Annotated List 99 
209. Dendroica discolor Prairie Warbler. Rare 
transient, and common summer resident in the south- 
ern part of the county. Dr. Montgomery has seen 
it only on two dates, May 10, 1890, when three were 
seen and a female secured, and on May 2, 1897. 
Dr. Warren observed it on different occasions dur- 
ing the summer months on the Barren ridge (Bds. 
Pa., 1890, 293) ; Pennock and Carter found it quite 
abundant and probably breeding in the serpentine 
barrens of the southern border, June 16, 1911 (Auk, 
Xx1X, 245) ; and Burn saw a male near Chrome, in 
the same locality, on July 3, 1916. 
Spring arrival—May 2 (1897)—May 25 
(1907); ave. 4 yrs. May 11. 
210. Seiurus aurocapillus Ovenbird, “ground 
thrush.” Abundant summer resident. Nidification 
begins about May 18; average date for complete 
set, May 209. 
Berwyn: 
Arrival—Apr. 13 (1890)—May 12 (1888-9) ; 
ave. 28 yrs. Apr. 30. 
Common—Apr. 28 (1910-11 )—May 13 (1902) ; 
ave. 26 yrs. May 5. 
Bulk departure—Aug. 29 (1896-1902)—Oct. 3 
(1908) ; ave. 8 yrs. Sept. 9. 
Last seen—Sept. 12 (1913)—Oct. 7 (1897); 
ave. 9 yrs. Sept. 25. 
211. Seturus noveboracensis noveboracensis Wa- 
ter-Thrush. Not common. Montgomery took a 
specimen on May 10, 1896, West Goshen Twp., and 
I secured another at Berwyn, Sept. 22, 1906 (No. 
$92; coll Fi. By): 
