[Illustration: FIG. 27. Photographs of completed models of the Devonian fish _Drepanaspis_, from Devonian slates of North Germany, worked out by Professor Traquair. The models are in the Natural History Museum, London.] [Illustration: FIG. 28. The oldest fossil fish known--discovered in the Upper Silurian strata of Scotland, and named _Birkenia_ by Professor Traquair.] The discoveries by Seeley at the Cape, and by Amalitzky in North Russia of identical genera of Triassic reptiles, which in many respects resemble the Mammalia and constitute the group _Theromorpha_, is also a prominent feature in the palæontology of the past twenty-five years (fig. 26). Nor must we forget the extraordinary Devonian and Silurian fishes discovered and described by Professor Traquair (figs. 27 and 28). The most important discovery of the kind of late years has been that of the Upper Eocene and Miocene Mammals of the Egyptian Fayum, excavated by the Egyptian Geological Survey and by Dr. Andrews of the Natural History Museum, who has described and figured the remains. They include a huge four-horned animal as big as a rhinoceros, but quite peculiar in its characters--the _Arisinoïtherium_--and the ancestors of the elephants, a group which was abundant in Miocene and Pliocene times in Europe and Asia, and in still later times in America, and survives at the present day in its representatives the African and Indian elephant. One of the European extinct elephants--the _Tetrabelodon_--had, we have long known, an immensely long lower jaw with large chisel-shaped terminal teeth. It had been suggested by me that the modern elephant’s trunk must have been derived from the soft upper jaw and nasal area, which rested on this elongated lower jaw, by the shortening (in the course of natural selection and modification by descent) of this long lower jaw, to the present small dimensions of the elephant’s lower jaw, and the consequent down-dropping of the unshortened upper jaw and lips, which thus become the proboscis. Dr. Andrews has described from Egypt and placed in the Museum in London specimens of two new genera--one _Palæomastodon_, in which there is a long, powerful jaw, an elongated face, and an increased number of molar teeth (see figs. 29 and 30); the second, _Meritherium_ (fig. 31), an animal with a hippopotamus-like head, comparatively minute tusks, and a well-developed complement of incisor, canine, and molar teeth, like a typical ungulate mammal. Undoubtedly we have in these two forms the indications of the steps by which the elephants have been evolved from ordinary-looking pig-like creatures of moderate size, devoid of trunk or tusks. Other remains belonging to this great mid-African Eocene fauna indicate that not only the Elephants but the Sirenia (the Dugong and Manatee) took their origin in this area. Amongst them are also gigantic forms of Hyrax, like the little Syrian coney and many other new mammals and reptiles. [Illustration: FIG. 29.