220 DxVVENPORT ACADEMY OF NATURAL SCIENCES. 



the hard, undisturbed natural soil. Not the least trace of shells, ashes, 



human bones, or other relics, were found in this mound. (6) That pait 



of the second mound three feet above the original surface is entirely 



composed of a light earth, while two feet below the original surface, 



down to the hard, undisturbed- soil, consists of a hard mixed earth. No 



relics were found here, (c) The third mound resembles the first in 



every respect. 



II. 



There is another group of mounds in Jackson County, near Fairfield, 

 of the same number, height, diameter and construction as those on Mr. 

 Heisig's farm. They are erected also in the same triangular position as 

 those of the first group. The mounds of both groups are not burial 

 mounds, but they must have been built for some other purpose. 



III. 



A single mound, a mile from Spragueville, Jackson county, is situated 

 on a hill near a creek. The height of this mound is only a few feet, and 

 the diameter fifteen or twenty feet. The earth that composed this mound 

 is very light. Four feet down from the top of this mound a human jaw 

 bone was found. 



IV. 



My friends, in their communications about their explorations, related 

 also as follows : A farmer near by, in digging a ditch, found a human 

 skeleton. Close to it he discovered three copper ornaments, an arrow 

 head, and a small piece of blanket. The ornaments were wrapped up 

 in strings, and consisted not of hammered, but of rolled copper. These 

 relics are now in the Museum of the Academy. 



Respectfully submitted. J. Gass. 



The Corresponding Secretary presented, on behalf of the 

 author, the following paper : 



On the Synonomy of two Species of Spirifera. 



BY S. A. MILLER, CINCINNATI. 



To the Davenport Academy of Natural Sciences : 



One of the pioneers of American geology, and, as I shall show, the 

 first who described a Devonian fossil from American rocks, a learned 

 and distinguished archaeologist, whose name will forever be remembered 

 in connection with the growth of the sciences in the West, Mr. Caleb 

 Atwater, of Circleville, Ohio, figured and described a fossil shell in 1820, 

 in the second volume of the American Journal of Science and Arts, page 

 244, under the name of Terebratula pennata. Circleville is not far dis- 

 tant from exposures of the Hamilton Group of strata, and he says, " this 

 beautiful specimen is a light drab-colored limestone." 



After having carefully examined his figure and description, I entertain 

 no doubt that he had before him the same species which Conrad after- 

 wards called Delthyris mucronatus, and which is now so generally known as 

 Sxnrifera mucronata. And I appeal to his 'work, confident that few spe- 



