28 Mounds. — Siliceous Conglomerate. — Fossil Plants. 



together, obstructing the free passage of the air. It is a good spe- 

 cies for coaking, and contains a large portion of carbon for a bitu- 

 minous coal, it being about sixty per cent. About one hundred 

 feet below this, lies the coal bed noted in the foregoing section. 



Mounds. — Natural mounds of sand are common in this part of 

 Ohio, evidently thrown up by water, and similar in structure to 

 those noticed by Prof. Hitchcock, as common to the tertiary depos- 

 its of the west. I observed one near the village of Poland, about 

 fifteen feet in height, and from forty to fifty feet in diameter, so com- 

 pletely isolated, and of a form so perfectly resembling the barrows 

 of the ancient inhabitants, that many believe it to be artificial. It is 

 found by the neighboring inhabitants to be a useful depository of 

 sand for the manufacture of mortar, &c. 



Siliceous Conglomerate. Amongst the numerous bowlders of 



this region, I observed several of siliceous conglomerate, similar in 

 structure to the rock found in the Laurel and Alleghany Mountains, 

 and used in the manufacture of mill stones. In Geauga County, 

 forty miles north, it is found in place, and continues on nearly to 

 Lake Erie. It is associated with similar deposits, and is without 

 doubt a continuation of the same rock with that found in the moun- 

 tain ranges, on the south side of the valley of the Ohio. Some of 

 the bowlders are very large, sufficient to make a pair or two of 

 mill stones. 



Fossil Plants. — On examining the impressions and casts of fossil 

 plants obtained at Mariner's Mill, I found them to embrace several 

 species of Palm, Calamites, Sigillaria, he, several of them entirely 

 new to me, and eminently beautiful. They are so perfect that Mr. 

 Mariner, a plain farmer, kept them a number of years to show to his 

 neighbors as curiosities. He found them in opening a quarry by the 

 side of the stream, for the erection of a mill dam. A little lower 

 down in the same rock, opened this spring, are found very perfect 

 specimens of a new species of Carpohthus. They are very abun- 

 dant, and are imbedded amidst fragments md impressions of various 

 coal plants. We obtained about a dozen ^fccimens, some of which 

 are very fine, and will be described with a f^r other interesting casts 

 found here. The rock is a light gray sandstone, similar to that de- 

 scribed as lying at the base of the foregoing \section in the bed of 

 Yellow Creek, and is a continuation of the sartie deposit. 



