PREFACE. vii 



Species indicated in this list that have not yet appeared in his 

 work, together Avith such others as his unrivalled industry may 

 add to the existing Fauna. 



It is easy to perceive the advantages likely to result from a 

 careful comparison of the natural productions of a fully inhabited 

 country with those of another, the climate of which is in many 

 respects the same. Botanists have contributed much to further, 

 so to speak, our acquaintance with the Planet on which we live : 

 I refer especially to those Botanists who continue daily to add to 

 the edifice of Vegetable Geography ; — a temple of which the 

 foundations were laid, and the framework erected, by the truly 

 illustrious Humboldt. 



Zoologists, however, up to the present time have been most 

 remiss in their attention to Ornithological Geography ; and I am 

 not on that account the more backward in contributing my share 

 to this branch of knowledge. As in the Specchio Comparativo, 

 the reader will find in the same line the species which are common 

 to both Continents, as well as those which, although different, are 

 to be regarded as corresponding to each other, by a greater or 

 less degree of afiinity or analogy. 



A synonymy is added, to point out the species which I have 

 in view, and selected in such a way as always to give infor- 

 mation or present interest. 



