27 $Mm>^ 



degree. The females sometimes wholly lack the chestnut on the 

 wing-coverts, while in some it is nearly as hright as in average males. 



37. Passerculus savanna var. a»tkiiHiS~ Coues. Savanna 

 Sparrow. 



A single specimen was shot at Camp 56, on the Great Porcupine 

 Creek, August 29th, where a few others were seen. 



38. Pocscetes gramineus Baird. Grass Finch. 



One of the most common and uniformly distributed species met 

 with; particularly numerous in the valleys of the Yellowstone and 

 the Musselshell. 



39. Coturniculus passerinus var. perpallidus Ridgway 

 Yellow-winged Sparrow. 



Common at intervals from the Missouri to the Musselshell, but 

 apparently much more numerous over the comparatively moist prai- 

 ries east of the Yellowstone than beyond it. 



40. Centronyx Bairdii Baird. Baird's Sparrow.' 



Rather frequent in the moist hollows from the Missouri westward 

 to the Little Missouri. Found by Audubon about Fort Union, and Dr. 

 Elliott Coues reports it as abundant in Northern Dakota, west of the 

 Pembina Mountains. 1 A single nest (the only one thus far known) 

 was found by the writer July 1st, near Heart River, containing four 

 eggs. The nest was a substantial structure of dry grass placed on the 

 ground. The eggs are quite spherical, and of large size for the size 

 of the bird, measuring .82 of an inch by .65. The color is pale grayish 

 white, irregularly and quite thickly marked with specks and blotches 

 of reddish brown, varying to dark umber. 



41. Spizella SOCialis Bon. Chipping Sparrow. 



More or less common along the wooded bottom-lands of the streams 

 from the Missouri to the Musselshell ; quite abundant also in August 

 and September in the piny districts of the Yellowstone and Mussel- 

 shell. They were chiefly young birds, which, with Chondestes gram- 

 maca, often formed considerable flocks. 



42. Spizella pusilla Bon. Field Sparrow. 



Frequent along Davis Creek, in the Bad Lands of the Little Mis- 

 souri, but not observed elsewhere. No specimens were taken. 



43. Spizella pallida Bon. Clay-colored Sparrow. 

 Common in the thickets bordering the streams from the Missouri 



nearly to the Yellowstone. In the valley of the Yellowstone, and to 

 the westward, it seemed to be wholly replaced by the S. Breweri] at 



iAm. Nat., Vol. vn, Nov., 1873,!p. 697. 



