GENERAL DISTRIBUTION. __________________________________/\__________________________________ / \ NEOTROPICAL| NEARCTIC |PALÆARCTIC | ETHIOPIAN | ORIENTAL | AUSTRALIAN SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS. -----------+-----------+-----------+-----------+-----------+------------ | | | | | -- -- -- --|-- -- -- --|-- -- -- --|-- -- -- --|-- -- -- --|-- 2 -- -- | | | | | The _Echidna_, or Australian Hedgehog, although quite as remarkable in internal structure as the Ornithorhynchus, is not so peculiar in external appearance, having very much the aspect of a hedgehog or spiny armadillo. The two species of this genus are very closely allied; one inhabits East and South Australia, the other Tasmania. _Extinct Echidnidæ._--Remains of a very large fossil species of _Echidna_ have lately (1868) been discovered at Darling Downs in Australia. _Remark on the Distribution of the Monotremata._ This order is the lowest and most anomalous of the mammalia, and nothing resembling it has been found among the very numerous extinct animals discovered in any other part of the world than Australia. {255}CHAPTER XVIII. THE DISTRIBUTION OF THE FAMILIES AND GENERA OF BIRDS. _Order I.--PASSERES._ FAMILY 1.--TURDIDÆ. (21 Genera, 205 Species.) GENERAL DISTRIBUTION. __________________________________/\__________________________________ / \ NEOTROPICAL| NEARCTIC |PALÆARCTIC | ETHIOPIAN | ORIENTAL | AUSTRALIAN SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS|SUB-REGIONS. -----------+-----------+-----------+-----------+-----------+------------ | | | | | 1. 2. 3. 4 |1. 2. 3. 4 |1. 2. 3. 4 |1. 2. 3. 4 |1. 2. 3. 4 |1. 2. 3 -- | | | | | The extensive and familiar group of Thrushes ranges over every region and sub-region, except New Zealand. It abounds most in the North Temperate regions, and has its least development in the Australian region. Thrushes are among the most perfectly organized of birds, and it is to this cause, perhaps, as well as to their omnivorous diet, that they have been enabled to establish themselves on a number of remote islands. Peculiar species of true thrush are found in Norfolk Island, and in the small Lord Howes' Island nearer Australia; the Island of St. Thomas in the Gulf of Guinea has a peculiar species; while the Mid-Atlantic island Tristan d'Acunha,--one of the most remote and isolated spots on the globe,--has a peculiarly modified form of thrush. Several of the smaller West Indian Islands have also peculiar species or genera of thrushes.