650 REPORT— 1886. 



These specimens have heen carefully examined, and the result of this examina- 

 tion is, I think, worthy of notice. As regards fossils it is simply negative, my col- 

 leagues, Mr. G. Sharman and Mr. E. T. Newton, after washing and sifting pieces of 

 many specimens, were unable to detect any organism, with a solitary exception, 

 and that was a single example of a species of Rotalia, which, struggling into exist- 

 ance in Silurian times, has managed to survive to the present day ! I have some 

 doubt, too, whether this one fossil may not have fallen down the bore. Anyway 

 it proves nothing. As regards the character of the beds, however, I think that a 

 reasonable conclusion may be inferred from the specimens. 



In my published account certain beds are referred, with some doubt, to the 

 Lower Greensand. The reference is wrong and the doubt right. The top five 

 feet, of the forty-nine credited to Lower Greensand, really belong to the base of 

 the Gault, and the bottom thirteen feet to the Wealden, as I believe. The Lower 

 Greensand is left, therefore, with only thirty-one feet of clayey sand. It is curious 

 that specimens from the bottom part (838 to 848 feet) are exactly like the corre- 

 sponding specimens from the bottom part of the Lower Greensand in the Chatham 

 boring (932 to 943 feet), the two sets having about the same vertical extent 

 (10 or 11 feet). 



These specimens remind one of the division known as the Sandgate Beds, and 

 I am inclined to think that this division alone occurs at Dover, the Folkestone 

 Beds above and the Hythe Beds below having thinned out, although both those 

 divisions are thicker than the Sandgate Beds at ttie outcrop. 



The clayey beds beneath have been proved to a thickness of some 80 feet, the boring 

 ending at about 930 feet. In my paper I spoke of chalky matter occurring in them, 

 but in this I was wrong. The white specks in the small specimens first seen cer- 

 tainly looked calcareous, but the examination of better specimens has shown that 

 they are anything but that. Indeed, the prevailing character is the absence of 

 any effervescence when the clays are treated with hydrochloric acid ; in many 

 cases peculiarly fine-grained whitish beds simply absorb the acid, without any effer- 

 vescent action. 



On comparing the specimens with other clays they were found to be unlike any 

 of the marine Cretaceous and Jurassic clays, and it seemed to me that their affi- 

 nities lay rather with the Wealden series, and probably with the lower, or Hastings 

 division, than with the Weald Clay. 



I have only lately been able to test this by the help of a set of specimens that 

 Mr. G. Maw has been kind enough to send me. On examining them I found 

 that three specimens of Weald Clay, from Surrey, effervesced readily, which is per- 

 haps not surprising, as they came in two cases from close to Horsham stone and in 

 the other from near a Paludina bed. Nine specimens from a more distant district, 

 Dorsetshire, did not efl'ervesce ; but one can hardly give the exact position of these 

 in the Wealden Series. Ten specimens from the Ashdown Series, the lowest divi- 

 sion of the Hastings Beds, not only, in some cases, resembled Dover specimens in 

 character (I speak from memory, not having had the two sets side by side), but in 

 every case refused to notice the presence of hydrochloric acid. 



Should this classification be right it serves to strengthen very much the conclu- 

 sion, in my paper, that Dover is on all grounds a good site for a deep trial -boring,' 

 for it looks as if the bottom part of the great Wealden Series came there within 600 

 feet of the surface in the low ground, the boring described being on a site 280 feet 

 above the sea. 



13. On tlie Westward Extension of the Coal-measures into South-eastern 

 England. By Professor W. Boyd Dawkins, F.B.S. 



Geological evidence is conclusive that the valuable coalfields of South Wales 

 and of Somerset are connected with the equally valuable coalfields of North France 

 and of Belgium, some 1,200 square miles in extent, by a series of isolated fields or 

 basins concealed by the newer rocks. The coal-bearing rocks of Northern France 



' Quart. Journ. Geol. Soc. vol. xlii. p. 44. 



