To illustrate the character and construction of these mounds, and modes of burial in them, I will introduce here brief descriptions of the leading types found in the different northern districts heretofore mentioned, confining myself chiefly to the explorations made by the Bureau assistants. BURIAL MOUNDS OF THE WISCONSIN DISTRICT. Following the order of the geographical districts heretofore given, we commence with the Wisconsin section, or region of the effigy mounds. As a general rule the burial mounds in this area are comparatively small, seldom exceeding 10 feet in height and generally ranging from 3 to 6 feet. In all cases these belong to that class of works usually denominated "simple conical tumuli." Of the methods of construction and modes of burial there appear to be some two or three types, though not so different as necessarily to indicate different tribes or peoples. One of these is well represented in the following extract from Dr. I. A. Lapham's work describing some mounds opened by Dr. Hoy, near Racine: We excavated fourteen of the mounds, some with the greatest possible care. They are all sepulchral, of a uniform construction as represented in Fig. 1 [our Fig. 1.] Most of them contained more than one skeleton; in one instance we found no less than seven. We could detect no appearance of stratification, each mound having been built at one time and not by successive additions. During the investigations we obtained sufficient evidence to warrant me in the following conclusions. The bodies were regularly buried in a sitting or partly kneeling posture facing the east, with the legs placed under them. They were covered with a bark or log roofing over which the mound was built.[4] [Illustration: FIG. 1.--Section of mound near Racine, Wisconsin.] In these a basin-shaped excavation some 2 or 3 feet deep was first made in the soil in which the bodies were deposited, as shown in Fig. 1. Mr. Middleton, one of the Bureau assistants, in 1883, opened quite a number of small burial mounds in Crawford and Vernon counties, belonging to the same type as those just described; some with the excavation in the original soil in which the skeletons were deposited, though in others there were no such excavations, the skeletons being deposited on the original surface or at various depths in the mounds. I give here descriptions of a few of them from his notes: [Illustration: FIG. 2.--Section of burial mound, Vernon County, Wisconsin.] The one numbered 16, of the Courtois group, is about 20 feet in diameter, and at present scarcely more than 1 foot high, the ground having been in cultivation for several years and the mound considerably lowered by the plow. A vertical section is given in Fig. 2, _a a_, indicating the natural surface of the ground, _b_ the part of the mound removed, and _c_ the original circular excavation in the natural soil to the depth of 2 feet.