FAMILY TROCHILIDAE 35 1 



Description. — Length, 105-115 mm. Male, white-throated phase, 

 crown shining emerald-green; rest of upper surface, including lesser 

 to greater wing coverts, rather dark bronze-green, with upper tail 

 coverts more bluish ; tail blue-black ; wings dusky, with a slight pur- 

 plish sheen ; lores black ; edge of wing tawny, cheek feathers basally 

 black, tipped with dark green ; a white line above auricular region from 

 back of eye ; chin and throat white, viewed at an angle (with strong 

 light from the rear) with a faint pinkish cast ; occasionally with a few 

 purple feathers along the base of the gorget, or scattered elsewhere 

 in the white area ; sides of neck and breast bright metallic green ; 

 lower breast and abdomen gray ; glossed with dull bronze-green ; under 

 tail coverts bronzy gray, edged with paler gray ; tibial tufts white ; 

 under wing coverts dull bronze-green. 



Male, purple-throated phase, chin and throat shining metallic violet- 

 purple ; otherwise, as described for the male with white throat. 



Adult female, above shining metallic green, with the upper tail co- 

 verts more bluish green ; rectrices basally green, with a subterminal 

 band of black, three or more outer pairs tipped with grayish white ; 

 side of head, including lores, black, with a white or buff streak above 

 the auricular region ; under surface from throat to abdomen tawny- 

 buff; femoral tufts white; under tail coverts light gray centrally, 

 bordered with white, or buff ; edge of wing tawny-buff. 



The species ranges over the higher elevations in mountain areas 

 from northwestern Nicaragua through Costa Rica and Chiriqui to 

 Veraguas and western Code. Females throughout this area in the 

 main are uniform, except that those of Panama average slightly more 

 rufous on the under surface. Birds of this sex from the eastern end 

 of the range in Panama also are somewhat darker green above. Diffi- 

 culty in taxonomic treatment is found in the two distinct styles of 

 throat color of males. In early studies, the female and the two forms 

 of the male were believed to be separate species — a belief that con- 

 tinued for the males after the identity of the females was correctly 

 established. Berlioz (Ornith. als biol. wiss., Festschr. E. Stresemann, 

 1949, pp. 4-5) more recently has stated the belief that the group as a 

 whole is a complex of a species in which the males are not completely 

 stable. His conclusion was based on examination of about 50 males. 

 After study of more than three times that number found in American 

 museums and in the British Museum I have come to agree with his 

 conclusion. The long series available allows recognition of five groups, 

 separated geographically, in each of which more than 90 percent may 

 be recognized as distinct, and so may be treated as subspecies. The 



