In addition to plankton volumes, the following information is included 

 for each haul: location, date and time of collection, volume of water 

 strained in obtaining the haul, and the depth sampled. Many of the large 

 volumes reported for hauls taken in 1950 were made up predominantly of small 

 salps. A breakdown of plankton volumes by principal constituents is now 

 being made at Scripps Institution of Oceanography for many of the samples 

 included in this report. 



A different system of numbering stations was used in 1949 than has 

 been used subsequently. The 1949 scheme was abandoned as bein^ too inflexible. 

 The change involved more than the numbering of stations, as the position and 

 direction of station lines were more or less altered also. Since January 

 1950, a grid system has been in use which permits almost unlimited flexibility 

 in adding stations. The equivalents for 1949 station numbers in the number- 

 ing scheme now in use are given in the accompanying table. 



