BIEDS OF NORTH ATSTD MIDDLE AMERICA. 213 



Medium-sized or rather large semiterrestrial Icteridee, with long, 

 graduated, and plicate^ tail; anteriorly truncated and very prominent 

 median palatal ridge; bill about as long as head and strongly decurved 

 at tip; color black, with various and strongly contrasted metallic (green, 

 blue, violet, and bronze) hues. 



Bill about as long as head or a little longer, elongate-conical, but 

 upper outline decidedly convex terminally and decurved at tip, its 

 basal depth less than one-half the length of culmen, but equal to or 

 more than one-half the distance from nostril to tip of maxilla, the basal 

 width a little less; culmen nearly straight (sometimes faintly depressed) 

 in middle, convex terminallj;^, with strongly decurved tip, elevated and 

 usually slightly arched basally, distinctly ridged but the ridge broad 

 and rounded; gonys straight or nearly so, sometimes faintly concave 

 terminally, sometimes faintly convex basally, slightly shorter than 

 maxilla from nostril; maxillary tomium slightly convex in middle, 

 slightly concave anteriorly and subbasally, strongly deflexed from 

 beneath nostril to rictus; mandibular tomium convex terminally, 

 straight or slightly concave in middle, more or less convex and ele- 

 vated opposite palatal ridge, then slightly deflexed for a short distance, 

 strongly deflexed from beneath nostril to rictus. Nostril more or less 

 triangular (obtusely pointed anteriorly), posteriorly in contact with 

 feathering of loral antise, overhung by a rather broad memfbraneous 

 or subcorneous operculum. Wing moderate (less than four to more 

 than four times as long as culmen, three and a half to nearly four times 

 as long as tarsus), the tip moderately produced (about equal in length to 

 tarsus or intermediate between length of tarsus and length of culmen), 

 subtruncate; ninth (outermost) primary intermediate between seventh 

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

 or eighth, seventh, and sixth primaries longest; inner web of three 

 outer primaries slightly but distinctly sinuated, but the middle portion 

 not conspicuously widened. Tail plicate, shorter than wing (the differ- 

 ence equal to about one-fourth to one-third the length of culmen), 

 graduated for a little less than length of culmen, the rectrices (except 

 middle pair) widest terminally and with obliquely subtruncated tips, 

 the inner web usually a little longer than the outer. Tarsus slightly 

 longer than culmen, with anterior scutella distinct; middle toe, with 

 claw, decidedly shorter than tarsus; lateral toes with claws falling 

 decidedly short of base of middle claw; hallux equal in length to 

 lateral toes, much stouter, its claw decidedly shorter than the digit; 

 claws only moderately curved. 



'Capable of being folded vertically so that a transverse section is V-shaped, the two 

 edges being brought near together when flying. On account of this folding and the 

 graduated form of the tip, the effect, when the bird is flying, is very peculiar, the 

 tail appearing as if much longer on one side than on the other. 



