The reptiles marked the introduction of a higher animal class than had previously existed, and being of a higher type, their destiny was to live and thrive and assert themselves. Almost immediately we note in the class two branches, or fashions, which continue to distinguish them. Some became very large, had enormous heads and jaws, and terrible teeth, resembling the present crocodiles. These, living on the shore, preyed upon fish or other animals. The second division comprised smaller and more delicate reptiles. They had better developed limbs and lungs, large ribs, beautiful, brightly colored scales and skins, lived on land, and fed on insects, spiders, and snails. Thus in the latter part of the Coal-making age, we may imagine the shores and bayous swarming with great reptiles ten feet long, furnished with thick armor and monstrous teeth; while the forests of tree-ferns, club-mosses, reeds, and other plants, were rustling with the agile feet of gayly colored, active little beasts, from a few inches to a foot in length. Here at last was an animal with a pair of nostrils through which it could inflate a pair of lungs. The reptile with his improved breathing apparatus and convenient feet had come into creation to stay. Individuals and families would indeed perish and leave only fossil remains to exhibit their characteristics, but the class was to remain. When the Coal period passed away, we find that the first lizards accommodated themselves in improved varieties, to the demands of the new time; their teeth, limbs, lungs, and tails, were better developed, and they could claim to be highly organized creatures; in fact, the reptiles became the leading animals of the epoch, which from them is often called the age of the reptiles. The crustaceans, corals, mollusks, and fish had had their day of being the rulers or leading families of the world; now came the turn of the reptiles; while certain groups, previously chief, sank into lower places. These crustaceans, polyps, crinoids, and others which we have mentioned, were the predecessors of the reptiles. They did not disappear when the reptiles arrived, nor have they disappeared yet. No doubt all these creatures, and others which have come into existence, will survive and share the globe, as long as the globe lasts. No researches have discovered any animals created since the arrival in the world of man.