FAMILY FORMICARIIDAE 175 



In eastern Colombia and western and southern Venezuela, south 

 to eastern Peru and northwestern Brazil, females average more olive- 

 brown above, with edgings in the primaries more rufescent, rump 

 and upper tail coverts more cinnamon-brown and the spots on the 

 wing coverts much less evident and more cinnamon-brown. These 

 have been recognized as Mynnothcrula axillaris melaena (Sclater). 

 Males (130 examined) in the two groups are highly variable from 

 dark gray to black. Females (84 compared), with considerable indi- 

 vidual variation, may be separated as indicated but only in series. 



MYRMOTHERULA SCHISTICOLOR SCHISTICOLOR 



(Lawrence) : Slaty Ant-wren, Hormiguerito Pizarroso 



Formicivora schisticolor Lawrence, Ann. Lye. Nat. Hist. New York, vol. 8, 

 1865, p. 172. (Turrialba, Costa Rica.) 



Small ; male, dark gray, black from chin to breast ; female, dark 

 brown above and below, including flanks. 



Description. — Length 90-105 mm. Tail longer than in M. a. 

 albigiiio. Adult male, upper surface, including tail, slate color ; a 

 small white patch, mainly concealed, at junction of wing and body; 

 lesser, middle, and greater coverts slaty black to black, tipped with 

 white; rest of wing like back, with outer primaries edged faintly 

 with grayish brown ; malar area black, barred with slate ; chin, throat, 

 foreneck, and in some upper breast, black ; rest of central under sur- 

 face slate color ; under tail coverts edged and tipped with white, each 

 feather with a subterminal bar of black; under wing coverts mixed 

 white, slate, and black ; inner margins of wing feathers white. 



Adult female, forehead narrowly bufif to cinnamon-buff ; crown 

 and hindneck buffy olive-brown ; back, scapulars, and upper tail 

 coverts grayer, less olive ; tail dark brown, edged with russet-brown ; 

 primaries and secondaries edged with dull reddish brown ; tips of 

 wing coverts dull cinnamon-brown, forming poorly defined spots ; 

 sides of head grayish buf¥ to buff ; chin and throat bufif ; rest of under- 

 parts tawny-buff to clay color, darker, more olive on sides and flanks ; 

 imder wing coverts and inner edging of wing feathers cinnamon- 

 buff. 



Immature male, like female, with the throat and foreneck early 

 becoming mixed with the black of the adult. 



Nestling, above Vandyke brown, with the tail duller ; under surface 

 russet. 



An adult male, taken on Cerro Mali, Darien, February 24, 1964, 

 had the iris reddish brown ; bill black, with neutral gray border on 

 the base of the cutting edge in maxilla and mandible and the gape ; 



