BUILDING A MONSTER. Reconstructing a Fossil Ancestor of the Whales. The National Museum has just finished the building of a monster, whose like has not been seen in the world for at least half a million years. It is a zeuglodon—the first one ever mounted and restored. For a long time scientists have been puzzling and disputing over this species of animal, fossil remains of which are found in large quantities in Alabama and Mississippi. Specimens have actually been exhibited as the skeletons of veritable sea serpents. The creature was at first supposed to be a reptile, but now it is known to have been a giant cetacean. It was an ancestor of the modern whales, and a remarkable point about it was that it had legs. After it had been settled that the beast was a mammal, some scientific men as- serted that it belonged to the seal family. Whether it had legs or not was an open question. To settle the point, the National Museum sent an expert, Mr. Charles Schuchert, to Mississippi, with instructions to procure a complete skeleton of a zeug- don if obtainable, sparing neither pains nor money in the quest. He had no trouble in finding plenty of the bones, which in some localities may be dug out of the ground in quantities with spade and pickax. Unfor- tunately, they are nearly always in such poor condition as to be valueless, being broken up by the action of frost mainly. When buried bones are permeated by moisture, a freeze shatters them. However, Mr. Schuchert succeeded in getting two fairly good skeletons, which, though lack- ing some of their parts, were better than any specimens discovered up to date. One of them had the bones of both fore legs. The authorities of the National Museum thought it would be a good idea to make a restoration of this fossil whale for the At- lanta exposition. This task they confided to the osteologist, Mr. Frederic A. Lucas. It was a labor of enormous difficulty, re- quiring the highest order of knowledge. All