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PREFACE. 



In the autumn of 18S7 the steamer Albatross, of the United States 

 Bureau of Fisheries, which had previously been employed on the 

 Atlantic coast of North America^ was despatched to the Pacific 

 Ocean J where it has since been engaged in fishery and deep-sea 

 investigations on the western coast of the United States, off British 

 Columbia and Alaska, and also in more distant regions. The bot- 

 tom samples obtained by the dredge and sounding cup during the 

 several cruises from 1888 to 1904, inclusive^ were referred to Dr. 

 Albert Mann, an expert student of the diatoms, for separating out 

 and reporting upon these miiuite plant organisms, a difficult aiid 

 painstaking task, the results of wdiich are given ui the paper here- 

 with presented. 



The titles in the bibliography and the citations throughout the 

 body of the report have, with very few exceplions, been verified 

 from the original papers by Mr. P. L. Ricker^ to whom acknowledg- 

 ment is here made. 



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