In conclusion I would beg to say, that having brought the “Birds of Australia” to a close, after devoting nearly ten years to its production, I trust it will be admitted that it has been terminated in the same spirit with which it was commenced, and that any errors which may be found will be viewed with leniency, when the extent of the work, and the difficulty of procuring and arranging so large a mass of materials, is taken into consideration; should my labours, such as they are, merit the approbation of those who have so liberally supported it, my own efforts will be amply repaid. Although the work comprises every species known to inhabit Australia up to the present time, it is not to be supposed that it contains the whole of the birds of that vast country, of which so large a portion is yet a _terra incognita_. Every new district towards the north-west that may be explored will doubtless afford additional species, and which may hereafter form the materials for a supplement. I originally intended to include the Birds of New Zealand in the present work, but upon further investigation of the subject I found that they belong to a distinct Fauna, which fact, coupled with the vast accession of new species from the continent of Australia, induced me to omit all but those that had been published in the first instance, and one or two others remarkable for their great interest. Enjoying, by the blessing of Providence, constant good health, and energies as yet unimpaired, I propose still to devote my humble efforts to the advancement of Ornithology, that science which treats of one of the most pleasing portions of the Almighty’s many wonderful works; and with ample materials at my command for illustrating the Birds of another magnificent portion of the domains of the British Crown—India—my next work will probably be on “the Birds of Asia,” which will, irrespective of all other considerations, be of no little interest as forming the connecting link between the Birds of Europe and the Birds of Australia. JOHN GOULD. June 12, 1848. INTRODUCTION.