the paintings of ancient Egypt, are greatly faded. A few, however, of the Secondary, and even Palæozoic shells, still retain the rich prismatic hues of the original nacre. Many of the Tertiary division still bear the distinctive painted spots. Some of the later fossil fishes, when first laid open in the rock, exhibit the pearly gleam that must of old have lighted up the green depths of the water as they darted through. Not a few of the fossil corals preserve enough of their former color to impart much delicacy of tint to the marbles in which they occur. But it is chiefly in form, not in shade or hue, that we find in the organisms of the geologic ages examples of that beauty in which man delights, and which he is ever reproducing for himself. There is scarce an architectural ornament of the Gothic or Grecian styles which may not be found existing as fossils in the rocks. The Ulodendron was sculptured into gracefully arranged rows of pointed and closely imbricated leaves, similar to those into which the Roman architects fretted the torus of the Corinthian order. The Sigillaria were fluted columns ornately carved in the line of the channelled flutes; the Lepidodendra bore, according to their species, sculptured scales, or lozenges, or egg-like hollows, set in a sort of frame, and relieved into knobs and furrows; all of them furnishing examples of a delicate diaper work, like that so admired in our more ornate Gothic buildings, such as Westminster Abbey, or Canterbury and Chichester Cathedrals, only greatly more exquisite in their design and finish. The scroll shells, a very numerous section of the class in the earlier ages, such as Maclurea, Euomphalus, Clymenia, and the great family of the ammonites, were volutes of varying proportions, but not less graceful than the ornament of similar proportions so frequently introduced into Greek and Roman architecture, and of which we have such prominent examples in the capitals of the Ionic, Corinthian, and composite orders. In what is known as the modern Ionic the spiral of the volute is not all on one plane; it is a Euomphalus: in the central volutes of the Corinthian the spiral is an open one; it is a Lituite or Gyroceras: in the ancient Ionic it is either wholly flat, as in Planorbus or the upper side of Maclurea, or slightly relieved, as in the ammonites. There is no form of the volute known to the architect which may not be found in the rocks, but there are many forms in the rocks unknown to the architect. Nor are the spire-like shells (see Fig. 105) less remarkable for the rich and varied style of their ornamentation than the whorled ones. They are spires, pinnacles, turrets, broaches; ornate, in some instances, beyond the reach of the architect, and illustrative, in almost all, of his happiest forms and proportions. We detect among the fossils the germs of numerous designs developed in almost every department of art; but merely to enumerate them would require a volume.