326 BIRDS OF PENNSYLVANIA. 



The Gray-cheeked Thrush is a rather plentiful spring- and fall migrant 

 in Pennsylvania ; frequents woods and thickets. The food is similar to 

 that of the Wilson's Thrush. 



NOTE. A race of this species, Bicknell's Thrush (Turdus alicice bicknelli) has 

 been described by Mr. Ridgway. A description of this bird as given by Mr. Ridgway 

 (Vol. I, Ornithology of Illinois) is as follows: "Similar to Turdus alicice Baird, but 

 much smaller and (usually) with the bill more slender. Wing, 3.40-3.80 (3.65) ; tail, 

 2.60-2.90 (2.75); culmen, .50-.52 (.51) ; tarsus, 1.10-1.25 (1.13); middle toe, .65-.70(.68)." 

 A single specimen believed to belong to this newly discovered race, named in honor 

 of its discoverer Mr. Eugene P. Bicknell, who first obtained it on the Catskill Moun- 

 tains, was captured by Prof. H. J. Roddy, near Chickies' Rock, Lancaster county. 

 I have never seen the specimen taken by Mr. Roddy, who since the above was written 

 writes me as follows concerning it. 4< Turdus alicice bicknelli, I am not quite sure 

 of. The more I study my specimen the more I think it is Turdus alicice somewhat 

 changed in some way and yet not bicknelli." The habitat of this bird as given in 

 Ridgway's Ornithology of Illinois is the higher mountains of northeastern United 

 States, from the Catskills and Adirondacks, in New York, to the White mountains 

 of New Hampshire ; breeding from an elevation of 4,000 feet upward. Straggler to 

 Illinois (Warsaw, May 24, 1884; Chas. K. Worthen)." 



Turdus ustulatus swainsonii (CAB.). 



Olive-backed Thrush. 



DESCRIPTION (Plate 100). 



Length about 7 inches; extent about 11| ; upper parts uniform greenish-olive; 

 conspicuous yellowish ring round eye ; lores, sides of head, chin, throat and breast 

 strongly tinged with yellowish ; anterior lower parts, except chin and upper part of 

 throat, marked with numerous and large dusky and blackish spots ; sides grayish- 

 olive ; middle of abdomen and under tail-coverts white ; wings and tail dusky ; 

 somewhat paler on under surface. 



Habitat. Eastern North America, and westward to the Upper Columbia river and 

 East Humboldt mountains, straggling to the Pacific coast. Breeds mostly north of 

 the United States. 



Common spring and fall migrant, generally distributed throughout 

 the state ; arrives here usually about the last of April and departs in 

 October. The Olive-backed Thrush breeds occasionally, it is said, in 

 our higher mountainous regions. 



Turdus aonalaschkae pallasii (CAB.). 



Hermit Thrush. 



DESCRIPTION (Plate 100). 



Size about the same as last. Upper parts olive ; rump and tail reddish-brown ; 

 yellowish ring round eye ; below white ; shaded on sides with grayish-olive ; mid- 

 dle of upper part of throat usually immaculate ; sides of head, in some specimens, 

 very similar to back ; but usually sides of head, sides of neck, lower part of throat 

 and breast are tinged with buff; lower throat and breast conspicuously marked with 

 large blackish and dusky-olive spots ; upper surface of tail reddish-brown, below 

 paler ; outer webs of wing-quills similar but lighter ; inner webs blackish. 



Habitat. Eastern North America, breeding from the northern United States 

 northward, and wintering from the Northern states southward. 



