4 PREBPACE 
exhaustion of the edition of ‘‘West Coast Shells,’ has 
led to the preparation of this volume, in the hope that it 
may have a still more extended usefulness than its 
predecessor. It is not a mere revision of the former book, 
but it has been very largely rewritten, while the arrange- 
ment is wholly different and more in accord with 
modern views. A great number of new species have been 
noted, and more than a hundred new engravings have 
been added. While the unsatisfactory descriptions of 
some minute shells have been omitted, an extended 
Check-List has been added, which gives a fairly com- 
plete classified table of the valid species existing on this 
coast, including references to standard scientific works 
in which these species are mentioned or described. While 
the body of the book is designed for less advanced stu- 
dents and collectors, it is hoped that the “List” may 
prove helpful not to them only, but also to scientists in 
general. In giving measurements, both the common and 
the metric systems have been employed. Remember that 
a millimeter (mm.) is nearly equal to one twenty-fifth 
(277s Gn ame iiele 
In order to adapt this book to readers of “West Coast 
Shells,” the old name of a species has been retained in 
parentheses, whenever a change has been made. A “‘com- 
mon name” has also been given to each species described, 
usually a more or less free translation of the accepted 
Latin name. 
As might be expected, much difficulty has sometimes 
been experienced in deciding between the claims of rival 
synonyms, and it is not to be hoped that all will accept the 
author’s conclusions; an honest endeavor, however, has 
been made to select the name which has been adopted by 
the best authorities. 
The grateful task remains to return thanks and ac- 
