BIRDS OF NORTH AND MIDDLE AMERICA 599 



dd. Size smaller; wings 405 mm. or less. 



P. plancus brasiliensis, ad. (extralimital) " 

 aa. No bars or transverse spots on^the underparts. 



b. Chin, throat, and upper breast whitish, unmarked anterior to lower throat. 

 c. Abdomen dark sepia in ground color. 



P. cheriway cheriway, juv. (p. 607) 

 P. cheriway audubonii, juv. (p. 602) 



cc. Abdomen paler, dresden brown P. cheriway pallidus, juv. (p. 609) 



bb. Chin, throat, and upper breast not whitish. 



c. Breast and abdomen dark sepia, with very conspicuous bu£fy white 

 streaks especially on the breast. 



P. plancus plancus, juv. (extralimital) 



P. plancus brasiliensis, juv. (extralimital) 



cc. Breast and abdomen dull fulvous isabelLine, with indistinct streaks of 



somewhat paler isabelline P. lutosus, juv. (p. 610) 



Wetmore, U. S. Nat. Mus. Bull. 133, 1926, 95 (habits; crit.); Peters, Check-list 

 Birds of World, i, 1931, 280. 



1' Polyborus plancus Brabourne and Chubb, Birds South Amer., i, 1912, 62, 

 part (Peru, s. Brazil); Swann, Synopt. List Accip., pt. 1, 1919, 7, part; Synop. 

 Accip., pt. 1, 1921, part. — Polyborus tharus Strickland, Orn. Syn., i, 1855, 19, 

 part; Gray, Hand-list, i, 1869, 6, No. 35, part (Brazil); Ridgway, Proc. 

 Acad. Nat. Sci. Philadelphia, 1870, 145, part; in Baird, Brewer, and Ridgway, 

 Hist. North Amer. Birds, iii, 1874, 177, footnote, part (synonymy; descr.); U. S. 

 Geol. and Geogr. Surv. Terr., ser. 2, Bull. 6, 1876, 455, part (monogr.); Man. 

 North Amer. Birds, 1887, 254, part; Sclater and Salvin, Nom. Av. Neotr., 1873, 

 123, part; Sharpe, Cat. Birds Brit. Mus., i, 1874, 31, part (Rio de Janeiro; Mexiana 

 Island); Gurney, List Diurnal Birds of Prey, 1884, 12, part; Cat. Birds of Prey, 

 1894, 18, part; Ihering and Ihering, Aves Brazil, 1907, 82 (Amazonia; Pard,; Rio 

 Branco; Sao Paulo; Rio de Janeiro; Rio Grande do Sul; Bahia; Minas Geraes). — 

 Polyborus tharus a. var. tharus Ridgway, Proc. Boston Soc. Nat. Hist., xvi, 1873, 

 51 (Brazil). — Polyborus tharus var. tharus Ridgway, in Baird, Brewer, and 

 Ridgway, Hist. North Amer. Birds, iii, 1874, 177, part. — Poliborus tharus Ihering, 

 Rev. Mus. Paulista, vi, 1899, 337 (Paraguay). — Falco brasiliensis Gmelin, Syst. 

 Nat., i, pt. 1, 1788, 262 (Brazil; based on Circus brasiliensis Brisson); Latham, 

 Index Orn., i, 1790, 21; Daudin, Traits d'Orn., ii, 1800, 149; Shaw, Gen. Zool., 

 vii, pt. 1, 1809, 106; Maximilian, Beitr. Naturg. Bras., iii, 1830, 190 (Rio Parahyba; 

 Cabo Frio; Lagoa Feia; St. Bento; Barro de Furado; Muribeca on Rio Itabapuana, 

 prov. Bahia). — Polyborus brasiliensis Kaup, Isis, 1847, 349, part (monogr.) 

 373, 375, 381, part; Bonaparte, Consp. Gen. Av., i, 1850, 13, part; Schlegel, 

 Mus. Pays-Bas, ii. No. 9, 1863, 2 part (monogr.). — Falco cheriivay (not Falco 

 cheriway Jacquin, 1784) Lichtenstein, Verz. Doubl., 1823, 60, part (Brazil). — 

 Polyborus vulgaris Vieillot, Nouv. Diet. Hist. Nat., v, 1816, 257 (cites Falco 

 brasiliensis Latham); Gal. Ois., i, 1825, 23, pi. 7; Spix, Av. Bras., i, 1824, 3, pi. la 

 (Minas Gerais; Capitana Piauhy; St. Johannis, Marajo) ; d'Orbigny and Lafres- 

 naj^e, Synop. Avium, 1839, 3, part (Brazil; Peru); Tschudi, in Wiegmann's Archiv 

 fiir Naturg., x, 1844, 263 (Peru); Fauna Peruana, Aves, 1845, 77; Burmeister, 

 Syst. Ueb. Th. Bras., ii, 1856, 41. — Polyborus caracara Spix, Av. Bras., i, 1824, 

 pi. 1 a (young). — Polyborus plancus brasiliensis Swann, Monogr. Birds Prey, 1, 

 1925, 69 (monogr.); Wetmore, U. S. Nat. Mus. Bull. 133, 1926, 97 (habits; Para- 

 guay; crit.); Naumburg, Bull. Amer. Mus. Nat. Hist., Ix, 1930, 102 (Matto 

 Grosso, BrazU; crit.); Peters, Check-list Birds of World, i, 1931, 280. 



