In the fruit-eating section of the Cheiroptera are only the Pteropidae or the Fox-bats, so called from the resemblance of the head to that of a fox (fig. 444, B). The head in these bats is long and pointed. The ears are simple and of moderate size, and the nose is destitute of any appendages. Cutting incisors and canines are present in both jaws, and the Fox-bats do not altogether refuse to eat small birds or mammals. They live, however, almost exclusively upon fruits, and the molars are therefore not cuspidate, but are furnished with blunt tubercular crowns. The tail is very short, or is entirely absent. The inter-femoral membrane is much reduced in size; and the index (as well as the pollex) is almost always clawed. The Pteropidae are amongst the largest of the Bats, one species - the Pteropus edulis, or Kalong - attaining a length of from four to five feet from the tip of one wing to that of the other. The Pteropidae are especially characteristic of the Pacific Archipelago - Java, Sumatra, Borneo, etc. - but they also occur in Asia, Australia, and Africa. They do not occur, however, in either North or South America.
Fig. 444. - A, Head of Vampire-bat (A lectops ater) ; B, Head of Fox-bat (Pteropus personatus). (After Gray.)
As regards the distribution of the Cheiroptera in time, the order dates from the Eocene Tertiary, where we find the remains of Vespertilionidae, essentially similar to existing forms. Professor Marsh has also detected the remains of the first American Tertiary Bats hitherto discovered in the Eocene of Wyoming. No fossil remains of Pteropidae are known, but the bone-caves of Brazil (Post-pliocene) have yielded traces of several species of Phyllostomidae.