INTRODUCTION. 



The present volume is the third of a series dealing with the Forami- 

 nifera of the North Pacific Ocean. It contains the Foraminifera 

 included in the family Lagenidse. The first part, issued in 1910, 

 included the families Astrorhizidse and Lituolidae. The second part, 

 issued in 1911, included the family Textulariidse. The fourth part 

 will be devoted to the Chilostomellidse, Globigerinidse and Num- 

 mulitidse, and further volumes will take up the remaining families 

 of the Foraminifera as they are represented in the North Pacific. 



Joseph Augustine Cushman. 



