_Plate IV. Characteristic Neotropical Mammalia._--Our illustration represents a mountainous forest in Brazil, the part of South America where the Neotropical Mammalia are perhaps best {24}developed. The central and most conspicuous figure is the collared ant-eater, (_Tamandua tetradactyla_), 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 _Tillandsia usneoides_, 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 azaræ_), 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 altogether unique in the animal kingdom. Below them, in the distance, are a group of Sapajou monkeys (_Cebus_ 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: Sylviidæ (1), Troglodytidæ (2), Coerebidæ (4), Tanagridæ (26), Fringillidæ (8), Icteridæ (5), Pteroptochidæ (3), Dendrocolaptidæ (12), Formicariidæ (16), Tyrannidæ (22), Cotingidæ (16), Pipridæ (10). Of the Picariæ there are 76 peculiar genera belonging to 9 families, viz., Picidæ (2), Rhamphastidæ (1), Cuculidæ (1), Bucconidæ (2), Galbulidæ (5), Momotidæ (2), Podargidæ (1), Caprimalgidæ (4), Trochilidæ (58). There are 3 peculiar genera of Psittaci, 8 of Gallinæ, the only genus of Opisthocomidæ, 3 of Accipitres, 1 of Rallidæ, _Psophia_ and _Eurypyga_ types of distinct families, and 1 genus of Ardeidæ, Palamedeidæ, and Anatidæ respectively. The preceding enumeration shows how very rich this sub-region is in peculiar types of all the most characteristic American families, such as the Tanagridæ, Tyrannidæ, Cotingidæ, Formicariidæ, Trochilidæ, and Galbulidæ. A considerable proportion of the genera of the Chilian and Mexican sub-regions also occur here, so that out of about 680 genera of Neotropical land-birds more than 500 are represented in this sub-region. Plate XIV. [Illustration] A BRAZILIAN FOREST, WITH CHARACTERISTIC MAMMALIA.