=A. nitida.= Wing, 9.80–11.50; tail, 6.70–8.00; culmen, .80–1.00; tarsus, 2.50–2.90; middle toe, 1.40–1.75. _Adult._ Above clear ash, paler on the head and darker on the rump; the general surface with more or less appreciable transverse bars, or indications of bars, of a paler shade, and with darker shafts. Upper tail-coverts immaculate white. Tail deep black, fading into pale grayish-brown at the end, narrowly tipped with white, and crossed by two to three white bands. Lower parts, including the tibiæ, axillars, and throat, regularly barred with deep ash and white, the two colors about equal in extent; chin and crissum immaculate white. _Young._ Above blackish-brown, variegated with pinkish-ochraceous. Tail umber, tipped with pinkish-brown or dull whitish, and crossed by six to seven narrow bands of black. Beneath white, sometimes tinged with ochraceous; the breast, abdomen, and sides with longitudinal tear-shaped spots of black. _Adult._ Upper surface distinctly barred, the lighter bars predominating; the top of the head as distinctly barred as the lower parts. _Young._ Tibiæ immaculate white or pale ochraceous. Culmen, .80–.90. _Hab._ South America, from S. E. Brazil and W. Ecuador, to Panama … var. _nitida_.[84] _Adult._ Upper surface only obsoletely barred, or almost uniform; the top of the head without any bars. _Young._ Tibiæ transversely barred with dusky. Culmen, .75–.80. _Hab._ Middle America, north to the southern border of the United States; straying northward in the Mississippi Valley, to Southern Illinois … var. _plagiata_. Asturina nitida, var. plagiata (SCHLEG.). MEXICAN HAWK. _Asturina nitida_, CASS. Birds N. Am. 1858, 35.—SCL. & SALV. Ibis, 1859, 217.—SALV. Ibis, 1861, 68.—SCL. P. Z. S. 1857, pp. 201, 227; 1859, pp. 368, 389; 1864, 178.—LAWR. Ann. N. Y. Lyc. IX, 133.—OWEN, Ibis, III, 1868 (egg white). _Asturina cinerea_, CASS. P. A. N. S. 1855, 283 (not of VIEILL.!). _Asturina plagiata_, SCHLEG. Mus. Pays-Bas. _Asturinæ_, p. 1.—SCL. & SALV. P. Z. S. 1868, 173; 1869, 130.—GRAY, Hand List, I, 30, 1869.—RIDGW. Am. Nat. VI, July, 1872, 430; VII, April, 1873, 203; (Southern Illinois, August).