We classify all the known forms of reptiles from the Lower Permian under three or four orders, the Cotylosauria, Theromorpha or Pelycosauria, Proganosauria, and possibly the Protorosauria, but the classification is yet provisional, representing merely the present stage of our knowledge. The Proganosauria and Protorosauria, including distinctively aquatic reptiles, will be more fully described in the following pages. To give even a brief description of the more terrestrial reptiles of this, the earliest known reptilian fauna, would be beyond our purpose; the accompanying life restorations by the author of some of the more typical and better known forms, based upon nearly perfect skeletons, will suffice. From the reptiles and amphibians of the Lower Permian of Texas and New Mexico to the ichthyosaurs of the Middle Triassic of California there is a complete gap in the records of the land life of North America. We do not know what became of all the remarkable animals of the Permian. There are few traces of their descendants elsewhere known, unless it be in South Africa. From the Middle and Upper Permian of South Africa and Russia, a marvelous reptilian fauna has been made known in recent years. More than a hundred species of six or seven groups, and at least two orders have been described. Of these the Cotylosauria are the continuation of the American order, but include more specialized forms, the Pareiasauria and the Procolophonia, all of them, like the more primitive American forms, characterized by the imperforate temporal region. The Therapsida, likewise, seem to be the continuation of the American Theromorpha, so closely allied to them that it is difficult to draw a distinguishing line between them. On the other hand, these African reptiles merge through the Theriodontia into the mammals in the Triassic. They are all terrestrial, crawling reptiles, except a few which are described on a later page under the Anomodontia. [Illustration: FIG. 27.—Restoration of _Labidosaurus_, a cotylosaur reptile from Texas, about three feet long.] The records of the lower part of the Triassic period are scanty everywhere in the world, save perhaps in Africa. Before the close of the period, however, probably every important group of cold-blooded air-breathing animals had made its appearance in geological history, if we except the snakes; even the mammals had appeared, and possibly the birds. The Cotylosauria, Theromorpha, and Therapsida disappeared, the latter giving birth to the mammals; the nothosaurs and plesiosaurs, the ichthyosaurs, dinosaurs, crocodiles, phytosaurs, rhynchocephalians, lizards, and turtles have all left records of their existence in Upper Triassic rocks; and the pterodactyls had also, in all probability, begun their career, though none is surely known till the Jurassic.