We shall here adopt the following divisions.
Sub-Order 1. XENARTHRA.
Fam. 1. Myrmecophagidae.—The family Myrmecophagidae contains three genera, all South American in range. These genera, Myrmecophaga, Tamandua, and Cycloturus, agree greatly in their outward form. They are all without teeth, and have long snouts and long protrusible tongues. The fur is thick, and they have powerful claws wherewith to break down the strong ant-hills upon whose inhabitants they feed. Tamandua and Cycloturus are arboreal, Myrmecophaga is terrestrial in habit. The claws of the arboreal forms are useful to destroy the bark, and thus bring to light insects which lurk in such situations.
Fig. 91.—Great Anteater. Myrmecophaga jubata. × 1⁄10.
The genus Myrmecophaga contains but one species, the Great Anteater, Myrmecophaga jubata. It is a large and handsome animal, with long, shaggy, greyish-black hair and a broad white stripe across the shoulder. The coloration is similar in the two sexes. Including the long and bushy tail it reaches a length of over 7 feet. It is on account of its long tongue and greatly developed salivary glands that this and the allied genera were originally placed with Manis. It is the submaxillary glands which are so enormous; they extend back over the chest, and open by three distinct ducts, of which two unite just before the external orifice.
Along their course these ducts are provided with a sphincter muscle, which squeezes the secretion towards the external orifice into the mouth-cavity. The stomach is somewhat gizzard-like. The intestine has no caecum.[[99]]
The Anteater's great claws are not only serviceable in tearing up the ground to get at its food; armed with them he does not fear, as Mr. Waterton remarked, "the fatal pressure of the serpent's fold or the teeth of the famished jaguar." An Anteater, too, is more than a match for a big dog, and will rip open its belly with the claws while the dog is vainly trying to make an impression with its teeth upon the shaggy hair.
Tamandua is a smaller animal than Myrmecophaga, and, as has been stated, is arboreal; associated with this habit is a prehensile tail. Like the last genus, Tamandua has a rudimentary clavicle, this bone being well developed in the little Cycloturus.