352 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



Subgenus Buteola Bonaparte 



Small buteonine hawks, with wing usually less than 350 mm. in 

 length, the middle toe without claw longer than the bare frontal por- 

 tion of the tarsus; the three outer primaries em.arginate on their inner 

 webs, the fourth one sinuate; nostrils round, with distinct central 

 tubercle. 



Plumage compact and full, coloration black and ^^■hite; dichromatic. 



Range.— Florida., eastern Mexico, south through Central America 

 and South Amxcrica to Bolivia. (Monotypic.) 



BUTEG BRACHYURUS VieiUot 



Short-tailed Hawk 



Adult (sexes alike). — White-bellied phase: Upper surface con- 

 tinuous and nearly uniform fuscous to blackish brown, darkest and 

 most uniform on the head, which, with the exception of the anterior 

 half of the lores, the anterior malar region, chin, and throat, is solid 

 fuscous-black, the occipital feathers snow white beneath the surface; 

 back with a strong chalky or glaucous cast in certain lights, the scap- 

 ulars and wings dull grayish brown with the feathers darker centrally; 

 sides of the rump strongly tinged with rufous. Tail grayish brown, 

 very narrowly tipped Vvdth dull white; crossed near the end by an 

 indistinct band of dusky, and showing, when widely spread, indica- 

 tions of about four other narrow broken bands, in the form of irregu- 

 lar, but mostly somewhat V-shaped, bars of black along the middle 

 portion of the feathers. Lateral upper tail coverts lighter brownish 

 gray, with broad but rather indistinct bars or spots of dusky. A spot 

 on each side of the base of the bill, covering the anterior half of the 

 loral and malar regions, chin, throat, middle of the jugulum, breast, 

 and remaining low^er parts, immaculate pure white, the tibiae, espe- 

 cially on their inner side, washed with pale ochraceous or light buff. 

 Sides of the jugidum rufous-brovvm, the feathers with dusky shaft 

 streaks; sides of the breast and anterior portion of the sides marked 

 with a few dusky shaft streaks, the more posterior ones of which 

 expand terminally into a broad streak of dusky brown. Lining of the 

 wing and axillars immaculate pure white, the under primary coverts, 

 however, with a large patch of dusky near the end. Bill black, 

 bluish basally; cere, legs, and feet, yellow; iris, brown. 



Females average a little less bright rufous on the sides of the breast, 

 but the difference is not constant in the series examined. 



Adult (sexes alike). — Melanistic phase: Uniform black or dusky, 

 varying from dark sooty brown to almost a coal black, freshly molted 

 specimens usually having a chalky or glaucous cast on the back, and 

 a more or less distinct purplish reflection to the general plumage; 



