæ, none of the African types; but instead of them three genera—Herpetodryas, Philodryas, and Heterodon—only found elsewhere in South and North America. The Psammophidæ, which are both African and Indian, are represented by a peculiar genus, Mimophis. The Dendrophidæ are represented by Ahætulla, a genus which is both African and American. The Dryiophidæ, which inhabit all the tropics but are most developed in the Oriental region, are represented by a peculiar genus, Langaha. The tropical Pythonidæ are represented by another peculiar genus, Sanzinia. The Lycodontidæ and Viperidæ, so well developed in Africa, are entirely absent.
The lizards are no less remarkable. The Zonuridæ, abundantly developed in Africa, are represented by one peculiar genus, Cicigna. The wide-spread Scincidæ by another peculiar genus, Pygomeles. The African Sepsidæ, are represented by three genera, two of which are African, and one, Amphiglossus, peculiar. The Acontiadæ are represented by a species of the African genus Acontias. Of Scincidæ there is the wide-spread Euprepes. The Sepidæ are represented by the African genera Seps and Scelotes. The Geckotidæ are not represented by any purely African genera, but by Phyllodactylus, which is American and Australian; Hemidactylus, which is spread over all the tropics; by two peculiar genera; and by Uroplatis, Geckolepis, and Phelsuma, confined to Madagascar, Bourbon, and the Andaman Islands. The Agamidæ, which are mostly Oriental and are represented in Africa by the single genus Agama, have here three peculiar genera, Tracheloptychus, Chalarodon, and Hoplurus. Lastly, the American Iguanidæ are said to be represented by a species of the South American genus Oplurus. The classification of Reptiles is in such an unsettled state that some of these determinations of affinities are probably erroneous; but it is not likely that any corrections which may be required will materially affect the general bearing of the evidence, as indicating a remarkable amount of Oriental and American relationship.
The other groups are of less interest. Tortoises are represented by two African or wide-spread genera of Testudinidæ, Testudo and Chersina, and by one peculiar genus, Pyxis; and there are also two African genera of Chelydidæ.
The Amphibia are not very well known. They appear to be confined to species of the wide-spread Ethiopian and Oriental genera—Hylarana, Polypedates, and Rappia (Polypedatidæ); and Pyxicephalus (Ranidæ).
Fresh-water Fishes.—These appear to be at present almost unknown. When carefully collected they will no doubt furnish some important facts.
The Mascarene Islands.
The various islands which surround Madagascar—Bourbon, Mauritius, Rodriguez, the Seychelles, and the Comoro Islands—all partake in a considerable degree of its peculiar fauna, while having some special features of their own.
Indigenous Mammalia (except bats) are probably absent from all these islands (except the Comoros), although Lemur and Centetes are given as natives of Bourbon and Mauritius. They have, however, perhaps been introduced from Madagascar. Lemur mayottensis, a peculiar species, is found in the Comoro Islands, where a Madagascar species of Viverra also occurs.
Bourbon and Mauritius may be taken together, as they much resemble each other. They each possess species of a peculiar genus of Campephagidæ, or caterpillar shrikes, Oxynotus; while the remarkable Fregilupus, belonging to the starling family, inhabits Bourbon, if it is not now extinct. They also have peculiar species of Pratincola, Hypsipetes, Phedina, Tchitrea, Zosterops, Foudia, Collocalia, and Coracopsis; while Mauritius has a very peculiar form of dove of the sub-genus Trocaza; an Alectrœnas, extinct within the last thirty years; and a species of the Oriental genus of parroquets, Palæornis. The small and remote island of Rodriguez has another Palæornis, as well as a peculiar Foudia, and a Drymœca of apparently Indian affinity.
Coming to the Seychelle Islands, far to the north, we find the only mammal an Indian species of bat (Pteropus edwardsii). Of the twelve land-birds all but one are peculiar species, but all belong to genera found also in Madagascar, except one—a peculiar species of Palæornis. This is an Oriental genus, but found also in several Mascarene Islands and on the African continent. A species of black parrot (Coracopsis barklayi) and a weaver bird of peculiar type (Foudia seychellarum) show, however, a decided connection with Madagascar. There are also two peculiar pigeons—a short-winged Turtur and an Alectrœnas.
