370 BuUetin American Museum of Natural History. [Vol. XXXVI, 



1936. Dysithamnus semicinereus semicinereus Scl. 



Dysithamnus semicinereus Scl., P. Z. S., 1855, p. 90, pi. 97 (Bogotd); Todd, 

 Bull. A. M. N. H., XXXV, 1916, p. 545 (part; Bogotd; La Candela; near San 

 Agustin; Andalucia; Buena Vista). 



Mr. W. E. Clyde Todd {I. c.) has presented us with such a careful study of 

 the relationships of the puzzling assemblage of birds forming the Dysithamnus 

 mentalis group, that I hesitate to advance conclusions differing somewhat 

 from those reached by him after an examination of our specimens. 



Whether we have one or more species in this group, I am not prepared 

 to say, and so far as specific relationships are concerned, the names here 

 ■ adopted must be considered as tentative. Far more material than is now 

 available is required before this exceptionally difficult problem can be 

 solved. Meanwhile, I merely attempt to identify our Colombian material, 

 using my knowledge of the faunal affinities of certain localities when the 

 specimens from them cannot be satisfactorily referred to one form or another. 



The specimens I should refer to the present race (the characters of which 

 have been fully described by Mr. Todd) are all from the Subtropical Zone 

 of the Eastern Andes, and eastern slope of the Central Andes. Seven 

 specimens from Mirafiores (= e. of Palmira) and two from La Frijolera, 

 both on the western slope of the Central Andes, referred by Mr. Todd to 

 this race, I place respectively under D. s. extremus, and an as yet unnamed 

 race of B. mentalis; while a series from the Pacific coast of- Ecuador, consid- 

 ered by the same author to be semicinereus, I believe to represent a third 

 race distinguished by its smaller size, slight color differences in the adult 

 male and pronounced color differences in the female and immature male. 



Buena Vista, 12; La Candela, 5; near San Agustin, 1; Andalucia 

 (5000 ft.), 1. 



(1936a) Dysithamnus semicinereus extremus Todd. 



Dysithamnus extremus Todd, Btill. A. M. N. H., XXXV, 1916, p. 549 (Salencio, 

 type; near Jimenez; Pavas; La Maria; San Luis; San Antonio; Las Lomitas; Rio 

 Frio; Salento). 



Dysithamnus semicinereus Scl. & Salv., P. Z. S., 1879, p. 525 (Concordia). 



Inhabits the Subtropical Zone of the Western Andes and western slope 

 of the Central Andes, descending to the upperpart of the Tropical Zone on 

 the western slope of the Western Andes and in the Cauca Valley. 



While adult males of this race can readily be distinguished from semi- 

 cinereus, immature males of the two forms, as Mr. Todd (/. c, p. 551) has 

 remarked, are " not distinguishable in any way . . . . " 



