The species are disposed into genera and families; and, although the location of the groups is not such as, in all respects, to satisfy me, the arrangement will, I trust, be found in some degree useful. It will be seen that, although I have adopted many of the modern groups, I have not sectioned our birds on so minutely divided a scale as that employed by some recent writers. Besides the characters of the Families, Genera, and Species, which are given with considerable detail, I have presented a short account of the Geographical Distribution of the species, and references to the principal authors by whom they have been described. I am confident that these notices will suffice to enable the student to determine with certainty any species that may come under his consideration, and that the information respecting its habits, which he will find in the works referred to, will afford him at least sufficient knowledge to form a basis for the more extended observation which he may contemplate. To the name of the genus I have appended that of the author by whom it has been instituted; and with the specific names I have dealt in the same manner, giving as authorities the individuals who first employed them, although they may have referred them to different genera. It is probable that many errors have been made in this department; but I shall be happy to see them corrected, as my wish is to do justice to all. On this occasion I have again to acknowledge the benefit derived from the aid of my friend Mr Macgillivray, whose general knowledge of ornithology, and perfect candour, have rendered his advice peculiarly valuable. J. J. AUDUBON. Edinburgh, _1st July 1839_. TABLE OF CONTENTS. Page FAMILY I. VULTURINÆ. VULTURINE BIRDS, 1 Genus 1. Cathartes. Turkey-Vulture, 1 II. FALCONINÆ. FALCONINE BIRDS, 3 1. Polyborus. Caracara, 4 2. Buteo. Buzzard, 5 3. Aquila. Eagle, 8 4. Haliaetus. Sea-Eagle, 9 5. Pandion. Osprey, 11 6. Elanus. Elanus, 12 7. Ictinia. Ictinia, 13 8. Nauclerus. Swallow-tailed Hawk, 14 9. Falco. Falcon, 15 10. Astur. Hawk, 17 11. Circus. Harrier, 19 III. STRIGINÆ. OWLS, 20 1. Surnia. Day-Owl, 21 2. Ulula. Night-Owl, 23 3. Strix. Screech-Owl, 24 4. Syrnium. Hooting-Owl, 26 5. Otus. Eared-Owl, 27 6. Bubo. Horned-Owl, 29 IV. CAPRIMULGINÆ. GOATSUCKERS, 30 1. Caprimulgus. Goatsucker, 31 2. Chordeiles. Night-Hawk, 32 V. CYPSELINÆ. SWIFTS, 33 1. Chætura. Spine-Tail, 33