VAUX'S SWIFT. 185 



California. The nest is described as composed of small twigs, glned together 

 with the saliva of the bird, and fastened to the side of a burned-out and hollow 

 sycamore tree. It was not lined, and evidently was quite similar to the nest of 

 the Chimney Swift. I have never seen a specimen, and therefore can not give 

 measurements. From three to five eggs are deposited to a set, and only one 

 brood appears to be raised in a season. The eggs resemble those of the Chim- 

 ney Swifts both in shape and color, but they are considerably smaller. 



The only specimens in the United States National Museum collection 

 measm-e 18.29 by 12.19, 17.78 by 12.70, and 17.63 by 12.45 millimetres, or 0.72 

 by 0.48, 0.70 by 0.50, and 0.69 by 0.49 inch, respectively. 



The type specimen, No. 21005 (PI. 1, Fig. 26, a single egg), was taken near 

 Santa Cruz, California, in June, 1874, and presented to the collection by Dr. 

 James C. Merrill, United States Army. 



65. Aeronautes melanoleucus (Baird). 



WHITE-THROATED SWIFT. 



Gypselus melanoleucus Baikd, Proceedings Academy Natural Sciences, Phila. June, 



1854, 118. 

 Aeronautes melanoleucus Haetert, Catalogue Birds in Britisb Museum, XVI, 1892, 459. 

 (B 107, C 269, E 349, 403, U 425.) 



Geographical range: Mountain regions of the western United States; nortli to 

 Montana; east to western South Dakota (Black Hills), western Nebraska, and Colorado; 

 south through Arizona, New Mexico, western Texas, and Lower California to Guatemala, 

 Central America. 



The range of the White-throated or "Rock" Swift does not appear to extend 

 nearly as far north in the mountains of the Pacific Coast districts as it does in 

 the Rocky Mountain region, where it is generally distributed, throughout suit- 

 able localities, from southern Arizona and New Mexico northward through Colo- 

 rado and Wyoming to Montana, which, as far as known, marks the northern limits 

 of its range. Here Mr. R. S. Williams found this species breeding in small 

 numbers in holes in a limestone cliff on Belt River, about the middle of July, 

 1881. He says: "A small opening in the rock, which a bird of this species was 

 seen to enter and reappear from several times, I approached near enough to hear 

 a vigorous twittering at each visit of the parent bird, from which I presume the 

 young were well advanced."^ 



On the Pacific coast in California I have not been able to trace it north of 

 Alameda, Contra Costa, and Mariposa counties, in about latitude 38°, and 

 somewhat farther north in Nevada, where Mr. Robert Ridgway found this 

 species extremely numerous in the Ruby Mountains, about the high limestone 

 cliffs, as well as in the East Humboldt range, in about latitude 40°, and less 

 abundantly in the Wasatch Mountains in Utah. I have been unable to find a 

 single record of its capture in either Oregon or Washington, and this is the more 



' Bulletin of the Nuttall Ornithological Club, vol. 1, 1882, p. 123. 



