INTRODUCTION. 



The present volume is the fourth of a series dealing with the 

 Foraminifera of the North Pacific Ocean. It contains the Forami- 

 nifera included in the families Chilostomellidse, Globigerinidse and 

 Nummulitidse. The last family while not appearing in its usual 

 place above the Rotalidse is included here simply for the better 

 balancing of the present part, the other two included families 

 being comparatively small. The first part, issued in 1910, included 

 the families Astrorhizidse and Lituolidse; the second part, issued in 

 1911, included the family Textulariidae; and the third part, issued in 

 1913, included the family Lagenidse. Part five will be devoted to 

 the Rotalidse and part six, the last, will be given to the Miliolidse. 



Joseph Augustine Cushman. 



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