Trenches cut across the wall at various points indicate, first, a layer of sand about 1 foot thick; immediately below this an accumulation of refuse matter forming a layer from 1 to 2 feet thick; under which was the original clay embankment 2 feet thick, resting on the natural surface of the ground. A section of the ditch, embankment, and excavation is shown in Plate II. The dotted line _a b_ indicates the natural surface; No. 1 the original clay layer of the wall; No. 2 the layer of earth and refuse material with which the ditch is filled; and No. 3 the top layer of sand. In No. 2 were found charcoal, ashes, fragments of pottery, fractured bones, etc. A broad belt of the inner area on the east side was explored, and the same conditions were found to exist here as were revealed by the trenches across the wall and ditch, except that here the shells were more abundant in layer No. 2, and there were many burnt stones. On the southeastern portion of the plateau (_B_, Plate I) are six nearly parallel lines of mounds running northeast and southwest, mostly circular in form, varying from 15 to 40 feet in diameter, and from 2 to 6 feet in height; a few, as indicated in the figure, are oblong, varying in length from 50 to 100 feet. The number in the group exceeds one hundred. While engaged in excavating these mounds Colonel Norris observed a number of patches of the level area quite destitute of vegetation. The owner of the land, who was present, could give no explanation of this phenomenon, simply remarking that they had always been so, never having produced a good crop of anything, although there was no apparent difference between the soil of these spots and the surface around them. As some of these extended across the area occupied by the mound group, he concluded to explore them, and was surprised to find them to be burying places, and scattered here and there among the graves, if such they could be called, were stone chips, shells, charcoal, and ashes. He was surprised at this, as he supposed the mounds alone were used as depositories of the dead, and was at first disposed to attribute these burials to a people who had occupied the ground long subsequent to the authors of the works. Possibly this may be the correct solution, but if so, they were certainly the same as those who buried in the mounds of this group, as no difference in the contents and internal arrangement could be observed. In both cases there was a compact layer of hard, light-colored earth, having the appearance of lime-mortar, possibly clay and ashes mixed together, which had been subject to the action of fire. As the burials in these sterile spots were seldom more than 18 inches deep, the only layer above them consisted of sand from the butte, while the mounds were uniformly covered with a layer of richer soil, although below this and covering the skeletons was a layer of hard, light-colored earth. Skeletons and bones were found in great abundance in the mounds