276 FIELD MUSEUM OF NATURAL HISTORY ORNITHOLOGY, VOL. I. 



Dendroica coronata (Linn.). 



3 specimens. Guayabo 2 <5\ i 9, January 20, 23. 



Dendroica virens (Gmeliri). 



7 specimens. Coliblanco i d\ February 20, 3 9 Feb. 9, 13, 22; 

 Vol. de Turrilaba 3 d\ Feb. 25, 26, 27. 



Dendroica fusca (Mull.}. 



6 specimens. Guayabo i d\ Jan. 24, 3 9, Feb. 4, 5, i sex? 

 Jan. 23; Coliblanco i d\ Feb. 22. Only one male in full spring 

 plumage. 



Dendroica pensylvanica (Linn.}. 



13 specimens. Guayabo d\ January 16, 17, 25, 26, 30, February 

 i, 9 January 27, 20, 24, 28, February 4, i; Port Limon 9, Mar. 9. 



But one of these specimens has the fully adult plumage a male 

 taken at Guayabo January 25. 



Oporornis Philadelphia (Wilson}. 



i specimen. Guayabo d\ February 4. 



Qeothlypis trichas (Linn.}. 



1 specimen. Guayabo o im., January 27. 



Geothlypis semiflava bairdi (Nutting). 



2 specimens. Guayabo i 6\ i sex?. 



Wilsonia pusilla (Wilson). 



5 specimens. Guayabo d\ January 20, 9 January 28, January 

 28, sex? January 25, January 26. 



These specimens are quite easily referable to the above species. 

 It is noteworthy that all specimens of pusilla were taken below 4,000 

 feet, they apparently not mingling with pileolata, the bird found at 

 higher elevations. Bangs records pusilla from northwestern Costa 

 Rica, and implies in his remarks concerning it that it is a bird occur- 

 ring at lower levels than pileolata*. 



Wilsonia pusilla pileolata (Pallas}. 



35 specimens. Coliblanco 15 d\ 8 9, 5 sex?; Vol. de Turrialba 

 3 cT, i 9,3 sex?. 



These birds were profusely abundant about the potrero at Coli- 

 blanco. They were in all conceivable situations, and frequently 



*Proc. Biol. Soc. Wash., XXII, p. 36, March 10, 1909. 



