326 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



green ; abdomen and under tail coverts light, somewhat greenish, 

 yellow ; under wing coverts pale gray. 



Immature male, like female, but with white of throat appearing 

 early. 



In several males the iris was dark brown to reddish brown ; maxilla 

 black ; mandible neutral gray ; tarsus fuscous to dark brown or dull 

 reddish brown ; toes fuscous to dark or dusky neutral gray. A female 

 had the iris dark brown ; maxilla and tip of mandible black ; base 

 of mandible dull neutral gray ; tarsus and toes dusky neutral gray. 



In early accounts based on few specimens, Corapipo altera and 

 heteroleiica of Panama and Costa Rica were listed as races under 

 Corapipo leucorrhoa, because of their close similarity in color and in 

 pattern of markings. The considerable series of all three now avail- 



FiGURE 30. — White-ruflfed manakin, saltarin gorgueriblanco, Corapipo altera, 

 head in males to illustrate throat pattern. Left, C. a. altera; right, C. a. 

 heteroleuca. 



able demonstrates two groups that logically should be treated as 

 species. In leucorrhoa, found from Guyana and southeastern Vene- 

 zuela (with that part of Brazil immediately adjacent) through 

 northern Colombia, the tenth (outermost) primary is slender, very 

 narrow and only 14 to 17 mm long. In altera and heteroleuca of 

 Central America, while the tenth primary is slender, it is broad 

 enough to be an appreciable element in the wing, with a length of 25 

 to 30 mm. The two groups, definitely distinct in this character, do not 

 show any indication of intergradation, and from available records 

 are not in contact. C. leucorrhoa in northern Colombia has not been 

 found west of the highlands above the eastern side of the valley of the 

 Rio Sinu. Typical altera ranges south from Darien in eastern 

 Panama west of the Atrato Valley to the Serrania de Baudo in 

 central Choco. Blake (Fieldiana: Zool., vol. 36, 1958, p. 535) recog- 

 nized the specific diflference of the birds of western Panama, which 

 is clearly evident from the series that I have examined. 



