BIRDS OF NORTH AND MIDDLE AMERICA 115 



slightly more; third or third and fourth primaries longest, the first 

 about equal to eighth; ^^ three to four outer primaries with inner webs 

 obliquely sinuated. Tail slightly more than two-thirds as long as 

 wing, slightly to decidedly rounded. Tarsus equal to or slightly 

 more than one-fifth as long as wing, much less than one-third as long 

 as tail, the acrotarsium feathered above for more than one-third its 

 length, the nude portion with a single series of large, broad, transverse 

 scutella, the planta tarsi with several series of longitudinally hexagonal 

 scales. 



Plumage and coloration. — Plumage soft and full, the feathers of 

 of dorsal region and underparts rather distinctly outlined, the feathers 

 rather broad, with rounded tips; primaries and rectrices rather soft, 

 the former with rounded, the latter with obliquely subtruncate tips; 

 loral and orbital regions nearly nude, the former with sparse, rather 

 small, bristles. Adults plain gray or slaty above, darker on primaries 

 (and, sometimes, on pileum), the tail banded with blackish (the paler 

 bands sometimes white or partly so) ; under tail coverts white, thighs 

 (sometimes axillars and under wing coverts also) cinnamon-rufous, 

 the remaining underparts mostly plain cinnamon-rufous or bluish 

 gray, or barred ^vith cinnamon-rufous, gray, and white. Young 

 dusky brown above, the feathers usually margined terminally with 

 dusky or tawny, the underparts whitish, usually more or less spotted 

 or streaked with dusky brown. 



Range. — Tropical continental America, from Guatemala to 

 southern BrazU. (Three species.) 



KEY TO THE SPECIES AND SUBSPECIES OF HARPAGUS 



a. Axillars rufous H. diodon adults (extralimital) ™ 



aa. Axillars white or cream color. 



6. Breast and upper abdomen fairly uniform rufous brown, lower abdomen 

 barred with grayish white. 



H. bidentatus bidentatus adult (extralimital) " 

 66. Breast and upper abdomen not uniform rufous-brown. 



c. Breast and upper abdomen barred rufous-brown and whitish (southern 

 Mexico to Panama) H. bidentatus fasciatus adult (p. 116) 



" Pterylographical characters, as given by Nitzsch (Pterylographia) are as 

 follows: "Remiges, 23. Pterylosis exactly as in Baza [an Old World Pernine 

 genus allied to Odontriorchis], but the outer branch of the inferior tract still 

 further united to the stem. Dorsal portion of spinal tract remaining far from the 

 scapular part, and without rows of feathers beside it, Powder-down tracts ex- 

 tended farther forward, in the shape of narrow bands, to the shoulders." 



™ Harpagus diodon (Temminck). — Falco diodon Temminck; PI. Col. Uvr., 

 34, 1822, pi. 198 (Brazil = Rio Peruhype, near Villa Vigosa, southern Bahia). 



" Harpagus bidentatus bidentatus (Latham). — Falco bidentatus Latham 

 Index Orn., i, 1790, 38 (Cayenne). 



839094—50 9 



