Diatomaceæ. 



Thalassiothrix, Cl. et Grun. 

 Th. longissima, Cl. et Grun. (188u) p. 108. 



Sj-B. Syneilra Thalassiofhn.c, Cl. (187:!, i;5) p. 'Z-2, T. IV, tig-, 22. 

 — — , SehUtt (189:i) p. 18, fin-. 4, p. 21, fig. 1 1. 



Forekommer i alle Nordhavs-expeditionens prøver. 

 Kommer ind til Norges kyst især vinter og vaar, men 

 ogsaa til andre aarstider, med atlantisk vand. 



Udhredelse. Atlanterhavet— Ishavet. 



Nitschia, W. Sm. 



N. longissima, (Bréb.) Halfs. 

 — — Cl. et Grun. (188U) p. 100. 



Syn. Nitschiella longissima. Van Heurck. Synopsis T. To. fig;. 2. 

 Ifølge Sar»'s tegninger er denne art funden paa Nord- 

 havs-expeditionen st. 345, sparsomt. Selv har jeg seet den 

 i prøver fra Lofoten (marts — april 1896, Nordgaard). 



Udhredelse. Atlanterhavet — Ishavet. 



Fragilaria, Lyngb. 



F. oceanica, Cl. (1873, 13) p. 22, T. IV, fig. 25. 

 Grun. (1884) T. II, fig. 14. 

 Syn. F. arctica, Grun. in Cl. et Grun. (1880) p. 110, T. VII, iig. 124. 

 Filamentets bredde varierer fra 7 — 39 /(. De ,,indre 

 celler-', som Cleve afbilder og omtaler (I. c. 1873), er ganske 

 vist hvilesporer; jeg har ogsaa selv iagttaget dem i flere 

 af mine præparater fra Ishavet og fra Lofotens kyst. 



Forel-oiiisf. Nordhavs-expeditionen st. 345, 354. Lo- 

 foten marts — april 1896 (Xordgaard) med Phæocystis Pou- 



Diatomaceæ. 



Thalassiothrix, Cl. et Grun. 

 Th. longissima, Cl. et Grun. (1880) p. 108. 



Syn. Syiiedra Tludassiothrix, Cl. (^187:!, 13) p. 22, Pl. IV, fig. 22. 

 — — ,Schutt(1893)p. 18, flg. 4, p. 21, fig. 11. 



Occurs in all the N. Atlantic Expedition samples. 

 Comes in to the shores of Norway especially in winter and 

 spring, bnt also at other times, with Atlantic water. 



Distrilmtion. Atlantic Ocean, Arctic Ocean. 



Nitschia, W. Sm. 



N. longissima, (Bréb.) Ralfs. 

 — — Cl. et Grun. (1880) p. 100. 



Syn. Xifschiclla longissima, ^'an Heurck. Synopsis T. 70, fig. 2 

 According to Sars's drawings, this species was found 

 at iStatioii 345 of the X. Atlantic Expedition, in small 

 numbers. I myself have seen it in samples from Lofoten 

 (March and April, 1896, Koydfiaard). 



Distrilndion. Atlantic Ocean, Arctic Ocean. 



Fragilaria, Lyngb. 



F. oceanica, Cl. (1873, 13) p. 22, Pl. IV, fig. 25. 

 Grun. (1884) Pl. II, fig. 14. 

 Syn. F. arctica, Grun. in Cl. et Grun. (1880) p. 1|0, Pl. VII, fig. 124. 

 The width of the filameuts varies from 7 to 39 li. 

 The ,,interior cells-', wliich CJere figures and describes, (1. 

 c. 1873), are without doubt spores. I too, have observed 

 them in several of my preparations from tlie Arctic Ocean 

 and the coast of Lofoten. 



Occurrence. N. Atlantic Expedition Stations 345, 

 354; Lofoten, March and April, 1896 (Nordgaard), with 



