Page 4, note 2, _for_ Water-hens _read_ Moor-hens. " 10, line 19, after Owls _read_ and _Pandion_. " 16, " 17, _for_ Lord Howe's _read_ Lord Howe. " 16, " 22, _for_ Galapagos _read_ Galápagos. " 26, note 1, delete comma after Bronn's. " 30, line 2 from bottom, _for_ Tarapaca _read_ Tarapacá. " 59, " 6 " " for _Pelecanoidinae_ read _Pelecanoïdinae_. " 60, lines 14, 26, 34, for _Pelecanoides_ read _Pelecanoïdes_. " 67, line 6, for _Thalassaeca_ read _Thalassoeca_. " 70, " 10, _for_ Phaenicopteridae _read_ Phoenicopteridae. " 91, " 12, for _ralloides_ read _ralloïdes_. " 118, " 17, for _dominicus_ read _dominica_. " 122, " 2, after _F. cristata_, _read_ the Tufted Duck. " 133, " 5, after Wavy, _read_ or Snow Goose. " 160, " 8 from bottom, for _cirrhatus_ read _cirratus_. " 215, " 10, for _praelatus_ read _praelata_. " 258, " 15, _for_ perhaps _read_ probably not. " 351, " 11, and page 357, line 6, for _Phaenicophainae_ read _Phoenicophainae_. " 357, " 11 from bottom, for _Phaenicophaës_ read _Phoenicophaës_. " 429, Fig. 89, for _jugularus_ read _jugularis_. " 550, line 20, for _Seenopoeetes_ read _Scenopoeetes_. " 568, " 9 from bottom, _for_ a scale-insect _read_ an Aphid. {1}CHAPTER I INTRODUCTION DEFINITION.–"A Bird is a feathered biped." This popular saying undoubtedly furnishes a definition in the world of to-day, since no other existing creature has a clothing of feathers, and even the word "biped" is thus superfluous. The above should, however, be somewhat expanded, in order to shew in greater detail the differences between Birds and other Vertebrata. Care must nevertheless be taken to avoid the fault common to many modern definitions, of giving an abstract of the main characteristics of the object, rather than a clear guide to distinction. Dr. Gadow[1] defines Birds as "oviparous, warm-blooded, amniotic Vertebrates, which have their anterior extremities transformed into wings. Metacarpus and fingers carrying feathers or quills. With an intertarsal joint. Not more than four toes, of which the first is the hallux."