PLIOCENE PERIOD IN ENGLAND. 527 



accumulated towards the end of Stage III., sprang up on the 

 moraine as it became thus uncovered many will probably doubt. 

 In my view, however, this was the case; as it also is that the 

 Hippopotamus lived in Europe during the time of frozen rivers 

 and throughout the year, the habits of the existing African species 

 no more indicating the habits of the European newer Pliocene 

 species than the habits of the ice-bear indicate those of all those 

 other species of bear which are closely allied to it ; but this, 

 however, together with the evidences of a brief though great 

 recurrence of cold during the period embraced within the second 

 portion of this memoir (which I still continue to regard as correctly 

 defined under the term " Post-glacial "), and which recurrence 

 culminated during the accumulation of the gravel ^, and of its syn- 

 chronous formations, the Hessle Clay, the Upper Clay of the Forth- 

 west, and the marine gravel of the Sussex low levels with blocks of 

 hypersthene rock, I shall examine in that portion. 



Note as to Map 2 in Plate XXI. 



From the difficulty in ascertaining elevations with sufficient exactness, I have 

 probably omitted some small islands in the south of Sheet 63. Of these one is 

 that of Saddington, mentioned at p. 510, which lies immediately north of the 

 island shown in the south-east of this sheet ; while others may be formed by 

 the water-partings between the tributaries of the Soar, and those of the Swift 

 and Welland ; but they are of minute dimensions, most of this sheet having, 

 from the westerly increment of submergence, been sea. The two small islands 

 in the south of Sheet 7 should have been omitted. ' In the south of Sheet 47 the 

 river-valleys were, at the stage of emergence shown by the map, fiords, divided 

 from each other by islands or peninsulas of Lower Tertiary and Chalk, in the same 

 way that the river-valleys of Sheets 50 and 56 were probably fiords, divided from 

 each other by peninsulas or islands formed of the beds of series a and b, nearly 

 all now concealed by the covering of d. In these fiords the gravel c accumulated ; 

 but the peninsulas, in consequence of the smallness of the scale, have not been 

 prolonged to their proper extent. They had been submerged during Stage II., 

 and some thin remains of gravel resting on London Clay corresponding to b', or 

 the higher part of c, occur on one of them to the south of Braintree, where a 

 small break in the pall of d exposes that clay. As the elevation of the parts 

 shown in outline in Sheets 62 and 64 includes the Chalky Clay, and this lies 

 thick there, they were probably shoals rather than islands when first covered by 

 the ice. The partially destroyed junction of c with d at Grafi'ham, mentioned 

 at p. 485, was on this outline. The continuation of this map south of the 

 Thames I have reserved for the second part of this memoir. 



Discussion. 



The Peesident spoke of the great value of the labours of Mr. 

 "Wood, carried on during so many years and with such indefatigable 

 energy. 



Mr. "Whitaeiee stated that the paper was most interesting as con- 

 taining an epitome of Mr. Wood's views. He thought too much 

 importance was attached to the Ped Crag, which probably repre- 

 sented only a very insignificant period of time. He remarked on 

 the changes in the East- Anglian sections resulting from the wasting- 

 back of the coast. Some of the geological surveyors were inclined 

 to regard the Hoxne brick-earth as older than the Boulder-clay, 

 while others considered it younger than that formation. In the 



