30 MOUND EXPLORATIONS. 



to 300 feet in diameter at the base. As a general rule the burial mounds 

 are of this form. 



The term " conical," although used in its widest and most general 

 sense, is scarcely broad enough to include all tumuli that are referred 

 to this class. The circular or nearly circular base is the usual form, 

 but oval and pear-shaped mounds, especially the former, are not rare. 

 Some t^yo or three of a crescent shape have been observed, but these 

 are exceptional cases. There are also some irregular forms which must 

 be placed in this class if we would avoid multiplying divisions in our 

 classification to an unwarranted extent. These are mostly irregular 

 heaps, similar to " refuse heaps," but which, as internal evidence shows, 

 can not be properly placed in the latter category. 



As the further subdivision of the class must be determined chiefly, 

 if not wholly, by what the interior of the works presents, this part of 

 the subject will be left for a subsequent chapter. However, it may be 

 stated here that no attempt has been made to divide the conical tumuli 

 into any further subclasses than burial mounds, and those not designed 

 for burial purposes. 



ELONGATE OR WALL JIOUNDS. 



This division is intended to include those singular elongate works 

 which seem to be confined strictly to the efflgyimmnd district. The 

 only characterisiic which distinguishes them from the conical type is 

 their wall like form ; in fact many of them, as may be seen by referring 

 to Dr. Lapham's "Antiquities of Wisconsin," might very properly be 

 called walls. This wall-like form is apparent even where the length 

 is not great compared with the width ; in other words, they seldom 

 assume the oval shape. The width varies from 20 to 40 feet; the length 

 from 50 to 900 feet, though the height seldom, if ever, exceeds 4 feet. 

 They appear to be simple lines of earth cast up from the adjoining 

 surface, and are seldom used toi' burial purposes, and even in these few 

 cases it is evident the burial in them was a subsequent thought, their 

 construction having no reference to this use. The object in building 

 them is yet an unsolved riddle. 



rVKAMIDAL MOUNDS. 



The typical form of this class is the truncated, quadrangular pyra- 

 mid. In some examples these are so reduced in height, compared with 

 extent, as to assume the appearance of mere earthen platforms; others 

 have a terrace extending outward from one or two sides. Although 

 the mounds of this class are usually four-sided, some are circular or 

 rounded, and a few pentagonal, but all are flat on top. The wearing 

 by the i)low and the elements has in most cases destroyed the sharp 

 outlines of the original form, so that it is difficult, sometimes, to deter- 

 mine this satisfactorily. In such cases the statements of the early 

 observers become important. But few w(U'ks of this class are found 

 in the northern districts. 



