12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



and abdomen somewhat darker, varying in the direction of vitellinus. 

 They are thus somewhat intermediate, but are definitely near milleri. 



It has been suggested that Manacus aurantiacus (Salvin) found on 

 the Pacific slope of western Panama would eventually prove to be 

 conspecific with M. vitellinus, but my studies to date do not bear out 

 this supposition. Brighter color, particularly in the male, and smaller 

 size mark aurantiacus uniformly throughout its range from south- 

 western Costa Rica through Chiriqui, southern Veraguas, and both 

 sides of the Azuero Peninsula in Veraguas, Herrera, and Los Santos. 

 Manacus vitellinus vitellinus from near Santa Fe, Veraguas, and 

 La Campana and Chorrera in the western section of the Province of 

 Panama, where intergradation, if present, should occur, show no 

 variation from the normal pattern of that race. From present infor- 

 mation the two groups appear to be separated by a savanna area in 

 which neither is found. The two appear so completely distinct that 

 there is no basis for uniting them. 



Aldrich (1937, p. 95) separated the population of the western side 

 of the Azuero Peninsula as Manacus aurantiacus flaviventris, as a 

 series from that area appeared brighter colored than those available 

 at the time from western Chiriqui and southwestern Costa Rica. 

 During the course of my own field investigations I have accumulated 

 a considerable series from Veraguas and eastern Chiriqui, and have 

 examined additional material from western Chiriqui and Costa Rica. 

 A study of this extensive material indicates that the supposed differ- 

 ences do not hold. Males in fresh plumage from both areas are 

 strongly orange, but as the season progresses there is fading, particu- 

 larly in the dry months when sun is more intense. 



The following measurements may be useful for comparison with 

 those of the races of Manacus vitellinus. 



Males (25 specimens), wing 44.8-47.8 (46.3), tail 26.0-30.2 (28.7), 

 culmen from base 11.2-12.2 (11.7), tarsus 19.5-20.6 (20.1) mm. 



Females (21 specimens), wing 47.8-50.0 (48.7), tail 29.0-30.9 

 (30.3), culmen from base 11.3-12.3 (11.8), tarsus 18.2-20.5 (19.1) 

 mm. 



Family Tyrannidae: Tyrant Flycatchers 



TYRANNUS MELANCHOLICUS CHLORONOTUS Berlepsch: Tropical King- 

 bird, Pechi-amarillo Grande 



Tyrannus chloronotus Berlepsch, Ornis, vol. 14, 1907, p. 474. (Temax, Yuca- 

 tan.) 



A female was collected and several others seen along a stretch of 

 sandy beach, where they rested on the open ends of branches, or on 

 the tops of low shrubs. 



