NATURAL SCIENCES OF PHILADELPHIA. 57 



Dr. Cooper tells me that the nests which he found on the Mojave River were 

 composed entirely of the soft white downy cotton of Platanus and Salix. 



(49.) Atthis cost m (Bourc.) Reich. 



A species generally distributed throughout the Territory, particularly in its 

 southern and southwestern portions. Not taken at Fort Whipple, though 

 observed some fifty miles south. From Bill William's River, Dr Kennerly, in 

 February ; from Fort Mojave, Dr. Cooper. Doubtless winters withiu the lim- 

 its of the Territory. 



(50.) Selasphorcs platycercus (Sw.) Gould. 



Numerous specimens seen on the sumuiit of Whipple's Pass of the Rocky 

 Mountains in July, feeding among clumps of wild roses. Not observed at 

 Fort Whipple ; but the range northward of this species, as now known, in- 

 cludes the whole of New Mexico and Arizona ; and further north, at least, 

 as far as Fort Bridger, Utah. 



51. Selasphorus rpfus Swains. 



Very abundant at Fort Whipple, as it is elsewhere along the whole Pacific 

 slope of the Rocky Mountains, and across their southern extensions into the 

 Rio Grande valley. Summer resident, breeding abundantly ; arrives April 

 10 ; remains until middle of September. Found in all situations, particularly 

 meadows, open copses, ravines, etc., where flowers are most abundant. 



CYPSELTD^E. 



52. Panyptila melanolefjca Baird. 



Acanthylis saxatilis, Woodh. Sitgreave's Expl. Zuiiiand Col. Riv. Birds, 



18(33, p. 64. ("Inscription Rock," N. M.) 

 Cypselus melanoleucu*, Baird, Pr. A. N. S. Ph. vii. 1854, p. 118. (San 

 Francisco Mts. Ariz.) Cassin, Illust. Bds. Cal. and Texas, i. 1855, p. 

 248. 

 Panyptila melanoleuca, Baird. B. N. A. 1S58, p. 141. Coues, Newton's 

 Ibis., 1865, p. 

 Rather sparingly distributed throughout the Territory ; chiefly in the 

 neighborhood of cliffs and precipices, which, I believe, it almost exclusively 

 inhabits. 



I think there can he no doubt that the bird described by Prof. Baird, as 

 above, is the same as that briefly and somewhat incorrectly indicated by Dr. 

 Woodhouse. While encamped at Inscription Rock, July 3, 1864, I saw great 

 numbers of tbese Swifts ; but, as unfortunate as Dr. W., I was unable to pro- 

 cure a single specimen, though many passed so near me that I could posi- 

 tively identify them. The cbief point of discrepancy is the white rump 

 mentioned by Dr. Woodhouse, which does not exist in Prof. Baird's speci- 

 mens. But I am perfectly satisfied, in my own mind, that Dr. Woodhouse, 

 from the imperfect observations he was only enabled to make, mistook the 

 white patches on each side of the rump, which in life often reach nearly or 

 quite across the uropygium till they coalesce on the median line. There is a 

 corroboration of this view afforded by the Tachycincta thalassina. Observa- 

 tions of the latter in life gives the impression of a white rump ; whereas this 

 species has that part concolor with the back ; but the large white cottony 

 patches on the flanks are long and loose enough to meet each other on the 

 rump. Moreover the localities whence the two supposed species come are so 

 near as to render it unlikely there should exist two such closely allied 

 Swifts. 

 From Inscription Rock* to the San Francisco Mountains, I continually met 



* Inscription Rock is a huge mass of sandstone protruding from the side of a hill, with a front of 

 great height perpendicular to the plain below; situate a days march west of Whipple's Pass of 

 the Rocky Mountains, and rather more than that distance east of the Pueblo of ZuEi. The San 

 Francisco Mountains are a well known locality. 



I860.] 



