104 Horner's Geological Address. 



Stigmarioe ten feet thick has a seam of coal over it only an 

 inch thick. 



/*. Between the sixty- seventh and sixty-eighth coal-seams, 

 the former with associated carbonaceous shale only fourteen 

 inches thick, there are 170 beds of sandstone and argillaceous 

 shale, from six inches to 132 feet thick, their aggregate 

 thickness being 2620 feet, and the sixty-eighth coal-seam is 

 only called coaly clay, two inches thick, with an underclay 

 containing Stigmaria leaves of six feet. 



g. In the. 2274 feet of sandstones, &c. lying above the 

 highest seam of coal, fragments of plants are seen in several 

 of the beds ; they first occur in a bed of sandstone 218 feet 

 from the top, and the plants are converted into coal ; they 

 are often called " drift plants,'' and stated to be " coated 

 with coal/' In one bed there are " carbonized drift plants 

 of large diameter," say one foot, the stems lying prostrate ; 

 and 1520 feet below this, there is a sandstone " fit for grind- 

 stones, with a few Calamites nearly at right angles to the 

 plane of the beds, as if in situ, but forced over at the top ;'' 

 this sandstone rests on a black carbonaceous shale two feet 

 thick, but it is not stated whether the Calamites are fixed in 

 this carbonaceous stratum. Between this last and the first 

 seam of coal, which is only one inch thick, there are three 

 feet of a " greenish-grey sandstone with Stigmaria ficoides^ 

 succeeded by two feet of " grey argillaceous shale, with im- 

 pressions oi ferns and other plants.'' 



Between the seventy-fifth seam, half an inch, and the 

 seventy-sixth, two inches thick, are eighty-four beds of sand- 

 stone from a foot to 1 17 feet thick, together 1223 feet ; and 

 twenty of these beds, all called greenish-grey sandstone, are 

 said to contain carbonized drift plants ; and in one of these 

 beds there is said to be '' a vast confused collection of car- 

 bonized drift plants ; one lying prostrate measured twenty- 

 five feet in length, and about one foot in diameter at the 

 small end." So likewise in the 2800 feet of sandstones, &c. 

 vvhich are beneath the seventy-sixth or lowest seam of coal, 

 ten of the beds are said to contain carbonized drift plants. 



h. At a distance of 4400 feet from the surface there occurs 

 a " bituminous limestone with shells and fish-scales," four 



