110 The Ornithology of Chester County 
Arrival—Sept. 24 (1898)—Nov. 30 (1890); 
ave. 24 yrs. Oct. 9. 
Departure—Mar. 14 (1899)—May 2 (1904- 
1Ql4) save. BE west Apriag. 
239. Regulus calundula calundula Ruby-crowned 
Kinglet. Abundant transient. 
Berwyn: 
Spring arrival—Apr. 15 (1917)—Apr. 27 
(1910) saves yrs, ; Apre ae, 
Spring departure—May 2 (1904)—May 18 
(1905); ave. 6 yrs. May g. 
Fall arrival—Sept. 21 (1898-1901)—Oct. 15 
(1696) sv ave. Ts) yrs. (Oct. 6: 
Fall departure—Oct. 12 (1898)—Nov. 27 
(TOES).4. aver (aA yrs. Oct.\2b: 
240. Polioptila cerula cerula Blue-gray Gnat- 
catcher. Straggler; Formerly a summer resident. 
Michener considered it frequent in summer and 
Barnard notes its arrival Apr. 15 to 25. The only 
recent records are of one observed at Kennett 
Square, Apr. 19, 1914, by Thomas (Cass., xviii, 
61), and another at Berwyn, May 19-21, 1914, by 
the writer. 
241. Hylocichla mustelina Wood Thrush, “Peter 
and Paul,” “song thrush,” “wood robin.” Common, 
in some localities, abundant; summer resident. Nid- 
ification begins about May 16; average date for 
complete set, May 27. 
Berwyn: 
Arrival—Apr. 11 (1890)—May 9 (1885) ; ave. 
33 yrs. May 1. 
Common—Apr. 30 (1890)—May 18 (1898); 
