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).......... sadigeoere Synallaxis erythrothorax, adults (p. 189). 
bb. Pileum partly cinnamon-rufous or rufous-chestnut; chest grayish or white. 
ce. Greater wing-coverts and basal portion of primaries cinnamon-rufous or 
chestnut-rufous; chest slate-gray to blackish slate. (Synallaris pudica.) 
d. Paler, the back, etc., olive-brown, tail brown, chest dull slate color or slate- 
gray. (Eastern Panam4 to western Ecuadér.) 
Synallaxis pudica pudica (p. 191). 
dd. Darker, the back, etc., dark sooty brown, tail blackish brown, chest dark 
slate to blackish slate. (Western Panamé to southern Honduras.) 
Synallaxis pudica nigrifumosa, adult (p. 192). 
ce, 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). 
f. 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).b 
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).¢ 
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 
Pana). ccccuvinceesceaseee Synallaxis albescens latitabunda (p. 194). 
@In Sharpe’s Hand-List of the Genera and Species of Birds, Vol. III, 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 S. ruficapilia (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, July, 1902, 264 (Margarita 
Island, Venezuela; coll. E. A. and O. Bangs). 
¢ 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 (Caicar4, Altagracia, and Suapuré, 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 8. 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, Pl. Col., iii, livr. 38, Sept., 1823, pl. 227, fig. 2 (Brazil; coll. Mus. 
Pays-Bas); Sclater, Cat. Birds Brit. Mus., xv, 1890, 43, part.—Synallavis albescens 
albescens Hellmayr, Novit. Zool., xv, 1908, 59 (crit.). 
