Genus— CUCUL US. 
CUCULUS Linne, Syst. Nat., 10th ed., 1758, p. 110 . . . . Type C, canorus, 
Nicoclarius Bonaparte, Ateneo Italiano, No. 8, p. 121 
(Consp. Volucrum Zygod., p. 6), 1854 Type C. optatus. 
The true Cuckoos are birds of medium size, with decurved bills, long wings, 
long tail, and small legs and feet. 
The bill is straight, with tip sharp and decurved, but not hooked ; base 
comparatively narrow, under mandible somewhat flattened. The nostrils appear 
as circular apertures situated near the base of the upper mandible, rather low 
down. 
The wing is long, the feathers pointed towards their tips, otherwise rather 
broad ; three feathers comprise the tip, the first primary being short, not much 
more than half the length of the third, which is longest ; the second is not much 
shorter than the third and a little longer than the fourth, which much exceeds 
the fifth and succeeding primaries. 
The tail is long, feathers broad, of a rounded wedge shape ; it is about 
two-thirds the length of the wing. 
The tarsus is very short, almost hidden by the feathers of the thigh, but 
unfeathered, roughly scutellate in front, and reticulate behind. The toes are 
long : the middle toe being longest, the inner shorter than the outer, the 
hind small. 
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