234 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



wing, plicate,' graduated for neai'ly one-third to nearly one-half its 

 length; sexes very different in size and coloration, the adult males 

 glossy blue-black or violet-black, the wings and tail more gi-eenish; 

 adult females conspicuously smaller, brownish above, paler brown, 

 buffy, or whitish below. 



Bill equal to or longer than head, slender, more or less (usually 

 strongly) decurved at tip, compressed, its basal depth much less than 

 half the length of exposed culmen, its basal width about one-third as 

 long as exposed culmen, or less; culmen nearly straight for most of 

 its length, more or less (usually strongly) decurved terminally, the 

 middle portion sometimes slightly depressed, rounded, or forming a 

 rather flattened ridge; gonys nearly or quite straight, the tip usually 

 more or less decurved, shorter than maxilla from nostril; commissure 

 nearly straight, but more or less decurved terminally, and rather 

 abruptly but not strongly deflexed for the rictal portion. Nostril 

 longitudinal, obtusely pointed anteriorly, with broad superior opercu- 

 lum, the posterior end touching feathering of frontal antise. Wing 

 moderate (about three and a half to four times as long as culmen), the 

 tip moderately produced (by much more than length of culmen and 

 usually less than length of tarsus, never more), rather pointed; outer- 

 most (ninth) primary intermediate between sixth and fifth, equal to 

 sixth, or equal to fifth; seventh and eighth, eighth, seventh, and sixth, 

 or seventh and sixth primaries longest; three or four outer primaries 

 very faintly sinuated on inner webs (five more strongly sinuated in 

 M. tenuirostris and M. nicaraguensis). Tail nearly or quite equal to 

 wing, sometimes longer, strongly graduated (distance between tips of 

 lateral and median rectrices between one-third and one-half the length 

 of the latter), the rectrices broadest terminally, with inner webs decid- 

 edly longer than the outer (except in M. temdrostris). Tarsus long 

 (more than one-fourth to nearly one-third as long as wing, much longer 

 than culmen), its anterior scutella distinct (less so in M. tenuirostris?); 

 middle toe, with claw, shorter than tarsus; outer toe with claw falling 

 decidedly short of base of middle claw, the inner slightly longer, with 

 its claw reaching nearly or quite to base of middle claw; hallux decid- 

 edly shorter than lateral toes, but much stouter, its claw shorter than 

 the digit (nearly as long in M. tenuirostris). 



Coloratiori. — Adult males glossy blue-black or violaceous-black, the 

 wings and tail greenish black; adult females conspicuously smallei- 

 than adult males, brownish above, paler brownish, tawny, buffy, or 

 whitish beneath. 



Range. — South Atlantic and Gulf coasts of United States southward 

 through Mexico and Central America to western Peru. 



' Transverse section of the tail V-shaped, as in Qmscalus and Holoquiscalus. 



