BIRDS OF NORTH AND MIDDLE AMERICA. 61 
distinctly but not sharply ridged, straight for about basal half then 
more and more decurved terminally, the tip of maxilla minutely but 
distinctly uncinate; maxillary tomium slightly but decidedly con- 
cave, minutely but distinctly notched subterminally; mandibular 
tomium nearly straight, minutely notched subterminally; gonys 
nearly straight terminally, gently convex basally. Nostril exposed, 
widely separated from feathering of frontal anti (the intervening 
space occupied by membrane), broadly (longitudinally) oval, the 
internal tubercle visible within the posterior half. Rictal bristles 
present but minute. Wing moderate, with longest primaries extend- 
ing decidedly beyond secondaries; sixth and seventh, fifth, sixth, 
and seventh, or sixth, seventh, and eighth, primaries longest, the 
tenth (outermost) more than half to about three-fifths as long as 
the longest, the ninth shorter than secondaries. Tail decidedly less 
than half as long as wing (I. pygmea) to slightly more than half as 
long, very slightly to decidedly rounded, the rectrices (10 in M. 
pygmea and M. cinereiventris?,? 12 in M. surinamensis and M. 
assimilis) rather narrow, rounded terminally. Tarsus much longer 
than exposed culmen, much shorter than tail and about one-third 
as long as wing in M. surinamensis, very much shorter than tail and 
decidedly less than one-third as long as wing in I. cinereiventris and 
M. assimilis, nearly as long as tail and much more than one-third 
as long as wing in UM. pygmeza, distinctly scutellate, the plantar 
scutella in two longitudinal series; middle toe, with claw, much 
shorter than tarsus; outer toe, without claw, reaching to beyond 
middle of subterminal phalanx of middle toe, the inner toe decidedly 
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 much shorter than the digit. Plumage soft and full, that 
of the rump much developed and fluffy; pileum not crested. 
Coloration. Adult males black above, conspicuously streaked 
with white, the wing with two broad white bands, or else plain gray 
or slate color above, with small white tips to wing-coverts, the tail 
with white terminal spots; the under parts white streaked with black 
(MU. surinamensis) or immaculate pale yellow (1. pygmea), or plain 
gray or slate color (M. cinerewentris and M. assimilis); adult females 
with head and neck tawny or cinnamomeous, streaked with black 
above, otherwise much like adult males, or else with under parts 
cinnamomeous.? 
Nidification—Nest made of fine roots and grass and suspended 
in a fork; eggs white or greenish-white. 
@ According to Dr. Sclater M. pygmxa has only 10 rectrices, and a specimen of 
M. cinereiventris apparently has only 10. 
b I have not seen females of M. cinereiventris nor of M. assimilis. 
