NORTH STAFFORDSHIRE COAL-FIELD ORGANIC REMAINS. 49 



opened up at Hawley's sinkings, there are no known indications of the intro- 

 duction of other forms of life than those of which this genus is the type. 



In the Woodhead coal-shales of the Cheadle field, and other basement beds 

 of the lower thick measures at Norton and Bucknall, Anthracomya and An- 

 thracoptera are found in association with Anthracosia, the latter being repre- 

 sented by the species subconstricta, robusta, ovalis, and others ; Anthracomya by 

 Adamsii, and Anthracoptera by two new species, and others. In the Bullhurst 

 coal and its succeeding shales these bivalves frequently occur in immense num- 

 bers, especially in the Cockshead ironstone, the Hard Mine, Little Mine, and 

 the various Banbury coals of the Silverdale and Kidsgrove districts, and in 

 the Bassey Mine, Gutter Mine, Cannel Mine, and Black-band ironstones of 

 the upper thick measures. It is however remarkable that, where they are 

 unusually abundant, fish-remains become scarce and fragmentary ; in fact 

 none of the deposits which retain their original condition afford conclusive 

 evidence of other than the occasional commingling of these vertebrate and 

 invertebrate animals in the waters of the period, and it is only in the aggre- 

 gated bone-beds that their remains are associated in anything like equal 

 proportions. 



In many cases the bone-beds covering the surface of coal pass into thick 

 irregularly-deposited masses of shells, which by their persistency become 

 valuable guides in mining operations. Not unfrequently, however, they are 

 confined to a definite horizon, the shales above them being destitute of other 

 remains than those of plants matted together and imperfectly preserved. As 

 a rule the coal-beds are of greater extent and of a more uniform character 

 than ironstone deposits. In the upper measures both are usually but 

 slightly divided, and, generally speaking, where the ironstone thickens the 

 coal becomes inferior. The Longton ironstone-beds in many instances die 

 out altogether, or are but obscurely represented in the Silverdale and the 

 more easterly districts, and this is in fact the case with the coal in many 

 cases. The position of the shells varies according to the character of their 

 matrix ; in some instances they appear in situ, smoothly laid out, and rising 

 layer upon layer to the thickness of several feet. In this form they are 

 generally compressed, but in many others, such as the Moss coals, Hard 

 Mine, and Cockshead ironstone-shales, they retain their original shape. 



Until within the last two or three years there was no published evidence 

 to show that the generally received opinion of the restriction of marine 

 fossils to the lower measures of the British coal-fields was incorrect; but 

 some sinkings at Longton in the spring of 1863 revealed the existence of 

 a series of such remains in the shales of a thin unworked coal called the 

 Bay Coal, situated towards the base of the upper thick measures. These 

 remains consisted of Aviadopecten, Goniatites, languid, Orthoceras, Spirifer, 

 Ctenodonta, Macrocheilus, Katicopsis, Nautilus, Loxonema, and Biscina. The 

 discovery of Lingula, which at the time was the only form met with, was 

 announced in the Report of your Committee read at the Meeting at New- 

 castle, and the occurrence of the additional forms was also noticed in their 

 Report read at Bath last year. It has, however, been subsequently found 

 that, about eight years ago, Discince were discovered in nodules of the Priors- 

 field ironstone at Fenton Park. 



From the Bay Coal not being a workable seam, its extension can only be 

 proved by sinkings in other parts of the field, where it will have to be looked 

 for under different names and position, no other section appearing to agree 

 with the one at Longton. The Priors-field ironstone, which lies below the 

 Bay Mine, also yielded at the same sinkings Lingulce and Discince, but, 



