562 



form du ring the three weeks in which he mach' gatherings, and 

 occurred in large quantities; the main part of it consisted of Dia- 

 toms, especially Rhizosolenia (according to my investigations it has 

 probably been R. Shrubsolii) ; Peridiniaceae were also common. Phaeo- 

 cystis Pouchetii, one of its constituents, is mentioned as an organ is m 

 of special interest; it was named after Pouchet, as he was the 

 hist to observe it in the Arctic Ocean. 



I. LIST OF THE PROTOPHYTA FOUND IN THE MARINE 

 PLANKTON FROM THE SEA AROUND THE FÆROES. 



In the following list, I have enumerated the Bacillariaceae which 

 belong to the plankton in the samples I examined (with regard to 

 the other Diatoms I beg to refer to the above paper of E. Østrup), 

 as also the Peridiniaceae and the single representatives for other 

 Protophyta, which may occur in plankton. I have mentioned the 

 chief papers dealing on each species under their own heading. 



I. Bacillariaceae. 



A. Centricae 1 . 



COSCINODISCEAE. 



I. PARALI A Heiberg, 1863. 



1. P. sulcata (Ehbg.) Clevc, Året. Sea, Bih. Sv. Vet. Akad. Handl. 

 Bd. 1, No. 13, 1873, p. 7; Galionella sulcata Ehbg.; Orthosira marina 

 W.Smith, Syn. Brit. Diat., IL, p. 59, PI. 53, hg. 338; Paralia marina 

 Heiberg, Consp. crit. Diat. Dan., 1863, p. 33; Melosira solida, var. 

 Sarsii Ostenfeld, Iagttagelser, 1898, Tab. V and Melosira solida 

 Ostenfeld, Iagttagelser, 1899, Tab. II, V, VII, VIII, 1900, p. 53, Tab. I, 



II, V, VIII, non Eulenstein in Van Heurek, Synops., PI. 86, figs. 36—42. 



This dialom is not rare in the plankton. It is not a true plankton- 

 form, but a temperate, littoral form which is easily broken ol! and car- 

 ried away by the sea. 



Found in January— March and July— December, most characteristic 

 of the poor winter- plankton in November— March. As it is not a true 

 plankton form, it is only found in the coastal regions, not in the open 

 Ocean; optimum ol* temperature about 5° — 10°C. [See tablcs] 2 . 



1 The genera are arranged much in the same way as in F. Schutt: Bacil- 

 lariaceae, in Engler & Prantl: Die Naturlichen Pflanzenfamilien 1 11). 1896. 



'-' Where the more common species and their occurrence around the Færdes 

 are speeified (pp. 593 — 596 and pp. 600 — (>04). 



