38 BULLETIl^ 50, U]>fITED STATES ]S^ATIO]SrAL MTTSEUM. 



"svings; females grayish, with wino-s and tail hhu-lvish. varied with wliite; 

 young not streaked. 



Bill veiy large, but decidedly longer than deep, with culinen very 

 broad, not ridged, decidedly convex only tit base and tip; gonys very 

 long, nearly or quite equal to length of maxilla from nostril; depth of 

 bill at base greater than length of hind toe with claw, and nearly 

 equal to length of tarsus; distance between nostrils more than half the 

 length of the gonvs; maxillar}' tomium gently concave for terminal 

 half or more, nearly straight basalh". where not abruptly deflexed; 

 mandibular tomium without sul)basal angle, but genth' arched, the 

 sunnuit of the arch nearly midwav between the base and tip. AYing 

 long (nearly live to more than five times as long as the short tarsus), 

 pointed (ninth, eighth, and seventh primsiries longest, the ninth longer 

 than the sixth): primaries with normal tips, the longest exceeding the 

 secondaries by nearly twice the length of the tarsus. Tail short 

 (about three times as long as tarsus), emarginated, more than half 

 hidden by the upper coverts. Tarsus very short, little if any longer 

 than the culmen, about equal to middle toe and half its claw; lateral 

 toes short, their claws falling considerabh' short of base of middle 

 claw; hallux decidedly shorter that lateral toes, but much stouter. 



Colors. — Plumage rather compact; adult males largel}' yellow, the 

 wings and tail black, with innermost secondaries and greater wing- 

 coverts whitish; at least the crown and occiput black; females with 

 graA'ish, or j^ellowish gray, replacing the ^^ellow; young not streaked. 



Ramjc. — Western temperate North America, from British Prov- 

 inces to highlands of Guatemala. 



KEY TO THE SPECIES AND SUBSPECIES OF HESPEKIPHOXA. 



o. Foivhead and su}>erciliary region yellow. 



//. Bill relatively shorter and thicker (culmen averaging 19.05, depth at base 16.51, 

 width of mandible at base 14.48); yellow frontal band broader (averaging 

 8.89). (Interior of North America, northward, east of Eocky Momatains, 

 straggling eastward in winter. ) .Hesperiphona vespertina vespertina, male (p. 39) 

 hh. Bill relatively longer and narrower (culmen averaging 20.32 or more, depth of 

 bill at base averaging not more than 16.00, width of mandible at base averag- 

 ing not more than 13.97) ; yellow frontal band narrower (averaging not more 

 than 7.62). 

 c. Bill larger and stouter (culmen averaging 20.57, depth at base 16.00, width of 

 mandible at base 13.97); yellow frontal band broader (averaging 7.62). 

 (AVestern North America soutli to northern ^Mexico. ) 



Hesperiphona vespertina montana, male (p. 41) 

 cc. Bill smaller and narrower (culmen averaging 20.32, depth at l)ase 13.97, width 

 of mandible at base 12.70) ; yellow frontal band narrower (averaging 5.59). ■ 

 (Highlands of southern ^Mexico. ) 



Hesperiphona vespertina mexicana, male (j). 43) 

 aa. Forehead and superciliary region not yellow. 



Ik Head and neck entirely black. (Highlands of southern ^lexico and Guate- 

 mala. ) Hesperiphona abeillii, male ( p. 44) 



