Sciurus(100-120 sp., including the sub-genera Spermosciurus, Xerus, Macroxus, Rheithrosciurus, and Rhinosciurus), comprises the true squirrels, and occupies the area of the whole family wherever woods and forests occur. The approximate number of species in each region is as follows: Nearctic 18, Palæarctic 6, Ethiopian 18, Oriental 50, Australian (Celebes) 5, Neotropical 30.Sciuropterus(16-19 sp.), comprises the flat-tailed flying squirrels, which range from Lapland and Finland to North China and Japan, and southward through India and Ceylon, to Malacca and Java, with a species in Formosa; while in North America they occur from Labrador to British Columbia, and south to Minnesota and Southern California.Pteromys(12 sp.), comprising the round-tailed flying squirrels, is a more southern form, being confined to the wooded regions of India from the Western Himalayas to Java and Borneo, with species in Formosa and Japan.Tamias(5 sp.), the ground squirrels, are chiefly North American, ranging from Mexico to Puget's Sound on the west coast, and from Virginia to Montreal on the Atlantic coast; while one species is found over all northern Asia.Spermophilus(26 sp.), the pouched marmots, are confined to the Nearctic and Palæarctic regions; in the former extending from the Arctic Ocean to Mexico and the west coast, but not passing east of Lake Michigan and the lower Mississippi; in the latter from Silesia through South Russia to the Amoor and Kamschatka, most abundant in the desert plains of Tartary and Mongolia.Arctomys(8 sp.), the marmots, are found in the northern parts of North America as far down as Virginia and Nebraska to the Rocky Mountains and British Columbia, but not in California; and from the Swiss Alps eastward to Lake Baikal and Kamschatka, and south as far as the Himalayas, above 8,000 feet elevation.Cynomys(2 sp.), the prairie-dogs, inhabit the plains east of the Rocky Mountains from the Upper Missouri to the Red River and Rio Grande (Plate XIX., vol. ii. p.129).Anomalurus(5 sp.), consists of animals which resemble flying-squirrels, but differ from all other members of the family in some points of internal structure. They form a very aberrant portion of the Sciuridæ, and, according to some naturalists, a distinct family. They inhabit West Africa and the island of Fernando Po.
Extinct Sciuridæ.—These are tolerably abundant. The genus Sciurus appears to be a remarkably ancient form, extinct species being found in the Miocene, and even in the Upper Eocene formations of Europe.Spermophilusgoes back to the Upper Miocene;Arctomysto the Newer Pliocene. Extinct genera are,Brachymys,LithomysandPlesiarctomys, from the European Miocene, the latter said to be intermediate between marmots and squirrels.
In North America,Sciurus,Tamias, andArctomysoccur in the Post-pliocene deposits only. The extinct genera areIschyromys, from the Upper Miocene of Nebraska;Paramys, allied to the marmots, andSciuravus, near the squirrels, from the Eocene of Wyoming.
Here we have unmistakable evidence that the true squirrels (Sciurus) are an Old World type, which has only recently entered North America; and this is in accordance with the comparative scarcity of this group in South America, a country so well adapted to them, and their great abundance in the Oriental region, which, with the Palæarctic, was probably the country of their origin and early development. The family, however, has been traced equally far back in Europe and North America, so that we have as yet no means of determining where it originated.
Family62—HAPLOODONTIDÆ.—(1 Genus, 2 Species.)
The genusHaploodonorAplodontia, consists of two curious rat-like animals, inhabiting the west coast of America, from the southern part of British Columbia to the mountains of California. They seem to have affinities both with the beavers and marmots, and Professor Lilljeborg constitutes a separate family to receive them.
Family63.—CHINCHILLIDÆ. (3 Genera, 6 Species.)
