50 REPORT — 1865. 



except in one instance, of the association of the young of Discina with An- 

 thracoptera, none of the other forms were found in direct contact with them. 

 Discince have recently been met with at Kidsgrove in grey ironstone nodules, 

 which would appear to be representatives of the Longton Priors-field bed. 



The Bay Coal fossils appear to be confined to a thin stratum of shale, 

 containing grey flattish nodules of lean ironstone overlying the coal. The 

 Lingulce were never known to pass into the ironstone, but appeared to lie 

 near the top of the shales in association with Discince. Below these come 

 Orthoceras, Spirifer, and the others, and the nodules were generally taken 

 up with Aviculopecten, Spirifer, and Productus. Immediately above these 

 shales came another nodular bed of ironstone and thick shales, and these 

 were the depositories of several species of Anthracosia with Gytheropsis ; but 

 here, as in the Stinking Coal, the line of demarcation was in no case passed 

 by either of the forms above or below it. The Priors-field group appears to 

 be equally defined, Anthracoptera and Gytheropsis overlying the Linyuhe 

 and Discince. This isolation of Lingulce from all other than Discince is a 

 somewhat curious fact, but the cases cited are not the only ones which have 

 come under notice. It occurs in the shales of a coal worked on the western 

 flank of Axedge, and referred to the middle beds of the Millstone-grit. 



In June and July of the present year a bed of greyish shale, lying a few feet 

 above the Gin Mine coal, belonging to the upper part of the lower thick mea- 

 sures, was sunk through on the hill which divides Longton from Adderley Green. 

 These shales far surpass the Bay Mine in the number and variety of their 

 organic contents. They contain Productus, Chonetes, Lmgula, Aviculopecten, 

 Ctenodonta, A-vinus, Natteopsis, Ghemnitzia, Lo.vonema, Platyschism i, Pleu- 

 rotomaria, Discites, Goniatites, Nautilus, Orthoceras, and others, most of them 

 being represented by two or more species, some of which are new. 



More than one of these forms are common in the carboniferous rocks of 

 Scotland, and others are found abundantly in the Millstone-grits of Stafford- 

 shire. It is an interesting feature in these deposits that they contain Pro- 

 ductus, Spirifer, and Nautilus, which are absent in the lowest measures of 

 these fields. The occurrence of this bed is important as showing that the 

 two great divisions of the upper and lower thick measures are at widely 

 separated intervals, interlined by deposits which point to the sudden cessa- 

 tion of one order of natural operations, and the introduction of another, 

 which obtained for a comparatively short period and then passed away, to be 

 repeated Ion? after in two distinct but less important forms, but still equally 

 clear and equally conclusive. Whether there are other instances of these 

 isolated marine conditions in the middle measures, or whether they stretch 

 into the upper strata of the coal-field, a careful examination of beds passed 

 through in future sinkings will alone determine. 



On the extreme western outcrop of the coal strata at Longton a bed of 

 limestone, supposed to be of freshwater origin, overlies the Bassey Mine 

 ironstone at a distance of about 30 feet. Recent sinkings on the Longton 

 Hall estate have revealed a second band of limestone 30 feet below the 

 other, and like it divided into three beds by thin partings of clayey shale. 

 The upper bed has long been known, but in no other instance has the second 

 bed been met with, although there are several pits within the space of 300 

 yards. Far above this, however, a little below the base of the brick clays of 

 the upper measures, a third, if not a fourth bed of similar limestone has been 

 exposed at distant points, in each of which the fossil contents specifically 

 agree. The lower beds are the more fossiliferous, and include great numbers 

 of Gytheropsis, Microconchus, Anthracosia Phillipsii, with scales and teeth of 



