BURIAL MOUNDS OF THE ILLINOIS OR UPPER MISSISSIPPI DIS- 
TRICT. 
This district, as heretofore stated, includes eastern Iowa, north- 
eastern Missouri, and northern and central Illinois as far south as the 
mouth of the Illinois River. 
Although we are justified in concluding that this area was occupied 
during the mound-building age by tribes different from those residing 
in the Wisconsin district. yet the distinguishing characteristics are more 
apparent in the forms of the works than in the modes of burial and in- 
ternal construction of the burial mounds. We shall see by the illustra- 
tions hereafter given that at least one of the types found in one district 
is common in the other. But this is to be expected and is readily ex- 
plained by the supposition that the tribes which have occupied these re- 
gions moyed back and forth, thus one after another coming upon the 
same area. The absence of evidence of such movements would indicate 
that the mound-building period was of comparatively short duration, a 
theory which I believe has not been adopted by any authority, but to 
which I shall have occasion again to refer. One class of the burial mounds 
of this district is well represented in a group, explored by the members 
of the Davenport Academy of Natural Sciences, on the Cook farm, near 
Davenport, Iowa. The mounds of this group are situated on the imme- 
diate bank of the Mississippi at a height not exceeding 8 to 12 feet above 
high-water mark; they are conical in form and of comparatively small 
size, varying in height from 3 to 8 feet. Nine of them were opened, of 
which we notice the following: 
In No. 1 the layers from above down were, first, a foot of earth; then 
a layer of stones 14 feet thick; then a layer of shells 2 inches thick; 

Fic. 7.—Section of burial mound, Davenport, Iowa. [From the Proceedings of the Davenport Acad- 
emy of Sciences. ] 
next a foot of earth, and lastly a second layer of shells 4 inches thick. 
Immediately under this, at the depth of 5 feet, were found five skeletons 
stretched horizontally on the original surface of the ground, parallel to 
each other, three with heads toward the east and two with heads west. 
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