Xlviii PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



tidal and diurnal action of the sea. If the form of these sharp angu- 

 lar flints is not to be received as the evidence of the action of a trans- 

 itory agent, in contradistinction to that of the ordinary action of the 

 sea, I know of no evidence or reasoning on the subject worthy of our 

 acceptance. 



In the author's discussion of the Drift pheenomena on the southern 

 slope of the South Downs, the Elephant Bed at Brighton occupies, of 

 course, a prominent place. He regards the bed of rounded shingle, 

 subjacent to the bed of angular materials which constitutes the Ele- 

 phant Bed, as a true ancient beach, a point on which all geologists, I 

 presume, are agreed ; but he differs entirely from those who regard 

 the superincumbent bed as due to any long-continued action of the 

 sea, similar to that which rounded the pebbles of the bed beneath. 

 In this view, I cannot but consider him fully justified, by the differ- 

 ence in the character of the materials forming these beds respectively. 

 He also equally disagrees with those who would refer this bed of an- 

 gular flints to the cause to which Mr. Austen has directed our atten- 

 tion, with reference to certain other cases, the mere descent of 

 materials dislodged from the heights above ; and for this view he 

 assigns an adequate reason in the extent to which this accumulation 

 can be traced; for as I have already remarked, aggregations so formed 

 cannot possibly extend beyond a very limited distance from the foot 

 of the eminence from which they fall. 



In the south-western part of the district, from the slopes of Good- 

 wood, by Chichester, to the foot of Portsdown Hill and Portsmouth, 

 there is a large mass of detrital matter, including clay and sand mixed 

 up with angular chalk-flints, but in no case, the author states, are 

 rolled pebbles included in it. Again, we find the same angular-flint 

 breccia, only that the proportion of flints is smaller, about Bognor 

 and Little Hampton. One mass, however, of rounded pebbles exists 

 at Clapham Common, half a mile east of Patcham, but the author 

 refers it to the pebble-beds of the plastic clay. 



Following the Chalk-escarpment on the west, the author describes 

 it as entirely denuded of flints (as are also the surfaces of the Upper 

 Greensand and Gault), while considerable quantities of them are found 

 on the Lower Greensand. The distribution here is similar to that of 

 the flint-detritus, already described, along the escarpment of the South 

 Downs, and Sir Roderick considers them as probably derived from 

 the same origin near Petersfield. Proceeding northward, however, to 

 the high central ridge of Lower Greensand about Hind-Head, the 

 flints entirely disappear, until we advance still farther northward to- 

 wards Farnham and the escarpment of the Hog's Back, where much 

 debris is again found on each side of the River Wey. In this north- 

 western angle of the denuded district, the flints, broken and angular, 

 are spread out in great quantities, not only on the Lower Greensand, 

 but also over the Gault on the broad plateau of Alice Holt, and extend 

 continuously (as the author believes) to the north of Farnham, over 

 the Tertiary beds, and, on the other hand, for three or four miles 

 eastward along either bank of the Wey, where fossil mammaUa have 

 been found. 



