210 Brewster on a Collection of A rizona Birds. 
individuals were secured, but neither the nest nor the remainder 
of the brood — if indeed there were any more — could be found. 
On the following day this episode was repeated, a second female 
being found in attendance on another young bird of nearly the 
same age as that obtained on the previous occasion. 
308, $ ad., Tucson, April 29. Length, 4.80; extent, 7.20; wing, 2.28; 
tail, 2.04; culmen, .40; tarsus, .55. “Iris dark brown; bill black, basal 
half of lower mandible reddish-brown ; legs black. Contents of stomach 
worms and insects.” 
313, $ ad., Tucson, May 1. Length, 4.60; extent, 7.20; wing, 2.23; 
tail, 1.96; culmen, .42; tarsus, .56. 
446, $ ad., Tucson. Maj 28. Length, 4. 50 : extent, 6.70; wing, 2.04; 
tail, 1.78; culmen, .40; tarsus, .52. Parent of the next. 
447, $ juv., first plumage, same locality and date. 
450, $ ad., Tucson, May 29. Length, 4.30; extent. 6.80. Parent of 
the following. 
45 1 , J juv., first plumage, same locality and date. 
1 16. Trochilus alexandri Bourc. & Muls. Black- 
chinned Hummingbird. — The first specimen met with was a 
female which, with a nest and two eggs, was taken at Tucson on 
April 23. The species was also found breeding among the 
Santa Rita Mountains, as W’ell as near Camp Lowell. At all 
these points it was decidedly the most abundant of the Hum- 
mingbirds. 
Six of the seven examples collected are females, and Mr. 
Stephens remarks on the apparent absence of the males during 
the breeding season. 
The nest just mentioned, and another obtained April 28 in the 
same locality, are now in my possession. Both were built in 
willows, one being saddled on a small branch, while the other 
rested lightly in the fork of a slender twig. Their construction 
is homogeneous, the only material used being a creamy-white 
down, probably from willow catkins. One nest, however, has a 
few delicate, faded leaves attached to its exterior. The eggs are 
indistinguishable from those of T. colubris. The first set was 
fresh, the second slightly incubated. 
1 17. Calypte costce {Bourc.) Gould. Costa’s Hum- 
mingbird. 
289, $ ad., Tucson. April 26. Length, 3.70; extent, 4.60. “Iris dark 
brown ; bill and legs black.” 
294, $ im., Tucson, April 27. Length, 3.55; extent, 4.52. This speci- 
men lacks the ruffs of the adult male, but has a patch of violet feathers on 
the centre of the throat. 
