BIRDS OF NORTH AND MIDDLE AMERICA 421 



under tail coverts distinctly barred and mottled with grayish white 

 (nearly uniform blackish in the nominate race) . 



Other plumages unlcnown. 



Adult male. — Wing 530, tail 252, culmen from cere 39.5; tarsus 132; 

 middle toe without claw 62 mm. (1 spec). 



Adult female. — Wing 552, tail 260, culmen from cere 43.6; tarsus 

 131 ; middle toe without claw 66 mm. (1 spec, the type). 



Known only from the mountains of extreme southeastern Sonora 

 near the Chihuahua boundary, from about latitude 27°40' N. south- 

 ward an unknown distance. 



Type locality. — Extreme southeastern Sonora, near the Chihuahua 

 boundary (Guirocoba). 



Urubitornis solitaria sheffleri van Rossem, Proc. Biol. Soc. Washington, Ixi, 1948, 

 67 (orig. descr.; meas.; crit.). 



GenuslMORPHNUS Dumont 



Morphnus "Cuvier" Dumont, Diet. Sci. Nat., ed. 2, i, 1816, Suppl., 88. (Type, 



as designated by Chubb, 1916, Falco guyanensis Daudin.) 

 Morphinus (emendation) Fleming, Philos. ZooL, ii, 1822, 235. 

 Morphyus (emendation) Boie, Isis, 1822, 548. 

 Morpheus (emendation) Kaup, Isis, 1847, 84 (bis). 

 Morphus (emendation) Antinori, Cat. Coll. Ucc, Africa, 1864, 16. 



Large crested^eagles (wing about 440-515 mm.), resembling Harpia 

 but much more slender, the tail relatively longer (nearly as long as 

 wing), tarsus more than twice as long as middle toe (without claw) 

 and with transverse scutella of acrotarsium and planta tarsi forming, 

 each, a continuous uniform series, crest plumes narrow^er, and primaries 

 considerably exceeding secondaries in length. 



Bill moderate in size, relatively short and deep, its depth at anterior 

 margin of cere equal to more than two-thirds the length (curve) of 

 culmen, that of maxilla alone equal to nearly half the curve of culmen; 

 culmen very strongly curved from base, the terminal portion curving 

 slightly backward; gonys about half as long as chord of culmen, 

 distinctly convex, slightly ascending terminally; anterior outline of 

 cere forming a nearly straight vertical line, but slightly convex in 

 middle portion and faintly concave below; nostril nearly vertical, 

 elliptical, beveled off anteriorly to edge of cere, midway between 

 upper and lower edges of latter. Wing relatively short, broad, and 

 rounded, but longest primaries exceeding distal secondaries by about 

 one-fourth the length of wing; fifth to seventh (usually sixth?) pri- 

 maries longest, the fourth about equal to eighth, the first (outermost) 

 shortest; inner w^ebs of seven outer primaries shallowly sinuated, the 

 outer w^ebs of second to ninth sinuated. Tail nearly as long as wing 

 (about eight-ninths as long), rounded, the rectrices, 10 in number, 

 very broad, with broadly rounded tips. Tarsus stout, nearly one- 



