found in the Vicinity of Manchester. 355 



been confounded with the magnesian limestone, which latter 

 stratum had never been distinctly identified in this neighbour- 

 hood, until an examination of the fossils of Collyhurst led me 

 to the conclusion, that the clays and thin limestones there 

 exposed were the representatives of that series, so important 

 in Yorkshire and Durham. On comparing the fossils of the 

 magnesian series with those from Ardwick, we shall find that 

 no one species found at the latter place agi'ees with any yet 

 discovered in the magnesian limestone in England, the stron- 

 gest evidence that they do not belong to the above series of 

 rocks. The small fish bears a considerable resemblance to 

 the Paleeoniscus from the copper slate or zechstein, a stratum 

 concerning the relative position of which I have some doubt. 



On comparing the fossils, however, with those from the car- 

 boniferous system, we immediately observe their identity : we 

 have Stigmaria Jfcoides, the almost universal characteristic of 

 the coal measures ofLancashire and Yorkshire; several Filices, 

 especiaUy a Sphenop/iylhim, a genus, I believe, confined to the 

 coal series; Calamites, and the still more important leaves and 

 stems of the Lepidodendroii, Sternbergii. However undecided 

 we might be previously, the discovery of these remains cannot 

 leave the slightest doubt as to their connexion with the car- 

 boniferous group. 



The merit of the discovery of this important generalization 

 belongs to Dr. Phillips, who, in May last, explained his views 

 to the section of the Manchester Philosophical Society, and 

 expressed his firm conviction that geologists had hitherto been 

 in error in connecting these limestones with the magnesian 

 series ; and the deciding upon the relative position of so large 

 a mass of strata, in such close connexion with the Lancashire 

 coals, cannot be viewed otherwise than as an important result. 



On a slight examination of the fossils, we observe another 

 important i'act: no marine remains whatever have yet been dis- 

 covered. When we find freshwater remains mingled with 

 those of marine origin, the probability is that the deposit was 

 formed in some estuary or mouth of some large river ; but 

 here the remains are entirelyof freshwater origin. All the most 

 important fossils which guided Dr. Hibbert in arriving at his 

 splendid results at Burdiehouse, we find here. The entire abs- 

 ence of marine remains : the extreme abundance of microscopic 

 freshwater Entomostraca, of Unionidae; fish of the genus Pa- 

 Iceoniscus; minute univalves, in all probability of the freshwater 

 genus Planorhis; and lastly, the discovery of remains aH Me- 

 galichthi/s Hibbertii, all concur in assigning to the limestones 

 a freshwater origin. It would be needless for me to enter 

 here into any long discussion on the nature of freshwater 

 2 T 2 