Most of the birds of the Comoro Islands are Madagascar species, only two being African. Five are peculiar, belonging to the genera Nectarinia, Zosterops, Dicrurus, Foudia, and Alectrœnas.
Reptiles are scarce. There appear to be no snakes in Mauritius and Bourbon, though some African species are said to be found in the Seychelle Islands. Lizards are fairly represented. Mauritius has Cryptoblepharus, an Australian genus of Gymnophthalmidæ; Hemidactylus (a wide-spread genus); Peropus (Oriental and Australian)—both belonging to the Geckotidæ. Bourbon has Heteropus, a Moluccan and Australian genus of Scincidæ; Phelsuma (Geckotidæ), and Chameleo, both found also in Madagascar; as well as Pyxis, one of the tortoises. The Seychelles have Theconyx, a peculiar genus of Geckotidæ, and Chameleo. Gigantic land-tortoises, which formerly inhabited most of the Mascarene Islands, now only survive in Aldabra, a small island north of the Seychelles. These will be noticed again further on. Amphibia seem only to be recorded from the Seychelles, where two genera of tree-frogs of the family Polypedatidæ are found; one (Megalixalus) peculiar, the other (Rappia) found also in Madagascar and Africa.
The few insect groups peculiar to these islands will be noted when we deal with the entomology of Madagascar.
Extinct fauna of the Mascarene Islands and Madagascar.—Before quitting the vertebrate groups, we must notice the remarkable birds which have become extinct in these islands little more than a century ago. The most celebrated is the dodo of the Mauritius (Didus ineptus), but an allied genus, Pezophaps, inhabited Rodriguez, and of both of these almost perfect skeletons have been recovered. Other species probably existed in Bourbon. Remains of two genera of flightless rails have also been found, Aphanapteryx and Erythromachus; and even a heron (Ardea megacephala) which was short-winged and seldom flew; while in Madagascar there lived a gigantic Struthious bird, the Æpyornis. Some further details as to these extinct forms will be found under the respective families, Dididæ, Rallidæ, and Æpyornithidæ, in the fourth part of this work; and their bearing on the past history of the region will be adverted to in the latter part of this chapter. Dr. Günther has recently distinguished five species of fossil tortoises from Mauritius and Rodriguez,—all of them quite different from the living species of Aldabra.
Insects.—The butterflies of Madagascar are not so remarkable as some other orders of insects. There seems to be only one peculiar genus, Heteropsis (Satyridæ). The other genera are African, Leptoneura being confined to Madagascar and South Africa. There are some fine Papilios of uncommon forms. The most interesting lepidopterous insect, however, is the fine diurnal moth (Urania), as all the other species of the genus inhabit tropical America and the West Indian Islands.
The Coleoptera have been better collected, and exhibit some very remarkable affinities. There is but one peculiar genus of Cicindelidæ, Pogonostoma, which is allied to the South American genus, Ctenostoma. Another genus, Peridexia, is common to Madagascar and South America. None of the important African genera are represented, except Eurymorpha; while Megalomma is common to Madagascar and the Oriental region.
In the Carabidæ we have somewhat similar phenomena on a wider scale. Such large and important African genera as Polyhirma and Anthia, are absent; but there are four genera in common with South Africa, and two with West Africa; while three others are as much Oriental as African. One genus, Distrigus, is wholly Oriental; and another, Homalosoma, Australian. Colpodes, well developed in Bourbon and Mauritius, is Oriental and South American. Of the peculiar genera, Sphærostylis has South American affinities; Microchila, Oriental; the others being related to widely distributed genera.
The Lucanidæ are few in number, and all have African affinities. Madagascar is very rich in Cetoniidæ, and possesses 20 peculiar genera. Bothrorhina, and three other genera belonging to the Ichnostoma group, have wholly African relations. Doryscelis and Chromoptila are no less clearly allied to Oriental genera. A series of eight peculiar genera belong to the Schizorhinidæ, a family the bulk of which are Australian, while there are only a few African forms. The remaining genera appear to have African affinities, but few of the peculiarly African genera are represented. Glyciphana is characteristic of the Oriental region.
The Buprestidæ of Madagascar consist mainly of one large and peculiar genus, Polybothris, allied to the almost cosmopolite Psiloptera. Most of the other genera are both Ethiopian and Oriental; but Polycesta is mainly South American, and the remarkable and isolated genus Sponsor is confined to the Mauritius with a species in Celebes and New Guinea.
