806 P. T. CLEVE, SOME ATLANTIC PLANKTON-ORGANISMS. 



August. BetAveen soath of Iceland and Greenland (abundant 

 at 65° N. 36' W.). — Not rare north of Spitzbergen. 



September. Rare near Beeren Island. — W. of Green- 

 land, 59° N. 53^ W. 



December. From 45' N. 51 W. (common) to 42 N. 63° 

 W. (rare). 



Nitzschia delieatissima Cl. 1898. 



April. Abundant at 59° N. 22' — 28° W. 



May. N. of Rockall, 59° N. 13°— 15° W. At 57°— 60° 

 N. 28° W. Abundant at 60=— 58° N. 31°— 35° W. 



June. Rare at the Färöes. Abundant in Denmarks 

 Sound. 



July. Färöe Channel. Abundant at 60°— 58° N. 23° — 

 32° W. 



August. Common south of Iceland. — At 65° N. 33° W. 



September. Common at 64° N. 32° W. Rare at 64° N. 

 31° W. 



Thus this species belongs to the Irminger Sea and spreads 

 from the south of Iceland towards the Färöes and into Den- 

 marks Sound. 



Nitzschia seriata Cl. in 1896. 



(A^. fraudulenta included.) 



March. Rare at the Azores, 41° N. 21° W. and 43° N. 

 48° W. 



April. NW. of the Azores, 39° N. 24° W. At 49° N. 

 19° — 23° W. Rare at the Orkneys. — Irminger Sea, 59° N. 

 22°— 28° W. 



May. At 49° N. 23° W. Not rare, and in some places 

 common, from 60° N. 9° W. to 57°— 59° N. 28° W. 



June. Rare at 57° N. 34° W. More or less scarce from 

 the S. of Iceland to the Färöes and Scotland. Denmarks Sound 

 from 67° N. 24° W. to 65° N. 31° W. (abundant at 65° N. 

 29° W.). 



