BIRDS OF NORTH AND MIDDLE AMERICA. 201 



conspicuous erectile ruff with a naked or sparsely downy space (con- 

 cealed) immediately behind the lateral portions of the ruff. 



Coloration. — Adult males bronzy black with a soft, silky luster, the 

 wings and tail gloss}' bluish green; adult females dull black or grayish. 



Range. — Southern Texas and northwestern Mexico to northern South 

 America. (Three species.) 



KEY TO THE SPECIES AND SUBSPECIES OF CALLOTHRUS. 



a. Wings and tail strongly nietallit- (bluish or greenish). (Adult males.) 

 b. Plumage of head, neck, and body dark greenish bronzy. 



c. Rump bronzy, like back, etc. ; plumage of head, neck, and body roughly 

 silky; bill more slender. (Southern Texas, through eastern Mexico to 



Veragua. ) Callothrus robustus, adult male (p. 201 ) 



CO. Rump violet; plumage of head, neck, and l)ody smoothly silky; bill stouter. 

 d. Larger (wing averaging 119.1, tail S4.8, culmen 23.1). (Northwestern 



Mexico. ) Callothrus aeneus aeneus, adult male (p. 203) 



dd. Smaller (wing averaging 10S.7, tail 77.5, culmen 21.3). (Southwestern 



Mexico. ) Callothrus aeneus assimilis, adult male (p. 204) 



hi). Plumage of head, neck, and body lustrous silky brown. (Caribbean coast of 



Colombia. ) Callothrus armenti, adult male (extralimital)^ 



aa. Wings and tail not strongly metallic. (Adult females and young.) 

 h. General color black or very dark sooty, 

 c. Wings and tail glossed with bluish green. 



Callothrus robustus, adult female (p. 202) 



cc. Wings and tail not glossed Callothrus robustus, young male (p. 202) 



hh. General color grayish sooty or sooty grayish, 

 c. Faintly glossed above, the feathers of back, etc., with darker centers. 



Callothrus aeneus aeneus, adult female (p. 204) 

 cc. Without gloss above, and feathers of back without darker centers. 

 d. Darker, especially the under }>arts, which are unstreaked. 



Callothrus robustus, young female (p. 202) 



dd. Paler, especially the under parts, which are indistinctly streaked with 



paler, more yellowish, gray. .Callothrus aeneus aeneus, young male (p. 204) 



CALLOTHRUS ROBUSTUS (Cabanis). 

 RED-EYED COWBIRD. 



Adult male. — Head, neck, and body dark greenish bronzy, the 

 plumage soft and silky, but not smooth, presenting the appearance of 

 having been wet and imperfectly dried; tail-coverts blue-black, the 

 upper ones glossed with violet; wings glossy dark greenish blue, 

 brightest on greater coverts and tertials, less bright, as well as more 

 greenish, on primaries, primary coverts, and alula; lesser wing-coverts 

 dark metallic violet, the middle coverts violet-bluish; tail dark metallic 

 bluish green or greenish blue; bill black; iris red; legs and feet black or 

 brownish black; length (skins), 196.8-223.5 (206.5); wing, 111.8-120.1 

 (116.3); tail, 75.7-82.3 (79.2); culmen, from base, 22.3-23.9 (23.1); 



^ M\_olot}irus] armenti Cabanis, Mus. Hein., i, Sept., 1851, 192, footnote (Cartagena, 

 Colombia; coll. Berlin Mus.). This species, which I have not seen, is introduced 

 into the key for sake of comparison. It is the only known extralimital form. 



