PR EP A © RB: T AM induced to lay before the scientific world the present Monograph of a tribe of birds which has already claimed the attention of many of the most able ornithologists; first, because I am thereby afforded an opportunity of introducing to their notice several new species, which are here delineated for the first time; and secondly, from a desire to revise and set forth in as clear a light as possible the numerous species which this family contains, endeavouring at the same time to show their affinities to each other, by which they seem to divide themselves even into more minute groups than those of genera,—groups which are characterized by peculiar and unvarying though subordinate points of difference. These sections should, perhaps, be designated by some kind of nomenclature, and indeed it has been suggested to me that a distinguishing title to each is required. In this attempt, however, I do not feel myself quite warranted at present; but adhering to the established genera of Ramphastos and Pteroglossus, I have thrown the members of each together, as far as my views go, according to the indications of nature in their mutual affinities. I have spared no pains in order to obtain all possible information on the subject, having for this purpose visited and carefully examined most of the collections on the Continent, as well as those of our own island; and I beg to add, that every species I have figured is at present in existence, and has been personally inspected. I mention this expressly, because there are two or three species figured in Levaillant’s “ Oiseaux de Paradis,’ as well as one or two others characterized in Professor Wagler’s “Systema Avium,” of which I have never yet been able to meet with examples. These I have omitted, being doubtful as to whether they ought to be regarded as the delineations of true species, or not: if they are, I hope at some future time to be enabled to discover them; but at present I am not sanguine as to their actual existence. I would here beg to express my obligations to those who have rendered me assistance in b