Vol. XXviii.] PAL.5:0NT0L0GY OF LANCASHIRE COAL MEASURES. 379 



The coal seams in descending order are as follows : — 

 Pasture, B asset, and other Thin Coals. 



Ft. ir 



Upper Mountain Mine. 



Fireclay Coal. 



Upper Foot Mine \ ^^ 



^^ ' Mountain 4 ft. 



I 



Lower Mountain Mine 

 Lower Foot Mine. 

 Salts Mine. 

 10 First Coal. 



It will be noticed that none of the coals are of great 

 thickness, the chief being the Mountain Four Feet, which 

 has been worked under a variety of names in the Burnley 

 and Colne districts. 



The Lower Mountain Mine, better known as the Gannister, 

 has been very generally worked, and to a still less degree, 

 the Upper Mountain Mine, and the Salts or Bassey seams. 



The remarkable series of names which have been applied 

 to the various seams in different districts, and at various 

 times, has been dealt with in a previous paper by the 

 author, and needs no further reference here.* 



With the exception of one horizon, and the occasional 

 occurrence of bands of Carbonicola (Anthracosia) in the 

 shales, the beds are but moderately fossiliferous in point of 

 species, although at times prolific in numbers. 



Fossils are most abundant in the black shales which 

 overlie the coal seams, and scanty in the coarse sandstones, 

 flags and grits. 



In this paper it may appear that fossils are most often 

 found in the shales which lie in close relation to the coal 

 seams, but this apparent segregation is doubtless due in 



*"The Nomenclature of the Seams of the Lancashire Lower Coal 

 Mesi&uves.''— Trans. Manch. Geol. Soc, Vol. XXV., Fart XVI. 



