TRANSACTIONS OF THE SECTIONS. ‘he 
attributed the increased quantity of mud that it holds in suspension. Of 
five samples taken from the surface, the following are the results : 
per Imperial Gal. 
At the mouth of the Avon the water contains 26°3 grs. 
Tn the deep part of the Channel . 2 Ealehttie Se ae 
Advancing farther, where the water rary 35:0 
NELLIS i nee RE CP aia 
nthe opposite coast: 2... 655 j604!) e be) pou eee 
ioe Or tie (Usk. os ele d! sicke. p Wiloth on are 
5 | 201°3 
Average . . 40°3 
“If that part of the area of the Channel to which these data apply 
be taken at 225 square miles, and the above as an average at the 
depth of one fathom, the quantity of mud in suspension will be about 
700,000 tons. The mud in suspension gradually increases from the 
surface downwards.” 
Dr. Jeffreys of Liverpool exhibited to the Section two boxes of 
teeth and bones from the Caves of Cefn, in Denbighshire. 
On the Geology of the Coal District of South Lancashire. By Jans 
Heywoop, F.G.S., Senior Optime of Trinity College, Cambridge. 
The great coal district of Lancashire occupies an area of more than 
400 square miles, of which the largest and the most important portion, 
including an area of at least 250 square miles, is contained in the 
southern division of the county. 
Extensive beds of gravel, sand, marl, and moss, generally conceal 
the rugged outline of the Lancashire coal measures from the eye of the 
geologist ; but the industry excited by commercial enterprise has found. 
a way to obtain access to the mineral treasures of the district through 
the deepest superincumbent strata, and the rich produce of the coal 
mines has aided, at the same time, in the centralization of manufac- 
_ turing and commercial power in Lancashire. 
The eastern boundary of the great Lancashire coal district is formed 
by the lofty range of gritstone hills which separates the county of 
Lancaster from the West Riding of Yorkshire. 
This gritstone range of hills is continued from the heights of Pendle 
Hill, Padiham, and Boulsworth, in North Lancashire, py Cliviger, 
_ Todmorden, Blackstone Edge, Stanedge, and Longdendale, to the 
_ north of Derbyshire. From the steep acclivities above Todmorden, a 
_ transverse ridge of gritstone hills breaks into the central portion of the 
Lancashire coal district, and elevates, in detached masses, many isolated 
