NOTE ON THE SOUTH DUEHAM SALT BOEINGS. 225 



Mr. James Kirkby places these Brotherton Beds on the same 

 horizon as the Yellow Concretionary and Crystalline lime- 

 stones of Marsden, Fulwell, Roker, Hartlepool, etc. ; but I 

 think they are much higher, are the top beds of the Upper Mag- 

 nesian-lime stone, and that they are the exact equivalents of the 

 Plattendolomit of Germany, and have never been seen at the 

 surface in Durham or North Yorkshire ; they form, in fact, the 

 uppermost series of beds of the Magnesian -limestone both in 

 England and Germany, and the uppermost limit of the Permian. 

 See Quart. Journ. Geol. Soc, Vol. XYII., pt. 1, p. 287 et seq. 



Fossils. 



Some years since, now, I spent a summer's day in company 

 with Mr. Howell and Dr. Yeitch, in visiting and examining the 

 cores from the bore-holes in the South of Durham. 



At the Newcastle Chemical "Works bore-hole ISTo. 1, I soon de- 

 tected on a dark ash-coloured limestone core distinct impressions 

 of Chondrites virgatus, Miinst., and subsequently a specimen of 

 Axinus dnbius, Schloth., the latter very small and dwarfed in 

 size. Since that time Dr. Yeitch has found a few more examples 

 in the same bed of limestone, and also very minute specimens of 

 Myalina Hausmanni, and traces of another species of bivalve 

 shell. Many of the cores at this place are quite oolitic in struc- 

 ture, and agree well with a bed of limestone which I have seen 

 in situ only in. the cliffs at Hartlepool, where it is, however, of 

 a more yellow colour. The cores containing the Axinus and 

 Chondrites closely resemble a deposit on the coast near the mouth 

 of Castle Eden Dene, but the cores from the bore-hole are more 

 crystalline and of greater density. 



As the cores at this place were not in order, but much thrown 

 about, it would be difficult, perhaps, to identify them with any 

 particular part of the section, but they belong, without doubt, 

 to the Upper-series of the Magnesian-limestone, and high up in 

 that series. 



S EATON CAEEW BOBE HOLE. 



A few weeks since I had an opportunity of visiting Seaton 

 Carew, and spent a few hours in carefully examining such of 



