TURDID;E THE THRUSHES. 51 



Key to the species of Eastern North America. 



COMMON CHARACTERS. Above plain brown: beneath white, more or less spotted 

 with brown or dusky. Young, with the upper parts, including wing-coverts, spotted and 

 streaked with yellowish fulvous. 



a 1 . Sides distinctly spotted, as well as the breast; culmen, .70 or more, and 

 wing usually more than 4.25. 



1. T. mustalinus. Above cinnamon-brown, brighter and more rufous 

 on the crown, more olive on the tail; beneath, including the sides, 

 white, the breast and sides marked with roundish or inversely cordate 

 spots of black. Wing 4.10-4.50, tail 3.00-3.30, culmen .70-.75, tarsus 

 1.20-1.30, middle toe .70-.75. 



a". Sides uniform grayish or brownish, without distinct spots; jugulum, etc., 

 more or less tinged with buff. Culmeu .60 or less, and wing usually less than 

 4. 1'5. 



b 1 . Second primary shorter than fifth, the fourth longest. Tail and upper 



coverts rufous, in decided contrast with the olive of the back, etc. A. 



distinct buff orbital ring. 



2. T. aonalaschkae pallasii. Jugulum with very large triangular spots of 

 dusky. Wing 3.40-3 90 (3.64), tail 2.55-3.15 (2.82), culmen .50-.60 (.54), tarsus 

 1.15-1.30 (1.19), middle toe .65-.75 (.70). 



b". Second primary much longer than fifth, the third longest. Tail and 

 upper coverts, not noticeably different in color from the other upper 

 parts. 



c 1 . A distinct buff orbital ring. 



3. T.ustulatus swainsonii. Above uniform olive, of variable shade, 

 the outer surface of the wings (and sometimes the tail also), very 

 slightly browner, or less olive, than the back. Jugulum bright buff 

 with rather large triangular spots of dusky. Wing 3.80-4.10 (3.9ti), tail 

 2.80-3.10(2.95). culmen .50-.55f.52), tarsus 1.05-1.18 (1.10), middle toe .65- 

 .72 ( 69). 



c 2 . No trace of light orbital ring. 



4. T. aliciae. Very similar to H. ustulatus swainsonii, but buff of jug- 

 ulum. etc., usually very much paler, and buff orbital ring wholly ab- 

 sent, the whole side of the head nearly uniform grayish. 



a alicice. Wing 3.75-4.40 (average 4.07), tail 2.95-3.40 (3.09), culmen 

 .45-.5S (.55), tarsus 1.12-1,30 (1.18). middle toe .60-. 75 (.68). 



(3 bicknelli. Wing 3.40-3.80 (average 3.65), tail 2.60-2.70 (2'75), culmen 

 .39-.52(5I), tarsus 1.10-1.25 (1.13), middle toe .65-.70 (.68). 

 Bill more slender, and colors usually darker. 



5. T. fuscescens. Above uniform fulvous-brown or tawny, jugulum 

 creamy buff, marked with small cuneate spots or streaks of brown, 

 somewhat darker than the crown. Two races, as fellows: 



a fuscescens. Above light fulvous-brown, ortawny; jugulum creamy 

 buff with narrow cuneate markings of brown, scarcely 

 dai ker in tint than the upper parts. Wing 3.75-4.15 (3.90), 

 tail 2.70-3.30 (2.96), culmen .52-.60 (.55), tarsus 1.05.-125 (1.15), 

 middle toe .G5-.72 (.69). (The prevalent eastern form.) 



ft i-alicicolus. Above russet-olive, jugulum very pale buff, with 

 euuuulc markings of dark brown. Wing 3.80-4.25 (4.02), 

 tail 2.95-3.40(3.20), culnien .55-.60 (.57), tarsus 1.15-1.28(1.17), 

 middle toe .C5-.75 .69). (Rare straggler from the Rocky 

 Mountains). 



