242 PROCEEDINGS OP THE MALACOLOGICAL SOCIETY. 



Trans., vol. xxv, No. 305, 1706, pp. 2210-14). The investigation 

 was carried out in the true scientific manner by means of a special 

 excavation ; the identifications of the shells can be easily checked 

 by the references to Lister, whilst the postulating of a deluge as 

 an explanation of the observed facts is not unknown even to-day. 



Later workers have not always maintained the high standard 

 which was thus set, and the illuminating phrase, " a number of 

 snail shells occurred at this level," has been considered quite 

 sufficient to satisfy all the reasonable demands of the student. 



A very long period of quiescence then ensued, and it was not until 

 early Victorian times that any additions to our knowledge were 

 made, principally by John Brown, of Stanway, Lyell, Mantell, and 

 S. P. Woodward. Their work, however, was of a sporadic nature, 

 and no real systematic work was accomplished until 1890, when the 

 foundations were laid by B. B. Woodward by the publication of 

 a paper dealing partly with the Holocene moUusca of the London 

 district {Proc. Gfeol. Assoc, vol. xi, pp. 331-88). The great feature 

 in this paper is the careful checking of previous records, a pro- 

 cedure entailing great labour, but the results amply justified the 

 work, the drudgery of which can only be estimated by those who 

 have worked on similar lines. It is far easier, and more imposing 

 to the uninitiated, to publish long lists of undigested records, many 

 of them dating from the early days of science, the names of the species 

 and the deposits occurring again and again under their various 

 synonyms, but the real value is nil. 



Inspired by Mr. B. B. Woodward's work, a number of papers 

 have been published by many writers dealing with numerous 

 deposits in many parts of England, whilst archaeologists and 

 geologists have begun to realize the importance of these formerly 

 despised objects in helping to solve their problems. Though much 

 still remains to be done, yet Sufficient facts have been accumulated 

 to enable us to see that there is a coherent story, though, alas, too 

 often the details are blurred and obscure. 



In a civilized area like England human activities have had an 

 enormous efiect on the state of the country, and those of us who, 

 like myself, have no personal acquaintance with a virgin country 

 necessarily find it difficult to visualize an England untouched by 

 the hand of man, yet such it was within, geologically speaking, recent 

 times. These human activities have had great influence on the 

 fauna, especially that branch with which we are more interested, 

 an influence sometimes beneficial and sometimes inimical. 



The uniting of drainage areas by the canalization of rivers and the 

 construction of canals has enabled the freshwater species to pass 

 barriers which were formerly insurmountable, and has greatly 

 increased the number of suitable habitats for the deeper water forms 

 such as Dreissensia polymorpha (Pall.). The making of innumerable 

 ponds and of lakes and reservoirs has also been favourable to many 



