The Editor desires to express his sincere thanks to the subscribers 

 to the MANUAL. OF CONCHOLOQT for their continued patronage, 

 und for the many kind expressions of interest in the continuation 

 of the work which he has received. 



The introduction in the present volume of full synonymic refer- 

 erences into the text of the work, and the practice of giving de- 

 scriptions extending- to every character shown by cadi species, are 

 innovations which the author trusts will lighten the labor of those 

 who have occasion to consult the MANUAL. 



All descriptions which are not drawn from specimens are followed 

 by the authority from whom they are taken, in parenthesis. This 

 acknowledgement serves also to indicate the species lacking in the 

 Academy's collection, and shows the amount of material upon 

 which the present work is based. 



H. A. P. 



March, 1889. 



