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Freshwater Diatoms 



by E. Östrup — Copenhagen. 

 (With plate I.) 



The following list of freshwater Diatoms has resulted from the 

 examination of 33 samples collected by the Danish expedition to 

 Siam (1899 — 1900). Of these 33 samples two only contained no 

 Diatoms; the localities of the remaining 31 samples are: 



Koh Chang: Klong Son 2 samples 



„ Lern Dan 16 „ 



„ Klong Munsé 5 „ 



„ Klong Majum 2 „ 



„ Klong Prao 1 „ 



„ Klong Sarlakpet 1 „ 



Naval station opposite Koh Kong ... 1 „ 



Koh Samit 1 „ 



Lem Ngob 2 „ 



Total. . . 31 samples. 



Placochromaticæ. 



Caloneis GL, Syn. I, p. 46. 

 1. f. fasciata Lgst.? tab. nostr., fig. 1. 



L. 0,028 mm., B. 0,006 mm., striæ in the middle at least 25 in 

 0,01 mm. denser towards the apices. 



Striæ radiate. The apical area dilated towards the middle 

 and here forming a transapical fascia. 



Solitary in a sample from Lem Dan. 



With some doubt 1 have referred this small form to Cai. fasc. Lgst. 

 because the striæ are more radiate and because I am not sure, that I 

 have seen the longitudinal lines. 



Area: Col. fasc. : ubiquitous. 



