24 
ZOOLOGICAL GEOGRAPHY. 
[PART III . 
developed. The central and most conspicuous figure is the collared 
ant-eater, ( Tamandua tetradadyla), one of the handsomest of the 
family, in its conspicuous livery of black and white. To the left 
are a pair of sloths (. Arctopithecus flaccidus) showing the curious 
black spot on the back with which many of the species are marked, 
and which looks like a hole in the trunk of a tree ; but this mark 
seems to be only found on the male animal. The fur of many of 
the sloths has a greenish tinge, and Dr. Seemann remarked its 
resemblance to the TiUandsia icsneoides, or “ vegetable horsehair/' 
which clothes many of the trees in Central America; and this 
probably conceals them from their enemies, the harpy-eagles. On 
the right are a pair of opossums (Didelphys azarce), one of them 
swinging by its prehensile tail. Overhead in the foreground are 
a group of howling monkeys (. Mycetes ursinus ) the largest of the 
American Quadrumana, and the noisiest of monkeys. The large 
hollow vessel into which the hyoid bone is transformed, and 
which assists in producing their tremendous howling, is alto- 
gether unique in the animal kingdom. Below them, in the dis- 
tance, are a group of Sapajou monkeys (Oebus sp.) ; while gaudy 
screaming macaws complete the picture of Brazilian forest life. 
Birds. — A very large number of genera of birds, and some 
entire families, are confined to this sub-region, as will be seen 
by looking over the list of genera at the end of this chapter. 
We can here only notice the more important, and summarize the 
results. More than 120 genera of Passeres are thus limited, 
belonging to the following 12 families: Sylvikke (1), Troglo- 
dytidae (2), Coerebidae (4), Tanagridae (26), Fringillidae (8), Ic- 
teridae (5), Pteroptochidae (3), Dendrocolaptidae (12), Formi- 
cariidae (16), Tyrannidae (22), Cotingidae (16), Pipridae (10). Of 
the Picariae there are 76 peculiar genera belonging to 9 families, 
viz., Picidae (2), Bhamphastidae (1), Cuculidae (1), Bucconidae 
(2), Galbulidae (5), Momotidae (2), Podargidae (1), Caprimalgidae 
(4) Trochilidae (58). There are 3 peculiar genera of Psittaci, 8 
of Gallinae, the only genus of Opisthocomidae, 3 of Accipitres, 
1 of Pallidae, Psophia and Eurypyga types of distinct families, 
and 1 genus of Ardeidae, Palamedeidae, and Anatidae respectively. 
The preceding enumeration shows how very rich this sub-region 
