BIRDS OF NORTH AND MIDDLE AMERICA. 255 



6. Nostrils roundish, non-opereulate, more or less covered by antrorse latero- 



frontal tufts; bill more or less compressed, with base of culmen narrow and 



extended but little behind the frontal antise; color of plumage not blue; 



wing more than 175 mm. 



c. Larger (wing not less than 230 mm., usually much more); bill compressed 



(much higher than broad), the culmen strongly curved; nasal tufts more 



than one-third as long as maxilla; plumage (in American species) wholly 



black Corvus ( p. 256) 



cc. Smaller (wing much less than 230 mm.); bill nearly cylindrical (slightly 

 higher than broad), the culmen nearly straight (slightly curved termi- 

 nally) ; nasal tufts less than one third as long as maxilla; plumage mainly 

 gray, or brown with white spots or streaks, the wings and tail black and 



white Nucifraga (p. 280) 



bb. Nostrils longitudinal, distinctly operculate, wholly exposed (no antrorse latero- 

 frontal tufts) ; bill depressed, with basal portion of culmen broad and flat- 

 tened, extending considerably behind the frontal antise;« color of plumage 



blue; wingless than 175 mm Cyanoceplialus (p. 283) 



la. Tail nearly if not quite as long as wing, often longer, sometimes much longer, 



the latter comparatively short and rounded, with primaries exceeding longest 



secondaries by much less than length of tarsus, the fifth, sixth, and seventh 



longest. (Subfamily Garrulinse.) 



6. Tail much longer than wing, graduated for half its length, or more. 



c. Nostrils covered by antrorse nasal tufts; orbits partly naked ; no crest; tenth 



primary falcate; wings and tail metallic bluish and greenish, the latter 



without white tips; scapulars white - - Pica (p. 286) 



cc. Nostrils wholly exposed; orbits entirely feathered; a conspicuous recurved 



crest; tenth primary normal; wings and tail plain blue or grayish blue, the 



latter with broad white tips; scapulars bluish, like back . .Calocitta (p. 292) 



66. Tail not much, if any, longer than wing, not graduated for more than about 



one-third its length (usually much less, sometime nearly even). 



e. Nostrils completely exposed, with considerable of a naked space behind 



them Psilorhinus (p. 298) 



cc. Nostrils more or less hidden by antrorse nasal tufts. 

 d. Under parts of body either white, yellow, green, or purplish, abruptly 

 defined against black or dark brown of chest and throat. 

 e. Larger (wing not less than 139.5 mm.); under parts of body white or 

 pale yellow (purplish in some South American species) ; back, etc., blue 



or purplish Cyanocorax (p. 303) 



ee. Smaller (wing less than 139 mm.); under parts deep yellow or green; 

 back, etc., green (sometimes tinged or washed with blue). 



Xanthoura (p. 305) 

 dd. Under ^arts of body neither white, yellow, green, nor purplish. , 

 e. Under parts uniform black or with at least the anterior half abruptly 



black; head and neck entirely black Cissilopha (p. 312) 



ee. Under parts not uniform black; if black anteriorly, the black merging 

 gradually into blue of posterior portions and the head conspicuously 

 crested. 

 /. Plumage partly blue; longest primaries exceeding secondaries by less 

 than length of commissure. 

 g. Without any distmct crest. 

 h. Sides of head, including nasal plumes, black, conspicuously and 

 abruptly contrasted with the color (blue or lavender) of crown 

 or throat, or both Cyanolyca (p. 318) 



a The form of the bill in this genus is very siriiilar to that of Stumus and Stumella, 

 of the families Sturnidse and Icteridee, respectively. 



