the Family of Cuculida. 433 
sands, just as larva are the caterpillars of trees ; while the soft, de- 
licate, dipterous insects upon which the humming-birds occasionally 
feed, by licking them from the flowers with their tongue, are per- 
fectly analogous to the soft food of the waders, the cuckoos, the ca- 
terpillar catchers ( Ceblepyrinaz ) , and the orioles (QrioliufK.) 
On the geographic distribution of the typical cuckoos, little can 
be said of a general nature, but what is subject to exceptions when 
treating of the subordinate groups. Those composing the genus 
Cucnlus are restricted entirely to the Old World, and are abun- 
dant in those regions mid-way between Europe and New Holland, 
the two extremes of their latitudinal range. In the other, or longi- 
tudinal direction, they extend from Western Africa to the Indian 
islands. The birds which we now, for the first time, distinguish as 
the genus Oxylophus, are also excluded from the New World, arid 
appear to be confined to the tropical latitudes of Africa and India, 
where they represent the American genus Erythropkrys. The two 
remaining genera of this division are likewise excluded from the 
New World, Chalciies being African, while Eudynamys belongs 
more especially to Australia and the Indian islands. 
In venturing to characterize so many new groups in this family, 
it is incumbent upon me to lay before ornithologists those reasons 
which have led to this determination. The present state of our 
science demands this, for the time has gone by when genera will be 
received on the unsupported opinion of the mere systematist, with- 
out any appeal to acknowledged facts, or palpable analogies ; and it 
is the more necessary to avoid this error in the present instance, 
because many new genera of the Cuculidce have recently been pro- 
posed in the French publications, which I cannot possibly adopt. 
They appear to me, in almost every instance, forced and artificial, 
neither characterized by their geographic distribution, or by those va- 
riations of structure which are their true distinctions. 1 may be 
excused, also, from adopting such names as Jaccocua, Bubulus, 
Guira, &c. as they cannot be admitted into our classical nomencla- 
ture, without a violation of those rules to which we are all bound to 
adhere. 
The distinctions by which I propose to characterize the genus 
Cuculus have already been dwelt upon : its exclusive or essential 
character, however, is to be found in the great breadth and convexi- 
ty of the bill at the base, and in the short and feathered tarsus : 
the plumage, moreover, is never vivid, and the upper mandible has 
a slight or obsolete notch. From the great uniformity of colour 
which runs through this genus, I am persuaded that several species 
have been overlooked as varieties of the European cuckoo, some of 
