Marine Diatoms 5F 
to those illustrations and descriptions which best record the characteristics of 
the species in question. 
Only the species that are new or that show exceptional variations from the 
type forms are illustrated in this paper. The species recorded were collected by 
Mr. F. Johansen and the localities are as given in his field list of collecting 
‘stations. 
The specimens of these new forms are deposited in the diatom collection of 
the United States National Museum, Washington, D.C., as well as nearly all 
the known species herein recorded. Each specimen is mounted separately on a 
properly labeled slide; so that the difficulty of finding the individual diatom 
named, so difficult to locate on the ordinary strewn slides, is wholly avoided. 
All the specimens in the Museum diatom collection are freely available for 
examination by interested diatomists. 
The nomenclature followed in this report is that which has received the 
general approval of diatomists. It rejects some obscure names which a few 
authors claim to antedate and be synonymous with those in common use, such 
as, Tessella for Rhabdonema, etc. “The author feels that sufficient doubt exists 
as to the generic boundaries of these archaic names to justify their abandonment 
to the oblivion in which they have long reposed, especially as much needless 
confusion must result if they now supplant the well known and classical names 
used in our most valuable diatom books. This is the position taken by Van 
Heurck, DeToni, Schmidt, Brun, and the majority of diatom writers. There 
is also a rejection here of the set of new generic names proposed by P. T. Cleve 
(see Cleve’s Naviculoid Diatoms) for breaking up the huge genus Navicula into 
more compact divisions. The genus is unwieldy; but the writer agrees with the 
above mentioned diatomists that these proposed new genera are too misty in 
outline to be workable, useful as they may be for subgeneric grouping. 
There is a chance of confusion in the record of the marine diatoms found 
by the Canadian Arctic Expedition because of a report already published on the 
fresh-water diatoms of the expedition. In it quite a number of marine diatoms 
are included. Its author, Mr. Charles W. Lowe, is careful to refer to this in his 
introductory remarks and to explain the reason for the mixed character of the 
diatom flora, as well as the fauna, found in some of the ponds and lagoons ad- 
jacent to the sea. He also notes the marine character of many of the species in 
his list. I find there are twelve marine species in the list which do not appear in 
the following enumeration, because the writer has found no specimens of them 
in any of the marine gatherings secured, and not having seen Mr. Lowe’s speci- 
mens the following additions to my list are on his authority: 
Grammatophora angulosa Ehr. See vol. IV, Part A, page 36a of this report 
ce 
Navicula Crabro Ebr o ae 4la “ 
Navicula Hennedyi W. Sm. “ eo a 42a is es 
Navicula humerosa Breb. “ ne 7 42a ee me 
Niteschia acuminata (W.Sm.) Grun. ee es 394 i eo 
Niteschia lanceolata W. Sm. oh . 39a a 2 
Opephora Schwartzit (Grun.) P. Petit EB 37A . me 
Pleurosigma hippocampus W. Sm. es 434 se ‘S 
Stauroneis Gregorti Ralfs o a Ala ae is 
Surirella fastuosa Ehr. a “f 40a as a 
Surirella recedens A. Sch. ts a 40a es . 
} } “ [73 
Surirella regina Jan. ‘“ & As 
