589 



Ostenfeld, Zoologischer Anzeiger, XXII. 1899, p. 436, fig. 1. Loh- 

 mann has included my C. atlantica in Wallich's C.pelagica and he 

 is perhaps right in doing so, bul I am not quite sure, nevertheless 

 I am with him, until further researches have cleared up lliis pro- 

 blem; Ihe distinguishing point between the species is thai C. atlan- 

 tica has fewer and larger coccoliths than C.pelagica. 



Found only three times in the plankton from the Færoes October 

 1 900, March 1901 and Mav 1902), but is undoubtedly rather common. 

 Temperate, oceanic species. 



VI. Flagellata. 



I. DINOBRYON Ehbg., 1838. 



90. D. pellucidum Levander, Acta Soc. pro Fauna el Flora 



Fennica, 12, No. 2, 1894; Dinodendron balticum Schiitt, nom. nud.; 



Das Pflanzenleben der Hochsee, 1893, p. 36. 



This boreal-aretic, neritic species which is the only marine form 

 of the genus Dinobryon, was found twice (May 1902) in the plankton. 



II. PHAEOCYSTIS Lagerh., 1893. 



91. P. Pouchetii (Hariot) Lagerheim, Botaniska Notiser, 1893, 

 p. 32; Tetraspora Pouchetii Hariot in Pouchet, Compt. rend. des 

 seances de la Soc. de Biologie, 1892. 



Occurs every year and usually in great quantities, bul during few 

 months. In theyéars of 1890 (Pouchet), 1895 (Borgesen), 1897, 1899 

 and 1900 it occurred in July— August, in 1896, 1898 and 1902 in May- 

 June; temperature about 7°— 11°C. [See tables.] 



It is a boreal, neritic species which plays a conspicuous part 

 in the plankton of the north-west coast of Europe, Ihe Norwegian 

 Sea and around Iceland and Greenland. 



VII Chlorophyceae. 



1. HALOSPHAERA Schmitz, 1879. 



92. H. viridis Schmitz, Mitteil. aus d. zoolog. Slation zu Neapel, I, 

 PI. 3; H. minor Ostenfeld, Iagttagelser 1899, p. 51 ; cfr. Gran, Plankton 

 des Norweg. Nordmeeres, 1902, pp. 12— 16; PI. I, ligs. 10 — 15. 



In my publications on the plankton of Ihe North Atlantic Ocean 

 (Iagttagelser, etc, 1899, p. 51 and 1900, p. 47) I have described a 

 lillle form of Halosphaera as H. minor. It is much smaller than 



