6 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



g. Culmen (from base) much shorter than tarsus, decurved from near 

 base; depth of bill at anterior end of nostril equal to slightly less 

 than half the distance from nostril to tip of maxilla; gonys decidedly 

 longer than mandibular rami; rectrices wider distally; pileum not 

 crested; coloration plain; small (wing less than 112 mm.). 



Moroooccyx (p. 70). 

 gg. Culmen (from base) equal to tarsus, nearly straight for basal half or 

 more, strongly and rather abruptly decurved terminally; depth 

 of bill at anterior end of nostril equal to only one-third the distance 

 from nostril to tip of maxilla; gonys decidedly shorter than man- 

 dibular rami; rectrices narrower distally; pileum crested; coloration 

 conspicuously streaked; large (wing more than 136 mm.). 



Geocoecyx (p. 74). 



ff. First to fifth primaries longest and not longer than longest secondaries; 



nostril narrow, nearly closed by the broad, convex operculum; meso- 



rhinium narrow, sharply ridged; depth of bill at anterior end of nostril 



equal to more than half the distance from nostril to tip of maxilla. 



Neomorphus (p. 83). 



cc. Depth of bill at anterior end of nostril less than at angle of gonys, the latter 



prominent by contraction of mandibular rami; bill slender, not strongly 



decurved terminally; upper tail-coverts greatly developed, covering whole 



of tail Dromococcyx (p. 85). 



aa. Rectrices 8; loral region wholly naked; plumage of head and neck harsh, stiffened. 



(Crotophaginx.) 



b. Culmen not elevated, very broadly rounded; gonys shorter than mandibular 



rami, rounded; nostril very narrow, slit-like; rump and under parts plain 



white or pale buff; pileum, back, etc., conspicuously streaked; tail with a 



buff basal and a white terminal zone Guira (extralimital) ." 



bb. Culmen elevated (sometimes strongly arched), compressed into a knife-like 

 ridge; gonys equal to or longer than mandibular rami, more or less distinctly 

 ridged ; nostril oval ; coloration wholly blackish (more or less metallic in parts) . 



Crotophaga (p. 90) 

 Genus CUCULUS Linnaeus. 



Cuculus Linn^btjs, Syst. Nat., ed. 10, i, 1758, 110. (Type, C. canorus Linnaeus.) 

 Nicoclarius Bonaparte, Ateneo Italiano, ii, 1854, 121 (Consp. Vol. Zygod., 1854, 



6). (Type, Cuculus optatus Gould=C intermedins Vahl.) 

 Penthoceryx Cabanis, Mus. Hein., iv, 1862, 16. (Type, Cuculus sonnerati 



Latham.) 

 Heteroscenes Cabanis, Mus. Hein., iv, 1862, 26. (Type, Columba pallida 



Latham.) 



Medium-sized Cuculinae (length, in typical species, about 300-345 

 mm.) with wing long and pointed (the seventh and ninth primaries 

 next to longest, .the tenth equal to fourth), tarsi with upper third, 

 or more, feathered, and tail much shorter than wing. 



Bill small (about half as long as head), gently but decidedly de- 

 curved from base; culmen narrowly rounded, the exposed portion 

 slightly shorter than middle toe without claw; gonys slightly more 



a Guira Lesson, Trait6 d'Orn., 1831, 149. (Type, Cuculus guira Gmelin.) — Octo- 

 pteryx Kaup, Das Thierreich ("Die Vogel, System, beschr. "), Bd. 11, Th. 1, 1836, 25. 

 (Type, Cuculus guira Gmelin.) — Ptiloleptus Swainson, Classif. Birds, ii, 1837, 323. 

 (Type, P. cristatus Swainson= Cuculus guira Gmelin.) 



Brazil to Paraguay and Argentina. (Monotypic.) 



