One of the most interesting uses of turquois-mosaic decoration was in the embellishment of wooden covers for the ancient books or codices. We are fortunate in still having preserved even a single example bearing traces of this art. In 1896 the Due de Loubat had reproduced the first of his series of Mexican codices, being the first to appear in exact facsimile, even to the ancient binding. This work was Codex Vaticanus No. 3773, a pre-Columbian Nahua picture-writing preserved in the Vatican Library. In a pamphlet by Francisco del Paso y Troncoso which accompanies the reproduction is an interesting description of the book, from which we quote with respect to the covers: It is of fine and thin wood. Each cover measures six by five inches.... The wood of the covers is whitish, and traces of the brilliant lacquer which covered it may still be seen.... (One) cover bears a character which shows us that this is the point at which to begin the reading of the book. As in modern binding the first cover bears a lettering or coat-of-arms; so too, as a rule, the Indians indicated the beginning of their books, and placed on the first cover the decorative incrustations which indicate that here is the first page.... On the center of the cover, placed two in a line, are four reliefs. At first these appeared to have been made by impression on the lacquer, but Monseigneur Francisco Plancarte, who examined them with a microscope, has discovered that they are composed of a paste with which the Indians fasten precious stones in their settings, and in these incrustations we have the impress left by the inequalities of the materials once fixed on the surface. One round greenstone is left, of the kind used by the Mexicans in their mosaics; it is on the upper right-hand corner of the volume, when held ready to be opened. Below it, in the lower right-hand corner may be observed a corresponding conical shaped depression, and the remains of the lacquer in which a stone was fixed. In the other angles there is no trace of anything, proving that nothing existed there of the same kind as that which remains. In the Loubat reproduction all these features are faithfully represented, even to the single greenstone remaining in place. The existence of mosaic objects in the Zapotecan region of Oaxaca was one of the important discoveries made by the Loubat Expedition of the American Museum of Natural History, under the direction of the writer, during the winters of 1898 and 1902. In mounds locally called _mogotes_ were discovered stone burial chambers in which skeletons interred with numerous offerings were uncovered. In the burial vaults at Xoxo, excavated in 1898, practically no personal ornaments were found, but fragments of mosaic objects were discovered in the form of bits of shell, obsidian, jadeite, turquois, and hematite, on fragmentary stucco matrices.[76] [Illustration: PL. XVII MASK OF WOOD WITH MOSAIC DECORATION FROM HONDURAS