The construction was found, by very thorough excavation, to be as follows: the entire surrounding slope (No. 4, Fig. 40) was of hard, tough red clay, which could not have been obtained nearer than half a mile; the cylindrical core, 60 feet in diameter and extending down to the original surface of the ground, was composed of three horizontal layers; the bottom layer (No. 1) 10 feet thick, of rich, dark, and rather loose loam; the next (No. 2) 4 feet thick, of hard, beaten (or tramped) clay, so tough and hard that it was difficult to penetrate it even with a pick; and the uppermost (No. 3) of sand and surface soil between 1 and 2 feet thick. A trench was dug from opposite sides to the central core; and when the arrangement was ascertained, this central portion was carefully explored to the original surface of the ground. Nothing was found in the layer of clay (No. 2) except a rude clay pipe, some small shell beads, a piece of mica, and a chunkee stone. The burials were all in the lower layer (No. 1), of dark rich loam, and chiefly in stone cists or coffins of the usual box-shape, formed of stone slabs, and distributed horizontally, as shown in Fig. 41, which is a plan of this lower bed. [Illustration: FIG. 41.--Plan of burials in small mound.] According to Mr. Rogan's field-notes, the form and contents of these graves and the mode of burial in them were as follows: Grave _a_, Fig. 41.--A stone sepulcher, 2-1/2 feet wide, 8 feet long, and 2 feet deep, formed by placing steatite slabs on edge at the sides and ends, and others across the top. The bottom consisted simply of earth hardened by fire. It contained the remains of a single skeleton, lying on its back, with the head east. The frame was heavy and about 7 feet long. The head was resting on a thin copper plate, ornamented with stamped figures; but the skull was crushed and the plate injured by fallen slabs. Under the copper were the remains of a skin of some kind; and under this, coarse matting, probably of split cane. The skin and matting were both so rotten that they could be secured only in fragments. At the left of the feet were two clay vessels, one a water-bottle, and the other a very small vase. On the right of the feet were some mussel and sea shells; and immediately under the feet two conch-shells (_Busycon perversum_), partially filled with small shell beads. Around each ankle was a strand of similar beads. The bones and most of the shells were so far decomposed that they could not be saved. Grave _b_.--A stone sepulcher, 4-1/4 feet long, 2 feet wide, and 1-1/2 feet deep, differing from _a_ only in size and the fact that the bottom was covered with stone slabs. The skeleton was extended on the back, head east. On the forehead was a thin plate of copper, the only article found.