^ T- 



►f^ . - 



r- J 





r - 



RKPOET ON THE DIATOMS OF THE ALBATROSS 

 VOYAGES IN THE PACIFIC OCEAN, 1888-1904. 



By Aliikht Mann. 



[Assiftod in the l)ibli<)graphy and t:iUitions 1)y Y. L. Ricker.] 



INTRODUCTION. 



The paper here offered is a report of the diatoms found in the sea 

 drcdgings and soundings of the United States Bureau of Fisheries 

 stcnmoxAlhatross, which covers all the material collected and avail- 

 able up to January 1, 1905, exclusive of what is embraced in a short 

 report already published by the author.* 



. The preliminary work was done in the Smithsonian Institution, 

 Wasbin-ton, D. C, durin- the winters of 1890-1900 and 1904-5. The 

 crude material, as a rule bottled and preserved in alcohol, was first 

 examined under the microscope, using magnifying powers ranging 

 from 23 to 590 diameters, so as to discover which gatherings gave 

 promise of affording diatomaceous material. In very many cases no 

 trace of diatoms was discoverable. The gatherings thus selected were 

 then prepared for more accurate investigation by methods that are 



briefly described as follows: 



The mud is first passed through a sieve of bolting cloth with a mesh 

 of about one thirty-second inch, so as to strain out large pieces of for- 

 cicrn material, such as bits of animal tissue, fragments of shells, etc. 

 The alcohol is then eliminated by washing in filtered or distilled water 

 in a glass beaker and decanting of the liquid after all solid material lias 



ttled. The mud is next boiled in a beaker with c 



com 



merc.ial hydrocliloric acid for one-half hour. Tlic acid when cold is 

 decanted and the residue washed with water to get nd of the resultant 



The material is then boiled in concentrated 



salts. 



acid for fifteen to thirty nhnntes and again 



coinmerc 



washed. 



snffic 



i^Vvoc. V.S, Nat. Mas. 16: 303-312. 1894. 



221 



