COUES ON BIRDS OF DAKOTA AND MONTANA. 553 



List of specimens. 



SIALIA AECTICA, *S7r. 



EocKY Mountain Bluebird. 



The ^N^orthern Boundary appears to be slightly beyond the limit of 

 distribution of the Eastern Bluebird, since the species was not ob- 

 served at Pembina, where the avifauna is almost entirely Eastern in its 

 composition. The Western Bluebird, S. mexicana, is still further re- 

 moved from the region now under consideration. The third and only 

 other species of this country has a more northerly distribution than 

 either of the others, reaching to about latitude 64^ or 65° north ; it is 

 found from the eastern foothills of the Rocky Mountains to the Pacific, 

 and in some localities is very abundant. A few individuals were ob- 

 served by the Commission in the Rocky Mountains, at Chief Mountain 

 Lake, but no specimens were preserved. Its habits are much the same 

 as those of its well-known Eastern congener. 



REGULUS CALENDULA, LieJit 

 Ruby-crowned Kinglet. 



This species, of general distribution throughout the wooded portions 

 of North America, was observed on Mouse River, in September, during 

 the autumnal migration, frequenting the dense undergrowth of the 

 river-bottom in company with SelmintJiophaga celata and Dendroeca 

 coronata. In its spring and autumn movements, it undoubtedly passes 

 the several wooded points of the line, and may yet be found breeding 

 in the mountains in this latitude. 



Its nest and eggs long remained among the special desiderata of 

 American ornithologists. So far as known, no authentic specimens 

 reached our hands until two or three years ago, when Mr. J. H. Batty, 

 then attached to Dr. Hayden's Survey, discovered a nest in Colorado, 

 July 21, 1873. It was placed on a spruce bough, about 15 feet from 

 the ground, and contained fi.ve young and one egg. The structure, 

 which I have examined at the Smithsonian, is larger than such a tiny 

 architect would be expected to produce, and consists of a loosely blended 

 mass of hair and feathers, mixed with moss and short pieces of straw. 

 Other observers, notably Mr* T. M. Trippe, had previously indicated the 

 undoubted breeding of the species in the higher wooded portions of 

 Colorado, which is confirmed by the discovery of this nest. 



