As there can be scarcely a doubt that the mounds of this group were built by one tribe, we have here additional evidence that the same people were accustomed to bury their dead in various ways. Some of the skeletons are found lying horizontally side by side, others are placed in a circle in a sitting or squatting posture, while in another mound we find the dismembered bones heaped in a confused mass. In one place is a single huge frame decked with the ornaments of savage life, while in other places we see the members of a family lying side by side, and in others the bones, possibly of the ordinary people, heaped together in a common ossuary. The timber-covered vault in mound No. 16 calls to mind very vividly the similar vaults mentioned by Squier and Davis,[20] found in the valley of the Scioto in Ohio. In the latter the walls as well as the covering were of logs, instead of stone, but the adaptation to circumstances may, perhaps, form a sufficient explanation of this difference. While there are several very marked distinctions between the Ohio works and those of the district now under consideration, there are also some resemblances, as we shall see as we proceed, which cannot be overlooked, and which seem to indicate relationship, contact, or intercourse between the people who were the authors of these different structures. [Illustration: FIG. 13.--Pipe from Illinois mound. (After Smithsonian Report.)] [Illustration: FIG. 14.--Pipe from Illinois mound, 1/2. (After Smithsonian Report.)] [Illustration: FIG. 15.--Pipe from Illinois mound, 1/2. (After Smithsonian Report.)] In additional support of this view, I call attention to the carved pipes found by members of the Davenport Academy of Natural Sciences, in the mounds near Davenport, Iowa, already referred to, which are represented on Plates IV and XXXIV of Vol. I of the Proceedings of that society, and to others obtained by Judge J. G. Henderson from some mounds near Naples, Illinois, and described in the Smithsonian Report for 1882. The latter are shown in Figs. 13, 14, and 15. The relation of these to the pipes found in the Ohio works by Squier and Davis is too apparent to be attributed to accident, and forces us to the conclusion that there was intercourse of some kind between the two peoples, and hence that the works of the two localities are relatively of the same age. The mode of burial in one of the mounds near Naples is so suggestive in this connection that I quote here Judge Henderson's description: The oval mound No. 1 was explored in April, 1881, by beginning a trench at the north end and carrying it to the original surface and through to the south end. Lateral trenches were opened at intervals, and from these and the main one a complete exploration was made by tunneling.