10 



Dansk Botanisk Arkiv, Bd. 2, Nr. 4. 



Fig. 2. Asterionella notatet Grun., a chain showing its twisted appearance. 

 (Drawn by Dr. Justesen). 



Asteromphalus heptactis (Bréb.) Ralfs, I.e., p. 838, tab. 8, fig. 21; 

 Gran, Diatomeen, in Nord. Plankton, 1905, p. 45, fig. 49. 

 Found in the sample. 



Bacteriastrum hyalinum Lauder, Transact. Microscop. Soc., 1864, 

 p. 8, pi. 3, fig. 7; Ostenfeld, Botan. Tidsskr., 25, 1902, p. 232, fig. 9. 

 Some of Dr. Justesen's drawings seem to be this species. I re- 

 produce one of them (fig. 3) to show the chain imbedded in a 

 mucilage and the numerous small chromatophores. 

 With regard to the awns (setæ) the drawing is 

 / rather insufficient. 



B. varians Lauder, 1. c, p. 8, pi. 3, fig. 1—6. 

 Seems to be common in the plankton of the 

 Boeton Strait, and very varying. One of the 

 drawings answers well to var. hispida (Castracane) 

 B. Schroeder, Vierteljahrsschr. Naturf. Ges. Zürich, 

 51, 1906, p. 347. fig. 11. 



Biddulphia mobiliensis (Bail.) Grunow, in Van 

 Heurck, 1. c, tab. 101, figs. 4-6; Boyer , Proc. 

 Acad. Nat. Sc. Philadelphia, 1900, p. 698; Osten- 

 feld, Medd. Komm. Havundersog., Ser. Plankton I, 

 No. 6, 1908, p. 7, fig. 2. 



Seems to be rare in the Boeton Strait. 

 B. sinensis Greville, Transact. Microsc. Soc, 

 London, 1866, pi. 9, fig. 9; Ostenfeld, 1. c, 1908, 



fig. I- 



Very common according to the many figures 

 drawn by Dr. Justesen. I reproduce one of them 

 (fig. 4) to show a very large cell, most probably 

 an initial cell from an auxospore. 

 Fig. 3. Bacteriastrum Besides the two plankton forms, several other 



hyahnum Laud a species f Biddulphia were present in the sample 

 chain lmhedded in ^ , , . r» ■ * 



mucilage. (Drawn by or amongst the drawings, e. g. B. vesiculosa 

 Dr. Justesen.) (Agardh) Boyer and B. tridens Ehbg. 



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