1917.] Chapman, Distribution of Bird-life in Colombia. 371 



In view of this fact, it does not seem to me to be desirable to follow Mr, 

 Todd in referring immature males from east of Palmira (Miraflores) on the 

 western slopes of the Central Andes to semidnereus. Study of our Colom- 

 bian material shows that when a certain species is represented by different 

 forms in the Eastern Andes and Western Andes, specimens from the western, 

 or Cauca Valley slope of the Central Andes agree, as indeed might be 

 expected, with the form from the Western Andes, while those from the east- 

 ern, or Magdalena Valley slope of the Central Andes agree with the East 

 Andean form. Indeed, a specimen from Salento, a locality on the western 

 slope of the Central Andes which has essentially the same avifauna 'as 

 Miraflores, is typical of extremus. Either, therefore, we have to treat ex- 

 trevius as a full species which occurs in the same fauna as semidnereus, or as 

 a representative, intergrading form. The specimens at hand unfortunately 

 do not afford conclusive evidence of the status of the West Andean bird, but 

 all things considered, it seems to me more probable that the Miraflores speci- 

 mens are immature examples of extremus rather than adults of semidnereus. 



Salencio, 3; Las Lomitas, 7; San Antonio, 7; Rio Frio, 5; Miraflores, 7; 

 Salento, 2. 



(19366) Dysithamnus mentalis subsp. 



nthamnus semidnereus Todd, Bull. A. M. N. H., XXXV, 1916, p. 549 (La 

 Frijolera specimens only). 



Dysithamnus mentalis lateralis Todd, Bull. A. M. N. H., XXXV, 1916, p. 541 

 (Honda specimens only). 



A fully adult male and a female from La Frijolera, in Antioquia on the 

 lower Cauca River, and two females from El Consuelo, above Honda, belong, 

 in my opinion, to the same form. The male has the back olive-green clearly 

 defined from the plumbeous of the nape and head, and the yellow of the 

 abdomen extends well up to the breast. It therefore closely resembles 

 specimens of mentalis recently taken by us in the Organ Mountains, west 

 of Rio Janeiro. 



The female has the underparts much clearer and stronger yellow than 

 any bird in a series of some twenty specimens of semidnereus and extremus, 

 and in this respect agrees essentially with two females of D. mentalis latera- 

 lis Todd, from northeastern Venezuela. 



The two females from El Consuelo, near Honda, have been referred by 

 Mr. Todd to his D. m. lateralis, but there can be no doubt that they belong 

 to the same form as the birds from La Frijolera. This, as the male from 

 that locality shows, is not lateralis, but is nearer true mentalis. In my 

 opinion, these four birds represent an as yet unnamed race, which occupies 

 the lower Cauca-Magdalena humid fauna. I should, however, prefer to 