The Longicorns are numerous and interesting, there being no less than 24 peculiar genera. Two of the genera of Prionidæ are very isolated, while a third, Closterus, belongs to a group which is Malayan and American.
Of the Cerambycidæ, Philematium ranges to Africa and the West Indies; Leptocera is only found eastward in Ceylon and the New Hebrides; while Euporus is African. Of the peculiar genera, 2 are of African type; 3 belong to the Leptura group, which are mostly Palæarctic and Oriental, with a few in South Africa; while Philocalocera is allied to a South American genus.
Among the Lamiidæ there are several wide-ranging and 7 African genera; but Coptops is Oriental, and the Oriental Praonetha occurs in the Comoro Islands. Among the peculiar genera several have African affinities, but Tropidema belongs to a group which is Oriental and Australian; Oopsis is found also in the Pacific Islands; Mythergates, Sulemus, and Coedomæa, are allied to Malayan and American genera.
General Remarks on the Insect-fauna of Madagascar.—Taking the insects as a whole, we find the remarkable result that their affinities are largely Oriental, Australian, and South American: while the African element is represented chiefly by special South African or West African forms, rather than by such as are widely spread over the Ethiopian region. In some families—as Cetoniidæ and Lamiidæ—the African element appears to preponderate; in others—as Cicindelidæ—the South American affinity seems strongest; in Carabidæ, perhaps the Oriental; while in Buprestidæ and Cerambycidæ the African and foreign elements seem nearly balanced. We must not impute too much importance to these foreign alliances among insects, because we find examples of them in every country on the globe. The reason they are so much more pronounced in Madagascar may be, that during long periods of time this island has served as a refuge for groups that have been dying out on the great continents; and that, owing to the numerous deficiencies of a somewhat similar kind in the series of vertebrata in Australia and South America, the same groups have often been able to maintain themselves in all these countries as well as in Madagascar. It must be remembered too, that these peculiarities in the Malagasy and Mascarene insect-fauna are but exaggerations of a like phenomenon on the mainland. Africa also has numerous affinities with South America, with the Malay countries, and with Australia; but they do not bear anything like so large a proportion to the whole fauna, and do not, therefore, attract so much attention. The special conditions of existence and the long-continued isolation of Madagascar, will account for much of this difference; and it will evidently not be necessary to introduce, as some writers are disposed to do, a special land connection or near approach between Madagascar and all these countries, independently of Africa; except perhaps in the case of the Malay Islands, as will be discussed further on.
Land-shells.—Madagascar and the adjacent islands are all rich in land-shells. The genera of Helicidæ are Vitrina, Helix, Achatina, Columna (peculiar to Madagascar and West Africa), Buliminus, Cionella (chiefly Oriental and South American, but not African), Pupa, Streptaxis, and Succinea. Among the Operculata we have Truncatella (widely scattered, but not African); Cyclotus (South American, Oriental, and South African); Cyclophorus (mostly Oriental, with a few South African); Leptopoma (Oriental); Megalomastoma (Malayan and South American); Lithidion (peculiar to Madagascar, Socotra, and South-West Arabia); Otopoma (with the same range, but extending to West India and New Ireland); Cyclostomus (widely spread but not African); and Omphalotropis (wholly Oriental and Australian). We thus find the same general features reproduced in the land-shells as in the insects, and the same remarks will to a great extent apply to both. The classification of the former is, however, by no means so satisfactory, and we have no extensive and accurate general catalogues of shells, like those of Lepidoptera and Coleoptera, which have furnished us with such valuable materials for the comparison of the several faunas.
On the probable Past History of the Ethiopian Region.
Perhaps none of the great zoological regions of the earth present us with problems of greater difficulty or higher interest than the Ethiopian. We find in it the evidence of several distinct and successive faunas, now intermingled; and it is very difficult, with our present imperfect knowledge, to form an adequate conception of how and when the several changes occurred. There are, however, a few points which seem sufficiently clear, and these afford us a secure foundation in our endeavour to comprehend the rest.
