Be this supposition right or wrong the evidence is conclusive that the area on which this group is situated has been the abode of at least two tribes or peoples: first, it was occupied by the authors of the enclosures, whose stay was probably not very protracted, and after they had abandoned the locality or been driven from it by a second tribe, evidently comparatively numerous, that made it for a long time a dwelling place; a tribe differing in customs from its predecessor, and one that did not rely upon enclosures for protection. By no other supposition can we account for the fact that the refuse layer which covers the interior of the circle also spreads in equal depth over the ditch and clay remains of the enclosing wall, as those who left this refuse layer could have made no possible use of the wall as a defensive work, for which the position chosen and other particulars show it was designed. The form of this enclosure, as we have before intimated, seems to connect it with some one of the Indian tribes; its age is uncertain but the accumulation of refuse matter and sand since the abandonment by the first occupants indicates considerable antiquity. Although we cannot say positively that the second occupants were the builders of the mounds, as the investigation was not as thorough as it should have been, still I think we may assume, with almost absolute certainty, that such was the fact. The mounds in the square work marked D, in Plate I, present considerable differences from those in the group, and are probably the work of those who built the enclosures. The stone grave in the oblong mound indicates the presence of individuals of a more southern tribe[18] at this place, during its second occupancy. The position of the cist in the mound would seem to forbid the idea of an intrusive burial, otherwise I should certainly suppose such to be the fact. I cannot, in the present paper, enter into a discussion of the question "to what tribe or people are the box-form stone graves to be attributed," but will state my conviction to be, after a somewhat careful study of the question, that they are to be ascribed to the Shawnees, Delawares, and Kickapoos. [Illustration: PL. II. ENLARGED FIGURE AND SECTION OF EARTHWORK A, PL. I.] Without further discussion of this group, which, as before intimated, presents, so far as the mounds are concerned, some features which appear to ally the latter to one class of burial mounds found in Wisconsin, we will now refer to some other works of this district explored by the Bureau assistants.