370 REPORT OF NATIONAL .MUSEUM, 1890. 



metallic bronze-green terminally, light cinnamon-rufous basally ; rest 

 of under parts light cinnamon-rufous, the anal region and under tail- 

 coverts paler. Bill with basal half or more pale brownish (coral-red in 

 life), the terminal portion blackish. Length (skin), 3.40; wing, 205; 

 tail, 1.40; the middle feathers, about 0.10 shorter; exposed culmen, 0.65. 



Adult female (No. 16935, Cape St. Lucas, Lower California, October 

 1859; J. Xantus):* Sides of forehead dull cinnamon-rufous; median 

 portion of forehead, with crown, dull grayish brown ; rest of upper parts, 

 including middle pair of tail-feathers, metallic bronze-green, the upper 

 tail-coverts margined and somewhat mixed with rusty; tail-feathers 

 (except middle pair) chestnut, becoming gradually paler on the outer- 

 most, the second and third (from the middle) with a large blackish lon- 

 gitudinal subterminal spot on each web, the fourth with a similar spot 

 on the inner web and a trace of such a spot on the outer ; outermost 

 feather without any spot on the outer web, and with a mere speck of 

 blackish on the inner web ; remiges dull brownish slate or dusky, faintly 

 glossed with purplish. A distinct stripe of buffy whitish behind eye, 

 above upper margins of the ear coverts, the latter dusky grayish brown ; 

 chin, throat, and other lower parts dull cinnamon-rufous, becoming 

 paler and somewhat mixed with whitish posteriorly. Upper mandible 

 black, becoming more brownish at base; lower pale brownish (reddish 

 in life), with blackish tip. Length (skin), 3.10; wing, 1.85; tail, 1.20, 

 the lateral feathers about 0.10 shorter; exposed culmen, 0.60. 



Among adult males the principal variation in color affects the green 

 of the throat, which may be a decidedly yellowish green or a nearly 

 pure emerald- green, and the extent of bronze-green on tiie middle tail- 

 feathers, which sometimes covers the entire outer \\eb and the greater 

 part of the inner web also. 



Adult females obtained during midsummer are much paler, the color 

 of the lower parts being a dull grayish buff, and the post-ocular stripe 

 quite white. 



A specimen, labeled " Mazatlan, Mexico " (No. 24853, J. Xantus), is 

 similar to Lower California specimens and is doubtless not from the 

 ascribed locality. 



What appears to be an adult female, but may be an immature male 

 (No. 24855, Cape St. Lucas, April, 1860, J. Xantus), differs from the 

 usual plumage of the adult female in having a quite extensive patch of 

 metallic yellowish green covering nearly the whole of the throat, arid 

 some blackish feathers in the region extending from the side of the 

 chin to the ear- coverts. 



What little we know of the habits of Xantus's Humming Bird is due 

 to Mr. L. Belding who observed it at several localities in the southern 

 part of Lower California, where he informs us it is a mountain-loving 

 species, and usually to be found near fresh water, while in winter he 

 found it only in the mountain canons. "It was common at the western 



* Type of Amazilia zantusi, LAWE. 



