304 PKOr. J. PRESTWICH ON THE EAISED 



questions of the greatest interest. They would regret that the 

 Author was prevented by illness from being present that evening, 

 but he hoped that he would be able to attend when the second part 

 of the paper was read and when the full discussion of this wide 

 subject could be entered upon. 



Dr. Evans concurred in the advisability of postponing the dis- 

 cussion of the paper until the second part had been read. 



Paet II. (Eead February 24th, 1892.) 



Contents. 



Page 

 § 6. The Coast Caves and their Fauna ; the Zone of Eaised Dunes or Blown 



Sands 304 



§ 7. Inland Eange of the Eubble-drift ; Stream-tin Detritus ; Ossiferous 



Fissures 306 



§8. On the origin of the Head or Rubble-drift 322 



§ 9. Theoretical Considerations ; the Eubble-drift due to a wide Sub- 

 mergence of the Land 329 



§ 6. The Coast Caves and their Pauna ; the Zone of Eaised 

 Dunes or Blown Sands. 



The long rest indicated by the maintained level of the Eaised 

 Beaches, and the wear of the cliffs against which they abut, was 

 brought to an end by a rise of the land which placed the Beach 

 above the level of tidal action. It has been suggested that the 

 Eaised Beaches do not indicate any alteration of level, being merely 

 the remaining portions of the upper part of the inclined planes 

 up which the shingle was driven by storm-waves ; but, amongst 

 other reasons, besides the considerable and varying heights (10 to 

 50 feet) of the Beaches on the coast, the double cliffs (Weston, 

 fig. 10, and Porthclaus, fig. 12), the presence of Balani attached to 

 the upraised rocks (Barnstaple Bay), at or above that at which they 

 could possibly have lived, and the many uninjured shells (Hope's 

 Nose, Portland), clearly show that there has been a change of level. 

 Besides, it must be remembered that the present level of the 

 Beaches has nothing to do with the levels which prevailed at the 

 time of their formation. The present level is the result, not of one 

 upheaval, but of the several upheavals and subsidences which have 

 taken place since that time. It merely represents the difference 

 between the several movements. I need not, however, dwell on 

 this subject as Mr. Pengelly has already proved that the Beaches 

 could not have been formed at the level at which they now 

 stand.^ 



^ Trans. Devon Assoc, for 1867, p. 1. 



