38 BULLETIN" 50, UNITED STATES NATIONAL MUSEUM. 



wings; females grayish, with wings and tail blackish, varied with white; 

 _young not streaked. 



Bill A'cry large, but decidedlj^ longer than deep, with culmen very 

 broad, not ridged, decidedly convex onlj- at base and tijD; gonys A'ery 

 long, nearly or quite equal ti^) 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 gonys; maxillary tomium gently concave for terminal 

 half or more, nearly straight basallj', where not abruptly deflexed; 

 mandibular tomium without subbasal angle, but gently arched, the 

 summit of the arch nearly midway between the base and tip. Wing 

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

 pointed (ninth, eighth, and seA'enth primaries 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 sluj longer 

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

 toes short, their claws falling considerably short of base of middle 

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



Colors. — Plumage rather compact; adult males largelj* yellow, the 

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

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

 grayish, or yellowish gray, replacing the yellow; young not streaked. 



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

 inces to highlands of Gruatemala. 



KEY TO THE SPECIES AM) SUBSPECIES OF HESPEEIPHONA. 



a. Forehead and superciliary region yellciw. 



h. 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 Xorth America, northward, east of Rocky Mountains, 

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

 lib. 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). 

 0. 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). 

 (Western North America south to northern Mexico.) 



Hesperiphona vespertina montana, male (p. 41) 

 ce. Bill smaller and narrower (culmen averaging 20.32, depth at base 13.97, width 

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

 (Highlands of southern Mexico. ) 



Hesperiphona vespertina mexioana, male (p. 43) 

 aa. Forehead and superciliary region not yellow. 



h. Head and neck entirely black. (Highlands of southern Jlexico and Guate- 

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



