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FOUNDERS OF OCEANOGRAPHY 



the four chief groups of organisms present, viz. Diatoms, 

 Dinoflagellates, Copepoda and the Nauplii of Copepoda. 



In all there are about fifty species of organisms that 

 occur with fair regularity throughout the series : twenty- 

 four species of Diatoms, four of Dinoflagellates, eight of 

 Copepoda and about fourteen other organisms or groups 

 of organisms which are not of so much importance and may 

 be omitted. Of the twenty-four species of Diatoms, as a 

 general rule, if a species occurs in one of the hauls of a series 

 it occurs in all, and in many cases in much the same propor- 

 tions in all ; that is, there may be two or three or even 



