4 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



ing, beiiig without representatives of the family. The group is much 

 more numerously represented in the Eastern than m the Western 

 Hemisphere, only eleven of the forty-six genera and forty-three of 

 the two hundred and two species enumerated in Sharpe's "Hand-list 

 of the Genera and Species of Birds" (ii, 1891, 155-175) being Ameri- 

 can. AH the American forms are peculiar, however, none of the 

 genera being represented elsewhere. 



As a rule the Cuckoos are birds of dull plumage, a more or less plain 

 grayish, brown, or partly rufous coloration prevailing ; but there are 

 exceptions in some of the Old World genera, notably Chrysococcyx 

 and Metallococcyx, of Africa, in which the upper parts are a beautiful 

 metallic green and the under parts satiny yellow, recalling and rival- 

 ing, the brilliant coloring of the Trogons. No American species of 

 the group is remarkable for showy coloration, the nearest approach 

 being the South American Crotophaga major, in which the general 

 color is glossy blue-black verging in parts to semi-metallic violet- 

 blue, varied with edgings of greenish bronze or bronze-green. 



The classification of the Cuculidse has not yet been placed on even 

 an approximately satisfactory basis, and therefore the present work 

 will deal with the American forms exclusively, except when necessary 

 to refer to an Old World form for sake of comparison. 



KEY TO THE AMERICAN GENERA OF CUCULID^. 



a. Rectrices 10; loral region mostly (usually wholly) feathered; plumage of head and 



neck soft (normal). {Cuculinx.) 



b. Tarsus with upper portion feathered; wing-tip much longer and more pointed, 



the distance from tip of longest primaries to tip of distal secondaries equal to 



about half the length of wing, the tenth (outermost) primary equal to fourth, 



the ninth equal to or longer than seventh; nostril roundish, with raised margin; 



tail much shorter than wing Cuculus (p. 6). 



66. Tarsus wholly naked; wing-tip much shorter and more rounded, the distance 

 from tip of longest primaries to tip of distal secondaries much less than half 

 the length of wing, the tenth (outermost) primary not longer (usually much 

 shorter) than second, the ninth not longer (usually much shorter) than sixth; 

 nostril variable, but never as in Cuculus; tail very nearly as long as to much 

 longer than wing. 

 c. Depth of bill at anterior end of nostrils not less (usually greater) than at base of 

 gonys, the latter not prominent; bill much stouter, more strongly decurved 

 terminally; upper tail-coverts not unusually developed, or else (genus 

 Ta'pera) the rectrices relatively much narrower and bill, from rictus, shorter 

 than middle toe without claw, deep, and with culmen very strongly decurved. 

 d. Tarsus not more than one-fourth as long aa wing. 

 e. Wing more pointed, the ninth primary equal to or longer than fourth 

 (sometimes much longer than sixth) ; tail much less than one and a half 

 times as long as wing. 

 /. Wing-tip much longer and more pointed, the longest primaries exceeding 

 distal secondaries by nearly to much more than one-third the length 

 of wing, the ninth primary equal to or longer than fifth, the tenth 

 (outermost) little if any shorter (usually longer) than distal second- 

 aries; tail much longer than wing, graduated for at least one-third its 

 length Coccyzus (p. 10). 



