X 
PREFACE. 
derived from the examination of all public and privat e collections ; but this is evidently beyond the 
power of any single individual to accomplish. Much might, however, be done to further this most 
desirable object by the combined exertions of the curators of the principal collections of birds uniting 
to publish their remarks on the less known and doubtful species, described from their several collections. 
But even this resource would sometimes fail ; as, for instance, in cases where such unique birds have 
disappeared from the collections in which they formerly existed, and may consequently remain for years 
unknown and almost forgotten, until by some lucky chance they may be rediscovered and more correctly 
defined, when I doubt not that they would in some instances prove to be synonymous with species more 
recently described. For these reasons it is obviously improper to discard species from our lists, merely 
because they have not been recently seen and examined, thereby casting an unwarranted doubt on the 
accuracy of previous writers, and leaving an opening for the redescription, as new, of old species already 
more or less correctly recorded in our systems. 
It is hardly necessary to do more than to allude to the artifices of dealers and others, who have 
occasionally produced what have been regarded as new and splendid species by artificial means, which 
supposed species have been innocently introduced into works of science, on the writers of which the 
falsification has been imposed. Such forgeries require no small degree of caution to insure their 
rejection, and many other difficulties might be mentioned to which a full and accurate enumeration of 
species is exposed; but enough has been said to show both that my task has been attended with 
considerable labour, and that it would be unjust to hold me entirely responsible for any apparent want 
of correctness in the list of species which may be discovered in the monographic study of any particular 
group. This will more especially appear when it is considered that my researches have been extended 
to upwards of 8000 species, such being the number which I have considered entitled to be enumerated 
as species in this Work, but in which many changes will necessarily take place as they become better 
known ; and that the entire series from which I have extracted this number of species contains 
about 15,000 specific names, as is shown by the Index which I have given at the end of the Work. The 
placing in their proper genera of this mass of specific names, and the indication at the same time 
of those Avhich I regard as merely synonymous, must have at least the beneficial influence of 
making the literature of the science better known and more readily capable of examination by others, 
and thus of preventing, to a great extent, the application of further synonymous terms to birds that have 
been already sufficiently recorded, paving the way, as a further consequence, to a uniform system of 
nomenclature of the species, which might be agreed upon and adopted by the ornithologists of all 
nations. 
I trust, therefore, that some allowance will be made for such errors as may be discovered to exist ; 
that the difficulties with which I have had to contend will be taken into consideration ; and that, it will 
be remembered that the present is the first attempt that has been made, for many years, to collect 
together a list of species from all available sources , many of them very difficult of access and scattered 
through the ever increasing multitude of Transactions, Journals, and Voyages, a large portion of which 
have rarely been examined by ornithological writers. 
