BIRDS OF NORTH AND MIDDLE AMERICA 



379 



wing coverts spotted black and white (s. Mexico to Guate- 

 mala and Brit. Honduras). 



L. albicoUis ghiesbreghti, juv. (p. 382) 



//. Back of head unstreaked; lesser upper wing coverts with Uttle 



or no black (s. Mexico to Guatemala and Brit. Honduras). 



L. albicoUis ghiesbreghti, imm. (p. 382) 



LEUCOPTERNIS ALBICOLLIS COSTARICENSIS Sclater 



Costa Rican White Hawk 



Adult (sexes alike). — Entire head and body above and below pure 

 white, except the lores and circumocular areas, which are almost nude 

 bluish gray; skin sparsely clothed with fine blackish bristles; upper 



Figure 24. — Leucopternis semiplumbea. 



median and lesser and under wing coverts pure white, occasionally 

 some of the lesser upper coverts near the bend of the wing with a little 

 blackish in the form of shaft streaks; greater upper coverts blackish 

 slate tipped with white; the primaries blackish slate, the inner webs 

 white basally distal to the emargination, level of the outer ones, the 

 outer webs with a small, usually concealed, white-barred area at the 

 base of the outermost primary; the blackish slate area on all but the 

 outer three primaries barred with black; the inner ones broadly, the 

 outer ones narrowly tipped with white; secondaries deep neutral gray 

 to blackish slate barred with black and very broadly tipped with \^'hite 

 and with broad white margins on the inner webs, the width of these 

 margins increasing from the carpal joint inward, and extending across 

 both webs in the innermost secondaries v/hich often have the blackish 

 slate restricted to an elongated spot on the outer webs; rectrices white 

 with a broad subterminal band of black, this band varying from 26- 



