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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jail. 22, 



through it, with dimensions proportionate to the depths indicated by 

 the alluvia in the higher parts of its continental course, and to the 

 accessions it would receive from all those rivers which now discharge 

 into the North Sea. It was on the banks of this vast river and on its 

 islands that the herds of elephants lived, whose remains are so abun- 

 dant and perfect beneath the waters of the German Ocean. By 

 adopting the line of greatest depression along this area, we may even 

 now conjecturally trace the course which this river then had, and it 

 will be found to correspond in a very remarkable manner with that 

 along which the large mammalian remains have occurred (See Map, 

 PI. VII.). 



At this time, and in conformity with what many other considera- 

 tions would lead us to expect, we find a wide-spread coniferous vege- 

 tation extending itself across the whole of the British Islands, from 

 the coast of Norfolk to that of Cardigan, consisting of Pinus sylvestris, 

 and, what is more interesting, of the Abies excelsa *,, from the whole 

 of which tract the latter afterwards disappeared, until re-introduced 

 by man. This, however, was not the case with the Pinus sylvestris, 

 which appears to have lived on over those northern portions of these 

 islands which were not submerged. From the Orkneys, where at pre- 

 sent no trees can grow, to the area of the English Channel, we find a 

 former like extension of coniferous trees, rooted in beds passing be- 

 neath the existing sea-level. It is with the growth of the Norway 

 spruce that the large mammalia were contemporaneous in the East of 

 England ; and we have learned from the investigations of Prof. Owen 

 (Fossil Mammalia, Introduction, Table, p. xlvi.) the very curious 

 fact, that at the same time the Hein-deer and the Lagomys ranged 

 into the south-western counties. 



The westward extension of this former area of land may perhaps 

 have had some relation to the greatest amount of elevation it then 

 had, as compared with what it has now. The highest portions of 

 the Dartmoor range, so far as I have been able to ascertain, afford no 

 evidences of ancient glaciers. The greatest elevation of this region 

 now is 2000 feet ; while all the British ranges which afford indubi- 

 table proofs of such masses have at present an elevation considerably 

 in excess of this. An extension of the land to the distance of the 

 remarkable line of sudden depression which occurs at 200 fathoms 

 (Quart. Journ. Geol. Soc. vol. vi. p. 86) would place the area of the 

 British Islands under physical conditions sufficient to satisfy all the 

 observed phenomena of a former permanent snow-line and broader 

 rivers. In a paper to which this is partly a sequel, I have already 

 pointed out some considerations which imply former littoral conditions 

 along this line. To these may be added a very remarkable fact re- 

 corded by Capt. Martin Whyte, in his c Survey of the English 

 Channel,' and which adds great weight to the conjecture of an exten- 

 sion of the land equal to what is here assumed, that Unio pictorum 

 was brought up from 50 and 100 fathoms water, in N.L. 48° 55', 

 W.L. 9° 28', and in N.L. 51° 21', W.L. 8°, fourteen miles from the 

 nearest land (see Map, PI. VII.). 



* R. Brown, 



