488 PALAEONTOLOGY OF ILLINOIS. 



cr smaller quantity, extends from Athens southward, to the Ohio river, and in 

 Virginia, as far up the Great Kenawha river as Charleston, or about one hun- 

 dred miles in a direct line. There is no trace of any volcanic agency in that 

 country. No distubance of any kind is observable in the strata, which have 

 their normal, slightly-marked dip to the eastward; nor does the sandstone it- 

 self indicate, in its appearance, by a variation of its compounds or of its density, 

 any trace of metamorphism. At Gallipolis, near the mouth of the Great Ken- 

 awha, a number of fossilized trunks, still buried in the sandstone, are seen 

 protruding from the bank, in which they have been petrified in a prostrate 

 position. As these trees have been examined already by "other geologists, and 

 mentioned as indicating a peculiar direction of a current, by which they have 

 been brought and deposited, a short account of them here may not be uninter- 

 esting. There are five of them, from four to fifteen inches in diameter, their 

 length unknown, lying, two in a southeastern direction, one due east, and the 

 two others due south. The part seen out of the sandstone is much decayed, 

 the outer surface, where it is preserved, is covered by a coat of coal varying in 

 thickness from one-half to one-fourth of an inch. What is most remarkable, 

 and bears directly on the question of their petrification, is that they appear to 

 have been transformed into stone by different substances, showing a different 

 kind of mineralization. In one of these trees the internal texture has been 

 destroyed, and the woody tissue is replaced by a hard calcareous sandstone or 

 clay, separating in layers of about one-fourth of an inch in thickness. A second 

 is a compound of small crystals of iron flint, its interior being perforated 

 lengthwise by a number of irregularly placed cylindrical apertures, filled with 

 small iron crystals, forming regular stars of more than twenty rays. A third, 

 of which I have obtained large pieces, it being of smaller size, four inches in 

 diameter, is transformed into a compact, opaque, black silex, which does not 

 preserve any trace of organic structure. (1) As these trees, of course, have 

 been petrified where they are found now, it would appear as if different min- 

 eral substances, held in solution in the water, had acted upon the woody tissue 

 in different ways, according to its nature. In any case, it is evident that the 

 petrification has been performed in various ways, by the slow action of the 

 liquids penetrating the sand, and not by the uniform crystallization of silica as 

 it is now produced in the hot springs of volcanic origin: This is more evi- 

 dent, in considering silicified wood of our more recent formations. Neither in 

 the plains of Kansas and Nebraska, nor in Eastern Arkansas, nor in Missis- 



(1) It is marked by inflated articulations, like a species of Anarlhrocanna, Gopp., and 

 is as yet the only specimen found in our Coal Measures which might be compared to the 

 trunks seen by Prof. Brongniart in the coal mines of St. Etienne, France, and compared to 

 Bamboos, from their inflated articulations. (Lyell. Manual, 4th ed., p. 319.) 



