CHAP, xviii.] BIRDS. 279 



They range over all North America from Panama to the Arctic 

 regions, but do not extend far beyond the tropic in Southern 

 America. They are almost as abundant in the Nearctic as in 

 the Neotropical region ; and considering the favourable condi- 

 tions of existence in Tropical America, this fact, in connection 

 with their absence from the South Temperate zone would lead us 

 to suppose that they originated in North Temperate America, and 

 subsequently spread southward into the tropics. This supposi- 

 tion is strengthened by the fact that their metropolis, in the 

 breeding season, is to the north of the United States. The 

 genera adopted by Messrs. Sclater and Salvin are as follows : 

 ( 918 ) Siurus (4 sp.), Venezuela and West Indies to Eastern States 

 and Canada ; Mniotilta (1 sp.), Venezuela, Mexico, and Antilles 

 to the Eastern States ; Parula (5 sp.), Brazil to Mexico, and the 

 Eastern States, and Canada ; Protonotaria (1 sp.), Antilles to 

 Ohio ; Helminthophaga (8 sp.), Columbia to Arctic America ; 

 Helmintherus (2 sp.), Central America to Eastern States ; Peris- 

 soglossa (1 sp.), Antilles and Eastern States ; Dendrceca (33 sp.), 

 Amazon to Antilles, and Arctic America, and south to Chili ; 

 Oporornis (2 sp.), Guatemala to Eastern States; Geothlypis (11 

 sp.). all North America and Brazil ; Myiodioctes (5 sp.), all North 

 America and Columbia ; Basileuterus (22 sp.), Bolivia and Brazil 

 to Mexico ; Setopkaga (15 sp.), Brazil to Canada ; Ergaticus (2 

 sp.), Guatemala and Mexico ; Cardellina (1 sp.), Guatemala and 

 Mexico ; ( 144 ) Granatellus (3 sp.), Amazon to Mexico ; ( 1441 ) Tere- 

 tristis (2 sp.), Cuba; ( 1439 ) Icteria (2 sp.), Costa Rica and United 

 States to Canada. 



FAMILY 28. VIEEONID^E. (7 Genera, 63 Species.) 

 GENERAL DISTRIBUTION. 



(Messrs. Sclater and Salvin are followed for the Neotropical 

 genera ; Professor Baird and Mr. Allen for those of the Nearctic 

 region.) 



VOL. II. 19 



