FAMILY FORMICARIID.E 



cc. Abdomen white, upper parts chestnut 



rufous. 



d. Throat, chest and sides of breast black. . 

 . . Myrmeciza longipes panamensis, male 



dd. Throat and chest tawny, breast white, 



washed with tawny 



Myrmeciza longipes panamensis, female 



aa. With no conspicuous white on under parts, 

 b. Plumage black or gray on upper parts, 

 c. Upper and lower parts black. 



d. Stouter, terrestrial, top of head with bare, 



bright blue skin 



Gymnocichla n. nudiceps, male 



dd. More slender, not terrestrial, top of head 

 not bare. . . . Cercomacra nigricans, male 



cc. Upper and lower parts gray, not terrestrial. 



d. Blackish slate below (throat, chest and 



breast finely streaked with white) 



Cercomacra nigricans, female 



dd. Lower parts slate gray. 

 e. Plain slate gray. 



f. Head with black crown; back mixed 



with black 



Thamnophilus punctatus atrinu- 

 chus, male 



ff. Head plain slate color, no black on 



back Cercomacra tyrannina 



rufiventris, male 



ee. Throat and chest streaked with white; 

 middle of breast and abdomen white 

 Dysithamnus puncticeps, male 



bb. Upper parts chestnut brown, olive or tawny 

 rufous. 



c. Upper parts chestnut or brown; terrestrial. 



d. Stout with short tail, upper parts dark 

 chestnut, head black. 



e. Throat black, chest and breast blackish 

 slate Myrmeciza e. exsul, male 



ee. Chin gray, remainder of under parts 



vandyke brown 



Myrmeciza e. exsul, female 



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