162 Geological Society. 



to the Heliolidae, and the third new family to the Homoiopteridac, 

 or, as the writer believes, near to the Lithomantidse. 



The East Kent insect-remains contain one wing, referable to the 

 genus Soomylacris (EUohlattina), a species of which is already 

 known from the Forest of Dean Coalfield. 



The finding of two species of the same genus in coalfields so 

 widely separated as those of the Forest of Dean and East Kent is 

 not without interest, in view of the generally-accepted belief in the 

 former continuity of the Coal Measures across the South of England. 



June 5th, 1912.— Prof. W. W. Watts, Sc.D., LL.D., F.E.S., 

 Vice-President, in the Chair. 



The following communications were read: — 



1, ' The Further Evidence of Borings as to the Range of the 

 South-Eastern Coalfield and of the Palseozoic Floor, and as to the 

 Thickness of the Overlying Strata.' By Hon. Professor W. Boyd 

 Dawkins, M.A., D.Sc, F.K.S., F.S.A., F.G.S. 



In this paper the Author gives an outline of the history of the 

 experimental borings made in order to verify Godwin-Austen's theory 

 concerning ' the Axis of Artois,' which led to the discovery of the 

 South-Eastern Coalfield. The first of these was at Netherfield(1872- 

 75) near Battle (Sussex). Here the borehole, ending in Oxford 

 Clay at a depth of 1905 feet below the surface, showed that 

 the Palaeozoic floor is buried under so great a thickness of rock 

 that it was advisable to look farther north for a site for further 

 experiments. The second boring (1886-92), under the Shakespeare 

 Cliff, Dover, on the site of the Channel Tunnel works, resulted in 

 the discovery of the Coal Measures belonging to the Pennant or 

 Middle Series of the Bristol and South Wales Coalfields, at a depth 

 of 1100 feet below O.D. This aff'ords a practical basis for further 

 exploration. The extension of the coalfield to a distance of 

 8 miles north of Dover was proved by the boring (1897-99) at 

 Ropersole, where the same Pennant Series occurred at 1180 feet 

 below O.D., and its extension in the intervening area about 5 miles 

 to the west of Dover by a boring under the direction of M. Breton 

 at Ellinge (1901-1902), where the coalfield was struck at 1286 feet 

 below O.D. 



In these three borings the strata of the Coal Measures are 

 practically horizontal, a fact which, in the opinion of the Author, 

 implies that they form the bottom of a syncline with its long axis 

 passing from Dover in a north-westerly direction parallel to the 

 scarp of the North Downs. 



The boring at Brabourne (1897-98), under the direction of 

 Mr. Brady and the late Mr. Etheridge, gave the next fixed point in 

 the enquiry. It established the fact that, at the base of the North 

 Downs, the Palaeozoic floor consists of highly inclined strata (in the 

 opinion of the Author, of Devonian age) at 1789 feet below O.D. 