The Chinchillidæ, including the chinchillas and viscachas, are confined to the alpine zones of the Andes, from the boundary of Ecuador and Peru to the southern parts of Chili; and over the Pampas, to the Rio Negro on the south, and the River Uruguay on the east.Chinchilla(2 sp.), the true chinchillas, are found in the Andes of Chili and Peru, south of 9° S. lat., and from 8,000 to 12,000 feet elevation (Plate XVI. vol. ii. p.40);Lagidium(3 sp.), the alpine viscachas, inhabit the loftiest plateaus and mountains from 11,000 to 16,000 feet, and extend furthest north of any of the family; whileLagostomus(1 sp.), the viscacha of the Pampas, has the range above indicated. The family is thus confined within the limits of a single sub-region.
Extinct Chinchillidæ.—Lagostomushas been found fossil in the caves of Brazil, and in the Pliocene deposits of La Plata. The only known extinct forms of this family areAmblyrhizaandLoxomylus, found in cavern-deposits in the island of Anguilla, of Post-Pliocene age. These are very interesting, as showing the greater range of this family so recently; though its absence from North America and Europe indicates that it is a peculiar development of the Neotropical region.
Family64.—OCTODONTIDÆ. (8 Genera, 19 Species.)
The Octodontidæ include a number of curious and obscure rat-like animals, mostly confined to the mountains and open plains of South America, but having a few stragglers in other parts of the world, as will be seen by our notes on the genera. The most remarkable point in their distribution is, that two genera are peculiar to the West Indian islands, while no species of the family inhabits the northern half of South America. The distribution of the genera is as follows:—Habrocomus(2 sp.), Chili;Capromys(3 sp.), two of which inhabit Cuba, the third Jamaica (Plate XVII. vol. ii. p.67);Plagiodontia(1 sp.), only known fromHayti;Spalacopus, includingSchizodon(2 sp.), Chili, and east side of Southern Andes;Octodon(3 sp.), Peru, Bolivia, and Chili;Ctenomys(6 sp.), the tuco-tuco of the Pampas, the Campos of Brazil to Bolivia and Tierra del Fuego;Ctenodactylus(1 sp.), Tripoli, North Africa;Pectinator(1 sp.), East Africa, Abyssinia, 4,000 to 5,000 feet.
CapromysandPlagiodontia, the two West Indian genera, were classed among the Echimyidæ by Mr. Waterhouse, but Professor Lilljeborg removes them to this family.
Extinct Octodontidæ.—Species ofCtenomyshave been found in the Pliocene of La Plata, and an extinct genusMegamys, said to be allied toCapromys, in the Eocene of the same country. In Europe,PalæomysandArchæomysfrom the lower Miocene of Germany and France, are also said to be allied toCapromys.
Family65.—ECHIMYIDÆ. (10 Genera, 30 Species.)
The Echimyidæ, or spiny rats, are a family, chiefly South American, of which the Coypu, a large beaver-like water-rat from Peru and Chili is the best known. Two of the genera are found in South Africa, but all the rest inhabit the continent of South America, East of the Andes, none being yet known northof Panama. The genera are as follows:—Dactylomys(2 sp.), Guiana and Brazil;Cercomys(1 sp.), Central Brazil;Lasiuromys(1 sp.), San Paulo, Brazil;Petromys(1 sp.), South Africa;Myopotamus(1 sp.), the coypu, on the East side of the Andes from Peru to 42° S. lat., on the West side from 33° to 48° S. lat.;Carterodon(1 sp.), Minaes Geraes, Brazil;Aulacodes(1. sp.), West and South Africa;Mesomys(1 sp.), Borba on the Amazon;Echimys(11 sp.), from Guiana and the Ecuadorian Andes to Paraguay;Loncheres(10 sp.), New Granada to Brazil.
Fossil and Extinct Echimyidæ.—The genusCarterodonwas established on bones found in the Brazilian caves, and it was several years afterwards that specimens were obtained showing the animal to be a living species. Extinct species ofMyopotamusandLonchereshave also been found in these caves, with the extinct generaLonchophorusandPhyllomys.
No remains of this family have been discovered in North America; but in the Miocene and Upper Eocene deposits of France there are many species of an extinct genusTheridomys, which is said to be allied to this group or to the next (Cercolabidæ).Aulacodon, from the Upper Miocene of Germany, is allied to the West AfricanAulacodes; and some other remains from the lower Miocene of Auvergne, are supposed to belong toEchimys.
