4 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



across the Pacific passes a little too far south of the Hawaiian Islands 

 to carry away any appreciable amount of its marine flora. 



There is no necessity to record in detail the technique used in pre- 

 paring material for this investigation, beyond the statement that a 

 sufficient number of strewings of each cleaned sample was made by 

 spreading on a microscope slide and drying over a spirit lamp. These 

 were then carefully searched for new forms, which when found were 

 picked up and mounted separately in styrax, Canada balsam, or 

 some other medium. By this method each species is preserved as a 

 single herbarium speicmen and, when properly labeled, represents the 

 species recorded here, with none of the uncertainty that always goes 

 with identification based on strewn slides. The labor involved of 

 course is considerable, but the great convenience and accuracy 

 secured fully justify it. No attempt was made to preserve duplicate 

 specimens of species if they were subsequently found in material from 

 other localities. The labor of making these and of preparing a list 

 of species for each one of the many dredgings examined would have 

 been great; and in this case it would have been nearly superfluous, 

 seeing that, as above mentioned, the precise location of each dredg- 

 ing was unknown. 



All the new species herein described are represented by their type 

 specimens deposited in the United States National Museum, and the 

 serial number of each one is given at the end of the description. 

 With the exception of four or five specimens all the other species here 

 enumerated and any specially noted varieties are also deposited in 

 the Museum, the few lacking having been on slides made by other 

 diatomists and duplicates of them not having been subsequently 

 found by the author. None of these missing species, however, are 

 rare, and authentic examples of them can be seen in the general 

 diatom collection of the Museum. 



A few strictly plankton diatoms are incidently included in this 

 report, but they doubtless represent merely accidental additions to 

 the true flora, the bottom-living diatoms. No plankton samples were 

 available, nor could they have been taken as characteristic of any 

 particular locality. Doubtless the Philippine Islands as a whole 

 have a plankton life differing in a general way from that of far dis- 

 tant places. But as all marine plankton forms are wanderers, swept 

 from one locality to another by sea currents and the surface drift of 

 the waters they inhabit, it is quite idle to report them as belonging 

 to any one locality. American students of plankton diatoms are 

 well aware of how closely the European species correspond to those 

 drifting along our own Atlantic seaboard or even those of the Pacific 

 coast, a parallel conspicuously absent from the diatom floras of the 

 bottom-living species of Europe and America. 



