ASHLEY : NOTES OX ADWALTOX AND HALIFAX COAL. 257 
the bottom 3 inches. In other parts of this mine the cannel 
coal is found 10 inches thick. 
At East Ardsley the cannel is underlaid by bright coal 2 feet 
thick, there being no parting between them, the bottom half of 
the ordinary coal being inferior. This corresponds very nearly 
to the section found at Hartley Bank Colliery, the bright coal 
there being 1 foot 10 inches thick. 
Isolated patches of cannel are found in the south as well as 
in the north, as at Kirby, where a cannel is met with on the top 
of the Flockton Thick Coal 4 inches to 5 inches thick, and further 
south still at Hoyland Silkstone a cannel coal is found above 
the Flockton 10 inches thick. Other instances could be given. 
Overlying Strata. The roof over the cannel coal is always of 
the same character, and is composed of from 1 to 2 feet of black 
shale containing few traces of animal life. 
Above this shale is a stratum 10 inches to 1 foot thick, 
sometimes running thicker, which is crowded with the shells of 
Anthracosia. Above this shell bed are about 20 feet of bluish- 
white shales containing several layers of ironstone nodules. Shells 
of Anthracosia are common in the ironstone but do not occur in 
the shale. 
This band of ironstone nodules is found overlying the Flockton 
Thick Coal, north of Sheffield, where it has been extensively 
worked. It has also been worked at West Ardsley, where it 
closely resembles that of the south. To the north, however, 
along with the disappearance of both the cannel and the under- 
lying coals, the ironstone measures die away. 
The cannel itself contains very numerous remains of fishes 
in the form of scales, plates, and spines ; also very numerous 
remains of a small animal belonging to the group Ostracoda. 
This is in marked contrast to any case of bright coal, and indeed 
remains of marine animals have never been found in any true coal. 
(2) The Halifax Hard Bed Coal. — The Halifax Hard Bed 
Coal along w4th the Halifax Soft Bed Coal lying a short distance 
belovv', and more generally known as the "Canister Coals," are 
the lowest seams of the Lower Coal Measures. 
