314 



Оле Pai'lsen. 



In all the specimens seen by me the antapical horns were long 

 and hollow, so that, strange to tell, the arctic species P. parallelum 

 Broch was not found in the present material. 



P. depressum was found in single specimens only in the neigh- 

 bourhood of the coast, repeatedly but rarely in the pack-ice and in 

 the open sea. 



D ist rib. Boreal oceanic species, widely distributed. 



19. Peridinium oceanicum Vanhoffen, in Grönl.-Exp. d. Ge- 

 sellsch. für Erdk. zu Berlin II, 1897, tab. V, fig. 2; Paulsen, Nord. 

 Plankton, p. 54, fig. 69. 



var. typicum Broch, Nyt Magaz. f. Naturvid. Christiania, 44, 

 1906. fig. 3. 



Found as a single cell in the open sea outside the ice. 

 I) ist rib. Oceanic boreal species. 



20. Peridinium conicoides Paulsen, Meddel, fra Kommis, f. 

 Havundersøg. Ser. Plankton, Bd. I, Nr. 3, 1905, p. 3, fig. 2; Nord. 

 Plankton, p. 58, fig. 75; Broch, Spitzbergen Plankton, p. 53. 



Not rare in several samples from the coastal water and the 



pack-ice in 1908. 



Distril). Arctic neritic species, known from Iceland, Spitzbergen and 

 Greenland. 



21. Peridinium sp. 

 A small species (length 20 /л) represented in fig. 14 was found 

 in three samples from Danmarks Havn in 1907. I suppose it is a 



young stage of the precee- 

 ding species. In favour of 

 this conception speeks: the 

 whole form of the body, 

 with convex outlines, the 

 small hollow protuberances 

 distant from each other, 

 the orbicular girdle and the 

 characteristic curvature of 

 the longitudinal furrow's 

 left margin. On the other 

 hand, the number and ar- 

 rangement of the plates do 

 not permit to unite the two species at once. There is only one 

 intercalary plate, as illustrated in fig. E, at least I have not been 

 able to find any sutures to separate between y, о and e. 



22. Peridinium subinerme Paulsen, Plankton invest. Iceland 



E F 



Fig. 14. Peridinium sp. 750 t. m. 



