382 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
men with much more white; rectrices blackish blue below, the lateral 
ones with a grayish white apical spot; wing, 55-57; culmen, 14.5-15.% 
Nicaragua (Matagalpa). 
Basilinna leucotis (not Trochilus leucotis Vieillot) Satvin and Gopman, Biol. 
Centr.-Am., Aves, ii, 1892, 312, part (Matagalpa, Nicaragua). 
Basilinna leucotis pygmaea Simon and Heitimayr, Novit. Zool., xv, June 25, 
1908, 12 (Matagalpa, Nicaragua; coll. E. Simon). 
BASILINNA XANTUSII (Lawrence). 
XANTUS’S HUMMING BIRD. 
Differing from B. leucotis in having the tail mostly chestnut and 
under parts vinaceous-cinnamon; adult male with forehead, chin, 
etc., black (sometimes faintly glossed with bluish) instead of bright 
metallic violet or violet-blue. 
Adult male.—Forehead (sometimes crown also) loral, suborbital, 
auricular and malar regions and chin black, the first and last some- 
times faintly glossed with blue in certain lights; rest of upper parts 
metallic bronze-green, the feathers of rump and the upper tail- 
coverts more or less distinctly margined with rusty; middle pair of 
rectrices chestnut margined with metallic bronze-green, sometimes 
mostly of the latter color; rest of tail chestnut, the rectrices some- 
times margined terminally with dull bronzy; remiges purplish 
dusky; a white or buffy white postocular stripe, following upper 
and posterior margins of black auricular area to side of neck; throat 
brilliant metallic emerald green, passing into more yellowish green 
on chest, the feathers more or less distinctly margined (very nar- 
rowly) with dull whitish; rest of under parts vinaceous-cinnamon 
or pale cinnamon-rufous, the breast (especially laterally) and sides 
spotted with metallic green; femoral tufts white; bill pale brownish 
(coral red or pinkish red in life), dusky terminally; iris dark brown; 
feet dusky; length (skins), 86-96 (93); wing, 50-54 (52.3); tail, 
30-32.5 (81.1); culmen, 17-19 (17.7)2 
Adult female——Above similar to the adult male but forehead dull 
brownish gray, instead of black, and rectrices (except middle pair 
and outer web of lateral pair) with a more or less extensive blackish 
subterminal area on each web; auricular area dusky grayish brown 
instead of black, the whitish postocular stripe more cinnamomeous or 
buffy; whole under parts pale vinaceous-cinnamon or cinnamon-buff, 
except the white femoral tufts; maxilla wholly dusky, the mandible 
dusky for terminal half (more or less); iris and feet as in adult male; 
length (skins), 79-90 (84); wing, 43.5-52.5 (48.9); tail, 27-31 (28.7); 
culmen, 17-19 (17.8). ; 
@ Characters taken from original description. 
b Ten specimens. 
