Bag sho.t Beds of the London Basin. 241 



as they should be, and that the records of the canal show the retro- 

 gression of " fan " and " reach" demanded by the hypothesis. 



Accepting this agreement of fact with hypothesis as proof of the 

 correctness of the latter, it follows that the fundamental principle 

 on which it is founded is correct, and that, in the absence of inter- 

 fering causes of greater potency, it is the coarseness or fineness of 

 the debris cast upon a stream that will determine its gradient and 

 velocity, and not, as stated in text-books, the velocity of a stream 

 that will determine its gradient and the coarseness of the debris 

 transported by it : — a conclusion that might be arrived at inde- 

 pendently, from the fact that it is in the upper reaches of a stream, 

 where coarse debris prevails, that high velocities of current prevail, 

 while in the lower reaches, where the debris is finer in grain, the 

 velocity of current is also diminished. 



2. " Supplementary Notes on the Stratigraphy of the Bagshot 

 Beds of the London Basin." By the Bev. A. Irving, B.Sc, B.A., 

 F.G.S. 



This paper contained the results of field-work during the year 1887. 

 Additional notes on the stratigraphy of the Bracknell and Ascot 

 Hills were given, justifying the reading of the country as shown in 

 figs. 1 and 2 of the author's last paper (Q,. J. G. S. August 1887), 

 the examination of this line of country having been extended as far 

 as Englefield Green. Sections of the beds of the Middle Group as 

 they crop out at Csesar's Camp, Swinley Park, Ascot, and Sunning- 

 dale, were described and correlated with the 76 feet of beds which 

 constitute that group in the Well-section at "Wellington College. 



The stratigraphy of the hills known as Finchampstead Bidges has 

 been worked out from numerous sections on their flanks ; and the 

 strata of the Bearwood Hills were correlated directly with them. 



All along the northern margin a general attenuation of (a) the 

 Lower (fluviatile) Sands, and of (6) the Middle (green earthy) Sands 

 was shown to occur, and in some places on the northern margin they 

 are found to have entirely thinned away, admitting of distinct 

 overlap at more than one horizon. 



The second part of the paper dealt with the Highclere district, 

 where the author believes he has established the full succession of 

 the three stages of the Bagshot Formation, a section being given 

 across the valley south of Highclere Station, showing the succession 

 of the whole Eocene series (with the Ostrea bellovacina-'hed for its 

 base) as it is developed there. 



Some important conclusions were drawn as to the Tertiary physio- 

 graphy of the South of England ; and the revised tabulation of the 

 Tertiaries put forward by Prof. Prestwich at the Society's last 

 meeting was referred to as supporting some of the main points for 

 which the author has contended. 



3. " The Bed-Bock Series of the Devon Coast Section." By the 

 Bev. A. Irving, B.Sc, B.A., F.G.S. 



From a recent examination of this section, and from the facts 



