176 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



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 carbonized 

 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. which 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 " bitumi- 

 nous limestone with shells and fish-scales," four feet thick, and lower down, 

 in the succeeding 2000 feet, there are eighteen beds of similar bituminous 

 limestone, one of them only half an inch thick, eleven of them under six 

 inches, and the thickest two feet. Neither the shells nor the nature of the 

 fish-scales are described, but that these are freshwater limestones may be 

 inferred from this, that several of them are mixed with Stigmarise and other 

 plants : thus, associated with the twenty-eighth seam of coal is a " bitu- 

 minous limestone and carbonaceous shale in alternate layers of one to 

 three inches, -with, plants, shells and fish-scales;" under the thirty-first, 

 " with Stigmarise, shells and fish-scales ;" along with the thirty-sixth, 

 ** black bituminous limestone with branches and leaves of Stigniarios well- 

 marked, and very minute shells ;" under the forty-fourth, "with Stigrna- 

 riee branches and leaves, fragments of other plants, and minute shells." 

 Mr. Lyell states that he observed " not far above the uppermost coal-seams 

 with vertical trees, two strata, perhaps of freshwater or estuary origin, 

 composed of black calcareo-bituminous shale, chiefly made up of com- 

 pressed shells, of two species of Modiola, and two kinds of Cypris.'* It is 

 possible, therefore, that the " minute shells" of Mr. Logan are Cypris. 

 Beneath the lowest seam of coal are intercalated fourteen beds of what is 

 called a " Concretionary limestone," and " Limestone in concretionary 

 nodules," from one to three feet thick, one of them as much as eight feet, 

 and in one instance the limestone is said to contain carbonized drift 

 plants. 



i. Several instances are given of stems of plants standing perpendicular 

 to the plane of stratification ; the first is 2l60 feet from the top of the up- 

 permost bed. 



cf. Calamites ''as \i in situ." 



/3. Lower down, 570 feet below a, two upright stems of Calamites, 

 two inches in diameter, coated with coal, start from the top of a dark 

 grey argillaceous shale, and penetrate into a grey shale with sandstone 

 above. The length of the stems is not given. 



y. Forty feet below is a foot of sandstone and then a foot of shale, and 

 *' in this shale, and running into the sandstone above, is a Calamite at an 

 angle of 45° : it appears to start from a coal-seam below, an inch thick." 



I. Beneath this, 640 feet, a seam of coal three inches thick occurs, and 

 from it "there springs up an erect Sigillaria eighteen inches in diameter, 

 and it penetrates the shale and sandstone above it, five feet of the plant 

 being visible." Underneath the coal is "a grey sandstone with Stigmaria 

 Jicoides (imderclay) . " 



g. The next instance given is 1038 feet lower down, where, from a grey 

 argillaceous shale, rises an upright Sigillaria, one foot in diameter, pene- 

 trating to a height of two feet into argillaceous shale above. There are sixteen 

 feet of sandstone and shale below this Sigillaria, and without Stigmaria. 



^. The next is 2/0 feet lower, where, from an argillaceous shale, " springs 

 an upright Sigillaria of one foot in diameter ; the lower part commences 

 to spread." There are seven feet of argillaceous shales, with ironstone balls, 

 beneath this Sigillaria, without Stigmarioe. 



V}. The next is 228 feet lower, where from a " gray, crumbly, argillaceous 



