PREFACE. 
IX 
to 815) I have endeavoured to convey the characters in a short and concise manner, but I trust 
sufficiently detailed to embrace and circumscribe the species which they are severally presume to 
comprise. The generic characters are followed by a short notice of the habits of the birds which are 
best known or most characteristic of the genus under which they are placed. These I have usually drawn 
up from the writings of other authors, but iu a few instances I have been able to add some particulars 
derived from private information. This is a subject of the greatest interest; but unfortunately little 
is known of the habits of very many forms, and it is therefore to be hoped that those naturalists who 
have the means will not neglect the opportunity of adding such facts as may come to them knowledge 
regarding these species, and thus while contributing towards the history of their economy, assist 
the same time in exemplifying their proper position in the general system. 
Then follows an extensive List of Species, with references to the names of the older authors, and to 
the numerous specific descriptions that have been published within the last few } ears, and^ y . 
which are scattered through a multitude of publications not always easy of examination 1 . 
of the Work has been attended with no small amount of labour and research ; and its due execution is 
beset with numerous sources of error, some of which it may not be improper to mention here. Ihus, tor 
instance, the undefined nature of the genus in which many of the species were placed by their original 
describers, their location in an improper genus, or even the imperfect nature of the description Use , 
frequently rendered it difficult, if not impossible, to determine to what genus, in the system employed m 
the present Work, many species really belonged. Again, it is not always easy, even wit a very 
extensive knowledge of species, to define what is really to be regarded as a true species. This grea y 
depends on individual opinion ; some ornithologists, for example, considering the a ie examp es ount 
in the two hemispheres to belong to the same species; while others consider t ose e ongmg o 
each of these great divisions of the world to be specifically distinct; and we frequently find different 
states of the same bird, or even hybrids between two species, described as distinct. t is some imes 
scarcely possible to clear up such difficulties by means of descriptions only, whereas a careful examina- 
tion of the original specimens would generally be sufficient to enable an experienced ornithologist to 
determine on their right to be regarded as distinct species. 
Some, too, of the species described by the older authors, from the Leverian and other museums now 
dispersed, have not since been recognised in other collections. Yet it is essential that they should be 
inserted in the list of species, inasmuch as it is probable that many, if not most, of them 1 Y 
brought to light, as has actually been the case in several recent instances. Numerous species 
been recorded, on the authority merely of drawings more or less coirect, and the exam' . 
drawings, when practicable, has not unfrequently led to the superseding of names a iven y 
writers, by those employed by the older describers. It will be found, moreover, that many descriptions, 
even of a modern date, are so imperfect, either from their brevity 01 from a laxity # ’ 
n . . croppies which could in such cases only be 
as to be wholly insufficient for the identification of the 1 > 
„ , . . , Wh an extent of information could only be 
arrived at by the inspection of the original specime . ^ 
VOL. I. 
