36 LAND-BIRDS. 



breast and sides of the throat spotted with dark brown. It is 

 said that specimens of this species grade inseparably into 

 others of swainsonii (-O). But distinctions are not to be based 

 wholly on coloration.* 



b. The Gray-cheeked Thrushes build their nests in arctic 

 countries, most often on the ground. The only egg of this 

 species in my collection is like that of the Swainson's Thrush, 

 but more thickly and minutely marked. (See Z), 5.) 



c. The Gray-cheeked Thrush is thought by some orni- 

 thologists not to be a valid species, but, if not a species dis- 

 tinct from the Swainson's Thrush, it is a very distinct variety 

 or geographical race. It differs from that bird slightly in 

 coloration, and markedly in distribution, habits, song, and 

 notes. 



The Arctic Thrushes are the rarest of those who migrate 

 through Massachusetts, particularly that part which borders 

 upon the sea, since they generally prefer a more inland route 

 to the north than this State affords. I have occasionally seen 

 them in the latter part of April or in May, but they are shy 

 and very timid, so that it is difficult to approach them closely, 

 as, when startled, they fly about restlessly. Perhaps, on this 

 account, they have escaped general observation. They are 

 eminently terrestrial birds, and spend nearly all their time on 

 the ground, picking up their food among the fallen leaves in 

 such places as the Hermit Thrush frequents ; often preferring, 

 however, dry land and solitary spots, where they run but little 

 risk of being disturbed. They stand rather more erectly than 

 the " Swamp Eobins " so called (T 7 . pallasii), but it must be 

 remembered that erectness of bearing is a general character- 

 istic of all "Wood Thrushes." They pass the summer in the 

 arctic region, and, on their return to the South, pass through 

 the neighborhood of Boston about the first of October, but are 

 then extremely rare, since " in the fall migrations they follow 

 for the most part a route far from the sea-shore." 



* Since this was written the specific name biclcnelli (see Appendix), breeds 

 distinctness of these Thrushes has been commonly among, but does not inter- 

 established beyond question by the breed with, the Swainson's Thrushes, 

 discovery that a small form of T. alicice, which inhabit the upper slopes of many 

 recognized as a subspecies under the of the New England mountains. W. B. 



