A third species was the huge †Imperial Elephant (_E. †imperator_), the largest of American forms, to which Osborn’s calculations give the almost incredible height of 13 ft. 6 in. This great creature was characterized not only by its enormous stature, but also by the proportionately very large size of its grinding teeth, and was a survivor from the preceding Pliocene epoch; it is not known to have passed beyond the middle Pleistocene and was thus the first of the species to become extinct. In geographical range, the †Imperial Elephant was a western form, extending from the Pacific coast almost to the Mississippi River, east of which it has never been found, and from Nebraska southward to the City of Mexico. The meaning of this distribution is probably that this elephant shunned the forests and was especially adapted to a life on the open plains. Over most of its area the winters were severe, and this fact makes it likely that the animal was clothed with hair, but nothing is definitely known on this point. [Illustration: FIG. 115.—A Horse (_Equus †scotti_) from the older Pleistocene of Texas. Restored from a skeleton in the American Museum of Natural History.] Many other hoofed animals, far more than now inhabit North America, are found in this Pleistocene fauna. The Perissodactyla were represented by horses and tapirs, but not by rhinoceroses; it might seem superfluous to say that there were no rhinoceroses, but, as a matter of fact, that family had a long and varied American history and became extinct only during or at the end of the Pliocene epoch. The horses were extremely numerous, both individually and specifically, and ranged, apparently in great herds, all over Mexico and the United States and even into Alaska. All the known species (at least ten in number) belong to the genus _Equus_, but the True Horse (_E. caballus_), to which all the domestic breeds are referred, is not represented. The smallest known member of the genus is the pygmy _E. †tau_ of Mexico. _E. †fraternus_, likewise a very small species, is found especially in the southeast, but extended as far north as Pennsylvania and west to Nebraska. On the other hand, _E. †giganteus_ of Texas exceeded the heaviest modern draught-horses in size and was the largest of the American species; of other Texan forms, one (_E. †scotti_) resembled Burchell’s Zebra (_E. burchelli_) in the proportions of head and neck, body and limbs, while another (_E. †semiplicatus_) was more ass-like. The forest horse of the eastern states has been named _E. †pectinatus_, an animal of moderate size. The Great Plains must have been fairly covered with enormous herds of horses, the countless bones and teeth of which, entombed in the Sheridan formation, have given to it the name of “Equus beds.” The most abundant of the plains species is _E. †complicatus_, a horse of about 14½ hands in height (_i.e._ 4 feet 10 inches at the shoulder) which also ranged down the