BIRDS OF FORTH AND MIDDLE AMERICA. 331 



strongly concave terminally, the tip of mandible more or less strongly 

 decurved; mandibular rami contracted and truncate basally; base 

 of maxilla truncate or subtruncate, raised abruptly above the level 

 of the head. Nostrils transversely oval, opening posteriorly in pos- 

 terior rim of maxilla, quite concealed by the frontal feathers. Orbital 

 region naked, the interramal space also naked anteriorly, sparsely 

 feathered posteriorly. Wing rather large but primaries relatively 

 short, the longest extending only slightly beyond secondaries ; fourth, 

 fifth, and sixth, or fifth, sixth, and seventh primaries longest, the 

 eighth usually shorter than secondaries (rarely slightly longer than 

 second primary), the ninth much shorter than secondaries, the tenth 

 (outermost) about two-thirds as long as ninth; ninth and tenth (two 

 outermost) primaries conspicuously attenuated terminally, the con- 

 tracted terminal portion rounded at tip, sometimes subspatulate. 

 Tail a little more than two-thirds to more than five-sixths as long as 

 wing, truncate or slightly rounded, the rectrices gradually widening 

 terminally, with tip broadly rounded or subtruncate. Tarsus less 

 than one-fourth to more than one-fourth as long as wing, longer than 

 longest toe with claw. 



Coloration. — General color uniform black; auricular and malar 

 regions, throat, and foreneck immaculate white, yellow, or orange, 

 succeeded by a jugular band of red (this sometimes extending over 

 whole chest, breast, and sides); imder tail-coverts bright red, the 

 upper coverts red, orange, yellow, or white ; bill brilliantly colored in 

 life, also the bare skin of orbital region and chin. (Sexes alike in 

 coloration.) 



Range. — The whole of continental tropical America (except south- 

 western Mexico); north to southeastern Mexico, south to eastern 

 Peru, Bolivia, Argentina, Paraguay, and southeastern Brazil. (Four- 

 teen species.) 



There are considerable and marked variations in details of external 

 Structure among the species of this genus, but these variations do not 

 serve to divide the genus into well-defined groups of species. Thus, 

 in R. dicolorus and R. ariel, relatively small-billed species, the sides 

 of the maxilla are distinctly concave or hollowed out along each side 

 of the culmen, all the other species examined having the same portion 

 inflated to the level of the general surface. In a specimen of what 

 appears to be a young R. inca (from Yungas, Bolivia), however, this 

 same concavity along the upper portion of the sides of the maxilla is 

 very evident, the adult having no trace of it. Taking the larger-billed 

 species, R. erythrorJiynchus and R. inca have the culmen broadly 

 rounded throughout its length, except for the decurved terminal por- 

 tion; in R. toco, R. carinatus, and R. hrevicarinatus the culmen is 

 compressed and carinate, while in R. swainsonii it is indistinctly 



