30 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



February 23, 1961, had the iris dark mouse brown; maxilla and tip of 

 mandible black; base of mandible fuscous-black; tarsus and toes 

 fuscous-brown; claws black. 



Measurements. — Males (10 from northern Code, eastern Province 

 of Panama, San Bias, and Darien), wing 80.5-88.5 (84.8), tail 37.5- 

 45.8 (40.5), culmen from base 7.1-8.4 (7.7), tarsus 9.2-11.0 (10.1) 

 mm. 



Females (10 from eastern Colon, Darien, and San Bias), wing 80.5- 

 88.1 (85.1), tail 35.7-46.4 (41.4), culmen from base 7.2-10.3 (8.2), 

 tarsus 9.0-10.5 (9.9) mm. 



Figure 2. — White-thighed Swallow, Golondrina Muslos Blancos, Neochelidon 



tibialis minima. 



Resident. Found locally in pairs or small flocks in humid forest 

 areas of central and eastern Panama; on the Pacific slope, in the high 

 levels of Cerro Azul, especially around the lake; and in Darien, on the 

 lower Rio Sambu, the Rio Tuira at the mouth of the Paya, at Cana, 

 along the Rio Pucro to the village of Pucro; and around Cerro Tacar- 

 cuna from the base to 1250 m; on the Caribbean side, in northern Code; 

 in the Canal Zone near the lower Rio Chagres; and eastern San Bias 

 near Armila. 



On February 28, 1962, I collected a male from a small flock near 

 the head of the Rio Guabal, northern Code. Ridgely (1976, p. 262) 

 saw 6 at El Valle, Code, April 27, 1969. On January 13, 1976, J. J. 