Family66.—CERCOLABIDÆ. (3 Genera, 13-15 Species.)
The Cercolabidæ, or arboreal porcupines, are a group of rodents entirely confined to America, where they range from the northern limit of trees on the Mackenzie River, to the southern limit of forests in Paraguay. There is however an intervening district, the Southern United States, from which they are absent.Erethizon(3 sp.), the Canadian porcupine, is found throughoutCanada and as far south as Northern Pennsylvania, and west to the Mississippi (Plate XX., vol. ii. p.135); an allied species inhabiting the west coast from California to Alaska, and inland to the head of the Missouri River; while a third is found in the north-western part of South America;Cercolabes(12 sp.), ranges from Mexico and Guatemala to Paraguay, on the eastern side of the Andes;Chætomys(1 sp.), North Brazil.
Extinct Cercolabidæ.—A large species ofCercolabeshas been found in the Brazilian caves, but none have been discovered in North America or Europe. We may conclude therefore that this is probably a South American type, which has thence spread into North America at a comparatively recent epoch. The peculiar distribution ofCercolabesmay be explained by supposing it to have migrated northwards along the west coast by means of the wooded slopes of the Rocky Mountains. It could then only reach the Eastern States by way of the forest region of the great lakes, and then move southward. This it may be now doing, but it has not yet reached the Southern States of Eastern North America.
Family67.—HYSTRICIDÆ. (3 Genera, 12 Species.)
The true Porcupines have a very compact and well-marked distribution, over the whole of the Oriental and Ethiopian regions (except Madagascar), and the second Palæarctic sub-region. There is some confusion as to their sub-division into genera, but the following are those most usually admitted:—Hystrix(5 sp.), South Europe to the Cape of Good Hope, all India, Ceylon, and South China;Atherura(5 sp.), "brush-tailed porcupines," inhabit West Africa, India, to Siam, Sumatra, and Borneo;Acanthion(2 sp.), Nepal and Malacca, to Sumatra, Borneo, and Java.
Extinct Hystricidæ.—Several extinct species ofHystrixhavebeen found in the Pliocene and Miocene deposits of Europe, and one in the Pliocene of Nebraska in North America.
Family68.—CAVIIDÆ. (6 Genera, 28 Species.)
The Cavies and Agoutis were placed in distinct families by Mr. Waterhouse, in which he is followed by Professor Carus, but they have been united by Professor Lilljeborg, and without pretending to decide which classification is the more correct I follow the latter, because there is a striking external resemblance between the two groups, and they have an identical distribution in the Neotropical region, and with one exception are all found east of the Andes.Dasyprocta(9 sp.), the agouti, ranges from Mexico to Paraguay, one species inhabiting the small West Indian islands of St. Vincent, Lucia, and Grenada;Cælogenys(2 sp.), the paca, is found from Guatemala to Paraguay, and a second species (somewhat doubtful) in Eastern Peru;Hydrochœrus(1 sp.), the capybara inhabits the banks of rivers from Guayana to La Plata;Cavia(9 sp.), the guinea-pigs, Brazil to the Straits of Magellan, and one species west of the Andes at Yça Peru;Kerodon(6 sp.), Brazil and Peru to Magellan;Dolichotis(1 sp,), the Patagonian cavy, from Mendoza to 48° 30′ south latitude, on sterile plains.
Extinct Caviidæ.—Hydrochœrus,Cælogenys,Dasyprocta, andKerodon, have occurred abundantly in the caves of Brazil, and the last-named genus in the Pliocene of La Plata.Hydrochœrushas been found in the Post-Pliocene deposits of South Carolina.CaviaandDasyproctaare said to have been found in the Miocene of Switzerland and France. No well-marked extinct genera of this family have been recorded.
If the determination of the above-mentioned fossil species ofCaviaandDasyproctaare correct, it would show that this nowexclusively South American family is really derived from Europe, where it has long been extinct.
