i36 EXPEDITION TO THE 



a bituminous character, so that a gradual and invisible, but 

 certain, transition from the charcoal to coal manifestly takes 

 place. These remains are, however, as far as we saw them, 

 so much impaired as to make it impossible to assign to 

 them any particular place in fossil botany, though of their 

 vegetable origin no doubt can exist. In remarking upon 

 their position, we ascertained, that they generally lay in 

 the direction of the stratification, very seldom intersecting 

 it. Besides fragments of charcoal and coal, we found im- 

 pressions of plants, some of which were tolerably well cha- 

 racterised. In one instance a jjhyllolithos, (Martin,) was 

 collected in a very good state of preservation. 



The sandstone in a few cases assumes a somewhat mi- 

 caceous appearance, consequently a more slaty structure, 

 and then resembles that hereafter to be noticed. The rock 

 immediately superincumbent is presumed to be a bed of 

 clay-slate ; though the junction being concealed and the re- 

 lative positions of the rock being judged of only by the 

 general level of the country, it was not in our power to de- 

 cide in a positive manner whether or not there were any 

 other strata interposed between the two. 



This slate-clay is very brittle, and easily divisible ; on 

 exposure to the atmosphere it readily crumbles, and lays 

 open to view concentric globules of argillaceous carbonate 

 of iron, in every respect similar to those observed in other 

 coal formations. 



The iron ore is found in rounded or oval masses, some- 

 what flattened in the direction of the stratification ; it ap- 

 pears to be quite abundant, and, we doubt not, if made the 

 object of an exploration, would be found sufficiently so to 

 justify the erection of iron works on a large scale. 



Resting upon the slate-clay, we observed a bed seve- 

 ral feet in thickness, composed of a dark gray limestone 



