4. “Iguanodon,” i-guāˈnō-don. This gigantic fossil reptile was discovered in the year 1882, in the Wealden beds of Kent and Sussex, also in the Isle of Wight, by Dr. Mantell. The enormous bones were very abundant, and from a close study of them, it has been estimated that the extreme length of the reptile must have been twenty-eight or thirty feet, of which the head was three, and the tail thirteen feet. It stood higher above the ground than any reptile now in existence. The teeth, which bear a remarkable resemblance to the teeth of the American lizard, the iguana, from which it was named, show that the animal was herbivorous. It probably fed on the trees growing along the borders of swamps and streams, and was able to lift its body for this purpose on its hind legs. 5. “Megˌa-lo-sauˈrus.” The word comes from the Greek, as do nearly all the words in this list, and means great lizard. The bones found in the rocks of the Oolite formation, the one next below the Wealden, show the animal to have been terrestrial and carnivorous. It fed upon smaller reptiles and the young of the larger orders. Its huge body was supported on four large, strong legs, the hind ones being estimated to have had a length of nearly six feet. The length of the animal must have been thirty or forty feet. In the first estimates made of all these saurians, their size was overestimated, the body of the iguanodon having been given as seventy feet in length, and the megalosaurus as sixty or seventy feet. 6. “Pleˌsi-o-sauˈrus.” The word means like a lizard. It is a remarkable fossil sea-reptile, which shows a long, snake-like neck, in which there are thirty-three vertebræ, ten more than in the longest neck of any bird. The body and head are comparatively short. Its whole length, when living, was probably twenty-five or thirty feet. Buckland describes it as follows: “To the head of a lizard it united the teeth of a crocodile, a neck of enormous length, resembling the body of a serpent, a trunk and tail having the proportions of an ordinary quadruped; the ribs of a chameleon, and the paddles of a whale.” There were fifty teeth in each jaw. Conybeare says of it: “That it was marine is evident from its paddles; that it may have occasionally visited the shore, the resemblance of its extremities to those of the turtle may lead us to conjecture; its motion must have been, however, very awkward on land; its neck must have impeded its progress through the water. May it not therefore be concluded—since, in addition to these circumstances, its respiration must have required frequent access to the air—that it swam upon or near the surface, arching back its neck like the swan, and occasionally darting it down at the fish which happened to float within its reach? It may, perhaps, have lurked in shoal water along the coast, concealed among the sea weed, and, raising its nostrils to the surface from a considerable depth, may have found a sure retreat from the assaults of dangerous