Before entering upon a description of the restorations of the Extinct Animals, placed on the Geological Islands in the great Lake, a brief account may be premised of the principles and procedures adopted in carrying out this attempt to present a view of part of the animal creation of former periods in the earth's history.Those extinct animals were first selected of which the entire, or nearly entire, skeleton had been exhumed in a fossil state. To accurate drawings of these skeletons an outline of the form of the entire animal was added, according to the proportions and relations of the skin and adjacent soft parts to the superficial parts of the skeleton, as yielded by those parts in the nearest allied living animals. From such an outline of the exterior, Mr. Waterhouse Hawkins prepared at once a miniature model form in clay.