BIRDS OF NORTH AND MIDDLE AMERICA. 75 



Genus MICRORHOPIAS Sclater. 



Mk'i'orhoplas Sclater, Oat. Am. Birds., ]iS«)2, 182. (Type, Thavinophihis qnixen- 

 sis Oornalia.) 



Small to very small FormicariitbB (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 antin? 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 lialf (more 

 or less) more and more decurved terminally, the tip of maxilla slightly 

 though distinctly uncinate; toniia straight or nearly so, distinctly 

 notched subterminally, the notch near tip of mandibular tomiumless 

 distinct; gonys gently convex, less so terminally. Nostril exposed, 

 longitudinally oval, nearly in contact with feathering of latero-frontal 

 antia?, the superior operculum very narrow or practically obsolete. 

 Rictal bristles well developed in M. houcardi and M. consohrina,^ 

 very minute (practically obsolete) in M. intermedia, M. grisea, M. 

 rufatra, and allies; feathers of chin and loral region with slender 

 terminal setie. 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 (J/, houcardi, M. consohrinus) to two-fifths as long 

 as wing {M. grisea, M. intennedia, M. rufatra), distinctly scutellate, 

 the plantar scutella in two longitudinal series but sometimes partly 

 fused or obsolete; middle toe, \nW\ 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 

 rum]) and flanks elongated and more fluffy; feathers of pileum not 

 elongated. 



" Probably also in the closely related M. quixensis and M. bicolor, which, however, 

 I have not seen. 



