30 



53. Xanthocephalus icterocephalus Baird. Yellow- 

 headed Blackbird. 



Seen but three or four times on the whole journey. A small colony 

 found breeding near the point where we crossed the Big Muddy, and a 

 single small flock seen near the head of the Great Porcupine Creek. 

 A small flock seen once also on Heart River. 



54. Sturnella ludoviciana var. neglecta All. Meadow 

 Lark. 



One of the most abundant birds of the plains, occurring every- 

 where. No other bird, perhaps, is so uniformly met with. 



The following are some of the variations in the size and color of 

 the eggs of this species: Extremes, 1.25 X -81 inches, and 1.02 X 

 .81 inches. Two eggs of the same set varied as follows: 1.20 X -90; 

 1.02 X -80. The markings vary from pale diffused rufous blotches to 

 sharply denned small dark purplish brown or black specks. One set 

 of eggs presents an almost exact likeness in size, shape and color to 

 the eggs of the whippoorwill. 



55. Icterus spurius Bon. Orchard Oriole. 



A few pairs seen near the " Second Crossing " of Heart River, 

 July 5th, were the only ones met with. 



56. Icterus Bullocki Bon. Bullock's Oriole. 



More or less frequent along all the wooded portions of the streams. 

 Observed at Fort Rice and on the Heart River; collected on Beaver 

 Creek, on the Yellowstone at the Crossing, and at the Big Bend of 

 the Musselshell. Dr. W. J. Hoffman, U. S. A., informs me that it is 

 common at the Grand River Agency and at Fort Randall. Dr. Hay- 

 den says this species " seldom passes above Fort Pierre," but that " it 

 occurs occasionally along the Lower Missouri." He speaks of having 

 met with but one specimen in all his explorations. On the other 

 hand, he gives I. Baltimore as " abundant throughout the wooded 

 portion of the Missouri country," and as " more common on the 

 numerous islands in the river, from the mouth to Fort Union," 1 while 

 not a single specimen was seen by us west of the Missouri. 



57. ScolecophagUS cyanocephalus Cab. Brewer's Black- 

 bird. 



Common along all the timbered portions of the streams everywhere. 

 In September seen in immense flocks along the Yellowstone and 

 Heart Rivers. I observed large flocks in Dakota, as far east even as 

 the James River. 



1 Trans. Am. Phil. Soc, xn, p. 170. 



