BIRDS OF NORTH AND MIDDLE AMERICA. 113 



jj. Feathers of cheeks short (normal), not covering sides of mandi- 

 ble; tail shorter than wing; bill longer and narrower, the 

 length of culmen nearly equal to that of tarsus and much 

 greater than width of maxilla at base, the tip of maxilla 

 (unguis) narrow, obtusely pointed; no gray on cheeks, throat, 

 etc., nor brown on pileum, the latter green, the primaries 



blue Psilopsiagon (extralimital).a 



ii. Cere only slightly tumid, broadly subfusiform (by encroachment 

 of frontal feathering on posterior portion); tail not more than 

 two-thirds as long as wing (sometimes but little more than half 

 as long), graduated for much less than half its length; tarsus 

 much shorter than outer front toe without claw; plumage with 

 neither gray nor yellow (green, sometimes barred or spotted 



withblack) Bolborhynchus (p. 178). 



gg. Maxilla much narrower, less swollen laterally (sometimes compressed 

 toward culmen, its width at base equal to little if any more (some- 

 times less) than half the length of culmen, the unguis relatively 

 long and narrow, its width (transversely) at base much less than 

 its length; depth of mandible at base less than length of gonys, 

 not greater than that of maxilla, the rami relatively long, the base 

 of mandible beneath deeply concave; cere narrower or else with 

 anterior outline nearly straight, the lower part well forward, not 

 tumid; oil-gland absent. 6 

 h. Tail more than two-thirds as long as wing, graduated for nearly to 

 more than half its length, the rectrices very narrow, attenuated 



distally Tirica (extralimital). c 



hh. Tail less than two-thirds (usually less than half) as long as wing, 

 graduated for much less than half its length, the rectrices not 

 attenuated distally (though pointed at tip) . .Brotogeris (p. 182). 

 56. Tail not more (usually a little less) than half as long as wing, or else tip of outer- 

 most primary abruptly attenuated; sexes different in coloration (the males 

 with more or less blue, the females with none; furcula absent; size very small 



(length less than 140 mm.) Psittacula (p. 187). 



oo. Tail not distinctly if at all graduated, the rectrices usually not distinctly if at all 

 acuminate or subacuminate,^ or else (Pionopsitta, Pyrilia, and Hapalopsittaca), 

 wing more than 130 mm. and tip of outermost primary not attenuated. 



° Psilopsiagon Ridgway, Proc. Biol. Soc. Wash., xxv, May 4, 1912, 100. (Type, 

 Trichoglossus aurifrons Wagler.) (\f/i\6s, naked; <nayi>v, jaw bone.) 



Peru, Bolivia, Chile, and western Argentina. (Three species?) 



I have not seen Conurus rubrirostris Burmeister nor Myiopsitta orbygnesia Bona- 

 parte, referred by Count Salvadori and others (together with Psittacus aurifrons 

 Lesson) to " Bolborhynchus," but, judging from descriptions, they seem much more 

 likely to belong here than to Amoropsittaca. The above characters are taken from 

 aurifrons exclusively. 



6 This not determined as to Nannopsittaca panyehlora. 



c Tirica Bonaparte, Rev. et Mag. de Zool., (2) vi, 1854, 151. (Type, Psittacus tirica 

 Gmelin.) Amazon Valley to southeastern Brazil. (Three species.) 



d In some species of Pionopsitta, Pyrilia, and Hapalopsittaca the tail is not essentially 

 different in shape and relative length and in form of the rectrices from that of Psitta- 

 cula; but the birds are very much larger, have the tip of the outermost primary not 

 attenuated, and differ materially in other respects. 



1957°— Bull. 50, pt 7—16 8 



