662 JOSEPH PEESTWICH. 



Iii 1868 he communicated to the Geological Society the first part of 

 his elaborate work On the Structure of the Crag Beds of Suffolk and 

 Norfolk. The three parts were published in 1871. They contained 

 the results of his long labors, and, as he remarks, "The greater part of 

 my observations date, in fact, so far back as from 1815 to 1855." 



In some respects this was unfortunate, since the author had been 

 too much occupied to work out the results of his observations while 

 they were quite fresh in his mind ; moreover, he did not fully realize 

 how much had been done by previous observers. In omitting to 

 notice in detail work that had been previously published, he observed, 

 "I may be further justified in this course by the circumstance that 

 my own researches are in great part anterior to most of the papers in 

 question" — a plea that fails to satisfy the worker who is keen on 

 priority of publication. One noteworthy result of this was the intro- 

 duction into Norfolk of the term " Westleton Beds," for strata pre- 

 viously described at certain localities by Wood and Harmer under the 

 name of Bure Valley Beds. It has now been clearly shown that the 

 Bure Valley Beds (of the Bure Valley) are of earlier age than the 

 Westleton Beds (of Westleton), the former being linked with the 

 Norwich Crag (Pliocene), and the latter being rightly regarded by 

 Prestwich as Pleistocene. What may be the particular horizon in 

 the Pleistocene group of the Westleton Beds is still a matter of dis- 

 pute. No fossils have yet been found in the Westleton Beds at Wes- 

 tleton, and it is therefore a matter of great uncertainty as to bow far 

 correlation is justified with the other unfossiliferous pebbly gravels of 

 the eastern and southern counties of England. Prestwich has, how- 

 ever, published a series of papers on these scattered deposits, and the 

 facts which he has made known must always prove of value, while his 

 theoretical conclusions, which have added largely to the interest taken 

 in the subject of gravels, can not fail to have beneficial results. 



The importance of an attentive study of the Glacial Drift and other 

 superficial deposits was pointed out by Joshua Trimmer, and he was 

 followed by S. V. Wood, jr., who, pursuing the subject in great detail, 

 personally surveyed on the 1-inch ordnance maps large areas of the 

 eastern counties, and stimulated others, like Mr. F. W. Harmer, in 

 Norfolk, and the Eev. J. L. Rome, in Lincolnshire, to cooperate with 

 him. Prestwich, meanwhile, had made particular observations here 

 and there, and chiefly between the years 1855 and 1861, in Holderness, 

 at Mundesley, Reculvers, Hackney, Salisbury, and Brighton. He 

 devoted his attention more especially to fossiliferous deposits of valley 

 drift and to raised beaches. He described a few sections of Glacial 

 Drift, but did not yet enter into any general discussions with regard to 

 the classification of our Pleistocene deposits. 



His most important researches among the latter deposits were unques- 

 tionably those relating to the valley or river gravels, and to the occur- 

 rence in them of flint implements and certain fossil mammalia. 



