426 NORTH AMERICAN BIRDS. 



tlie crevices of rocks, and tliat their e«;gs are pure white, and of an elongated 

 form. 



Dr. Cones fonnd this species rather sparingly distributed throughout Ari- 

 zona, always in the neighhorhood of clitis and precipices, which it exclu- 

 sively inhabits. From Inscription Kock, about one day's march from 

 Whipi>le's Vass, ti^ the San Francisco Mountains of Arizona, he found these 

 birds in great numbei's, exce})t along the valley of the Colomdo Chiquito, 

 where there were no suitable clitis for their habitation. He generally found 

 them congregated in consitlerable, sometimes in immense, numbers in the 

 vicinity of huge cliffs and piles of rocks. Their note, he adds, is an often and 

 quickly repeated twitter, loud and shrill, and quite different from that of 

 the C. pclagira. He states that they build their nest upon the vertical faces 

 of precijjitous rocks. 



Dr. Woodhouse met with a Swift in the same region referred to by Dr. 

 Coues, which he called AcantlufUs saxatills, which may possibly be the same 

 species, but of which no specimen was procured. They were breeding in 

 the crevices of the rocks. The description, however, does not at all corre- 

 spond. 



This species has lately been met with by Mr. Salvin, in Guatemala, where 

 it is by no means common, and so very local that its presence might readily 

 have been overlooked. He found it near Duenas, in a gorge with precipi- 

 tous rocks on the right hand, along tlie course of the river Guacalate. His 

 attention was drawn to a noise coming from the rocks, which he at first took 

 to be bats in some of the cracks. After watching for some time, he saw two 

 Swifts dart into a crack in the rock twenty feet from the ground, and the 

 noise became louder than before. liesorting to several expedients, in vain, 

 to make them ffy out, he climbed up part way, and there found one of them 

 killed bv a mndom shot of his gun. Another discharjie of his jiun brought 

 out five or six more, which were immediately pursued by the Cottflc scrri- 

 pennis. He obtained, three specimen?, in all. The spot was evridently their 

 common roosting-place, and by the noise they made he judged they were 

 there in large numbers. He found them about the middle of Fe])ruarv. 



Dr. C(K)per met with this species near Fort Mohave, but saw none before 

 ^lay. On the 7th of June, near tlie head of Mohave River, he found a few 

 about some lofty granite cliffs, and suc' 'oded in obtaining one. Their flight 

 was exceedingly swift and changeable, and they were very difficult to shoot. 

 He also found them about some high rocky bluffs close to the sea-shore, 

 twelve miles north of San Diego. They were seen the last of ^larch, but 

 may have been there for a montli previously. 



Mr. Allen encountered this little-known Swift near Colorado Citv, where 

 it was quite numerous about the high cliffs in the " Garden of the Gods," 

 and of which, with great difficulty, he procured four s])ecimens. It was 

 nesting in inaccessible crevices and weather-l)eaten holes in the rocks, about 

 midway up the high vertical cliffs, some of which w^ere not less tiuin three 