Family69.—LAGOMYIDÆ. (1 Genus, 11 Species.)
The Lagomyidæ, or pikas, are small alpine and desert animals which range from the south of the Ural Mountains to Cashmere and the Himalayas, at heights of 11,000 to 14,000 feet, and northward to the Polar regions and the north-eastern extremity of Siberia. They just enter the eastern extremity of Europe as far as the Volga, but with this exception, seem strictly limited to the third Palæarctic sub-region. In America they are confined to the Rocky Mountains from about 42° to 60° north latitude.
Extinct Lagomyidæ.—Extinct species ofLagomyshave occurred in the southern parts of Europe, from the Post-Pliocene to the Miocene formations.Titanomys, an extinct genus, is found in the Miocene of France and Germany.
Family70.—LEPORIDÆ. (1 Genus, 35-40 Species.)
The Hares and Rabbits are especially characteristic of the Nearctic and Palæarctic, but are also thinly scattered over the Ethiopian and Oriental regions. In the Neotropical region they are very scarce, only one species being found in South America, in the mountains of Brazil and various parts of the Andes, while one or two of the North American species extend into Mexicoand Guatemala. In the Nearctic region, they are most abundant in the central and western parts of the continent, and they extend to the Arctic Ocean and to Greenland. They are found in every part of the Palæarctic region, from Ireland to Japan; three species range over all India to Ceylon, and others occur in Hainan, Formosa, South China, and the mountains of Pegu; the Ethiopian region has only four or five species, mostly in the southern extremity and along the East coast. An Indian species is now wild in some parts of Java, but it has probably been introduced.
Extinct Leporidæ.—Species ofLepusoccur in the Post-Pliocene and Newer Pliocene of France; but only in the Post-Pliocene of North America, and the caves of Brazil.
General Remarks on the Distribution of the Rodentia.
With the exception of the Australian region and Madagascar, where Muridæ alone have been found, this order is one of the most universally and evenly distributed over the entire globe. Of the sixteen families which compose it, the Palæarctic region has 10; the Ethiopian, Nearctic, and Neotropical, each 9; and the Oriental only 5. These figures are very curious and suggestive. We know that the rodentia are exceedingly ancient, since some of the living genera date back to the Eocene period; and some ancestral types might thus have reached the remote South American and South African lands at the time of one of their earliest unions with the northern continents. In both these countries the rodents diverged into many special forms, and being small animals easily able to conceal themselves, have largely survived the introduction of higher Mammalia. In the Palæarctic and Nearctic regions, their small size and faculty of hibernation may have enabled them to maintain themselves during those great physical changes which resulted in the extermination or banishment of so many of the larger and more highly organised Mammalia, to which, in these regions, they now bear a somewhat inordinate proportion. The reasons why they are now less numerous and varied in the Oriental region, may be of two kinds. The comparatively small area of that region and itsuniformity of climate, would naturally lead to less development of such a group as this, than in the vastly more extensive and varied and almost equally luxuriant Palæarctic region of Eocene and Miocene times; while on the other hand the greater number of the smaller Carnivora in the tropics during the Pliocene and Post-Pliocene epochs, would be a constant check upon the increase of these defenceless animals, and no doubt exterminate a number of them.
The Rodents thus offer a striking contrast to the Ungulates; and these two great orders afford an admirable illustration of the different way in which physical and organic changes may affect large and small herbivorous Mammalia; often leading to the extinction of the former, while favouring the comparative development of the latter.
Order XI.—EDENTATA.
Family71.—BRADYPODIDÆ. (3 Genera, 12 Species.)
The Sloths are a remarkable group of arboreal mammals, strictly confined to the great forests of the Neotropical region, from Guatemala to Brazil and Eastern Bolivia. None are found west of the Andes, nor do they appear to extend into Paraguay, or beyond the Tropic of Capricorn on the east coast. The genera as defined by Dr. Gray in 1871 are:—Cholœpus(2 sp.), "Sloths with two toes on fore limbs, sexes alike," Costa Rica to Brazil;Bradypus(2 sp.), "Sloths with three toes on fore limbs, sexes alike," Central Brazil, Amazon to Rio de Janeiro;Arctopithecus(8 sp.), "Sloths with three toes on fore limbs, males with a coloured patch on the back," Costa Rica to Brazil and Eastern Bolivia (Plate XIV., vol ii. p.24).
