lilKDS OF NORTH AND MIDDLE AMEIMOA. 623 



CALYPTE COST^ (Bourcier). 



COSTA'S HUMMING BIRD. 



Adult male. — Head, oxcc])t ])ost()cular region, very l)rilliant metallic 

 violet or amethyst ])iirple, changing to violet-hlue or even greenish 

 and more reddish })urple (magenta) in certain lights, the latero- 

 posterior feathers of throat much elongated; rest of upper parts, 

 including four middle rectrices, rather dull metallic hronze-green or 

 greenish bronze; tail (except four middle rectrices) grayish browii or 

 brownish gray, faintly glossed with bronze-greenish, the rectrices darker 

 on shafts and toward tip; remiges brownish slate or dusk}'^, faintly 

 glossed with purplish; foreneck very ])ale brownish gray or grayish 

 white, passing into more decidedly grayish on chest and median 

 line of breast and abdomen; rest of under parts metallic bronze- 

 gi-een or greenish bronze, the feathers more or less distinctly mar- 

 gined with dull grayish; femoral tufts and conspicuous tuft on each 

 side of rump white ; under tail-coverts light brownish gray or bronzy 

 centrally, margined with wliitish; bill dull black; iris dark brown; 

 feet dusky; length (skins), 77-90 (S3); wing, 43-45.5 (44.4); tail, 

 22-24.5 (22.6); middle rectrices, 17.5-20 (IS. 6); exposed culmen, 

 16-19 (17.2).« 



Adult female. — Above rather dull metallic bronze-green or greenish 

 bronze, much duller on ])ileum, where (at least on forehead) some- 

 times dull grayish brown; mitldle pair of rectrices bronze-green, the 

 next pair similar but with terminal portion black; third pair tipped 

 with dull white or pale brownish gray, extensively black subter- 

 minally and dull brownish gray basally, the gray and black separated 

 (at least on outer web) by more or less of metalhc bronze-green; 

 fourth and outermost i)airs with whitish tip broader, basal grayish 

 more extended, and with little if any metallic greenish between the 

 gray and black; remiges brownish slate or dusky, faintly glossed 

 with purphsh; under parts ])ale brownish gray, ])alcr (dull whitish) 

 on cliin, upper throat, and under tail-coverts; femoral tufts and 

 tuft on each side of rum]) white; bill, etc., as in adult male; length 

 (sldns), 74-91 (81); wing, 43.5-4G (44.7); tail, 21.5-25.5 (23.6); 

 culmen, 17-20 (18.2).'' 



Young male. — Similar to the adult female but feathers of up])er 

 ])arts more or less distinctly margined with j^ale grayish bully, tail 

 double-rounded instead of rounded, and throat with a central ]nitch 

 of metallic purple or violet feathers (in older individuals similar 

 feathers on crown also). 



Young female. — Similar to the adult female but feat1u>rs of u])]>er 

 parts margined with pale grayish buffy. 



« Thirtcuii .sp(jciiu(jiiH. ^ Twelve speciineiis. 



