x Va refi we. 
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, 1917. 
* For a list of these, sce page 210 of this book. 
