88 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
Genus MICROBATES Sclater and Salvin. 
Microbates ¢ SctateR and Satvin, Nom. Av. Neotr., 1873, 155. (Type, M. tor- 
quatus Sclater and Salvin=Rhkamphocenus collaris Pelzeln.) 
Very small, long-billed, long-legged Formicariide, similar in appear- 
ance to Ramphocenus but with shorter and broader bill, longer tarsi, 
relatively longer toes (especially the hallux), narrower nostrils with 
differently shaped operculum, and much shorter tail (only about half, 
instead of four-fifths) as long as wing. 
Bill about as long as head, nearly straight, its width at latero- 
frontal anti much greater than its depth at same point and equal 
to much more than one-third the distance from nostril to tip of 
maxilla; culmen sharply ridged, straight for basal half (more or less), 
then very gradually decurved until near end, where more strongly 
decurved, the tip of maxilla minutely but distinctly uncinate; max- 
illary tomium faintly concave, minutely notched subterminally; 
mandibular tomium very faintly convex, at-least terminally, without 
trace of subterminal notch; gonys faintly convex basally, straight 
terminally. Nostril exposed, distinctly separated from feathering of 
latero-frontal antie, narrow, longitudinal (slit-like), overhung by a 
broad but not convex membraneous operculum. Rictal bristles 
distinct but rather few and slender; feathers of chin without terminal 
sete. Wing rather large, with longest primaries extending slightly 
beyond secondaries, much rounded; fifth and sixth primaries longest, 
the tenth (outermost) less than half as long as the longest, the ninth 
very much shorter than, the eighth about equal to, secondaries. Tail 
slightly more than half as long as wing, rounded (graduation equal to 
much less than half the distance from nostril to tip of maxilla), the 
rectrices (10) rounded at tip. Tarsus very long (decidedly longer 
than whole culmen, nearly half as long as wing), slender, the acro- 
tarsium faintly scutellate, the planta tarsi completely fused; middle 
toe, with claw, decidedly shorter than tarsus (equal to or slightly 
longer than exposed culmen); outer toe, with claw, reaching to about 
middle of subterminal phalanx of middle toe, the inner toe decidedly 
shorter; hallux much longer than inner toe (about as long as outer 
toe), much stouter; basal phalanx of middle toe wholly united to both 
lateral toes; claws moderate in size and curvature, that of the hallux 
much shorter than its digit. Plumage full, soft, and blended, that 
of rump and flanks elongated, more lax or fluffy; feathers of pileum 
not elongated. 
Coloration.—Above plain brown; sides of head blackish and white, 
or tawny; beneath white passing into dusky on flanks and under tail- 
coverts, the chest crossed by a band of black (MM. collaris) or under 
parts of body gray, chest streaked with black and white, and throat 
white bordered on each side by a black stripe; sexes alike. 
a“ wexpdc, parvus et Batic, qui incedit.”” (Sclater and Salvin.) 
