26 



RECORDS OF OBSERVATIONS, SCRIPPS INSTITUTION OF OCEANOGRAPHY 



dicators of total numbers for the station or for 

 particular levels below the surface. These 

 facts are well illustrated by the northern line 

 where, in twenty-eight yields of significant num- 

 bers, there were only seven at which the surface 

 numbers were as large as those at certain lower 

 levels. In a few instances the numbers at a 

 level below the surface were more than four times 

 as large as those at the surface. Still it is 

 true that the surface level held the lead in 

 abundance a little more often than any other. 

 The thirty-, forty-, and fifty-meter levels led 



in abundance almost as often. Large abundance 

 at any level was nearly always accompanied by 

 abundances nearly as large at two neighboring 

 levels. 



At some time in the year more than thirty 

 different species of diatoms, representing four- 

 teen genera, were sufficiently prominent to rank 

 among the leading five at one or more stations. 

 There was no significant difference in the lists 

 of names from different parts of the area sur- 

 veyed, and the prominent forms were all well 

 known from daily catches at shore stations. 



