Marine Flankton from the East-Greenland Sea. 



311 



13. Peridinium pallidum Ostenfeld, in Knudsen & Ostenfeld: 

 Iagttag, over Overtladevandets Temperatur, Saltholdighed og Plankton 

 paa islandske og grønlandske Skibsrouter i 1898 (1899), p. 60. 

 Paulsen, Nord. Plankton p. 48, fig. 60. Broch, Spitzbergen Plankton 

 p. 45, fig. 17. 



Fig. 9 shows an exceptionally low cell (length 56 ii without 

 spines) with broad intercalary bands. The relation between 1 and 



B C 



Fig. 9. Peridinium pallidum. 375 t. m. 



f is not as shown in Broch's figure. Found in few specimens but 

 in many samples from the pack-ice, the coastal water, and Dan- 

 marks Havn. Common in the open sea outside the ice. 



Di strib. Oceanic, boreal species, widelj^ distributed in the northern 

 Atlantic and its tributaries. 



14. Peridinium pellucidum (Bergh) Schutt, Die Perid. der 

 Plankton-Exp., tab. XIV, fig. 45; Paulsen, Nord. Plankton p. 49, 

 fig. 61; Broch, Spitzbergen Plankton, p. 44, fig. 15, 16. — Proto- 

 peridiniiim pellucidum Bergh, Morphol. Jahrb. 1881, p. 227, fig. 46 — 48. 



All the cells seen belong to the forma spinosa Broch (l.c) the 

 antapical spines being without fins. Only a single cell with fins 

 was seen (from Danmarks 

 Havn). In fig. 10 two speci- 

 mens are drawn. A and B re- 

 present a very young cell 

 (length 36 u) having thin walls, 

 and the sutures are not con- 

 spicuous without chemical 

 treatment. D— E are showing 

 another cell (length 40/7.) thick- 

 walled and with broad inter- 

 calary bands. The cell repre- 

 sented in fig. 11 has a length 

 of 60 fji, and the intercalary 



Fig. 10. Peridinium pellucidum. 37.') t. m. 



striae are very broad. Such big and thick specimens were common 

 in some of the samples, and I refer them to P. pellucidum because 

 of the girdle being not oblique as in P. pallidum. — Other length- 



