THIRD ANNUAL MEETINC! 81 



in darkness, there come two clear elusive notes from somewhere along 

 the rim-rock of the canon. It is the first call in the nig-htly serenade 

 of the poor-wills and is quickly taken up by the remainder of the 

 orchestra along the rocky walls. There is something exceedingly weird 

 and uncann3r about it all, that fascinates the listener; the sound is 

 echoed, magnified, and distorted by the canon walls until one is almost 

 led to believe that the sounds are of supernatural origin, and when a 

 bird is by chance seen, as it flutters and glides silent as a shadow 

 down to the bottom of the canon, its very appearance lends support 

 to the belief. Very seldom indeed are the birds seen in the daytime 

 and in spite of the fact that at least three pairs were positively known 

 to be somewhere within our canon, a nest was searched for in vain, 

 and we would have returned without eggs had it not been for the kind- 

 ness of Mr. O. A. Peterson, a paheoiitologist collecting in the vicinity, 

 who, while searching for fossil remains among the Diamonelix beds 

 along the brow of the canon on July 23, accideutly flushed a female 

 from her two white eggs. These lay in a slight depression on the 

 bare white rock, right in the blazing sun, and the bird was so well 

 protected by its remarkable adaptability to its surroundings, that it 

 was not seen by Mr. Peterson until it flushed a few feet in front of 

 him. The eggs were well advanced in incubation, in fact nearly upon 

 the point of hatching, but were saved by careful treatment, though in 

 a poor condition. They are pure glossy white, elliptical in shape and 

 measure respectively 28x19.75 and 27x19 mm. Whether this nesting is 

 the regular time or later than usual I do not know, but it seems to 

 me to be quite late, as the Whip-poor-will lays in Southern Nebraska 

 about the second week in June. 



White-throated Swift (Aeronautes melanoleucus) . — This interesting 

 bird has for several years been known to be an inhabitant of the canons 

 of Sioux and Dawes counties and has been supposed to breed there, but 

 until May 30, 1901, no nest or eggs had ever been seen or taken. Indeed 

 very little is known of the breeding of this bird anywhere on account 

 of the usually inaccessible situation which it selects for a nesting site. 



In May, 1900, a party consisting of Mr. J. S. Hunter, Mr. Merritt Gary, 

 and Mr. J. C. Crawford, Jr., located a colony of perhaps a dozen pairs 

 of these birds near the head of West Monroe Caiion in Sioux County, 

 but were unable to reach the places where the birds appeared to have 

 their nests. So in 1901 the partj' went with a firm determination to 

 secure eggs of the birds. On May 30, our party, consisting of Prof. 

 Bruner, Dr. Wolcott, Mr. Gary, and myself, visited the clitt" occupied by 

 the birds the year before and found that they had returned and to all 

 appearances had nests, under construction at least, in the crevices of 

 the clitf about seventy feet above the base of the perpendicular wall 

 of rock. 



The home of the birds was a bold, convex clift", forming one wall 

 of the canon and facing to the southwest. On the south side, about 



