514 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



RHYNCHOCYCLUS BREVIROSTRIS (Cabanis) : Eye-ringed 

 Flatbill, Piquichato Oscuro 



Medium size ; bill broad, flat ; breast dark gray, indistinctly streaked 

 with whitish ; generally similar to the Olivaceous Flatbill but darker, 

 with the ventral markings of foreneck, breast, and sides darker and 

 heavier. 



Description. — Length 145-160 mm. Adult male, outer margin of 

 10th primary lightly serrate; upper surface from base of bill to upper 

 tail coverts, including lesser wing coverts, deep olive-green ; wings 

 dusky, with primaries, secondaries, and greater wing coverts edged 

 with yellowish olive-green ; tail dark grayish brown, edged with deep 

 olive-green ; eye-ring white, wider and more prominent than in 

 R. olivaceiis ; lores faintly blackish ; auricular region faintly dusky 

 posteriorly, paler anteriorly ; foreneck, upper breast, sides, tibiae, and 

 under tail coverts dull olive-green ; chin and throat faintly grayish ; 

 lower breast and abdomen yellow, becoming paler, whiter at sides ; 

 outer under wing coverts dusky, forming a distinct spot ; rest pale 

 yellow ; edgings of under wing feathers pale brownish white, whiter 

 laterally toward the tips. 



Adult female, like male but outer margin of 10th primary smooth 

 or very faintly serrate ; color pattern somewhat duller. 



These are birds of Tropical and lower Subtropical Zone forests, 

 that in my experience in Panama have been less abundant than the 

 related Rhynchocyclus olivaceus. Two races are found in the Repub- 

 lic, one in the west, the other in the east. 



RHYNCHOCYCLUS BREVIROSTRIS BREVIROSTRIS (Cabanis) 



Cyclorhynchus brcvirostris Cabanis, Arch. Naturg., vol. 13, bd. 1, heft 2, 1847, 

 p. 249. (Jalapa, Veracruz, Mexico.) 



Characters. — Somewhat paler, both above and below ; dorsal surface 

 very faintly lighter ; breast and foreneck lighter, with the abdomen 

 faintly deeper yellow. 



Measurements. — Males (10 from Chiriqui), wing 78.7-83.7 (80.5), 

 tail 66.1-74.2 (70.1), culmen from base 15.1-16.2 (15.7), tarsus 

 18.2-18.8(18.7) mm. 



Females (10 from Honduras, Costa Rica, Chiriqui, and Veraguas), 

 wing 72.0-78.0 (75.2), tail 59.3-66.8 (62.8), culmen from base 

 14.1-16.6 (15.7, average of 9), tarsus 18.0-18.8 (18.4) mm. 



Resident. Found locally on the Pacific slope in tropical and lower 

 subtropical forests from western Chiriqui, east through Veraguas, 

 including the western side of the Azuero Peninsula, to Cerro Cam- 



