The rarity and incompleteness of the material render it impossible to give any such full account of the tapirs as is practicable for the horses and †titanotheres, but the circumstance is less unfortunate in the case of the tapirs than in that of many other families. This is because these creatures have been so conservative and unprogressive, that they have undergone comparatively little change since their earliest recorded appearance. They have been aptly termed “living fossils” and seem like belated survivors from some older world, out of place in the modern order of things. Attention has already been directed (p. 137) to the remarkable geographical distribution of the tapirs at the present time; Central and South America, southeastern Asia and the adjoining islands. [Illustration: FIG. 167.—American Tapir (_Tapirus terrestris_). By permission of W. S. Berridge, London.] The tapirs are all of moderate size, going back to very small forms at the beginning of their history and never at any period developing into large animals. The only striking and unusual feature about any of the existing members of the family is the long proboscis, a flexible, dependent snout, and, were they all extinct and nothing known of them but the skull, this proboscis could have been confidently predicated of them from the great shortening of the nasal bones. Small tusks, not showing when the mouth is closed, are formed in an exceptional way by the enlarged external upper incisor and the lower canine, the upper canine being much reduced and without function. The grinding teeth have very low crowns, premolars (except the first) and molars are all alike and of a very simple pattern, which has been independently repeated in several different orders of herbivorous mammals; in both upper and lower teeth, there are two elevated, straight, transverse crests. [Illustration: FIG. 168.—Skull of American Tapir, right side.]