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and 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 Leporido.-Species of Lepus occur in the Post-Pliocene and Newer Pliocene of France; but only in the PostPliocene 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 its

uniformity 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.

FAMILY 71.—BRADY PODIDÆ. (3 Genera, 12 Species.)

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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 Cholopus (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 Bradypodido.- In the caves of Brazil are found three extinct genera of Sloths-Cælodon, Sphenodon, and Ochotherium. More distantly allied, and probably forming distinct families, are Scelidotherium and Megatherium, from the caves of Brazil and the Pliocene deposits of La Plata and Patagonia.

FAMILY 72.—MANIDIDÆ. (1 Genus, 8 Species.)

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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, Pholidotus and Pangolin, the three former being confined to Africa, the last common to Africa and the East, while Pholidotus seems 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.

FAMILY 72.-DASYPODIDÆ. (6 Genera, 17 Species.)

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The Dasypodidæ, or armadillos, are a highly characteristic Neotropical family, ranging from the northern extremity of the region

in 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 of Dasypus and Xenurus have been found in the caves of Brazil, together with many extinct genera-Hoplophorus, Euryodon, Heterodon, Pachytherium, and Chlamydotherium, the latter as large as a rhinoceros. Eutatus, allied to Tolypeutes, is from the Pliocene deposits of La Plata.

FAMILY 74.-ORYCTEROPODIDÆ. (1 Genus, 2 Species.)

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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 Orycteropodido.—The genus Macrotherium, 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 the Ancylotherium, a huge animal found only in the Miocene deposits of Greece.

FAMILY 75.—MYRMECOPHAGIDÆ. (3 Genera, 5 Species.)

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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 anteaters, Guatemala, Ecuador to Paraguay (Plate XIV. vol. ï. 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 the Glossotherium, found in the caves of Brazil, and the Tertiary deposits of Uruguay. It is said to be allied to Myrmecophaga and Manis.

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 PostPliocene 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 to

VOL. II.-17

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