PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 375 



Adult in spring. — iVbovc nniforin russet-olivo (nuieli as in R.ustiilafa); 

 jugulum and lower part of throat pale buff, as in ustulata, much lighter 

 than in fusccscens, the markings, however, small and narrow as in the 

 latter. Sides of head dull grayish, without trace of lighter oibital 

 ring; sides of breast, sides, and llauks ash-gray (rather deeper than iu 

 fuscescom), the breast very faintly or not at all spotted with darker. 



Adult ill fall and tcinter. — Above darker, more umber, brown ; jugu- 

 lum and lower part and sides of throat deej^er buff", with much darker 

 spots. 



The general appearance of this bird at first glance is more that of 

 H. ustulata than true H. fusccscens, the upper i)aits and anterior lower 

 parts being quite similarly colored. A close examination, however, im- 

 mediately reveals radical differences, the most important of which is 

 the total absence of any light orbital ring, which is always present, and 

 very distinct, in ustulata. The wings and tail, instead of being ap- 

 preciably more rufescent than \\\q back and rump are, on the other 

 hand, less so ; the buff of the jugulum gives way very abruptly to the 

 ash-gray on the sides of the breast, and the spots end quite as abruptly, 

 the breast being plain ash-gray laterally, and white medially, with very 

 indistinct spots of grayish between the white and the gray. In ustulata 

 the sides are decidedly brown, with very distinct transverse sjiots of a 

 darker sliade of the same color entirely across the breast. Another ex- 

 cellent character consists in the color of the axillars and lining of the 

 M'ing, which are light grayish in the x>resent bird, and deep brownish 

 buff in ustulata. 



The differences from typical fusccscens of the Atlantic States, as in- 

 dicated in the above diagnosis, are exceedingly constant. 



A specimen from Chica,uo, 111., in the collection of H. K. Coale, of 

 that city (No. 1568, Coll. H. K. C, Sept. IG), is referable to this race, 

 and is evidently a fall straggler from the Rocky Mountain district. It is 

 even more olive above than most specimens from that region, having 

 almost exactly the same shade of color as a fall specimen of 11. sicainsoni 

 from Massachusetts, the latter, however, an unusually brown example. 

 The entire absence of any light orbital ring, the narrow, almost linear, 

 streaks of the jugulum, and the peculiar i^roportions, however, refer it 

 at once to fusccscens. 



I have called this new form salicicola on account of its marked pre- 

 dilection for willow thickets, to which, along the streams in the valleys 

 and lower caQons of the Rocky Mountain region, it is chiefly confined 

 during the breeding season. 



