. MICROPUS. 303 



tical-ovate, plain pure white. Hob. Eastern North America, north 

 to Labrador and to 50 in the interior, west to edge of Great 



Plains 423. C. pelagica (LINN.). Chimney Swift. 



b*. Wing decidedly less than 5.00. 



c 1 . Kump, upper tail-coverts, and tail light sooty grayish, very much 

 lighter than the olive-dusky back ; breast and belly light sooty 

 grayish ; length about 4.15-4,50, wing 4.30-4.75, tail (including 

 spines) 1.50-1.90. Nest like that of C. pelagica, but only (?) in hol- 

 low trees. Eggs .71 X -49. Hob. Western United States (chiefly 

 Pacific coast), north to British Columbia; south, in winter, to 



Guatemala 424. C. vauxii (TOWNS.). Vaux's Swift. 



c 2 . Upper parts entirely blackish (very slightly paler on rump, etc.), glossed 

 with olive-greenish on back and with bluish on wings ; breast and 

 belly deep sooty grayish brown ; wing 4.20-4.60, tail (including 

 spines) 1.70-1. 75. 1 Hab. Southern Mexico (Yucatan, including 

 Cozumel, Tehuantepec, etc.), Guatemala, and south to Costa Rica. 



C. gaumeri LAWR. Gaumer's Chimney Swift. 2 



a*. Throat not paler than rest of under parts ; male with a broad collar of rufous 

 round neck ; length about 4.75-5.00, wing 4.80-5.20, tail 1.80-2.10. Hab. Cen- 

 tral America, north to eastern Mexico (Orizaba), south to Ecuador. 



C. brunneitorques LAFR. Lafresnaye's Chimney Swift. 3 



GENUS MICROPUS MEYER & WOLF. (Page 302, pi. LXXXIX., fig. 4.) 



Species. 



Above dull blackish, usually becoming lighter and grayer on forehead ; sides 

 and under tail-coverts also dull blackish; other lower parts, tips of secondaries 

 (outer webs only), and a patch on each side of rump, white ; length 6.50-7.00, wing 

 5.30-5.90, tail 2.50-2.70. Hab. Western United States (in mountains), and south to 

 Guatemala 425. M. melanoleucus (BAIBD). White-throated Swift. 



FAMILY TROCHILID^E. THE HUMMINGBIRDS. (Page 297.) 



(Nest a beautifully felted cup-shaped structure, composed of plant-down, 

 spiders' webs, lichens, etc. the last exteriorly, the first internally. Eggs 2, ellipti- 

 cal-ovate or elliptical-oval, large in proportion to size of the bird, plain pure white.) 



Genera.* 

 a 1 . Anterior toes united for basal half; bill much compressed (except at base), about 



1 These spines usually worn entirely off in Yucatan specimens. 



2 Chsetura gaumeri LAWR., Ann. N. Y. Ac. Sci. ii. No. 8, March, 1882, 245. 



3 CJnetura brunneitorques LAFR., Rev. Zool. 1844, 81. 



4 Characters of all the Mexican genera are given, for the reason that almost any species of Hummingbird 

 found on the table-lands or mountains of Mexico may reasonably be expected to occur within our borders. In 