Let us then consider what are the main facts we have to account for.—1. In Continental Africa, more especially in the south and west, we find, along with much that is peculiar, a number of genera showing a decided Oriental, and others with an equally strong South American affinity; this latter more particularly showing itself among reptiles and insects. 2. All over Africa, but more especially in the east, we have abundance of large ungulates and felines—antelopes, giraffes, buffaloes, elephants, and rhinoceroses, with lions, leopards, and hyænas, all of types now or recently found in India and Western Asia. 3. But we also have to note the absence of a number of groups which abound in the above-named countries, such as deer, bears, moles, and true pigs; while camels and goats—characteristic of the desert regions just to the north of the Ethiopian—are equally wanting. 4. There is a wonderful unity of type and want of speciality in the vast area of our first sub-region extending from Senegal across to the east coast, and southward to the Zambezi; while West Africa and South Africa each abound in peculiar types. 5. We have the extraordinary fauna of Madagascar to account for, with its evident main derivation from Africa, yet wanting all the larger and higher African forms; its resemblances to Malaya and to South America; and its wonderful assemblage of altogether peculiar types.
Here we find a secure starting-point, for we are sure that Madagascar must have been separated from Africa before the assemblage of large animals enumerated above, had entered it. Now, it is a suggestive fact, that all these belong to types which abounded in Europe and India about the Miocene period. It is also known, from the prevalence of Tertiary deposits over the Sahara and much of Arabia, Persia, and Northern India, that during early Tertiary times a continuous sea from the Bay of Bengal to the British Isles completely cut off all land communication between Central and Southern Africa on the one side, and the great continent of the Eastern hemisphere on the other. When Africa was thus isolated, its fauna probably had a character somewhat analogous to that of South America at the same period. Most of the higher types of mammalian life were absent, while lemurs, Edentates, and Insectivora took their place. At this period Madagascar was no doubt united with Africa, and helped to form a great southern continent which must at one time have extended eastward as far as Southern India and Ceylon; and over the whole of this the lemurine type no doubt prevailed.
During some portion of this period, South Temperate Africa must have had a much greater extension, perhaps indicated by the numerous shoals and rocks to the south and east of the Cape of Good Hope, and by the Crozets and Kerguelen Islands further to the south-east. This would have afforded means for that intercommunion with Western Australia which is so clearly marked in the flora, and to some extent also in the insects of the two countries; and some such extension is absolutely required for the development of that wonderfully rich and peculiar temperate flora and fauna, which, now crowded into a narrow territory, is one of the greatest marvels of the organic world.
During this early period, when the great southern continents—South America, Africa, and Australia—were equally free from the incursions of the destructive felines of the north, the Struthious or ostrich type of birds was probably developed into its existing forms. It is not at all necessary to suppose that these three continents were at any time united, in order to account for the distribution of these great terrestrial birds; as this may have arisen by at least two other easily conceivable modes. The ancestral Struthious type may, like the Marsupial, have once spread over the larger portion of the globe; but as higher forms, especially of Carnivora, became developed, it would be exterminated everywhere but in those regions where it was free from their attacks. In each of these it would develope into special forms adapted to surrounding conditions; and the large size, great strength, and excessive speed of the ostrich, may have been a comparatively late development caused by its exposure to the attacks of enemies which rendered such modification necessary. This seems the most probable explanation of the distribution of Struthious birds, and it is rendered almost certain by the discovery of remains of this order in Europe in Eocene deposits, and by the occurrence of an ostrich among the fossils of the Siwalik hills; but it is just possible, also, that the ancestral type may have been a bird capable of flight, and that it spread from one of the three southern continents to the others at the period of their near approach, and more or less completely lost the power of flight owing to the long continued absence of enemies.
During the period we have been considering, the ancestors of existing apes and monkeys flourished (as we have seen in Chapter VI.) along the whole southern shores of the old Palæarctic continent; and it seems likely that they first entered Africa by means of a land connection indicated by the extensive and lofty plateaus of the Sahara, situated to the south-east of Tunis and reaching to a little north-west of Lake Tchad; and at the same time the elephant and rhinoceros type may have entered. This will account for the curious similarity between the higher faunas of West Africa and the Indo-Malay sub-region, for owing to the present distribution of land and sea and the narrowing of the tropical zone since Miocene times, these are now the only lowland, equatorial, forest-clad countries, which were in connection with the southern shores of the old Palæarctic continent at the time of its greatest luxuriance and development. This western connection did not probably last long, the junction that led to the greatest incursion of new forms, and the complete change in the character of the African fauna, having apparently been effected by way of Syria and the shores of the Red Sea at a somewhat later date. By this route the old South-Palæarctic fauna, indicated by the fossils of Pikermi and the Siwalik Hills, poured into Africa; and finding there a new and favourable country, almost wholly unoccupied by large Mammalia, increased to an enormous extent, developed into new forms, and finally overran the whole continent.
