The Megalosaurus was first described by Cuvier, and the family determined; he calculated the dimensions of the animal at from forty to fifty feet in length. Professor Owen, from better preserved specimens, has reduced it to thirty feet long: the head is five feet, the length of trunk with sacrum thirteen feet, and the tail about the same, allowing the Megalosaur to have had the same number of caudal vertebræ as the crocodile. The sacrum consisted of five anchylosed vertebræ, new in saurian anatomy: the hind-legs measure two yards, a metatarsal bone thirteen inches; the teeth are of corresponding dimensions, and curve backward in the form of a pruning-knife. The structure of the jaw indicates a long projecting snout, while the curvature of the teeth fitted them to retain like barbs the prey which they had once penetrated. All the organs of the monster declare the Megalosaur to have been a land animal, of carnivorous propensities, and in all probability performed, as headsman the same office upon the smaller herd of reptiles, sometimes making a snatch at a Plesiosaur, as both in turn did upon fishes and crustaceans. The sport of an Indian jungle is child’s play compared to the onslaught of these grim kings amidst their ancient preserves. The remains occur in the deposits at Malton in Yorkshire, Cuckfield in Sussex, Bath, the Purbeck limestone, Tilgate Forest, and the Wealden. The next genus of the land reptiles was remarkable for the size of the horny plates by which the body was protected. This is the Hylæosaurus—that is, forest-reptile—about twenty-five feet long, and covered with a series of large, flat, and pointed bones. These vary in length from five to seventeen inches, and are from three to seven and a half inches in breadth. In addition, as showing the kind of warfare to which he was exposed, a ridge of thick thorny scales pass along the back, and form an enormous dermal fringe, like the spines on the back of the living iguana tribes. The skeleton of the Hylæosaur has been found nearly entire, and all the parts in almost natural juxtaposition. The Wealden of Tilgate Forest, the deposits at Bolney and Battle of the same formation, contain the remains in considerable abundance.