BIRDS OF NORTH AND MIDDLE AMERICA 



111 



much shorter than tarsus, second primary (from outside) shorter 

 than fifth (nearly if not quite equal to fifth in A. mangle), some- 

 times (in A. cajanea) shorter than ninth, and with flanks, thighs, 

 and under tail coverts unicolored (usually gray or blackish) ' and 

 upperparts plain olive, becoming more or less ruf escent on primaries. 

 Bill longer than head but cuhnen much shorter than tarsus, nearly 

 straight, variable as to relative depth (but depth of base usually 

 equal to less than one-third the length of culmen)^; culmen more or 

 less elevated basally or subbasally, usually faintly depressed medially, 

 gently but decidedly decurved terminally; gonys less than, to con- 

 siderably more than, one-third as long as mandibular rami; nearly 

 straight, ascending terminally, its basal angle distinct, sometimes 

 prominent; mandibular rami with a more or less distinct shallow 

 lateral groove; nasal fossa large, well defined anteriorly, extending 

 from a little more than half to considerably more than two-thirds the 

 distance from loral feathering to tip of maxilla ; nostril usually nar- 

 rowly elliptical (rather broadly subovate in A. mangle and A. 

 aceillaris), parallel with maxillary tomium, its anterior end de- 

 cidedly nearer to loral antia than to tip of maxilla; loral antia at 

 or slightly below upper margin of nasal fossa, the anterior line of 

 feathering receding thence downward to rictus and upward to median 

 line of forehead, the usually more or less expanded base of culmen * 

 forming an angular indentation into frontal feathering. Wing rel- 

 atively large, much rounded, the longest primaries exceeding distal 

 secondaries by less than one-eighth the length of wing to between 

 one-fourth and one-fifth in A. axillaris or more than one-fourth in 

 A. mangle, usually not extending at all beyond tips of elongated 

 proximal secondaries, but in the two species named projecting con- 

 siderably beyond them; third to sixth primaries (from outside) 

 longest and subequal, except in A. axillaris and A. mangle, in which 

 the third and fourth are longest, the fifth and sixth much shorter, 

 the first (outermost) distinctly, to much, shorter than distal secon- 

 daries, except in A. axillaris and A. mangle, in which it is longer 

 than ninth (about equal to eighth in the latter) ; alula variable in 

 relative development, not reaching to tips of longest primary coverts 

 in A. cajanea, and A. axillaris, extending about as far in A. ypecaha, 

 extending decidedly beyond in A. saracura, and falling far short in 

 A. mangle. Tail a little more than one- third to slightly more than 

 two-fifths as long as wing, strongly rounded to graduated, the rec- 

 trices (12 ?) rather soft to moderately firm, rather broad, with 

 rounded tips, projecting but little beyond lower coverts. Tarsus 



'In A. mangle the flanks cinnamomeous, the thighs pale buffy grayish. 

 " Equal to one-third In A. mangle, equal to one one-fourth in A. saracura. 

 'The base of the culmen is very little if at all expanded in A. mangle and 

 A. axillaris. 



