180 



NORTH AMERICAN BIRDS. 



Icterus biiUnrki. 



diversity and brilliancy of plumage as the otliers are (with few exceptions) 

 for their uniform sombre black, scarcely relieved by other colors. Of the 

 four genera of this subfamily, recognized by Gray, all but Cacicus are well 

 represented in the United States. This differs from all the rest in hav- 

 ing the culmen widened and much depressed towards the base, where 

 it advances in a crescent on the forehead, separating the frontal plumes. 

 In the other genera the culmen advances somewhat on the forehead, but 

 it is in a narrow acute point, and not dilated. 



In studying the North Ameri- 

 can Orioles we have found it 

 exceedingly difficult to arrange 

 them in any sharply defined 

 sections, as whatever characters 

 be taken as the basis of classi- 

 fication, the other features will 

 not correspond. Thus, species 

 with the bill of the same pro- 

 portions and amount of curva- 

 ture differ in the shape and 

 graduation of the tail, while tails of the same form are accompanied by 

 entirely dissimilar bills and wings. The bill is sometimes much attenuated 

 and decurved, as in /. cucullatus, 

 while in vndaifioce'phaliis and Balti- 

 more it is stouter and straighter. 

 The tail is usually much graduated ; 

 in /. Baltimore and hullocki it is 

 only moderately rounded. These 

 last-mentioned species constitute 

 the genus Hijphantcs. Many of the 

 species have a naked space round 

 the eye, very evident in /. vulgaris, 



less so in mclanoccjihalus. I. vulgaris is peculiar in having the feathers of 

 the throat pointed and lanceolate, as in the ravens. 



In view of the difficulties attendant upon the definition of subordinate 

 groups among the United States Icterina, we propose to consider them all 

 under the single genus Icterus, leaving it for some one with more ingenuity 

 to establish satisfactory divisions into sub-genera.^ 



1 An attempt at division into subgenera is as follows : — 



Icterus, bill stout, conical, the culmen and gonys nearly straight. Tail graduated. Species : 

 vulgaris, auduhoni, melanocephalus. 



Xanthornus, bill slender, slightly decurved. Tail graduated. Species : wagleri, parisorum, 

 spurius, cucullatus. 



Hyphantcs, bill stout, conical ; the culmen and gonys straight. Tail slightly rounded. Spe- 

 cies : baltimorc, bidlocki, abcillei. 



We do not find, however, that these subgenera are very tangible, excepting Hyplmntcs, which 



Icterus bullocki. 



