566 Geological Society: — . 



oxides contain more oxygen near the surface than below it. Lime 

 and magnesia are both readily soluble, but lime much more so than 

 magnesia. Soda is more sensitive to weathering than potash. 

 The rocks contain more combined as wdl as uncombined water on 

 their surface than when sheltered from atmospheric influences. 



The paper was accompanied by an appendix on the microscopical 

 structure of some of the varieties of rocks by Prof. Bonney. 



4. " On the so-called Midford Sands." By James Buckman, 

 Esq., E.L.S., E.G.S. 



The author quotes from the works of Professor Phillips and 

 other authors certain passages, in which the sands below the Oolitic 

 Limestones of the Cotteswold Hills and Dorsetshire are correlated 

 with one another, and the name of " Midford Sands " is applied to 

 the formation represented by these strata. 



In opposition to these authors' views, Prof. Buckman maintains 

 that two distinct Ammonite bands have been by them confounded 

 with one another, that the sandy beds in the Cotteswolds really 

 belong to a much lower horizon than do the similar strata in Dor- 

 setshire and Somersetshire, and that, while the former lie quite at 

 the base of the Inferior Oolite series, the latter represent a great 

 part of that formation. 



In support of this view Prof. Buckman points to the fact that a 

 representative of the true Cephalopoda-bed lies at the base of the so- 

 called Midford Sands of Somersetshire ; he illustrates the rapid 

 transitions which take place between sandy and calcareous strata in 

 this part of the series ; and in conclusion he shows, by the study of 

 the somewhat fragmentary fossils found in the sands of Dorset- 

 shire and Somersetshire, that they are the true equivalents of several 

 different divisions of the Oolites of the Cotteswold Hills. He 

 admits, however, that some Liassic forms range upwards into these 

 beds. 



5. " On the Physical Geography of the North -east of England in 

 Permian and Triassic Times." By E. Wilson, Esq., E.G.S. 



In this paper the author seeks to utilize the information he has 

 acquired from the study of the Permian and Triassic rocks of the 

 above district, towards solving some of the difficult and much-de- 

 bated questions as to their origin. With this end in view he traces 

 the various members of the Magnesian Limestone formation between 

 Notts and Northumberland, noticing in particular the amplification 

 of that group of rocks in northerly and easterly directions. Inci- 

 dentally attention is called to the increased importance of the Marl 

 Slates as a distinct and characteristic series. One of the main ob- 

 jects of the paper is to establish the pre-Permian origin of the 

 Penine Chain. The nature and relative values of the stratigra- 

 phies! breaks which, in the district in question, occur between the 

 Carboniferous and Permian, the Permian and Bunter, and the 

 Bunter and Keuper formations are severally dealt with. The author 

 concludes by speculating as to the general conditions under which 

 the Permians may have been formed, and the physical fluctuations 



