EGGS OF NORTH AMERICAN BIRDS. 79 



424. Vaux's Swift, Ghcetura vauxii. Eggs, indistinguisli- 

 able from those of No. 423, but are perhaps a little smaller ; 

 .49 -\- .71. Breeds on the Pacific slope, from British Columbia 

 southward, iu May, nesting in hollow trees. 



425. White-throated Swift, Micropus melanoleucus. 

 Eggs, unknown. Breeds in the Western United States, from 

 the Rocky Mountain to the Pacific, south to Central America, 

 nesting in holes of inaccessible cliffs, in May. 



Family XLIV. — TROCHILID^. Humming-birds. 



Eggs, usually 2 in number, elliptical in form, white in 

 color, placed in delicately constructed nests that are fastened 

 to branches of trees or bushes or vines, and in some cases to 

 leaves. 



426. RivoLi Humming-bird, Eugenes fulgens. Eggs and 

 nests, similar to those of No. 428. Breeds in Southern Arizona 

 and through Mexico to Guatemala, in June. 



427. Blue-throated Humming-bird, Coeligena clemencim. 

 Eggs, unknown. Breeds in Mexico and Southern Arizona. 



428. Ruby-throated Humming-bird. (Type, Plate VIII.) 

 Trochilus colubris. Eggs, .35 -f .50 to .38 + .52. Nests, 

 composed of soft material like the cottony covering from ferns, 

 etc., usually covered with lichens. Breeds throughout Eastern 

 North America, west to the plains, north to the fur countries, 

 m June. Nests in trees, vines, or bushes, and fi*om three to 

 thirty feet from the ground. 



420. Black-chinned Humming-bird, Trochilus alexandri. 

 Eggs, indistinguishable from those of No. 428. Nests com- 

 posed of a yellowish down, evidently from the catkins of the 

 willow, and placed in willows. Breeds in the Pacific coast 

 region, from California east to Utah and Arizona and south- 

 ward, in April. 



429a. Violet-throated Humming-bird, Trochilus violajtt- 

 gulium. Eggs, unknown. Perhaps breeds in Southern Cali- 

 fornia. See Jelferys in "Auk," January, 1888, \,. 426. 



