The following scheme differs only in minor details from the more conservative of the generally accepted views, and those differences are, for the most part, the writer’s own opinions, to be taken for what they are worth. It may be said decisively that no classification of the reptiles into major groups, into super-families or subclasses that has so far been proposed is worthy of acceptance; there is no such subclass as the Diapsida or Synapsida, for instance. And we have very much more to learn about the early reptiles before any general classification of the reptiles can be securely founded. It is very probable that the primary radiation of the reptiles into the various lines of descent, into its main branches, occurred much earlier than we have been disposed to believe; that before the close of Paleozoic time, perhaps before the close of the Carboniferous, all the great groups of reptiles had gone off from the main stem, and that since then only smaller and smaller branches have appeared. There have been no new orders of reptiles in all probability since Triassic times, and perhaps none since Permian. Taxonomists are often disposed to cut the Gordian knots of relationships by raising the ranks of the animals they study to independent positions. More than thirty independent orders of reptiles have been proposed by different students, and quite as many of mammals and of birds; possibly after more forms have been discovered there will be as many proposed for the amphibians. Sometimes, indeed, it is better to make such independent groups than to unite lesser ones on doubtful evidence. But the writer, for one, believes that it is more worthy of the thoughtful scientific student to seek for relationships than for differences. It is far easier to destroy than to construct, to make new genera, families, and orders than to unite those already proposed. To raise every proposed suborder of reptiles to an order, as has been proposed by various writers, and the orders to subclasses, only leaves classification where it was; nothing has been added to taxonomy save a lot of new names to perplex and annoy the student. In the following scheme of classification three groups provisionally called orders are prefixed by an asterisk. CLASS REPTILIA Order =COTYLOSAURIA= Primitive reptiles with notochordal vertebrae, imperforate temporal region, persistent intercentra; two coracoids; plate-like pelvis, with all or most of the amphibian skull elements; short legs and short neck; phalangeal formula primarily 2, 3, 4, 5, 3(4). Suborder =Diadectosauria= Permocarboniferous, North America. =Pantylosauria= Permocarboniferous, North America. =Labidosauria= Lower Permian, North America. =Pareiasauria= Upper Permian, Europe, Africa. =Procolophonia= Triassic, Europe, Africa.