OF THE HAMILTON ASSOCIATION. 319 



Hab. Eastern North America, west to the Plains and Alaska, north to 

 the Arctic coast, south in winter to Costa Rica. Breeds chiefly north of the 

 United States. 



Nest and eggs, similar to those of the OHve-backed Thrush. 



It is still a question with many Ornithologists whether this 

 should be separated from the Olive-back, or regarded as only a 

 variety of that species. The Committee of the A. O. U. has 

 decided to separate it as above, and I quite agree with the 

 decision, for the few I have found could be identified at once by 

 the description. When seen in the woods it resembles the 

 Olive-back so closely that, till well acquainted with its appear- 

 ance, it is difficult to tell the one from the other. On this 

 account we cannot with certainty say which is the more numer- 

 ous ; but so far as I can judge, the proportion of the Gra}'- 

 cheeked species which pass this way is not more than one to 

 two of the other. Dr. Coues regards it as the northern form of 

 the Olive-back, and suggests that this difference in the breeding 

 range produces the change in size and color, which are regarded 

 as specific distinctions. Like all the other Thrushes it most 

 likely is musical at home, but here it comes and goes in silence. 



299. TURDUS USTULATUS SWAINSONII (Cab.). 758a. 

 Olive-backed Thrush. 



Above uniform greenish-olive ; below white, olive shaded on sides ; sides 

 of head, throat, neck and breast strongly tinged with buff; breast and throat 

 thickly marked with largedusky olive spots. Length, about 7 ; wing, 3J ; tail, 3 



Hab. 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. 



Nest, in a tree or bush, 6 or 8 feet from the ground; composed of rootlets, 

 leaves and moss. 



Eggs, 4 to 5 ; greenish-blue, freckled with brown. 



In Southern Ontario the Olive-backed Thrush is a regular 

 visitor during the season of migration, appearing in small 

 companies about the loth of May, and remaining till about the 

 25th of the same month, after which none are seen till they return 

 in the fall. While here they frequent low, moist woods, and 



