BIRDS OF NORTH AND MIDDLE AMERICA. 85 



Very small Formicariidae (lengtli about 120-135 mm.) with lon^i;, 

 slender bill (longer than head), long, slender tarsi (nearly as long as 

 exposed culmen) and with tail four-fifths as long as Ming. 



Bill very long (longer than head), straight, and slender, its width 

 at frontal antiae decidedly greater than its depth at same point and 

 equal to about one-fourth the distance from nostril to tip of maxilla; 

 culmen sharpl}' ridged, straight, the extreme end abruptly and rather 

 strongly decurved, the tip of maxilla very minutel^y uncinate; maxil- 

 lary tomium faintly concave for anterior half or more, very faintly 

 (obsoletely) notched subterminally ; mandibular tomium straight, 

 famtly decurved terminally, without trace of subterminal notch, the 

 tip of mandible very slightly decurved; gonys nearly straight, very 

 slightly promment basally. Nostril exposed, widel}' separated from 

 feathering of latero-frontal antife, narrow, longitudinal, overhung 

 by a broad, convex operculum, llictal bristles distinct, but rather 

 few and slender; feathers of chin without termhial setae. Wing 

 moderate or relatively rather large, with longest primaries extending 

 slightl.y but decidedly beyond secondaries; fifth, sixth, and seventh 

 primaries longest, the tenth (outermost) less than half as long as 

 longest, the ninth much shorter than secondaries. Tail about four- 

 fifths as long as wing, graduated (graduation less than distance from 

 nostril to tip of maxilla), the rectrices (10) rather nai'row, rounded 

 terminall.y. Tarsus about as long as bill from frontal anti«, two- 

 fifths as long as wing, slender, the scutella of acrotarsium fairly 

 distinct, those of tlie planta tarsi undivided; middle toe, with claw, 

 about two-thirds as long as tarsus; outer toe, without claw, reaching 

 to beyond middle of sul^terminal j)halanx of middle toe, the inner toe 

 decidedl}^ shorter; hallux about as long as inner toe but much stouter; 

 basal phalanx of middle toe wholly united to both outer and inner 

 toes, the second phalanx partly united to outer toe; claw^s moderate 

 in size and curvature, that of the hallux shorter than its digit. Plum- 

 age full, soft, and blended, that of rump and flanks elongated, more 

 lax or fluffy; fcatliers of pileum not elongated. 



Coloration. — Above plain brownish (back, etc., sometimes more 

 grayish), the tail blackish, with or without whitish tij) to rectrices; 

 beneatli whitish, more or less strongly buffy or rufescent laterally; 

 sexes alike. 



Eange. — Guatemala to southeastern Brazil. (Four s])ecies.) 



RAMPHOC/ENUS RUFIVENTRIS RUFIVENTRIS (Bonaparte). 



NORTHERN LONG-BILLED ANTWREN. 



Adults (sexes alike). — Pileum and liindneck plain olive-brown (be- 

 tween prouts brown and raw umber); rest of upper parts (except 

 tail) plain deep grayish olive or olive-slaty, the concealed portion of 



