592 Annals of the Carnegie Museum. 



230. Polioptila caerulea. Blue-gray Gnatcatcher. 



The status of this species here is uncertain. The only record is of 

 an individual seen and secured on August 25, 1900. It is not known 

 to breed so far north in Pennsylvania, and the bird taken may have 

 been migrating, and strayed out of its range. 



231. Hylocichla mustelina. Wood Thrush. 



Common, according to Mr. Bacon, as a summer resident, and the 

 best known of the small thrushes. This observation, however, must 

 refer to the mainland only, as we did not find the species on the 

 Peninsula at all, and our only record is of several seen May 28 in 

 woodland along the lake shore bluff, a few miles west of the city limits. 



232. Hylocichla fuscescens. Wilson's Thrush. 



Occurs as a moderately common summer resident, frequenting the 

 woodland and shrubbery, particularly along the board-walk. Its arrival 

 was noted May 10, 1900, and on May 26 a nest with four fresh eggs was 

 discovered, built on the ground in the woods, in an open place among 

 the dry leaves. May 11, 1875, i^ the date of the only specimen in 

 Mr. Sennett's collection. 



233. Hylocichla alicise. Gray-cheeked Thrush. 



This species was found to be of common occurrence as a migrant 

 in the fall of 1900, arriving September 18, and at once becoming 

 numerous, vying in abundance with the Olive-backed Thrush, with 

 which it was closely associated during its stay. Although the two 

 species are so similar in coloration, haunts, and habits, the Gray- 

 cheeked may always be readily distinguished from the other by its 

 call-note, which is more prolonged, quite different from the short, 

 low "chuck " of the Olive-backed. In addition it was often heard 

 to offer a variety of other notes, perhaps snatches from its song, 

 which greatly resembled those of the Wilson's Thrush. By the end 

 of September the present species had diminished in numbers, and by 

 October 6 the last had gone. The only spring record is afforded by 

 a specimen in Mr. Sennett's collection, taken May 13, 1875. 



234. Hylocichla ustulata swainsonii. Olive-backed Thrush. 



A transient visitant, only tolerably common in the spring, but much 

 more so in the fall, according to our experience in 1900. May 17 

 marked its vernal appearance, and May 26 its departure. During this 

 interval it was frequently heard singing. In the fall the earliest and 

 latest dates were respectively September 18 and October 3, thus coincid- 