Before this occurred, however, a great change had taken place in the geography of Africa. It had gradually diminished on the south and east; Madagascar had been left isolated; while a number of small islands, banks, and coral reefs in the Indian Ocean alone remained to indicate the position of a once extensive equatorial land. The Mascarene Islands appear to represent the portion which separated earliest, before any carnivora had reached the country; and it was in consequence of this total exemption from danger, that several groups of birds altogether incapable of flight became developed here, culminating in the huge and unwieldy Dodo, and the more active Aphanapteryx. To the same cause may be attributed the development, in these islands, of gigantic land-tortoises, far surpassing any others now living on the globe. They appear to have formerly inhabited Mauritius, Bourbon, and Rodriguez, and perhaps all the other Mascarene islands, but having been recklessly destroyed, now only survive in the small uninhabited Aldabra islands north of the Seychelle group. The largest living specimen (5½ feet long) is now in our Zoological Gardens. The only other place where equally large tortoises (of an allied species) are found, is the Galapagos islands, where they were equally free from enemies till civilized man came upon the scene; who, partly by using them for food, partly by the introduction of pigs, which destroy the eggs, has greatly diminished their numbers and size, and will probably soon wholly exterminate them. It is a curious fact, ascertained by Dr. Günther, that the tortoises of the Galapagos are more nearly related to the extinct tortoises of Mauritius than is the living tortoise of Aldabra. This would imply that several distinct groups or sub-genera of Testudo have had a wide range over the globe, and that some of each have survived in very distant localities. This is rendered quite conceivable by the known antiquity of the genus Testudo, which dates back to at least the Eocene formation (in North America) with very little change of form. These sluggish reptiles, so long-lived and so tenacious of life, may have remained unchanged, while every higher animal type around them has become extinct and been replaced by very different forms; as in the case of the living Emys tectum, which is the sole survivor of the strange Siwalik fauna of the Miocene epoch. The ascertained history of the genus and the group, thus affords a satisfactory explanation of the close affinity of the gigantic tortoises of Mauritius and the Galapagos.
The great island of Madagascar seems to have remained longer united with Africa, till some of the smaller and more active carnivora had reached it; and we consequently find there, no wholly terrestrial form of bird but the gigantic and powerful Æpyornis, well able to defend itself against such enemies. As already intimated, we refer the South American element in Madagascar, not to any special connection of the two countries independently of Africa, but to the preservation there of a number of forms, some derived from America through Africa, others of once almost cosmopolitan range, but which, owing to the severer competition, have become extinct on the African continent, while they have continued to exist under modified forms in the two other countries.
The depths of all the great oceans are now known to be so profound, that we cannot conceive the elevation of their beds above the surface without some corresponding depression elsewhere. And if, as is probable, these opposite motions of the earth's crust usually take place in parallel bands, and are to some extent dependent on each other, an elevation of the sea bed could hardly fail to lead to the submergence of large tracts of existing continents; and this is the more likely to occur on account of the great disproportion that we have seen exists between the mean height of the land and the mean depth of the ocean. Keeping this principle in view, we may, with some probability, suggest the successive stages by which the Ethiopian region assumed its present form, and acquired the striking peculiarities that characterise its several sub-regions. During the early period, when the rich and varied temperate flora of the Cape, and its hardly less peculiar forms of insects and of low type mammalia, were in process of development in an extensive south temperate land, we may be pretty sure that the whole of the east and much of the north of Africa was deep sea. At a later period, when this continent sank towards the south and east, the elevation may have occurred which connected Madagascar with Ceylon; and only at a still later epoch, when the Indian Ocean had again been formed, did central, eastern, and northern Africa gradually rise above the ocean, and effect a connection with the great northern continent by way of Abyssinia and Arabia. And if this last change took place with tolerable rapidity, or if the elevatory force acted from the north towards the south, there would be a new and unoccupied territory to be taken possession of by immigrants from the north, together with a few from the south and west. The more highly-organised types from the great northern continent, however, would inevitably prevail; and we should thus have explained the curious uniformity in the fauna of so large an area, together with the absence from it of those peculiar Ethiopian types which so abundantly characterise the other three sub-regions.
