576 ANTHROPOLOGICAL PAPERS. 



southeast portion of the mound, and occupying a jjositiou a few inches 

 above the layer of broken i)Ottery, were several plates from the lower 

 ])ortion of the carapace of a turtle. It is possible that these plates may 

 have gained this position long subsequent to the formation of the 

 mound. No human bones, or other relics than those mentioned, were 

 found. 



About the center of the southeast quarter of section 5, township 95, 

 range 17 north, and half a mile west from Flood Creek, in the western 

 part of Floyd County, a peculiar mound is located. The topography of 

 the country immediately adjoining this creek, in this region, is rather 

 low and level, but not usually wet. This mound is situated on the 

 margin of a belt of timber, bordering a low, wet depression of the gen- 

 eral surface of the land. It was about 16 feet in diameter, and 1 foot 

 high at the center, with a circular basilar outline and flat top, except a 

 rounded ridge 8 or 10 inches high and 1 foot wide at the base, which 

 occupied the outer edge of the surface area. All round the base was a 

 trench, about 10 inches deep and 1 foot wide, from which earth had no 

 doubt been taken to form the ridge, and, in part, the mouud itself. The 

 surface of the mound was densely covered by poplars {Populus tremu- 

 loidcs), wild plum {Primus americana), and hazel brush {Cceylus ameri- 

 cana). 



Mr. Mertou T. Webster and the writer together made a partial ex- 

 ploration of this mound by extending an excavation part of the way 

 through it, 2 feet wide and 1^ feet in depth, with the following result : 

 First there was a layer of decomposed plant remains and earth, and 

 then a layer of charcoal, then a bed of ashes, and afterwards a layer 

 of soil. Below this layer of soil was another bed of charcoal and ashes, 

 occupying the same i)osition relative to each other as those above. 

 Tliis bed of ashes rested directly upon the natural surface of the ground, 

 which did not show any particular evidence of strong heat. 



This description may be illustrated by the following cut, Fig. 1 : 



Fig. 1. — Section of ancicut mound near Flood Creek, Floyd County, Iowa 



A careful examination of the charcoal, wh^ch was mostly in large 

 pieces and finely i)reservefl, convinced us that the fuel had been largely 

 poi)lar wood. Xo burned bones or remains of artificial objects were 

 found. 



In the eastern part of Floyd County, near Charles City, a large and 

 very interesting group of ancient mounds occur, most of which have 

 been explored by tlic writer. 



All these mounds, thirty- one in number, are located, with one cxcep- 



