188 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Range. — Southeastern Mexico to southeastern Brazil. (Many 

 species.") 



KEY TO THE SPECIES AND SUBSPECIES OF SYNALLAXIS. 



a. Pileum partly rufous, or else chest rufous. (Adults.) 



b. Pileum dull brown; chest cinnamon-rufous or chestnut-rufous. (Southeastern 



Mexico to Honduras) Synallaxis erythrothorax, adults (p. 189). 



bb. Pileum partly cinnamon-rufous or rufous-chestnut; chest grayish or white. 

 c. Greater wing-coverts and basal portion of primaries cinnamon-rufous or 

 chestnut-rufous; chest slate-gray to blackish slate. (Synallaxis pudica.) 

 d. Paler, the back, etc., olive-brown, tail brown, chest dull slate color or slate- 

 gray. (Eastern Panamd, to western Ecuador.) 



Synallaxis pudica pudica (p. 191). 

 dd. Darker, the back, etc., dark sooty brown, tail blackish brown, chest dark 

 slate to blackish slate. (Western Panama to southern Honduras. ) 



Synallaxis pudica nigrifumosa, adult (p. 192). 

 cc. Greater wing-coverts and basal portion of primaries light brown or broccoli 

 brown; chest light gray to white. (Synallaxis albescens.) 

 d. Chest distinctly gray; brown of back, etc., darker. 



e. Larger (wing averaging 54 or more in male, more than 53 in female; tail 

 averaging more than 69 in male, more than 66 in female). 

 /. Slightly paler and smaller (wing averaging 54 in male, 55 in female; tail 

 69.7 in male, 73.5 in female). (Margarita Island, Venezuela.) 



Synallaxis albescens nesiotis (extralimital).& 

 ff. Slightly darker and larger (wing averaging 56 in male, 54.7 in female; 

 tail averaging 73 in male, 70.4 in female). (Colombia to Cayenne 

 and Amazon Valley.) 



Synallaxis albescens albigularis (extralimital).c 



ee. Smaller (wing averaging 52.2 in male, 49.9 in female; tail averaging 658" 



in male, 62.9 in female). (Southwestern Costa Rica and western 



Panamd) Synallaxis albescens latitabunda (p. 194). 



« In Sharpe's Hand-List of the Genera and Species of Birds, Vol. Ill, pp. 53-58 

 (1901), forty-nine species are referred to this genus. Of these I have examined about 

 one-half, but the above generic diagnosis and description are based on the three Central 

 American species and 8. ruficapilla (type of the genus) alone. I am nearly convinced 

 that the group requires subdivision, but it should not be attempted with so poor a 

 representation of the species, and I therefore leave the problem for others to work out. 



b Synallaxis albescens nesiotis Clark (A. H.), Auk, xix, Jidy, 1902, 264 (Margarita 

 Island, Venezuela; coll. E. A. and O. Bangs). 



c Synallaxis albigularis Sclater, Proc. Zool. Soc. Lond., 1858, 63 (eastern Ecuador; coll. 

 Verreaux). — Synallaxis albescens albigularis Berlepsch and Hartert, Novit. Zool., ix, 

 April, 1902, 59 (Caicard,, Altagracia, and Suapure, Venezuela; descr. nest and eggs). — 

 Synallaxis albescens (not of Temminck) Sclater, Cat. Birds Brit. Mus., xv, 1890, 43, 

 part. 



I am not able to examine a specimen of aS. albescens albescens during preparation of 

 this key; indeed, the material available is, for all the forms, exceedingly scanty 

 and unsatisfactory. The synonymy of S. a. albescens is as follows: Synallaxis albes- 

 cens Temminck, PI. Col., iii, livr. 38, Sept., 1823, pi. 227, fig. 2 (Brazil; coll. Mus, 

 Pays-Bas); Sclater, Cat. Birds Brit. Mus., xv, 1890, 43, part. — Synallaxis albescens 

 albescens Hellmayr, Novit. Zool., xv, 1908, 59 (crit.). 



