94 NATURAL SCIENCE. August, 



They contained the results of his long labours, and as he remarks, 

 " The greater part of my observations date, in fact, so far back as 

 from 1845 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 realise 

 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 

 previously 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 

 dispute. No fossils have yet been found in the Westleton Beds 

 at Westleton, and it is, therefore, a matter of great uncertainty as to 

 how far correlation is justified with the other unfossiliferous pebbly 

 gravels of the eastern and southern counties of England. Prestwich 

 has, however, 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, cannot 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, Junr., who, pursuing the subject in 

 great detail, personally surveyed on the one-inch ordnance maps 

 large areas of the eastern counties, and stimulated others like 

 Mr. F. W. Harmer, in Norfolk, and the Rev. J. L. Rome, in Lincoln- 

 shire, to co-operate 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 

 unquestionably those relating to the valley or river gravels, and 

 to the occurrence in them of flint implements and certain fossil 

 Mammalia. 



