ANNIVERSARY ADDRESS OF THE PRESIDENT. liii 



many terrestrial surfaces of the carboniferous period have remained 

 such ev6r since. The author then pointed out, that in palaeozoic 

 times there existed a main north and south ridge traversing what is 

 now Western Europe, and extending from Scandinavia to North 

 Africa. To the westward of this old range there was another tract, 

 also running north and south, which was even then bounded to the 

 west by the Atlantic valley, and is now traceable in the northern and 

 western portions of the British Isles. From very early times there 

 was an increase of land from this western or Atlantic tract to- 

 wards the present European area by the successive elevation of the 

 palaeozoic sea-beds ; and it was shown that this took place along 

 east and west lines, one of which became the axis of an elevation 

 which is distinctly traceable through a long series of geological 

 changes. Tn proof of these statements, the author alluded to the 

 evidence derived from the geological conditions and formations of 

 England and France, and particularly with reference to the east 

 and west ridge above alluded to : the author remarked that he 

 regarded the absence in France of the Upper Silurian system as 

 having been caused by an east and west barrier cutting off commu- 

 nication with the Upper Silurian zoological group of Shropshire and 

 Scandinavia, and constituting a division between two hydrographical 

 areas, in the northern of which the true Upper Silurian fauna had 

 its development, and in the other what the author considers as its 

 southern equivalent, viz. the Rhenane and Devonian group ; and he 

 showed that there was evidence of this barrier in the shingle-beds of 

 the Lower Silurian formation both in Northern France and in Corn- 

 wall, which point to a neighbouring east and west coast-line, — in the 

 half arch of cleavage of the chlorite schists of the Prawle, proving 

 the existence of an elevated east and west range of old rocks, now 

 locally destroyed and replaced by the English Channel, — and in the 

 occurrence of an elevatory axis ranging east and west along the 

 southern shores of Devonshire. 



The author then proceeded to consider the relation of the coal-beds 

 to this old east and west ridge, which he had traced from the valley 

 of the Ruhr by Aix-la-Chapelle through the Ardennes and the South 

 of Belgium by Liege, Namur, and Valenciennes, accompanied by the 

 palaeozoic formations lying on its northern flank, the contour of the 

 old coast-line being more or less clearly marked by the lithological 

 conditions of the conglomerates, grits, sandstones, &c. of the littoral 

 or the deep-sea deposits. The further continuation of this ridge to the 

 westward is proved by the chalk axis of elevation through Artois 

 (passing to the N.W. at a considerable angle to the eastern part of 

 the ridge), and by the denudation of the Boulonnais and of the 

 Weald of Kent and Sussex. At the same time, further to the west, 

 at Frome in Somerset, the identical series exposed in the Boulonnais 

 emerges again in similar unconformable relations, and Devon and 

 Cornwall supply evidence of the western extremity of this old ridge, 

 which united the two great north and south ranges of land, and 

 formed an extensive gulf-like configuration of this Western European 

 area in Palaeozoic times. It was along the inner (southern and 



VOL. XII. e 



