INTRODUCTION. 



This paper is the first part of a work the intent of which is to 

 describe and illustrate the Foraminifera of the North Pacific Ocean. 

 This part includes the families Astrorhizidse and Lituolida?, together 

 often known as the Arenaceous Foraminifera. These are usually 

 considered the more primitive group and are therefore treated first. 



The collection of recent Foraminifera in the United States National 

 Museum has been carefully studied in so far as it represents the area 

 in question. From the work of the various vessels of the Navy 

 Department, the Coast and Geodetic Survey, and the Bureau of Fish- 

 eries a mass of material has accumulated which has been of great 

 value in this work. A more detailed account of these collections will 

 be given later. 



There have been few works dealing with the Foraminifera of this 

 area, and such records as exist have been included here. Except 

 where acknowledgment is given, the figures have been drawn by the 

 writer from material in the collection of the U. S. National Museum or 

 have been reproduced from photographs taken at the National Mu- 

 seum of specimens in the same collection. Where recorded species 

 are not well represented in the collection, figures from other works 

 have been used and due acknowledgment given. 



A considerable number of changes in the nomenclature and syste- 

 matic arrangement have been made in an attempt to separate more 

 clearly species and groups which, after a study of this material, seem 

 to be distinctive. 



I wish to express my great appreciation of the kindness with which 

 the U. S. National Museum and its staff have so freely met my various 

 needs in the preparation of this work. 



Joseph Augustine Cushman. 



