cash: fossil fructifications of YORKSHIRE COAL MEASURES. 437 
minutest parts, whicli is not only highly instructive but also exceed- 
ingly beautiful to look upon; to quote the exclamation of the late 
Charles Darwin on his first acquaintance with these coal-plant micro- 
preparations, " It is marvellous to see structure so admirably preserved 
for so many ages." 
The Yorkshire localities for these fossils with minute " structure 
so admirably preserved," are the pits where the " Halifax Hard Bed 
Coal" has been Avorked, these may be studied all along a line parallel 
with the outcrop of the lower coal-measures extending from north to 
south by Leeds, Yeadon, Denholme, Holmfield, Sowthowram, Halifax, 
Elland, Huddersfield, Hepworth, Penistone, and Hazlehead near 
Sheffield. A portion of the Lancashire bed known as the "Upper 
Foot Coal," occurs near Saddleworth, on the Lancashire border of 
the county. 
The Hard Bed or Canister coal may be readily recognised and 
traced over the whole coalfield, it lies on hard ganister underlying, 
which there is usually a bed of fire-clay ; the roof of the bed of coal 
is generally composed of a dark shale containing fossil shells 
(Goniatites Listeri, Orthoceras Stienhaueri, Aviculopecten papyraceus, 
and other marine shells.) The coal itself and the superimposed 
shales often contain calcareous nodules with included fossils, the 
nodules in the coal known locally as coal balls, generally contain 
plant remains with the minute structure sometimes beautifully 
preserved but often, alas ! spoiled by the large quantity of contained 
iron pyrites. 
The order of superposition of the ganister group is given in 
" The Geology of the Yorkshire Coal Field : Memoirs of the Geological 
Survey." London, 1878, as follows : — 
[The average thickness in feet of the various groups on the 
south are given in the left-hand margin and those of the north in 
the right-hand margin.] 
S. 
Feet. 
N. 
Feet. 
The Elland Flagstone. 
Measures with irregular Sandstones and 
thin Coals- 
