BIRDS OF NORTH AND MIDDLE AMERICA. 75 
Genus MICRORHOPIAS Selater. 
Microrhopias Sciater, Cat. Am. Birds., 1862, 182. (Type, Thamnophilus quizxen- 
sis Cornalia.) 
Small to very small Formicariide (length about 105-135 mm:) 
with long, graduated tail of 12 round-tipped rectrices (nearly as long 
as to longer than wing), tarsus much less than half as long as wing, 
nostril broadly oval (much broader than the narrow, sometimes 
nearly obsolete, operculum), the adult males with at least the chin, 
throat, chest, and median portion of breast black, and wing-coverts 
tipped with white. 
Bill shorter than head, moderately stout, not compressed, its width 
at frontal antie little if any greater than its depth at same point and 
equal to about half the distance from nostril to tip of maxilla; culmen 
distinctly but not sharply ridged, nearly straight for basal half (more 
or less) more and more decurved terminally, the tip of maxilla slightly 
though distinctly uncinate; tomia straight or nearly so, distinctly 
notched subterminally, the notch near tip of mandibular tomium less 
distinct; gonys gently convex, less so terminally. Nostril exposed, 
longitudinally oval, nearly in contact with feathering of latero-frontal 
antie, the superior operculum very narrow or practically obsolete. 
Rictal bristles well developed in M. boucardi and M. consobrina,* 
very minute (practically obsolete) in UM. intermedia, M. grisea, M. 
rufatra, and allies; feathers of chin and loral region with slender 
terminal setz#. Wing moderate, with longest primaries extending, 
more or less decidedly, beyond secondaries; fifth and sixth, sixth and 
seventh, or fifth, sixth and seventh, primaries longest, the tenth 
(outermost) one-half to three-fifths as long as the longest, the ninth 
shorter than secondaries. Tail nearly as long as to longer than wing, 
graduated (graduation equal to length of tarsus or more), the rectrices 
(12) rather broad, rounded terminally. Tarsus longer than whole 
culmen, one-third (MM. boucardi, M. consobrinus) to two-fifths as long 
as wing (M. grisea, M. intermedia, M. rufatra), distinctly scutellate, 
the plantar scutella in two longitudinal series but sometimes partly 
fused or obsolete; middle toe, with claw, much shorter than tarsus; 
outer toe, without claw, reaching to slightly beyond middle of sub- 
terminal phalanx of middle toe, the inner toe slightly shorter; hallux 
about as long as inner toe but much stouter; basal phalanx of middle 
toe wholly united to outer toe, for about half its length to inner toe; 
claws moderate in size and curvature, that of the hallux decidedly 
. shorter than its digit. Plumage full, lax, and blended, that of the 
rump and flanks elongated and more fluffy; feathers of pileum not 
elongated. 
@ Probably also in the closely related -M. quizensis and M. bicolor, which, however, 
I have not seen. 
