x Preface. 



Mr. Jackson submitted a series of six reports* upon 

 his work to the Manchester Literary and Philosophical 

 Society and these were published in its Proceedings. The 

 Council of the Society has courteously given him per- 

 mission to republish the four more important of these 

 contributions, with certain additions. 



This book represents nothing more than the informa- 

 tion garnered in this preliminary survey ; and no one 

 recognises its incompleteness more than its author. But 

 I have urged Mr. Jackson to make these results more 

 generally accessible by collecting them into a book, because 

 they reveal the richness and the importance of this branch 

 of ethnography. It is hoped that by appealing to the 

 interest of conchologists and ethnologists it will stimulate 

 some of them to join in the search for further evidence 

 and assist in collecting and sifting the material for an 

 exhaustive treatise. 



The numerous letters which Mr. Jackson has received 

 from all parts of the world since he began the publication 

 of his reports suggests that the interest in this line of 

 investigation is real and widespread and that the wider 

 distribution of this collection of essays will achieve the 

 end he has in view, 



Mr. Jackson has already received help from so many 

 correspondents that it would be a difficult task to thank 

 them all individually. But the fact that Mr. Robert 

 Standen's help has always been given him is a sufficient 

 guarantee of the reliability of his identification of the 

 shells. 



G. ELLIOT SMITH. 



The University, 

 Manchester, 

 30 April, [917. 



* For a list of these, see page 210 of this book. 



