Marine Plankton from the East-Greenland Sea. 315 



1903, p. 24, fig. 10; Nord. Plankton, p. 60, fig. 78; Broch, Spitz- 

 bergen Plankton, p. 54, fig. 28. 



One of the commonest [species in the samples from the pack- 

 ice in 1906. More rarely it occurred in Danmarks Havn, the coastal 

 water (in 1909) and in the open sea. 



Dis t rib. Oceanic (?) arctic or boreal species, known from Iceland 

 Greenland, Spitzbergen and (in spring) from tlie North Sea. 



23. Peridinium catenatum J^evander, Acta soc. pro 

 fauna et flora fennica, IX, 1894; Paulsen, Nord. Plankton, 

 p. 63, fig. 84. 



This species, represented in fig. 15, was found rarely 

 but in several samples from Danmarks Havn, the coastal 

 water, and the pack-ice. 



Distrib. Neritic species, known from tbe inner part of the 

 Baltic, Limfjorden (DenmarlO, and West-Greenland. 



Fig. 15. Peridi- 



24. Peridinium minusculum Pavillard, Flore pela- nium catena- 

 gique de l'étang de Thau, Montpellier 1905, p. 57, tab. П1, '""' 'J'^t.m. 

 fig. 7 — 9 (I have seen Pavillards specimens); Lemmermann, Arch. f. 

 Hydrobiol. u. Planktonkunde, V, 1910, p. 336; Glenodinium bipes 

 Paulsen, Plankton invest. Iceland 1903 (1904), p. 21, fig. 3—4; Nord. 

 Plankton, p. 25, fig. 31. 



Lemmermann (1. c.) in pointing out that Glenodinium trochoideum 

 is a Peridinium says in a footnote that also G. bipes is a Peridinium 

 and that it is to be named P. minusculum (P. bipes it cannot be 

 named because another species, of Stein, bears that name.) It is 

 very likely that the species is a Peridinium. I have seen that it 

 has two antapicals. 



P. minusculum was found, always in single specimens, in several 

 samples from Danmarks Havn, the coast water, and the pack-ice. 

 Without doubt most of the cells pass through the net-meshes. 



Distrib. Neritic species, known from the Mediterranean, the North 

 Sea, the Baltic, Iceland, and Greenland. 



Ceratium Schrank. 



25. Ceratium arcticum (Ehrenberg) Cleve, The seasonal distrib. 

 of atl. Plankton-org., Gøteborg 1900, p. 207. Paulsen, Nord. Plankton, 

 p. 86, fig. 118; E. Jørgensen, Die Ceratien, Leipzig 1911, p. 85, fig. 181. 

 Peridinium arcticum Ehrenberg, Bericht ül). Verhandl. d. Berliner 

 Akad. d. Wiss. 1853, p. 528. 