We may now perhaps see the reason of the singular absence from tropical Africa of deer and bears; for these are both groups which live in fertile or well-wooded countries, whereas the line of immigration from Europe to Africa was probably always, as now, to a great extent a dry and desert tract, suited to antelopes and large felines, but almost impassable to deer and bears. We find, too, that whereas remains of antelopes and giraffes abound in the Miocene deposits of Greece, there were no deer (which are perhaps a somewhat later development); neither were there any bears, but numerous forms of Felidæ, Viverridæ, Mustelidæ, and ancestral forms of Hyæna, exactly suited to be the progenitors of the most prevalent types of modern African Zoology.
There appears to have been one other change in the geography of Africa and the Atlantic Ocean that requires notice. The rather numerous cases of close similarity in the insect forms of tropical Africa and America, seem to indicate some better means of transmission, at a not very remote epoch, than now exists. The vast depth of the Atlantic, and the absence of any corresponding likeness in the vertebrate fauna, entirely negative the idea of any union between the two countries; but a moderate extension of their shores towards each other is not improbable, and this, with large islands in the place of the Cape Verd group, St. Paul's Rocks, and Fernando Noronha, to afford resting places in the Atlantic, would probably suffice to explain the amount of similarity that actually exists.
Our knowledge of the geology and palæontology of Africa being so scanty, it would be imprudent to attempt any more detailed explanation of the peculiarities of its existing fauna. The sketch now given is, it is believed, founded on a sufficient basis of facts to render it not only a possible but a probable account of what took place; and it is something gained to be able to show, that a large portion of the peculiarities and anomalies of so remarkable a fauna as that of the Ethiopian region, can be accounted for by a series of changes of physical geography during the tertiary epoch, which can hardly be considered extreme, or in any way unlikely to have occurred.
TABLES OF DISTRIBUTION.
In drawing up these tables showing the distribution of various classes of animals in the Ethiopian Region, the following sources of information have been chiefly relied on, in addition to the general treatises, monographs, and catalogues, used for the Fourth Part of this work:—
Mammalia.—Blanford's Abyssinia; Peters's Mozambique; Heuglin and Schweinfurth for North East Africa; Grandidier Schlegel, &c., for Madagascar; the local lists given by Mr. Andrew Murray; numerous papers by Fraser, Gray, Kirk, Mivart, Peters, Sclater, and Speke; and a MS. list of Bovidæ from Sir Victor Brooke.
Birds.—Finsch and Hartlaub for East Africa; Heuglin for North-East Africa; Blanford for Abyssinia; Layard for South Africa; Hartlaub for West Africa; Dohrn for Princes Island; Andersson for Damaraland; and papers by Gurney, Hartlaub, Kirk, Newton, Peters, Sharpe, Sclater, Schlegel, and Pollen and a MS. list of Madagascar Birds from Mr. Sharpe.
FAMILIES OF ANIMALS INHABITING THE ETHIOPIAN REGION.
Names inclosed thus (......) barely enter the region, and are not considered properly to belong to it.Numbers are not consecutive, but correspond to those in Part IV.
