552 MOUND EXPLORATIONS. 



to state here, lest an eironeoiis impression be conveyed to tlie reader 

 wlio may be acquainted •with the works of the northern part of the dis- 

 trict, that one class of mountls fonnd in the northeastern part of Iowa 

 and northwestern part of Illinois, although within the limits assigned 

 to the district, is omitted from consideration, as the modes of construc- 

 tion and burial show this class to belong unquestionably to the Dakotan 

 types. On the Iowa side these appear to fade out going soiitli by the 

 time the Maquoketa river is reached, but continue on the Illinois side 

 into Rock Island and Stark counties. 



Excluding these we notice the following types as those which appear 

 to be most characteristic, some of which seem to be limited to particular 

 sections of the district and to indicate the locations of different tribes. 



In the region of Scott, ^Muscatine, and Louisa counties, Iowa, on the 

 west side of the Jlississippi but extending as fiir south as Calhoun 

 county, Illinois, on the east side, certain types both of mounds and 

 specimens of art are found which resemble so closely some of the an- 

 tiquities of the Ohio and Appalachian districts (hereafter described) 

 as to indicate some relationship between the mound builders of these 

 different sections. For example, M'e find at the bottom of some of the 

 mounds of the section indicated the basin-shai^cd clay mass, or more 

 correctly clay mass with basin-shaped depression in the middle, remind- 

 ing us of the so-called " altars" of the Ohio moxmds. These are usually 

 the larger mounds of this region, and are generally, though not always, 

 found on the low lauds. They are also in some cases burial mounds, 

 which is seldom true of the type in Ohio. A description of one is given 

 here in order that the reader may see upon what evidence this claim of 

 resemblance is based. A full description will be found in the account 

 of the field work, and also in Science. ' 



This mound, which forms one of a group of five located on the spur 

 of a bluff about loO feet high, overlooking the Illinois river, stood on 

 the very brink of a precipice. Roundly conical in form, it measured 95 

 feet in diameter at the base and about 17 feet in height. From the top 

 to the depth of 11 feet it consisted chiefly of yellow clay obtained from 

 the surrounding surface of the bluff'. In this, at the depth of 4 feet, 

 was a horizontal layer of hard, gray earth vS inches thick and 20 feet in 

 diameter. Three feet lower was a layer of burnt clay about the same 

 thickness and extent. Although particles of charcoal were mixed 

 through it, no ashes were observed on or about it (see Fig. 65). 



At the depth of 14 feet was reached what seemed to be a nucleus or 

 oiiginal mound over which the heavy mass of clay had been thrown. 

 Over this lay a thin covering of whitish material, apparently light ashes, 

 not more than 2 inches thick and extending entirely over the upper 

 surface of this nucleus, winch was nearly circular in otitline, about 40 

 feet in diameter, and rounded up to a height of a little over 3 feet in the 



I A'ol, 13 (1889), p. 349. 



