OF THE NORTH-WEST OF ENGLAND. 237 



and Wigan Canal, where the late Mr. Coleby formerly had 

 his lime works, beds of limestone parted with red clays, similar 

 to those at Astley, have been worked here for many years. 

 The limestones are full of fossil shells of the same genera as 

 those met with at Collyhurst, and before described in this 

 paper, as well as numerous sponges, one of which Professor 

 King has figured and described in his work on the Permian 

 Fossils as Tragos Binneyi, 



A complete section of the permian beds in this locality is 

 wanted. The late Mr. Coleby informed the writer that the 

 thickness of the marls was about 60 feet; ten feet of this 

 consisting of limestone in numerous beds. He also considered 

 that there was a bed of sandstone above, as well as one under 

 the red marls. 



Mr. Whitehead, solicitor, of Leigh, the proprietor of the 

 Bedford Lime Works, has favoured me with the following 

 section of the strata met with in his sinking : — 



Ft. In. 



A bed of limestone, called false band 5 



Red clay 3 o 



Band stone (this is the best stone) 1 o 



Red clay 1 o 



Limestone 7 



Red clay with thin beds of limestone the beds each 

 about one inch thick, clay and stone alternating, 



the former rather thicker than the latter 3 



Strong red clay 1 



Red clay with beds of limestone, the latter of which 



will vary from one to seven inches in thickness ... 3 



Red clay 1 o 



Limestone 1^ 



Red clay with beds of limestone, the top course of 

 stone 12 inches in thickness, called second band; 

 some of the beds of clay are 12 inches in thickness. 

 The layers of stone vary from one to three inches 

 in thickness. The stronger the stone, the thinner 

 the clay lo o 



24 1| 



