Chapter XXV: Part III: Zoological Geography (5)

_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 {269}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_, _Hytrichopus_, _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 {270}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 {271}2 genera, _Notioxenus_ and _Homoeodera_, 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 Rhyncophora.

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.

{272}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 {273}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:--

PRIMATES.
LEMURIDÆ.
Indrisinæ. Species.
_Indris_ 6

Lemurinæ.
_Lemur_ 15
_Hapalemur_ 2
_Microcebus_ 4
_Chirogaleus_ 5
_Lepilemur_ 2

CHIROMYIDÆ.
_Chiromys_ 1

BATS--(Chiroptera).
PTEROPIDÆ.
Pteropus 2

RHINOLOPHIDÆ.
Rhinolophus 1

VESPERTILIONIDÆ.
Vespertilio 1
Taphozous 1

NOCTILIONIDÆ.
Nyctinomus 1

INSECTIVORA.
CENTETIDÆ.
_Centetes_ 2
_Hemicentetes_ 2
_Ericulus_ 2
_Oryzorictes_ 1
_Echinops_ 3

SORICIDÆ.
Sorex 1

CARNIVORA.
CRYPTOPROCTIDÆ.
_Cryptoprocta_ 1

VIVERRIDÆ.
_Fossa_ 2
_Galidia_ 3
_Galidictis_ 2
_Eupleres_ 1

UNGULATA.
SUIDÆ.
Potamochoerus 1

RODENTIA.
MURIDÆ.
_Nesomys_ 1
_Hypogeomys_ 1
_Brachytarsomys_ 1

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 {274}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 _Potamochoerus_ 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 {275}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.

SYLVIIDÆ. Species.
1. Bernieria 2
2. Ellisia 1
3. Mystacornis 1
4. Eroessa 1
5. Gervasia 1

TIMALIIDÆ.
6. Oxylabes 2

CINCLIDÆ(?).
7. Mesites 1

SITTIDÆ.
8. _Hypherpes_ 1

PYCNONOTIDÆ(?)
9. Tylas 1

ORIOLIDÆ.
10. Artamia 3
11. Cyanolanius 1

MUSCICAPIDÆ.
12. Newtonia 1
13. Pseudobias 1

LANIIDÆ.
14. Calicalicus(?) 1
15. Vanga 4

NECTARINIIDÆ.
16. Neodrepanis 1

HIRUNDINIDÆ.
17. Phedina 1

PLOCEIDÆ.
18. Nelicurvius 1

STURNIDÆ.
19. Euryceros(?) 1
20. Hartlaubia 1
21. Falculia 1

PAICTIDÆ.
22. Philepitta 1

CUCULIDÆ.
23. Coua 9
24. Cochlothraustes 1

LEPTOSOMIDÆ.
25. Leptosomus 1

CORACIIDÆ.
26. Atelornis 2
27. Brachypteracias 1
28. Geobiastes 1

PSITTACIDÆ.
29. Coracopsis 2

COLUMBIDÆ.
30. _Alectrænas_ 1

TETRAONIDÆ.
31. _Margaroperdix_ 1

FALCONIDÆ.
32. Nisoides 1
33. Eutriorchis 1
--
Total species of peculiar genera 50

ÆPYORNITHIDÆ(extinct).
34. Æpyornis 1

{276}ETHIOPIAN OR ORIENTAL GENERA WHICH ARE REPRESENTED IN MADAGASCAR BY PECULIAR SPECIES.

TURDIDÆ. Species.
1. Bessonornis 1

SYLVIIDÆ.
2. Acrocephalus 1
3. _Copsychus (Or.)_ 1
4. Pratincola 1

PYCNONOTIDÆ.
5. _Hypsipetes (Or.)_ 1
6. Andropadus 1

CAMPEPHAGIDÆ.
7. Campephaga 1

DICRURIDÆ.
8. Dicrurus 1

MUSCICAPIDÆ.
9. Tchitrea 1

LANIIDÆ.
10. Laniarius 1

NECTARINIIDÆ.
11. Nectarinia 1

PLOCEIIDÆ.
12. Foudia 2
13. Hypargos 1
14. Spermestes 1

ALAUDIDÆ.
15. Mirafra 1

MOTACILLIDÆ.
16. Motacilla 1

CUCULIDÆ.
17. Ceuthmochares 1
18. Centropus 1
19. Cuculus 1

CORACIIDÆ.
20. Eurystomus 1

ALCEDINIDÆ.
21. Corythornis 1
22. Ispidina 1

UPUPIDÆ.
23. Upupa (?) 1

CAPRIMULGIDÆ.
24. Caprimulgus 1

CYPSELIDÆ.
25. Cypselus 2
26. Chætura 1

PSITTACIDÆ.
27. Poliopsitta 1

COLUMBIDÆ.
28. Treron 1
29. Columba 1
30. Turtur 1

PTEROCLIDÆ.
31. Pterocles 1

TETRAONIDÆ.
32. Francolinus 1

PHASIANIDÆ.
33. Numida 1

TURNICIDÆ.
34. Turnix 1

FALCONIDÆ.
35. Polyboroides 1
36. Circus 1
37. Astur 3
38. Accipiter 1
39. Buteo 1
40. Haliæetus 1
41. Pernis 1
42. Baza 1
43. Cerchneis 1

STRIGIDÆ. {277}
44. Athene 1
45. Scops 1

RALLIDÆ.
46. Rallus 3
47. Porzana 1

SCOLOPACIDÆ.
48. Gallinago 1

PLATALEIDÆ.
49. Ibis 1

PODICIPIDÆ.
50. Podiceps 1
--
Total peculiar species of Eth. }
or Or. genera } 56

SPECIES OF BIRDS COMMON TO MADAGASCAR AND AFRICA OR ASIA.

1. Cisticola cursitans.
2. Corvus scapulatus.
3. Crithagra canicollis.
4. Merops superciliosus.
5. Collocalia fuciphaga.
6. Oena capensis.
7. Aplopelia tympanistria.
8. Falco minor.
9. Falco concolor.
10. Milvus ægyptius.
11. Milvus migrans.
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_, _Alectrænas_, 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 {278}Depanididæ. _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 (_Potamochoerus 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.

Plate VI.

SCENE IN MADAGASCAR, WITH CHARACTERISTIC ANIMALS.

{279}_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 {280}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 {281}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 _Alectrænas_, 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 _Drymoeca_ 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 _Alectrænas_.

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 _Alectrænas_.

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 Gymnopthalmidæ; _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.

{282}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 _Meglaomma_ is common to Madagascar and the Oriental region.

In the Carabidæ we have somewhat similar phenomena on a {283}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 {284}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.[11] 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 {285}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 {286}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, {287}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 {288}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 {289}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 {290}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 {291}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 {292}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.

{293}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.

{294}TABLE I.

_FAMILIES OF ANIMALS INHABITING THE ETHIOPIAN REGION._

EXPLANATION.

Names in _italics_ show families peculiar to the 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.