148 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY, [Feb. 7, 



1. Ftjrther Notes on the Geology of the neighbourhood 0/ Malaga. 

 By M. D. M. d'Okijeta. Communicated by the President. 



[Abstract*.] 



In this paper, which is a continuation of a former note laid 

 before the Society (see Q. J. G. S. xxvii. p. 109) the author com- 

 menced by stating that his former opinion as to the Jurassic age of 

 the rocks of Autequera is fiiUy borne out by later researches upon 

 their fossils. They apparently belong to the Portlandiau series. 

 The author made considerable additions to his description of the 

 Torcal, near the foot of which he has found a sandstone containing 

 abundance of Grj/pJicea virgula and Ostrea deltoidea. This he re- 

 gards as equivalent to the Kimmeridge Claj^. In the Torcal he has 

 also found a soft, white, calcareous deposit, overlying the limestones of 

 supposed Portlandian age, and containing a fossil which he identifies 

 with the Tithonian Terehratala diphya. The author discussed the 

 peculiar forms assumed by the rocks of the Torcal under denuda- 

 tion, which he supposed to be due originally to the upheaval caused 

 by the rising of a great mass of greenstone, portions of which are 

 visible at the surface on both sides of the rang-e. 



2. On the RrvER-coTJKSES of England and Wales. 

 By Prof. Andrew C. Eamsay, LL.D., P.K.S., V.P.G.S. 



In the following paper I propose to show the origin of many of the 

 principal rivers of England and Wales — that is to say, what are the 

 special geological causes the operation of which led them to flow in 

 the general directions they now take. I am not aware that any 

 attempt has heretofore been made to do this on a large scale, though 

 I have already done something on the subject with regard to the 

 rivers of the Weald, in which line of argument I was afterwards 

 followed by Mr. Foster and Mr. Topley. 



I shall begin the subject by a rapid summary of certain physical 

 changes that affected the English Secondary and Eocene strata, long- 

 before the Severn (leaving the mountains of Wales) took its present 

 southern and south-western course along the eastern side of the 

 palaeozoic rocks that border that old land. 



About the close of the Oolitic epoch the strata of these formations 

 were raised^above the sea, and remained a long time out of water ; and 

 during that period those atmospheric influences that produced the 

 sediments of the great Purbeck and Wealden delta were slowly wear- 

 ing away and lowering the land, and reducing it to the state of a broad 

 undulating plain. At this time the Oolitic strata still abutted on the 

 mountain country now forming Wales and parts of the adjacent 

 counties. They also completely covered the Mendip Hills, and 



_ ^ * The publication of tbis paper is deferred. 



