1917.] Chapman, Distribution of Bird-life in Colombia. 531 



Our series of some fifty specimens of this species from Matto Grosso, 

 Bahia, southeastern Brazil, Dutch Guiana, the lower Orinoco, Santa Marta 

 and the other Colombian localities Hsted below, and eastern Panama, 

 presents much variation. As, with many other species inhabiting more or 

 less open or scrubby places the plumage shows the fading effect of wear and 

 exposure to light. Using, however, only comparable specimens and the 

 series at hand appears to represent two forms, one of which is found in 

 eastern South America from southeastern Brazil to the delta of the Orinoco ; 

 while the other ranges from southwestern Brazil to western South America 

 east of the Andes (except in Colombia) to eastern Panama, whence we have 

 ten specimens from El Real which considerably extend the known range of 

 the species. 



For the more eastern form the name atricapillus (Linn.) is evidently 

 available, for the more western I accept alboviUatus (Lafr. & d'Orb.) which 

 Hellmayr (I. c.) has definitely shown to be based on an immature specimen 

 of this species. Mimus brasiliensis Wied (type examined) is a synonym of 

 atricapillus (Linn . ) . 



The western form is characterized by its less rufescent coloration. 

 Thus the back is raw-umber rather than rich Brussel's-brown, the rump 

 clay-color to ochraceous-buff .rather than ochraceous-tawny, while the 

 underparts average paler. The color of the rump is the most constant 

 character and taken in combination with the other two, generally seems 

 diagnostic. In addition to the specimens listed below from Colombia, the 

 following localities are represented by specimens which appear to be refer- 

 able to this form: Brazil: Corumba, 2; Cuyaba, 2; Rio Taquary, 1; 

 Calama, R. Madeira, 1. Panama; El Real, 10. 



An immature female from Honda has a well-developed white line reach- 

 ing from over the eye to the nape. In a younger bird from Cienaga, Santa 

 Marta, this line extends to a point half way between the eye and the base 

 of the bill. Two specimens from La Morelia, one adult, one immature, 

 have a few white feathers on the postauricular region. 



Atrato River, 2; Cienaga, Santa Marta, 3; Algodonal, Magdalena 

 River, 1; Puerto Berrio, 4; Malena, 2; Honda, 1; Villavicencio, 5; La 

 Morelia, 5. 



(3499) Rhodinocichla rosea rosea (Less.). 



Fumarius rosarius Less., 111. Zool., 1834, pi. 5 ("Br^sil" = Colombia, cf. Lafr. 

 Rev. Zool., 1845, p. 10). 



San Antonio (south of Bogotd), 3. 



