The Great Serpent of Adam’s County, Ohio, occupies the extreme point of a crescent-formed spur of land formed at the junction of two tributary streams of the Ohio. This elevated site has been cut to a conformity with an oval circumvallation on its summit, leaving a smooth external platform ten feet wide, with an inclination towards the embankment on every side. Immediately outside the inner point of this oval is the serpent’s head, with distended jaws, as if in the act of swallowing what, in comparison with its huge dimensions, is spoken of as an egg, though it measures 160 feet in length. Conforming to the summit of the hill, the body of the serpent winds back, in graceful undulations, terminating with a triple coil at the tail. The figure is boldly defined, the earth-wrought relievo being upwards of five feet in height by thirty feet in base at the centre of the body; and the entire length, following its convolutions, cannot measure less than a thousand feet. This singular monument stands alone, and though classed here with the symbolic animal-mounds of Wisconsin, it has no analogue among the numerous basso-relievos wrought on the broad prairie-lands of that region. It is indeed altogether unique among the earthworks of the New World, and without a parallel in the Old; though it has not unnaturally furnished the starting-point for a host of speculations relative to serpent-worship. Among the miniature sculptures of the Mound-Builders, repeated examples of the serpent occur. On one of the altars of “Mound City” was a pipe of the form peculiar to the mounds, with a rattlesnake coiled round the bowl. From another mound of the same earthwork several sculptured tablets were recovered, representing the rattlesnake, delicately carved in fine cinnamon-coloured sandstone; and one of them carefully enveloped in sheets of copper. The character of these sculptures, and the circumstances under which they were discovered, suggested to the explorers that they were not designed for ornaments; but had some relation to superstitious rites. Other serpents are represented by the Mound-Sculptors; but the rattlesnake is the favourite type. I recently examined, in the Peabody Museum of Archæology at Cambridge, Mass., a series of eighteen engraved circular plates made from the shell of the _Pyrula_, which were obtained from the Brakebill and Lick Creek Mounds, in East Tennessee. Thirteen of them bear the same device of a rattlesnake. Among the Mexicans it was the symbol of royalty; and this helps to give a special interest to a remarkable tablet figured here, in the same style of art, so suggestive of Mexican affinities. It is a disk of fine-grained sandstone, nearly 8½ inches in diameter, and three-quarters of an inch, thick, on which is graven the elaborate device of two intertwined rattlesnakes, as shown in Fig. 73. On the back a slight ornament runs round the border; and a fractured mortice-hole, somewhat out of the true centre, shows where a handle has