Now we have got to a higher order of creation still, these fish-lizards, and they remind one of the next step in progress—birds. You know that all birds lay eggs, so do almost all reptiles, such as crocodiles, lizards, and most snakes, so that they are alike in this. Then the plesiosaurus with his long neck reminds us of such birds as the heron and the swan, but he is altogether more like a reptile than either a fish or a bird. There were also huge land reptiles, which lived in the forests of the time, and must have been a terror to the smaller animals. From the bones of one of these which have been found in the oolite clays near Weymouth in Dorsetshire (the _Cetiosaurus_), we see that it must have been nearly as large as an elephant, and there are others called the _Megalosaurus_, _Dinosaurus_, &c. All these names end with _saurus_, a name taken from the Greek word meaning lizard; and you will see now why the oolite, or “Jurassic”[10] age, as it is sometimes called, is well named the “reptile age,” for these creatures swarmed on the land and in the sea. Specimens of these you can see for yourselves in the cases on the walls of the third room in the North Gallery of the British Museum, where all the fossils are collected. But still more extraordinary animals than any of these lived at the time, and we can scarcely tell whether they were birds or reptiles, as they were something like both, but I suppose we must call them flying reptiles, and they are the nearest approach to birds that had yet existed. These creatures are called _Pterodactyles_, from two Greek words which mean “wing-fingered.” Suppose the little fingers of both your hands were a yard longer than the others, and suppose a thick leathery skin was stretched from the tips of your long little fingers to each of your feet, you would have wings something like a pterodactyl and also something like the wings of a bat. But the pterodactyl had a long neck and a long beak-like mouth, full of long sharp pointed teeth. It could not walk much I think, but it could hang itself up by its hind limbs to a tree or rock, head downwards like a bat, and must have been able to fly very strongly, with its huge leathery wings, but it had no feathers. There were swarms of these curious half lizard half bird-like animals on the land, and they were of all sizes, some no bigger than a crow, and some as large as the albatross, measuring twelve feet across their outstretched wings. Their skeletons are some of the commonest fossils in the oolite rocks, all through the great reptile age.[11]