26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



darker in color below. These characters hold in birds of Central 

 America south through the Isthmus of Panama, with intergradation 

 in extreme northwestern Colombia. In making comparison it is 

 necessary to separate adult from immature birds, since the distinctions 

 listed are masked when this is not done. I believe the confusion 

 regarding the two races has been due to lack of understanding of this 

 fact. 



The name given to the new race, in connection with its darker 

 coloration, is from the Latin caesitius, meaning bluish. 



LITERATURE CITED 



Aldrich, John W. 



1937. Annotated list of birds, in Aldrich, J. W., and Bole, B. P., Jr., The 

 birds and mammals of the western slope of the Azuero Peninsula 

 [Republic of Panama]. Sci. Publ. Cleveland Mus. Nat. Hist., vol. 

 7, pp. 27-139, Aug. 31. 

 Anderson, C. L. G. 



191 1. Old Panama and Castilla del Oro. Pp. i-xiv, 1-559, 7 maps, 35 pis. 

 Washington. 

 Blake, Emmet R. 



1958. Birds of Volcan de Chiriqui, Panama. Fieldiana: Zool., vol. 36, No. 

 5, pp. 499-577, June 25. 



BOUCARD, ADOLPHE. 



1878. On birds collected in Costa Rica. Proc. Zool. Soc. London, 1878, 

 PP. 37-71, 1 PL 

 Dampier, William. 



1697. A new voyage round the world, describing particularly, the Isthmus 

 of America, several coasts and islands in the West Indies, the Isles 

 of Cape Verd, the passage by Tierra del Fuego, the South Sea 

 coasts of Chili, Peru and Mexico; the Isle of Guam one of the 

 Ladrones, Mindanao, and other Philippine and East India islands 

 near Cambodia, China, Formosa, Luconia, Celebes&c. New Hol- 

 land, Sumatra, Nicobar Islands ; the Cape of Good Hope and Saint 

 Hellena. London, pp. (1-8), i-vi, 1-550, 5 maps. 

 Hakluyt, Richard. 



1904. The principal navigations voyages traffiques & discoveries of the 

 English nation made by sea or over-land to the remote and farthest 

 distant quarters of the earth at any time within the compasse of 

 these 1600 years. Vol. X, pp. 226-245. Glasgow. 

 Hellmayr, Charles E. 



1934- Catalogue of birds of the Americas and the adjacent islands. Field 



Mus. Nat. Hist., pt. 7, pp. i-vi, 1-531, Nov. 15. 

 1936. Idem, pt. 9, pp. i-vi, 1-458, Oct. 6. 

 Morison, Samuel Eliot. 



1942. Admiral of the Ocean Sea, A life of Christopher Columbus. Vol. 1, 

 pp. i-xlvi, 1-448, 14 maps, 25 ills.; vol. 2, pp. i-viii, 1-445, 18 maps, 

 2 illus. Boston. 