Extinct Bradypodidæ.—In the caves of Brazil are found three extinct genera of Sloths—Cælodon,Sphenodon, andOchotherium. More distantly allied, and probably forming distinct families, areScelidotheriumandMegatherium, from the caves of Brazil and the Pliocene deposits of La Plata and Patagonia.
Family72.—MANIDIDÆ. (1 Genus, 8 Species.)
The Manididæ, or scaly ant-eaters, are the only Edentate Mammalia found out of America, They are spread over the Ethiopian and Oriental regions; in the former from Sennaar to West Africa and the Cape; in the latter from the Himalayas to Ceylon, and Eastward to Borneo and Java, as well as to South China, as far as Amoy, Hainan, and Formosa. They have been sub-divided, according to differences in the scaly covering, into five groups,Manis,Phatagin,Smutsia,PholidotusandPangolin, the three former being confined to Africa, the last common to Africa and the East, whilePholidotusseems confined to Java. It is doubtful if these divisions are more than sub-genera, and as such they are treated here.
No extinct species referable to this family are yet known.
Family73.—DASYPODIDÆ. (6 Genera, 17 Species.)
The Dasypodidæ, or armadillos, are a highly characteristic Neotropical family, ranging from the northern extremity of the regionin south Texas, to 50° south latitude on the plains of Patagonia. The distribution of the genera is as follows:—Tatusia(5 sp.), has the range of the whole family from the lower Rio Grande of Texas to Patagonia;Prionodontes(1 sp.), the giant armadillo, Surinam to Paraguay;Dasypus(4 sp.), Brazil to Bolivia, Chili, and La Plata;Xenurus(3 sp.), Guiana to Paraguay;Tolypeutes(2 sp.), the three-banded armadillos, Bolivia and La Plata;Chlamydophorus(2 sp.), near Mendoza in La Plata, and Santa Cruz de la Sierra in Bolivia.
Extinct Armadillos.—Many species ofDasypusandXenurushave been found in the caves of Brazil, together with many extinct genera—Hoplophorus,Euryodon,Heterodon,Pachytherium, andChlamydotherium, the latter as large as a rhinoceros.Eutatus, allied toTolypeutes, is from the Pliocene deposits of La Plata.
Family74.—ORYCTEROPODIDÆ. (1 Genus, 2 Species.)
The Aard-vark, or Cape ant-eater (Orycteropus capensis) is a curious form of Edentate animal, with the general form of an ant-eater, but with the bristly skin and long obtuse snout of a pig. A second species inhabits the interior of North-East Africa and Senegal, that of the latter country perhaps forming a third species (Plate IV. vol. i. p. 261).
Extinct Orycteropodidæ.—The genusMacrotherium, remains of which occur in the Miocene deposits of France, Germany, and Greece, is allied to this group, though perhaps forming a separate family. The same may be said of theAncylotherium, a huge animal found only in the Miocene deposits of Greece.
Family75.—MYRMECOPHAGIDÆ. (3 Genera, 5 Species.)
The true ant-eaters are strictly confined to the wooded portions of the Neotropical region, ranging from Honduras to Paraguay on the East side of the Andes. The three genera now generally admitted are:Myrmecophaga(1 sp.), the great ant-eater, Northern Brazil to Paraguay;Tamandua(2 sp.), 4-toed ant-eaters, Guatemala, Ecuador to Paraguay (Plate XIV. vol. ii. p.24);Cyclothurus(2 sp.), 2-toed ant-eaters, Honduras and Costa Rica to Brazil.
Extinct Ant-eaters.—The only extinct form of this family seems to be theGlossotherium, found in the caves of Brazil, and the Tertiary deposits of Uruguay. It is said to be allied toMyrmecophagaandManis.
