TURDUS. 575 



p. Length about 6.25-7.25, wing 3.40-3.80 (3.65), tail 2.60- 

 2.70 (2.75), culmen .50-.52 (.51), tarsus 1.10-1.25 (1.13). 

 Eggs .87 X -63. Hab. In summer, higher mountains of 

 northeastern United States (Catskills, White Moun- 

 tains, etc.), and Nova Scotia ; Illinois (autumn) ; win- 

 ter quarters unknown 757a. T. alicise bicknelli 



EiDGW. Bicknell's Thrush. 



<P. A very distinct orbital ring of buff or whitish. (Above uniform 



olive, varying from a grayish to a russet tint, the wings, 



sometimes tail also, slightly browner, or less olive, than back ; 



sides of head with a strong buffy suffusion ; chest buffy, 



marked with triangular spots of brown or dusky. JSfest in 



bushes, usually near water, bulky, and compact, and neatly 



constructed of mosses, shreds of bark, etc. Eggs light gi-een- 



ish blue, averaging decidedly paler than in T. alicice, spotted 



with rusty brown.) 



e\ Above russet-brown, the wings and tail often appreciably 



browner or more rufescent ; chest pale buff, marked 



with rather small and usually narrow cuneate spots 



of dark brown ; length 6.90-7.60, wing 3.60-4.00 (3.87), 



tail 2.80-3.30 (3.05), culmen .50-.60 (.54), tarsus 1.10- 



1.20 (1.13). Eggs .93 X -67. Hab. Pacific coast, north 



to Sitka ; south, in winter, through western Mexico to 



Guatemala. 



758. T. ustulatus ISTutt. Russet-backed Thrush. 

 e'. Above decidedly olivaceous, sometimes even inclining to 

 grayish, the wings and tail concolor with, or at least not 

 very different from, the back ; chest yellower buff, marked 

 with large, broad, dusky (sometimes blackish) triangular 

 spots; length 6.35-7.55, wing 3.80-4.10 (3.96), tail 2.80- 

 3.10 (2.95), culmen .50-.55 (.52), tarsus 1.05-1.18 (1.10). 

 Eggs .90 X -65. Jlab. Eastern North America, but west 

 to and including Eocky Mountains (as far as East Hum- 

 boldt Mountains and the upper Columbia), breeding chiefly 

 north of the United States, wintering from Gulf States 

 and Mississippi Valley south to Cuba, Guatemala, Costa 

 Eica, Panama, and Peru.. 758a. T. ustulatus swainsonii 



(Cab.). Olive-backed Thrush. 

 Second quill shorter than fifth, the fourth longest ; tail and its upper 

 coverts rufous, in decided contrast with the color of the back. 

 (Chest, and a distinct orbital ring, buffy, sometimes nearly white, 

 the former marked with large triangular spots of dusky. JVest on 

 ground, in damp or swampy woods, composed of dead leaves, dry 

 grasses, etc. Eggs plain greenish blue, paler than in T. muste- 

 linus and T. fuscescens.) 



