Carriker : List of the Birds of Costa Rica. 595 



Few specimens of this[bird are collected in the fully adult plumage, 

 having the prominent silvery streak on each side of the pileum. It is 

 quite probable that the birds acquire this gradually, and that the older 

 the bird, the more pronounced becomes the silvery color. 



The species ranges over the whole of the interior of the country, 

 from an altitude of perhaps 6,000 feet up to the timber-line on the 

 high volcanoes. In Mr. Fleming's collection is a skin taken by Under- 

 wood and labelled " Carrillo," which is undoubtedly an error, the skin 

 probably having become mixed with other birds from Carrillo and 

 labelled wrongly. In a month's collecting there I never saw the bird, 

 neither did I get it at La Hondura, higher up the Rio Sucio gorge at 

 not less than 4,000 feet, although conditions there seemed very 

 favorable for its presence. It is partial to cold humid forests, 

 and always keeps on or near the ground, among the masses of brush 

 and ferns found at high altitudes where there is much moisture. I 

 found them quite common at Ujurras de Terraba, high up on the crest 

 of the continental divide, and had very good opportunities to study 

 them in life. (For additional notes on habits, see page 332, Intro- 

 duction. ) 



Family Formicariid^. 



Key to the Costa Rican Species. 



7. Tail equal in length to wing, or if shorter, the difference not greater than the 

 length of the hind claw. 

 a. Either barred or spotted prominently both above and below. 



b. Heavily spotted with black over back, wings, and breast; throat black; 

 chest chestnut. Phcenostictus macleannani saturatus, $ , 9 • 



bb. Barred above and below, but not spotted. 



c. Black above and below, finely barred throughout (except pileum) with 

 white. Cymbilanius lineatus fasciatus, $ • 



cc. Black above (except chestnut pileum), narrowly barred with buff-och- 

 raceous; buff-ochraceous below, finely barred with black. 



Cymbilanius lineatus fasciatus, 9 • 

 aa. Neither barred nor spotted above or below. 



b. Entire body black or very dark ashy, with more or less white on shoulders 

 or wing-coverts. 

 c. Whole body almost entirely black, no ashy below. 



d. Size small (wing 50 mm.); wing-coverts tipped with roundish white 

 spots, shoulder white and tail tipped with white. 



Formicivora boucardi virgata, $ . 



dd. Size larger (wing 80 mm.); entirely black, except edge of shoulder 



white. Myrmeciza immaculata, $ . 



cc. Ashy black above and grayish-ash below, shoulder white, wing-coverts 



black, tipped with white. Cercomacra tyrannina crepera, $ . 



