CRACIDiE. THE GENERA. 
163 
the long graduated tail, com- 
pression of the bill, and 
length of the hind toe, we 
see an evident approxima- 
tion to several of the cuc- 
kows. There are many 
species, mostly of a dull 
colour ; yet some have 
white crests, and nearly all 
are bare of feathers round 
the eyes and throat ; the skin on the latter being capable, 
as it is said, of inflation. Their windpipes are singularly 
twisted. In Ortalida, the head is entirely plumed. 
Close to these birds, some systematists have placed tile 
rare genus Opisthneomus, hitherto found only in the 
swamps of Guiana. M. Sonnini informs us, that it 
feeds on the berries of the Arum arhoresaens ; which, 
being a large tree, corroborates the singular fact he 
states, that these birds seldom go on the ground, but 
remain tranquilly perched upon those branches which 
hand over the water, the greatest portion of the day. It 
deserves, also, particular attention, that the toes, unlike 
those of all other gallinaceous birds, are totally destitute 
of a basal membrane. We have never been fortunate 
enough to see a living specimen of this rare bird, — 
the only one ofitsg'enus, — and can, therefore, offer no 
opinion on the degree of affinity it bears to the scanso- 
rial tribe ; or, according to M. Tcmminck, to the crows! 
The circumstances in its history lead us to suspect the 
former affinity must be the true one. Is the outer toe 
in any degree obliquely inserted The most beautiful 
examples of this family are seen in the crown or curas- 
sow birds {^Crax 174.). Their heads are adorned 
with short elevated crests of curled feathers, which 
assume the appearance of ending in little globules, 
giving a majestic appearance to the bird, whose gait 
is slow and majestic. Formerly, as M. Temminck 
records, these birds were very common in the menageries 
of Holland, where they became equally tame as the 
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