32 MOUND EXPLORATIONS. 



INCLOSURES. 



Ill this class are iucludcd some of the most important and most inter- 

 esting ancient monuments of our country. In form they are circular, 

 square, oblong, oval, octagonal, or irregular. Those which approach 

 regularity iu figure and symmetry in their parts are either circular, 

 square, or octagonal, and with a few exceptions are found in Ohio and 

 in the immediately adjoinining sections of Kentucky and Indiana, and 

 iu West Virginia. 



Of the irregular iu form there are several types; some, especially 

 those located on level ground where the space is ample, are irregularly 

 circular and in most cases are Hanked by a ditcli. This form is common 

 in the region bordering the northern lakes ; others, often of stone or 

 stone and earth combined, are found on elevated points, the figure 

 being determined by the boundaries or character of the area inclosed, 

 luclosures of this tyjie are frecjuently incomplete, a steep blufl', river, 

 or lake shore forming one or two of the sides. 



In this class are included a few works where there is iu reality no 

 wall, a ditch or line of picket holes alone marking the boundary. 



WALLS AND EMBANKMENTS. 



Double or jDarallel lines of walls are iu most, if not all, cases connected 

 with otlier works. Single lines of wall are mostly those of earth or stone 

 built across the neck of some projecting bluff or promontory or across 

 some peninsula formed by the bend of a river or curve in a lake shore. 

 These are evidently works thrown up for defensive purposes, often to 

 protect a temporary or permanent village. 



EXCAVATIONS. 



This term is usually applied to those basin-shaped or irregular, arti- 

 ficial depressions often observed in connection with the more extensive 

 groups. It is apparent in many cases that they have been dug with no 

 other object in view than to obtain dirt with which to build a mound 

 or construct a wall. But in other cases they have evidently been made 

 for some specific ])urpose. 



CANALS AND DITCHES. 



Indications of what may be properly designated as " ancient canals" 

 have been discovered at a few points, mostly in the south. 



Ditches are seldom found except in connection with inclosures or de- 

 fensive works. Yet, a few instances occur where they seem to replace 

 the walls of inclosures, one of the most important groups of the South 

 being thus surrounded. 



PITS AND CACHES. 



Pits as a matter of course are excavations and iu a strictly system- 

 atic arrangement should be placed under that head, nevertheless us the 



