106 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



cc. Abdomen slate color or gray. 

 d. Back with a large concealed patch of white; sexes nearly alike in color. 

 e. Throat uniform black. (Costa Rica and western Panamd.) 



Myrmeciza Isemosticta, adult male (p. 109). 

 ee. Throat spotted or barred with white. 



Myrmeciza Isemosticta, adult female (p. 109). 

 dd. Back without a concealed white patch; sexes very different in color. 

 e. All the wing-coverts with a white apical spot or dot; tail relatively shorter. 

 /. Darker, the back, rump, etc., deep mummy or vandyke brown, head 

 (all round) black, chest, breast, and abdomen blackish slate. (North- 

 western Ecuad6r). . .Myrmeciza maculifer, adult male (extralimital).«J 

 ff. Paler, the back, riimp, etc., mars brown, head (all round) blackish slate, 

 chest, breast, and abdomen slate-gray. (Eastern Panama and adja- 

 cent portion of Colombia) Myrmeciza cassini, adult male (p. 110). 



ee. Wing-coverts (except, sometimes, a few of the more anterior lesser coverts) 

 without white spots or dots. ( Myrynedza exsul.) 

 f. Slightly darker or duller in general coloration, with slate color of under 

 parts usually not paler on abdomen. (Caribbean slope of Panamd., 

 Costa Rica, and Nicaragua.) 



Myrmeciza exsul exsul, adult male (p. 111). 

 ff. Slightly brighter in coloration, with slate color of under parts usually 

 paler on abdomen. (Pacific slope of Costa Rica and western Panama). 

 Myrmeciza exsul occidentalis, adult male (p. 113). 

 hh. Back, wings, etc. (whole upper parts), also entire under parts, uniform black, 

 the anterior lesser wing-coverts white. 

 c. Forehead and lores densely (normally) feathered; white area on anterior mar- 

 gin of wing narrower; tarsus 31.5-32. (Central Colombia.) 



Myrmeciza immaculata, adult male (extralimital).^ 

 cc. Forehead and lores scantily feathered; white area on anterior margin of wing 

 broader; tarsus 33.5-36. 

 d. White area on anterior portion of wing smaller, involving only marginal 

 lesser coverts; tarsus 33.5-34.5. (Costa Rica and western Panama.) 



Myrmeciza zeledoni, adult male (p. 114). 



dd. White area on anterior portion of wing much larger, involving nearly the 



whole of the lesser covert area; tarsus 36. (Western Ecuador to central 



Colombia.) Myrmeciza berlepschi, adult male (extralimital).c 



aa. Under parts without any black. 



h. Throat and chest buff or ochraceous-buff (the former sometimes whitish); abdo- 

 men white. {Myrmeciza houcardi.) 

 c. Wing-coverts distinctly spotted or barred with black. 

 d. Spots or bars on wing-coverts larger, very conspicuous. 



Myrmeciza boucardi griseipectus, adult female (extralimital). 

 dd. Spots or bars on wing-coverts smaller, inconspicuous. 



Myrmeciza boucardi panamensis, adult female (p. 108). 



a Myrmelastes exsul maculi/er Hellmayr, Novit. Zool., xiii, no. 2, July 10, 1906, 340, 

 342 (Paramba, n. w. Ecuador, 3,500 ft.; coll. Tring Mus.). — M[yr7nelastes] maculifer 

 Ridgway, Proc. Biol. Soc. Wash., xxi, Oct. 20, 1908, 194, in text. 



6 T[hamnophilus]im:maculatus Lafresnaye, Rev. Zool., viii, Sept., 1845, 340 (Bogotd, 

 Colombia; types now in coll. Bost. Soc. N. H.). See Ridgway, Proc. Biol. Soc. Wash., 

 xxii, 1907, 74, under Myrmeciza berlepschi. 



c Myrmeciza berlepschi Ridgway, Proc. Biol. Soc. Wash., xii, April 17, 1909, 74 

 (Chimbo, n. w. Ecuador; coll. U. S. Nat. Mus.). This form (of which I have not seen 

 Colombian specimens) may prove to be only subspecifically distinct from M. zeledoni. 



