8 COAL MEASURES. 



and this is also the case with regard to the character of the formations 

 upon which the Coal Measures rest in the counties above named. So 

 far as is known at the present time, no Devonian or Lower Carbonifer- 

 ous rocks are known to exist in these counties, and the whole area east 

 of the coal field is supposed to be underlaid by upper and lower Silu- 

 rian strata; but it is by no means improbable that beds belonging to the 

 Devonian or even the Lower Carboniferous may yet be found in these 

 counties, as these formations are known to underlay the Coal Measures 

 on the Upper Wabash, in the vicinity of Williamsport, in Indiana, in 

 considerable force, and unless they thin out rapidly to the northwest- 

 ward, should extend into this State. 



