We will now consider the existing specimens of mosaic-work. It has been demonstrated, by the extended quotations from the old chronicles and codices, that this art was considerably employed in adorning objects of a special nature in connection with the dress of kings, nobles, warriors, and priests, and the paraphernalia of the gods. We have at present no actual examples of many of the objects which we have learned were thus ornamented, consequently whatever conception we may gain by a study of existing specimens will give us an inadequate idea of the art. It is evident that the most elaborate works in stone mosaic sent to Europe, as noted in the inventories, have not been preserved, a fact borne out by the descriptions in the early accounts of the discovery and “things” of Mexico. Moreover, many of the pieces now in European museums are either in a poor state of preservation or are incomplete. Until recently only twenty-four major examples of mosaic-work had come to light and been placed on record by printed description and illustration. Of these twenty-three are in Europe. The other specimen was found a few years ago in a cave in Honduras, and for some time was exhibited in the National Museum at Washington, but later came into the possession of the Museum of the American Indian, Heye Foundation. The twenty-three known specimens in Europe were probably all sent to the Old World by Cortés or his companions. Some years ago an Indian found a deposit of ceremonial objects of wood, incrusted with mosaic-work, in a cave in the mountains of the Mixteca region of the State of Puebla. These specimens, seventeen in number, are now exhibited in the Museum of the American Indian, Heye Foundation. The chief object of this monograph is to describe and illustrate this unique collection. We are also now enabled to record and illustrate, through the courtesy of the officials of the Peabody Museum, Harvard University, four other objects decorated with mosaic-work. These were found in the sacred _cenote_ at the ruins of Chichen Itza, Yucatan, and are now exhibited in the Central American hall of the Museum mentioned. This brings the number of known specimens to forty-five, of which twenty-two are in the United States, and twenty-three in Europe. These specimens are now preserved in the following museums: British Museum, London, nine specimens. Prehistoric and Ethnographic Museum, Rome, five specimens. Ethnographical Museum, Berlin, three specimens. State Natural History Museum, Vienna, three specimens. National Museum, Copenhagen, two specimens. Museum, Gotha, one specimen. Museum of the American Indian, Heye Foundation, New York, eighteen specimens. Peabody Museum, Cambridge, four specimens.