FAMILY SYLVIIDAE 



183 



spicuous, being confined to the centers of the two posterior projections. 



Measurements. — Males (2 from Colon and Colombia), wing 45.0- 

 45.8 (45.4), tail 40.7-41.5 (41.4), culmen from base 117, tarsus 15.2- 

 17.5 (16.4) mm. 



Female (1 from Colombia), wing 45.5, tail 41.3, culmen from base 

 10.5, tarsus 14.7 mm. 



Resident. Rare and little known. Hartert described this bird in 

 1898 from a specimen collected in Ecuador. Wytsman (Gen. Av., Part 

 17, 1911, p. 17) gives the range as northwest Ecuador (the type lo- 

 cality, Cachabi) and Isthmus of Darien, possibly based on an unsexed 

 adult in the Paris Museum collected by C. Viguier, as later reported by 

 Hellmayr (Cat. Birds Am., Field Mus. Nat. History, vol. xiii, 1934, 

 p. 492). Griscom (Bull. Mus. Comp. Zool., vol. 78, 1935, p. 362) 

 mentions only the Viguier specimen, and Eisenmann (Trans. Linn. 

 Soc. N.Y., vol. 7, 1955, p. 83) says "E. Panama (Darien)." Chapman 

 (Bull. Am. Mus. Nat. Hist., vol. 55, 1926, p. 560), giving the range as 

 northwestern Ecuador to northwestern Colombia, puts it in the Tropi- 

 cal Zone. 



I encountered this bird once, at the Peluca Hydrographic Station on 

 the Rio Boqueron in Colon, in March 1961. The bird worked in typical 

 gnatcatcher fashion through the tops of bushes on the bank of an open 

 quebrada, moving with the usual vibrations of the tail and quick move- 

 ments. Henry van Horn, who accompanied me on this trip, told me 

 that he had seen 2 in similar situations traveling with groups of other 

 small birds. The specimen I collected here and a male collected by Pedro 

 Galindo at Cerro Quia (800 m) in southeastern Darien (Ridgely, 

 1976, p. 279) are the only recent specimen records for Panama. 



Ridgely (in litt.) has seen this bird on two occasions in eastern 

 Darien: 1 on the slopes of Cerro Quia (500 m) on July 17, 1975; 1 

 above Cana (670 m) on March 2, 1981. In both instances the birds 

 were traveling with mixed flocks dominated by varions tanagers (Tan- 

 gara, H eterospingus, H emit hrau pis, etc.) in forest canopy, and were 

 observed to forage mostly on terminal branches and in leafy areas, 

 much as any other gnatcatcher. Neither bird vocalized. 



RAMPHOCAENUS MELANURUS RUFIVENTRIS (BonaparteJ: 

 Long-billed Gnatwren, Cazajejen Piquilargo 



Scolopacinus rufiventris Bonaparte, 1838, Proc. Zool. Soc. London, 5 (1837), p. 

 119. (Guatemala.) 



Small; bill long; upper surface brown; tail black, tipped white; 

 throat white with dark gray streaks; rest of undersurface buffy. 



