The most remarkable creatures of the period, however, were the great Edentates--the Glyptodon, the gigantic Megatherium, the Mylodon and the Megalonyx. The order of Edentates is more particularly characterised by the absence of teeth in the fore part of the mouth. The masticating apparatus of the Edentates consists only of molars, the incisors and canine teeth being, with a few exceptions, absent altogether, as the animals composing this order feed chiefly on insects or the tender leaves of plants. The Armadillo, Anteater and Pangolin, are the living examples of the order. We may add, as still further characteristics, largely developed claws at the extremities of the toes. The order seems thus to establish itself as a zoological link in the chain between the hoofed Mammals and the ungulated animals, or those armed with claws. All these animals are peculiar to the continent of America. The _Glyptodon_, which appears during the Quaternary period, belonged to the family of Armadilloes, and their most remarkable feature was the presence of a hard, scaly shell, or coat of mail six feet in length, and composed of numerous segments, which covered the entire upper service of the animal from the head to the tail. It was, in short, a mammiferous animal, which appears to have been enclosed in a shell like that of a Turtle; it resembled in many respects the _Dasypus_ or Anteater, and had sixteen teeth in each jaw. These teeth were channelled laterally with two broad and deep grooves, which divided the surface of the molars into three parts, whence it was named the Glyptodon. The hind feet were broad and massive, and evidently designed to support a vast incumbent mass; it presented phalanges armed with short thick and depressed nails or claws. The animal was, as we have said, enveloped in, and protected by, a cuirass, or solid carapace, composed of plates which, seen from beneath, appeared to be hexagonal and united by denticulated sutures: above they represented double rosettes. The habitat of _Glyptodon clavipes_ was the pampas of Buenos Ayres, and the banks of an affluent of the Rio Santo, near Monte Video; specimens have been found not less than nine feet in length. The tesselated carapace of the Glyptodon was long thought to belong to the Megatherium; but Professor Owen shows, from the anatomical structure of the two animals, that the cuirass belonged to one of them only, namely, the Glyptodon. The _Schistopleuron_ does not differ essentially from the Glyptodon, but is supposed to have been a different species of the same genus; the chief difference between the two animals being in the structure of the tail, which is massive in the first and in the other composed of half a score of rings. In other respects the organisation and habits are similar, both being herbivorous, and feeding on roots and vegetables. Fig. 185 represents the _Schistopleuron typus_ restored, and as it appeared when alive.