58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
growth thickets (rastrojo) and other similar ground cover. At the 
end of January there was such a decided increase in their singing that 
I believed that their main nesting season was at hand. 
They were secretive, but at the same time alert, so that by quietly 
waiting it was usually possible to draw them out from the denser 
coverts to places where they could be seen. Usually the pair came 
together, peering about with neck outstretched and erected crest, 
presenting a highly attractive appearance. In the higher trees I found 
them at times somewhat of a bother, since, against the brighter light 
above, birds were seen only in silhouette so that I was continually 
deceived by the antshrikes while searching for pepper-shrikes and 
other wilder game. 
This antshrike was another of the birds apparently long resident 
in Coiba that had darkened so in color in comparison with those of 
the mainland that this was easily seen as soon as the first examples 
came to hand. They represent a hitherto unrecognized race which I 
now describe. 
THAMNOPHILUS DOLIATUS EREMNUS subsp. nov. 
Characters.—Similar to Thamnophilus doliatus nigricristatus Law- 
rence,!? but definitely darker in both sexes; male with black bars 
broader below, the throat heavily streaked with black, and the white 
markings reduced on the dorsal surface; female decidedly darker 
brown both above and below, the darker coloration being especially 
prominent on the lower surface, where it spreads to the throat and 
under wing coverts. 
Description—Type, U.S.N.M. No. 460815, female, from Isla 
Coiba, Panama, collected Jan. 22, 1956, by A. Wetmore (orig. 
No. 20389) : Crown auburn, merging to Mars brown on the tips of 
the feathers; hindneck russet with indistinct shaft streaks of dark 
to dusky neutral gray; lower hindneck, back, and scapulars auburn ; 
lower rump cinnamon-buff; inner webs of remiges and of wing 
coverts dusky neutral gray; outer webs, and a narrow edging on 
inner webs, russett; upper surface of rectrices russet, lower surface 
verona brown, with a faintly indicated subterminal central wash of 
neutral gray forming an indefinite spot; frontal feathers immediately 
behind nostril light buff, with whitish bases; the rather bristly loral 
feathers likewise whitish basally, but with dull black tips; somewhat 
indefinite superciliary and side of head behind eye warm buff, with 
17 Thamnophilus nigricristatus Lawrence, Proc. Acad. Nat. Sci. Philadelphia, 
vol. 17, 1865, p. 107. (Lion Hill, Canal Zone.) 
