122 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



6. Crown and under surface from throat to abdomen streaked prominently 



with white 7 



Under surface and crown without streaks, or if streaked, these markings 

 indistinct, dull-colored, not white 8 



7. Wings and tail rufous, wing coverts spotted indistinctly with rufous. 



Black ant-shrike, Thaiunophilus nigriceps nigriccps, female, p. 142 

 Wing coverts black spotted with white, tail black tipped with white. 



Bridges' ant-shrike, Thaiunophilus bridgcsi, female, p. 140 



8. Dull black, wing coverts and tips of rectrices plain, or spotted with white 9 

 Slate, gray, or dull buff, not black ; plain or indistinctly streaked 10 



9. Wing coverts and tail plain black ; bill smaller, exposed culmen shorter 



than skull. 



Black ant-shrike, Thamnophilus nigriccps nigriccps, male, p. 142 

 Wing coverts and tail tipped with white. 



Bridges' ant-shrike, Thamnophilus bridgcsi, male, p. 140 



10. Back with a large concealed central spot of white ; crown dull black or 



brown without streaks ; under surface not streaked. 



Slaty ant-shrike, Thamnophilus punctatus atrimicha, p. 144 

 Back with no concealed white, crown and back lined indistinctly with buffy 

 brown and dull black ; base of bill with definite bristles. 



Spiny-faced ant-shrike, Xcnornis setifrons, p. 149 



11. Smaller, wing less than 55 mm 12 



Larger, wing more than 55 mm 22 



12. Outer webs of primaries rufous ; outer webs of two outermost rectrices 



white. 

 Rufous-winged ant-wren, Herpsilochmus rujomarginatus exiguus, p. 178 

 Outer webs of primaries not rufous ; outer webs of outermost rectrices not 

 white 13 



13. Feet stronger, toes larger, tarsus 20 mm or more ; crown and back plain 



with a prominent white superciliary line extending from lores to side 



of nape. . . .Black-breasted ant-wren, Foniiicivora grisca alticincta, p. 183 



Feet weaker, toes smaller, tarsus 17 mm or less ; superciliary, if present, 



not prominent 14 



14. Tail longer, 40 mm or more 15 



Tail shorter, not more than 36 mm 16 



15. Upper surface black, a large concealed white area in center of back. 



Dotted-winged ant-wren, Microrhopias quixensis, p. 179 

 Center of back rufous. 



Rufous-backed ant-wren, Tcrcnura callinota callinota, p. 185 



16. Upper surface heavily streaked with black and white 17 



Upper surface plain except for spots on the wings and tip of tail 18 



17. Throat plain white ; breast and abdomen yellow ; tail less than 20 mm. 



Pygmy ant-wren, Myrvwthcrula brachyura ignota, p. 161 

 Throat and breast heavily streaked with white. 



Streaked ant-wren, Myrvwthcrula sxirinanicnsis pacifica, p. 163 



18. Wing coverts spotted definitely with white 19 



Wing coverts plain, or spotted with cinnamon-bufT 20 



