306 Bangs, Birds from Western Costa Rica. [july 



Pygochelidon cyanoleuca (Vieill.). Sixteen specimens, adults and 

 young of both sexes, Boruca, Paso Real and Barranca, May-July. 



MNIOTILTID.E. 



Chrysocantor sestiva aestiva (Gmel). Four specimens, two males, two 

 females, Boruca and Pozo del Rio Grande, April 10 to April 27. 



Dendroica pensylvanica (Linn.). Two males, Pozo del Rio Grande, 

 April 6 and April 9. 



Oporornis formosa (Wilson). Two males, Pozo del Rio Grande, April 

 4 and April 17. 



Oporornis Philadelphia (Wilson). Three specimens, two males and a 

 female, Boruca and Pozo del Rio Grande, April 11 to April 27. 



Seiurus aurocapillus (Linn.). Four specimens, both sexes, Boruca and 

 Pozo del Rio Grande, April 12 to May 6. 



Seiurus noveboracensis noveboracensis (Gmel.). One male, Pozo del 

 Rio Grande, April 8. 



Chamaethlypis caninucha Ridgway. Eighteen specimens, adults and 

 young of both sexes, Boruca, Paso Real and Barranca, May-July. 



Young in nestling plumage, besides lacking all gray and black markings 

 on the head, differ from the adults in the color of the under parts which are 

 dull olive-yellow. 



Icteria virens virens (Linn.). One female, Pozo del Rio Grande, April 9. 



Basileuterus rufifrons delattrii (Bonap.). Seven adults, both sexes, 

 Boruca and Paso Real, April, May and July. 



Basileuterus semicervinus veraguensis (Sharpe). Eleven specimens, 

 adults of both sexes and one nestling female, Boruca and Paso Real, April, 

 May and July. 



This series presents much variation, and some skins are very close to B. 

 semicervinus leucopygius (Scl. & Salv.) if not really referable to that form, 

 while others are typical B. s. veraguensis. 



Rhodinocichla rosea eximia Ridgw. Thirty-three specimens, adults 

 of both sexes, immature of both sexes and two nestlings, both male. Bor- 

 uca, April-July. 



CCEREBID.E. 



Chlorophanes spiza exsul Berlepsch. Ninety-one specimens, adults 

 and young of both sexes, Boruca and Paso Real, April-July. 



This series is, like Chiriqui specimens, wholly referable to C. spiza exsul, 

 which in my opinion is an excellent form. The very short bill of exsul, 

 which in the adult male averages about 15 mm., at once distinguishes it 

 from the northern guatemalensis with a bill of 17.5 mm. 



Cyanerpes cyaneus (Linn.). Sixty-nine specimens, adults and young 

 of both sexes, Boruca, Paso Real and Lagato, April-July. 



Cyanerpes lucidus isthmicus subsp. nov. 



Five specimens, four adult males, one adult 9 (?)> Boruca and Paso Real, 

 July. 



