Giant Reptile Seven Million Years Old. Between seven and ten million years ago, in what is known as the Jurassic Age, there lived a group of giant reptiles called Dinosaurs, one family of which, the Stegosauridæ, or plated lizards, is perhaps the most fantastic and curious in all natural history. The most perfect and complete fossilized skeleton of the genus Stegosaurus, a smaller branch of this remarkable family group, is on exhibition in the new building of the United States National Museum, at Washington, just as it was found and dug out of the sandstone rock. Near at hand is a natural size and very lifelike restoration in papier-mâché so weird and monstrous in appearance as to give one the horrors. Back in the very early days of the world, this armor-plated, lizardlike monster dwelt in the western part of the United States in what is now the eastern slope of the Rocky Mountains, although at that time the mountains did not exist. He roamed about in the marsh and swamp lands of that region, feeding on the tropical grasses and plants, the fossil remains of which are found buried with his skeleton. The specimen mentioned above comes from Quarry No. 1, in Fremont County, near Cañon City, Col., where it was found by Mr. M. P. Felch in 1885. Brief articles concerning it were written from time to time, but it was not assembled and mounted until two years ago, and never completely described until recently. With the exception of the removal of some of the sandstone which surrounds this valuable specimen, it has been left in the position in which it was discovered so that the relation of the various bones and skin armor may be seen and studied by scientists. In order that the lower side of the skeleton and the back plates may be seen, two mirrors have been placed beneath it in such a manner as to reflect the exact structure and location of the various bones. The undisturbed position of the bones and the surrounding sandstone indicates that this monster died in the water, or on the bank of a stream, and from some natural cause. It is possible that the carcass floated down the stream, as the arrangement of the different bones and spine plates indicates a gradual washing and tipping over, rather than the crushing action of a heavy force. The skeleton is quite complete and lies partly on its side and back, with nearly all the bones in their relative positions, rendering it of infinite value to scientists for study and as a reference type.