According to the classification of Squier, these structures were employed for burial, sacrifice, and observation, and as temple-sites. Other structures often found in connexion with them are obviously enclosures, and were probably used for defence. The conical mounds are usually built of earth and stones, and are for the most part places of sepulture. The flat-topped structures were probably employed as sites for buildings, such as temples, council-houses, and chiefs' dwellings. Burials were rarely made in the wall-like enclosures or effigy mounds. Many of the enclosures are of true geometrical figure, circular, square, or octagonal, and with few exceptions these are found in Ohio and the adjoining portions of Kentucky, Indiana, and West Virginia. They enclose an expanse varying from one to a hundred acres. What the Mounds Contain In the sepulchral mounds a large number of objects have been found which throw some light on the habits of the folk who built them. Copper plates with stamped designs are frequent, and these are difficult to account for. In one mound were found no less than six hundred stone hatchet-blades, averaging seven inches long by four wide. Under another were exhumed two hundred calcined tobacco-pipes, and copper ornaments with a thin plating of silver; while from others were taken fragments of pottery, obsidian implements, ivory {19} and bone needles, and scroll-work cut out of very thin plates of mica. In several it was observed that cremation had been practised, but in others the bodies were found extended horizontally or else doubled up. In some instances the ashes of the dead had been placed carefully in skulls, perhaps those of the individuals whose bodies had been given to the flames. Implements, too, are numerous, and axes, awls, and other tools of copper have frequently been discovered. The Tomb of the Black Tortoise