V °S93 X ] Allen, Origin and Distribution of N. A. Birds. Ill 



The Icteridas are of course all American. Of the nine genera 

 represented in North America, three (Dolickonyx, XantJio- 

 cephalus, and Scolecophagus) are exclusively North American. 

 The six remaining genera range far into the tropics, two of them 

 being mainly tropical ; one of them {Quiscalus) is also mainly 

 limited in North America to the eastern half of the continent. 



The large cosmopolitan family Fringillidas is represented in 

 North America by thirty genera, twenty-one of which are strictly 

 American and nine circumpolar. Of the twenty-one American, 

 or twenty-three if we give generic rank to Passerculus, Ammo- 

 dramus and Cotur?iiculus, as I believe should be done, seventeen 

 are exclusively North American ; three others are mainly tropical, 

 and three are shared in common by both North and South 

 America. The Fringillidae, although a cosmopolitan family, 

 give a high ratio of forms peculiarly North American, amounting 

 to fully 60 per cent. Furthermore, three of the North Ameri- 

 can genera are strictly western, and two strictly eastern, while 

 five of the nine circumboreal genera are either arctic or subarctic. 



The tropical American family Tanagridae is represented by 

 only two genera, namely, Euphonia and Piranga, only the 

 latter extending over even the warm temperate portion of the 

 continent, while the former barely reaches our border. 



Of the six genera of Swallows none is essentially North Ameri- 

 can. Tachycineta, Progne and Stelgidopteryx range over both 

 Americas ; Chelidon, Petrochelidon and Clivicola are old 

 World, each with a single species in North America. 



Of the family Ampelidae, the genus Ampelis is common to the 

 colder parts of the northern hemisphere, but is most likely of 

 American origin ; the other genus, Phainopepla, is western and 

 southern. 



Lauius is the single representative of the very numerous and 

 otherwise exclusively Old World family Laniidas. 



The Vireos range over both Americas, to which they are lim- 

 ited, with their metropolis in Middle America. 



The Mniotiltidaa constitute the most characteristic family of 

 North American birds, 70 per cent, of the twenty genera occur- 

 ring in North America. Considering the family as a whole, three 

 genera are exclusively West Indian ; Basileuterus, which 

 scarcely reaches our border, is continental and tropical ; Comp- 

 sothlypis and Geothlypis range throughout the warmer parts of 



