A third wonderful reptilian form was fitted for airy flights; the pterodactyl was the reptile monarch of the air. While its cousins, the biped reptile and the fish reptile, were ravaging the land and sea, the flying reptile, or bat reptile, whichever we choose to call it, spread its parchment-like wings, lifted itself far above the trees, and swooped from its height upon fish, land animals, or the few stray insects of the period. The flying reptile was a prophecy of the coming bird, which arrived in the middle part of this period. When true birds came, they introduced a class that was very closely related to the reptiles. The lady who holds a pet canary on her finger, offers it sugar with her lips, kisses its pretty yellow head, and considers it one of the most dainty and delightful of living things would, perhaps, shriek wildly if a lizard ran across her foot, or upon her sleeve, and would call the innocent little reptile, hideous, disgusting, hateful. Some one says the bird is a “glorified reptile.” There is similarity of structure, but the bird class is not descended from the reptile class. The backboned animals are divided into the class of the fishes; the amphibians; the sauropsida, or class containing birds and reptiles, which you see are put together; and the highest class of all--the mammalians--to which we ourselves belong. Some years ago it was usual to class together as “four-legged creatures that lay eggs,” all turtles, tortoises, newts, salamanders, snakes, toads, frogs, lizards, and crocodiles. The great naturalist, Linnæus, named all these creatures amphibia, because they can live with equal ease in the water or on the land. After this some of the French naturalists concluded that the creeping method of locomotion of these animals was a more general characteristic than their amphibious habit, and called them reptiles, or crawling creatures. But as these animals have been more closely studied, wider differences have been noted between them, and the toads, frogs, newts, and salamanders have been set in a class by themselves.