BIRDS OF NORTH AND MIDDLE AMERICA. • - 173 



are parasitic, like tlie European cuckoo, always laying their eggs in 

 the nests of other l)irds. The plumage varies from uniform black 

 (sometimes with brilliant metallic gloss) or somber l)rown to the most 

 showy combinations of yellow, orange, or scarlet, and black. 



The group is peculiar to America and is essentially Neotropical. 

 Nearh' one hundred and lifty species are known, belonging to more 

 than thirty genera, of which by far the larger number are represented 

 only in South America. 



KEY TO THE GENERA OF ICTEHID.E. 



(/. Three to five i)rimaries (tlie eighth to sixth or fourtli inclusive) with outer webs 

 sinuated; rectrices not acuminate; wing-tip less than twice as long as culmen 

 (or else mesorhinium very broad, one-fourth as wide as length of culmen); 

 middle toe with claw little if any longer than tarsus (or else tarsi very stout 

 and plumage entirely black), usually shorter; middle toe with claw shorter 

 than its terminal i)lialanx; hallux with its claw shorter than the digit. 

 b. Nostrils without superior membrane or operculum, or if with the latter the 

 operculum t-ompletely coalesced with the mesorhinium. 

 c. Nostrils bored directly into the rhinotheca, the nasal fi)s,'<;t' completely oblit- 

 erated; neck without ruff. {Cacicl.) 

 d. Middle pair of rectrices decidedly shorter than the next pair and different 

 in color from outer rectrices; rump neither scarlet, orange-red, nor 

 yellow, and if black the tail jiartly yellow; nostrils much below lateral 

 median line of maxilla. ( " Oropendolas." ) 

 ('. Frontal shield very broad, its width decidedly greater than distance from 



nostril to tip of maxilla Zarhynchus (p. 175) 



cc. Frontal shield narrow, its width decidedly less than half the distance 

 from nostril to tip of maxilla. 

 /. Cheeks and ^'ides of throat naked; wing-tip short, less than length of 



culmen Gymnostinops (p. 178) 



ff. Whole head normally feathered; wing-tip long, much exceeding length 



of culmen Ostinops (p. 183) 



dd. Middle pair of rectrices not shorter than next pair, or else the tail uni- 

 colored (black); rump scarlet, orange-red, or yellow, or else whole 

 plumage black; nostrils not conspicuously below lateral median line of 

 maxilla. ("Caciques.") 

 <■. Particolored (black, with patches of scarlet, orange-red, or yellow); wing 

 more pointed, the outermost (ninth) primary not shorter than inner- 

 most (first) — usually much longer. 

 /. Not conspicuously, if at all, crested; ninth {irimary shorter than fifth. 



Cacicus (p. 186) 



ff. Conspicuously crested; ninth primary longer than fifth 



Cassiculus (p. 190) 

 ee. Unicolored (black); wing more roundetl, the ninth primary shorter 



than first Amblycercus (p. 192) 



cc. Nostrils in anterior end of well-detined nasal fossa», but the latter otherwise 

 completeh- filled by feathering of the loral antife; neck ruffed. ( Ca.mdices. ) 



Cassidix (ji. 196) 

 bb. Nostrils with more or less distinct superior operculum or membrane. 



c. Hallux not longer than lateral anterior toes; middle phalanx of middle toe 

 shorter than terminal phalanx; outer toe (without claw) reaching to or 

 beyond second (subterminal) joint of middle toe. 



