\6 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 28, 



theiipper boundaries of the carboniferous strata is to compare one 

 coal-tield with another; for, so far as I am aware, no one in England 

 has yet seen coal-measures fairly graduate and pass into the lower 

 new red sandstone formation. In Lancashire about 1490 yards of 

 strata, terminating upwards with the red measures of Ardwick, 

 have been found above the Riley or Daubhill mine. Now what is 

 the case in Yorkshire and Derbyshire ? In the measures occurring 

 between the black shale coal of Bromley, proved to be identical with 

 that of Sheffield and the Worth Wood coal, formerly worked by the 

 proprietors of the Swinton Pottery, only 633 yards of strata have been 

 met with. This distance is taken from the borings made some years 

 ago at the expense of Earl Fitzwilliam in and near to his Wentworth 

 estate. And in Derbyshire I know of no more than 600 yards of 

 measures having been found to exist above the same coal, so that if 

 the two coal-fields have been formerly one, we have evidence that 

 837 yards more of the coal-measures have been exposed in Lanca- 

 shire than in Yorkshire and Derbyshire, and in such case they exist 

 in all probability covered up by the new red sandstone formation. 



In the limestones and red shales of Ardwick *, we find both the 

 remains of large sauroid and other fishes, and an abundance of fossil 

 plants; but the former, as they are of little value in identifying par- 

 ticular coal-measures, it will not be necessary to mention. But 

 with regard to the latter, some, as Neuropteris cordata, a Lycopo- 

 dites^ a small tSphenopteris, an undescribed Pecopteris, a LepidO' 

 phyllum, and two Aster ophylliteSi not yet figured, are of considera- 

 ble importance. These plants, especially the first-named, have been 

 met with in the high coal-measures of Le Botwood and Uffington, 

 and in the Burdiehouse strata near Edinburgh (the true position of 

 which, some geologists contend, belongs to the upper and not to 

 the lower part of the field as first supposed t)> and some of them 

 also have been pointed out to me by Mr. Lyell among the fossils 

 brought by that geologist from the upper part of the coal-fields of 

 North America and from Autun in France. In Yorkshire and Der- 

 byshire I have not been able to discover any of these plants, not- 

 withstanding that most of the specimens of the fossil flora are com- 

 mon to both coal-fields. Although, generally speaking, these fossils 

 alone may not be sufficient to identify strata at different points, 

 still their absence in some measure tends to confirm the opinion 

 that the upper portion of the Yorkshire and Derbyshire coal-field 

 is not exposed. 



The Lancashire coal-field having been compared with that of 

 Yorkshire and Derbyshire, and having been proved to be continu- 

 ous with it, we are justified in concluding' from analogy, that not 

 only is the North Welch deposit similarly connected, but that those 

 of Shropshire, Staffordshire and Leicestershire, as well as that of 



* Murchison's * Silurian System,' p. 86. 



t If fossil organic remains are of any evidence in identifying strata at different 

 places, the Salopian, Lancastrian and Scotch deposits must be considered as being 

 oi the same age. 