General Remarks on the Distribution of the Edentata.
These singular animals are almost confined to South America, where they constitute an important part of the fauna. In Africa, two family types are scantily represented, and one of these extends over all the Oriental region. In Pliocene and Post-Pliocene times the Edentata were wonderfully developed in South America, many of them being huge animals, rivalling in bulk, the rhinoceros and hippopotamus. As none of these forms resemble those of Africa, while the only European fossil Edentata are of African type, it seems probable that South Africa, like South America, was a centre of development for this group of mammalia; and it is in the highest degree probable that, should extensive fluviatile deposits of Pliocene or Miocene age be discovered in the former country, an extinct fauna, not less strange and grotesque than that of South America, will be brought tolight. From the fact that so few remains of this order occur in Europe, and those of one family type, and in Miocene deposits only, it seems a fair conclusion, that this represents an incursion of an ancient Ethiopian form into Europe analogous to that which invaded North America from the south during the Post-Pliocene epoch. The extension of the Manididæ, or scaly ant-eaters, over tropical Asia may have occurred at the same, or a somewhat later epoch.
For a summary of the Numerous Edentata of North and South America which belong to extinct families, see vol. i. p. 147.
Order XII.—MARSUPIALIA.
Family76.—DIDELPHYIDÆ. (3 Genera, 22 Species.)
The Didelphyidæ, or true opossums, range throughout all the wooded districts of the Neotropical region from the southern boundary of Texas to the River La Plata, and on the west coast to 42° S. Lat., where a species ofDidelphyswas obtained by Professor Cunningham. One species only is found in the Nearctic region, extending from Florida to the Hudson River, and west to the Missouri. The species namedDidelphys californicainhabits Mexico, and only extends into the southern extremity of California. The species are most numerous in the great forest region of Brazil, and they have been recently found to the west of the Andes near Guayaquil, as well as in Chili. The exact number of species is very doubtful, owing to the difficulty of determining them from dried skins. All but two belong to the genusDidelphys, which has the range above given for the family (Plate XIV., vol. ii. p.24);Chironectes(1 sp.), the yapock or water opossum, inhabits Guiana and Brazil;Hyracodon(1 sp.), is a smallrat-like animal discovered by Mr. Fraser in Ecuador, and which may perhaps belong to another family.
Extinct Didelphyidæ.—No less than seven species ofDidelphyshave been found in the caves of Brazil, but none in the older formations. In North America the living species only, has been found in Post-Pliocene deposits. In Europe, however, many species of small opossums, now classed as a distinct genus,Peratherium, have been found in various Tertiary deposits from the Upper Miocene to the Upper Eocene.
We have here a sufficient proof that the American Marsupials have nothing to do with those of Australia, but were derived from Europe, where their ancestors lived during a long series of ages.
Family77.—DASYURIDÆ. (10 Genera, 30 Species.)
The Dasyuridæ, or native cats, are a group of carnivorous or insectivorous marsupials, ranging from the size of a wolf to that of a mouse. They are found all over Australia and Tasmania, as well as in New Guinea and the adjacent Papuan islands. Several new genera and species have recently been described by Mr. G. Krefft, of the Sydney Museum, and are included in the following enumeration.Phasgogale(3 sp.), New Guinea, West, East, and South Australia;Antechinomys(1 sp.), Interior of South Australia;Antechinus(12 sp.), Aru Islands, all Australia, and Tasmania;Chætocercus(1 sp.), South Australia;Dactylopsila(1 sp.), Aru Islands and North Australia;Podabrus(5 sp.), West, East, and South Australia, and Tasmania;Myoictis(1 sp.), Aru Islands;Sarcophilus(1 sp.), Tasmania;Dasyurus(4 sp.), North, East, and South, Australia, and Tasmania;Thylacinus(1 sp.), Tasmania (Plate XI., vol. i. p. 439).
Extinct species ofDasyurusandThylacinushave been found in the Post-Pliocene deposits of Australia.