46 report — 1865. 



Many of the coal and ironstone beds are either of local extent, or 

 evidence a variation of condition of deposit within a limited area, and con- 

 sequently the measures of one district are no sure guides in engineering to 

 those of another. This more frequently happens in the upper thick beds 

 with the ironstone group, and it is found that this diversity in the character 

 of the mineral deposits is partaken of in a somewhat similar degree by the 

 forms of life directly associated with them. Taking the Longton and Fenton 

 beds as one example, the Deep Mine shales show the predominating form to 

 be PalcEoniscus, the Knowles ironstone Platymmus, and the New Ironstone 

 Megalichihys. At Silverdale and Apedale Palceoniscus is rare, while the 

 Brown Mine teems as it were with Platysomi. Passing to the Kidsgrove 

 district, the Brown Mine becomes the New Mine, and Phttysomus gives place 

 to Rhizodopsis, and passing downwards to the Woodhead coal, Ccelacanthus 

 appears as the characteristic fossil of its bed. The life-zone, as it were, of 

 each of these deposits also varies. In the case of the Deep Mine, it is con- 

 hned to a few inches of black shale immediately overlying the stone, and in 

 no known instance passing into the mineral itself. In the Knowles ironstone 

 shales the same conditions are observable ; but the life-zone extends down- 

 wards into the stone, fine specimens of Rhizodus, Ccelacanthus. Acanthodes, 

 and Megalichihys beim>- of frequent occurrence in the upper division of the 

 bed. The Brown Mine of Silverdale and the New Mine of Kidsgrove present 

 parallel conditions ; but in the Brown Mine of the latter district the shales 

 form only the matrix of its interesting organisms. The beds of ironstone 

 and coal enumerated — the Woodhead and Ash coals, and the Cockshead, 

 Knowles, Deep Mine, Brown, and New Mine ironstones— appear to be the 

 great fish-zones of these fields ; but it may be accepted that the whole of the 

 mineral beds contain the remains of either fish or shells, generally both. These 

 remains, as previously stated, are rare in certain localities ; but no bed has 

 hitherto been found totally unfossiliferous over the whole of its proved area. 

 It is also worthy of note, that in almost all, if not every case, the divisional 

 line between each seam of coal and band of ironstone and their associated 

 shales or bass, consists of a thin film, as it were, of detached scales and teeth 

 of fishes or compressed mollusks, showing in a simple but conclusive manner 

 that whatever may have been the condition under which each bed of coal 

 was formed, it was immediately after its formation covered by water con- 

 taining the ordinary forms of life of that period, and which by its agency 

 were spread over the surface of each coal-bed before becoming charged with 

 the mud now forming its superimposed shales. Frequently the ironstones 

 are immediately overlain by thin beds of coal ; and in the case of the New 

 Mine at Kidsgrove, this coal is largely intermixed with fragments of Gyra- 

 carrihus, Megalichihys, and other fish-remains ; but this is the only instance 

 in the field in which such fossils have been detected within the body of coal 

 itself ; and in this case the coal which forms a parting between two bands of 

 stone is not of the ordinary character of coal-deposits, but evidently the 

 aggregated parts of an older bed brought from another point, and redeposited 

 by aqueous agency. 



In addition to the Ganoid fishes enumerated, Acanihodes, Acrolepis, 

 Gyrolepis, Pyyopterus, Dipkpterus, aai: Megalichihys are forms more or less 

 familiar to these beds, most being represented by two or more species, 

 winch appear here and there at intervals throughout the entire vertical strata. 

 Megalichihys Hibberti is by far the most common form ; but hitherto no 

 perfect specimen has been met with. The New Ironstone of Fenton Park, 

 the Gubbin ironstone shale of Shelton, and the Chalky Mine ironstone of 