|Order and Family||Sub-regions||Range beyond the Region.|
|3. Cynopithecidæ||—||—||—||Oriental, Palæarctic|
|9. Pteropidæ||—||—||—||—||Oriental, Australian|
|11. Rhinolophidæ||—||—||—||—||The Eastern Hemisphere|
|13. Noctilionidæ||—||—||—||—||All Tropical regions|
|15. Macroscelididæ||—||—||South Palæarctic|
|17. Erinaceidæ||—||Palæarctic, Oriental|
|18. Centetidæ||—||Greater Antilles|
|22. Soricidæ||—||—||—||—||All regions but Australian and Neotropical|
|23. Felidæ||—||—||—||—||All regions but Australian|
|25. Viverridæ||—||—||—||—||Oriental, S. Palæarctic|
|27. Hyænidæ||—||—||—||S. Palæarctic, India|
|28. Canidæ||—||—||—||Almost cosmopolite|
|29. Mustelidæ||—||—||—||All regions but Australian|
|33. Otariidæ||—||All temperate regions|
|36 to 41.||Oceanic|
|42. Manatidæ||—||—||Neotropical, Oriental, Australian|
|47. Suidæ||—||—||—||—||excl. Australia|
|52. Bovidæ||—||—||—||All regions but Neotrop. and Australian|
|55. Muridæ||—||—||—||—||excl. Oceania|
|56. Spalacidæ||—||—||—||Palæarctic, Oriental|
|57. Dipodidæ||—||—||—||Palæarctic, Nearctic|
|61. Sciuridæ||—||—||—||All regions but Australian|
|64. Octodontidæ||—||N. Africa, Neotropical|
|67. Hystricidæ||—||—||—||S. Palæarctic, Oriental|
|70. Leporidæ||—||—||All regions but Australian|
|1. Turdidæ||—||—||—||—||Almost Cosmopolite|
|3. Timaliidæ||—||—||—||—||Oriental, Australian|
|5. Cinclidæ?||—||Widely scattered|
|6. Troglodytidæ||—||—||—||Almost Cosmopolite|
|9. Sittidæ||—||Palæarctic, Oriental, Australian|
|10. Paridæ||—||—||—||All regions but Australian|
|14. Oriolidæ||—||—||—||—||Oriental, Australian|
|15. Campephagidæ||—||—||—||—||Oriental, Australian|
|16. Dicruridæ||—||—||—||—||Oriental, Australian|
|17. Muscicapidæ||—||—||—||—||The Eastern Hemisphere|
|19. Laniidæ||—||—||—||—||The Eastern Hemisphere and North America|
|23. Nectariniidæ||—||—||—||—||Oriental, Australian|
|24. Dicæidæ||—||—||—||—||Oriental, Australian|
|33. Fringillidæ||—||—||—||—||Cosmopolite, except Australian region|
|34. Ploceidæ||—||—||—||—||Oriental, Australian|
|35. Sturnidæ||—||—||—||—||Eastern Hemisphere|
|37. Alaudidæ||—||—||—||—||Eastern Hemisphere and North America|
|38. Motacillidæ||—||—||—||—||The Eastern Hemisphere|
|47. Pittidæ||—||Oriental, Australian|
|51. Picidæ||—||—||—||Cosmopolite, excl. Australian region|
|54. Megalæmidæ||—||—||—||Oriental, Neotropical|
|62. Coraciidæ||—||—||—||—||Oriental, Australian|
|63. Meropidæ||—||—||—||—||Oriental, Australian|
|66. Trogonidæ||—||—||—||Oriental, Neotropical|
|68. Bucerotidæ||—||—||—||Oriental and to N. Guinea|
|69. Upupidæ||—||—||—||—||Palæarctic, Oriental|
|74. Cypselidæ||—||—||—||—||Almost Cosmopolite|
|86. Pteroclidæ||—||—||—||Palæarctic, Oriental|
|87. Tetraonidæ||—||—||—||—||Eastern Hemisphere and N. America|
|88. Phasianidæ||—||—||—||—||Old World and N. America|
|89. Turnicidæ||—||—||—||—||Eastern Hemisphere.|
|94. Vulturidæ||—||—||—||All the continents but Australia|
|104. Glareolidæ||—||—||—||—||Eastern Hemisphere|
|106. Otididæ||—||—||—||Eastern Hemisphere|
|107. Gruidæ||—||—||—||All regions but Neotropical|
|114. Plataleidæ||—||—||—||—||Almost Cosmopolite|
|115. Ciconiidæ||—||—||—||—||Almost Cosmopolite|
|117. Phœnicopteridæ||—||—||—||—||Oriental and Neotropical|
|122. Spheniscidæ||—||South temperate regions|
|126. Struthionidæ||—||—||Temperate S. America|
|1. Typhlopidæ||—||—||—||—||All regions but Nearctic|
