On Spores in the Carhoniferous Formation of Scotland. 103 



profusely. Generally, the first two or three inches of fireclay 

 beneath the superincumbent coal is the most prolific. This 

 is well illustrated at the two following localities. The first 

 is the locality we originally examined for spores, and is 

 situated just under the Eailway Weigh-house of the Niddrie 

 Section of the Edinburgh Suburban Eailway. The lowest 

 bed is a sandstone eight inches in thickness, permeated with 

 Stigmarian rootlets : above this is a fireclay six inches thick, 

 of which the lower two inches were barren, while the upper 

 four inches contained great quantities of spores. The coal 

 above the fireclay, which was four inches thick, yielded only 

 a few spores. 



In the second instance, which was that of the fireclay 

 immediately under the coal beneath the limestone of Joppa 

 Quarry, spores were only found in the first three inches, 

 whilst the lower three inches were barren. The sandstone 

 underlying the fireclay also contained many Stigmarian roots 

 and rootlets. 



III. Bituminous Shales or Shale-like Coals. — These 

 may be considered poor or imperfect coals, composed of clay 

 or shale highly charged with bitumen or other form of hydro- 

 carbon. Where the process of bituminisation has been 

 arrested by the quantity of clay in the bed, the bitumen has 

 preserved the spores from decay by eremacausis, and they 

 are " mummified " or " embalmed " by its black oil. These 

 shale-like coals, when weathered, can be easily crushed, and 

 the spores liberated. 



IV. Plant Beds (such as at Blairpoint). — In such beds 

 where there is scarcely any formation of coal, and only a 

 blackening of the shale, with perhaps occasionally a few thin 

 streaks of coal, the shale readily yields to the process of arti- 

 ficial weathering, which consists in simply drying the shale 

 and steeping it in water, when it divides into small pieces, or 

 is reduced to a clay. The spores can then be easily washed 

 and floated off. 



Black Takes in Sandstone Beds. — At several places on 

 the shore at Joppa, and in Joppa Quarry, but especially in 

 Hailes Quarry, parts of the sandstone are divided into thin 

 lamince of black carbonaceous matter and white sandstone. 



