INTRODUCTION. 



In the North Staffordshire Coal-field there are at least two well-recognised 

 marine beds. The one " the Grin Mine," or " Golden Twist," containing — 



Goniatites excavatus, Phil. 



„ striatus, Phil. 



„ multilobus, Phil. 



Cypricardia glair ata, Phil. 

 Aviculopecten, sp. 

 Euomphalus tuber culatus, Flem. 

 Pleurotomaria, sp. 

 Productus semireticulatus, Mart. 

 Spirifer Urei, Flem. 

 Axinus (Schizodus), sp. 

 Orthoceras, sp. 



Solemya primseva, Phil. 

 Chonetes Laguessiana, De Kon. 

 Nucula gibbosa, Flem. 



„ lineata, Phil. 

 Machrocheilus JUichotianus, De Kon. 

 Bellerophon Bumontii, P. d'Orb. 

 Leda clavata, M'Coy. 

 Loxonema, sp. 

 Ctenodonta, sp. 

 Discites subsulcatus, Sow. 



The other bed, occurring above the " Knowles seams " and immediately 

 overlying the " Bay Coal," was discovered by Mr. John Ward, of Longton, in a 

 sinking at the Foley colliery, and he states in his work on the Geology of the 

 North Staffordshire Coal-fields, 1 " After a careful search I have failed to discover in 

 the North Staffordshire Coal-field mollusca of a fresh-water type in direct associa- 

 tion with those of a marine facies. In every instance where the two have 

 approached each other the line of demarcation has been clear and distinct." 



Even the beds over the Four-Foot coal of Wetley Moor and Biddulph, the beds 

 containing Lingula and Goniatites are perfectly distinct from those containing 

 Carbonicola, both in their horizon and lithological character — a fact I have been 

 able to observe very recently in a sinking near the top of Eaves Lane, Wetley 

 Moor. 



The following fossils occur in the Bay Coal band : 



Aviculopecten papyraceus, Sow. 

 Ctenodonta, sp. 

 Discina nitida, Phil. 

 Lingula squamiformis, Phil. 

 „ mytiloides, Sow. 



Machrocheilus, sp. 



Nautilus {Discites) falcatus, Sow. 



Productus, sp. 



Spirifer, sp. 



Another such marine band in the banks of the Tame at Ashton-under-Lyme 

 was discovered by Prof. A. H. Green, and a list of the contents is given by 

 Mr. Salter in the Memoir on the Country round Oldham, 2 which I quote here. 



Calamites, narrow ridges. 

 Wood. 

 Serpulites. 

 Aviculopecten fibrillosus. 



„ papyraceus, Goldf. 



Ctenodonta, sp. 

 Nautilus prsecox. 



Discites rotifer. 



sp. 2. 



sp. 3. 

 Goniatites, sp. 

 Orthoceras, sp., thin. 

 Megalichthys BZibberti, Agass. 



1 ' Trans. North Staffs Institute of* Min. and Meeh. Engineers,' vol. x, pt. 5, 1890, p. 49. 



2 ' Geol. Surv. Mem.,' " Geology of the Country round Oldham," 1864, p. 64. 