|5. Calamariidæ||—||—||—||Warm parts of all regions|
|7. Colubridæ||—||—||—||—||Almost Cosmopolite|
|8. Homalopsidæ||—||Oriental, and all other regions|
|9. Psammophidæ||—||—||—||—||Oriental and S. Palæarctic|
|11. Dendrophidæ||—||—||—||—||Oriental, Australian, Neotropical|
|12. Dryiophidæ||—||—||Oriental, Neotropical|
|13. Dipsadidæ||—||—||—||Oriental, Australian, Neotropical|
|17. Pythonidæ||—||—||—||—||All tropical regions|
|18. Erycidæ||—||Oriental, S. Palæarctic|
|20. Elapidæ||—||—||—||Tropical regions, S. U. States and Japan|
|23. Hydrophidæ||—||Oriental, Australian, Panama|
|25. Viperidæ||—||—||—||—||Oriental, Palæarctic|
|28. Amphisbænidæ||—||—||S. Europe, Neotropical|
|29. Lepidosternidæ||—||—||N. America|
|30. Varanidæ||—||—||—||Warm parts of E. Hemisphere|
|33. Lacertidæ||—||—||—||All continents but America|
|34. Zonuridæ||—||—||—||—||All America, N. India, S. Europe|
|41. Gymnophthalmidæ||—||—||Palæarctic, Australian, Neotropical|
|45. Scincidæ||—||—||—||—||Almost Cosmopolite|
|47. Sepidæ||—||—||—||—||South Palæarctic|
|48. Acontiadæ||—||—||—||Ceylon and Moluccas|
|49. Geckotidæ||—||—||—||—||Almost cosmopolite|
|51. Agamidæ||—||—||—||—||Oriental, Australian, S. Palæarctic|
|52. Chamæleonidæ||—||—||—||—||Oriental, S. Palæarctic|
|55. Crocodilidæ||—||—||—||—||Oriental, Neotropical|
|57. Testudinidæ||—||—||—||—||All continents but Australia|
|58. Chelydidæ||—||—||—||—||Australia, S. America|
|59. Trionychidæ||—||—||—||Oriental, Japan, E. United States|
|1. Cæciliadæ||—||Oriental, Neotropical|
|8. Phryniscidæ||—||—||Neotropical, Australia, Java|
|10. Bufonidæ||—||—||—||All regions but Australian|
|12. Engystomidæ||—||—||All regions but Palæarctic|
|15. Alytidæ||—||—||—||All regions but Oriental|
|18. Polypedatidæ||—||—||—||—||All the regions|
|19. Ranidæ||—||—||—||—||Almost Cosmopolite|
|20. Discoglossidæ||—||—||All regions but Nearctic|
|3. Percidæ||—||All regions but Australian|
|12. Sciænidæ||—||—||—||All regions but Australian|
|35. Labyrinthici||—||—||Oriental, Moluccas|
|38. Mugillidæ||—||—||—||—||Australian, Neotropical|
|52. Chromidæ||—||—||—||—||Oriental, Neotropical|
|59. Siluridæ||—||—||—||—||All warm regions|
|73. Cyprinodontidæ||—||—||—||Palæarctic, Oriental, American|
|75. Cyprinidæ||—||—||—||—||Absent from Australia and S. America|
|78. Osteoglossidæ||—||—||All tropical regions|
|92. Sirenoidei||—||—||Neotropical, Australian|
|1. Danaidæ||—||—||—||—||All warm countries and Canada|
|3. Elymniidæ||—||Oriental, Moluccas|
|6. Acræidæ||—||—||—||—||All tropical regions|
|9. Libytheidæ||—||—||Absent from Australia only|
|10. Nemeobiidæ||—||—||Absent from Australia and Nearctic region|
|19. Agaristidæ||—||—||—||—||Australian, Oriental|
|20. Uraniidæ||—||All tropical regions|
|22. Ægeriidæ||—||—||—||—||Cosmopolite, excl. Australia|
- Dr. Schweinfurth has accurately determined the limits of the sub-region at the point where he crossed the watershed between the Nile tributaries and those of the Shari, in 4½° N. Lat. and 28½° E. Long. He describes a sudden change in the character of the vegetation, which to the southward of this point assumes a West-African character. Here also the chimpanzee and grey parrot first appear, and certain species of plants only known elsewhere in Western Africa.
- There are also some special resemblances between the plants of Madagascar and South Africa, according to Dr. Kirk.