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



the above opinion that it is a dwarf-forni of the arctic Ch. 

 atlanticus, degenerated in the Atlantic water of high salinity. 



It is woi'thy of note that Chcetoceros atlanticus evidently has 

 its maximum near the entrance to the polar basin. This fact, 

 combined with the occurrence of that diatom in the tricho-plankton 

 of the Bering Sea, renders it not improbable that the tricho- 

 plankton may possibly ultiraately come frora the northern Pacific. 



Coscinodiscus oculus iridis Ehe. in 1898. ^) 



February. SW. of Iceland. — At 50^" N. 10^ W. (SW. 

 of Ireland). — From 49° 31' N. to 45° N. 50' W. — Abundant 

 at 34° N. 74° W. 



March. At 71° N. 1° 30' W. — S. and SW. of Iceland. 

 Färöe Channel. West of Norway, at 63° N. 1° 36' E. (abundant) 

 and 61° 33' N. 2° E. — Denmarks Sound (68° N. 26° W.) — 

 Davis Strait (65° N. 54° W.). — From 42° N. 42° W. to 40° 

 N. 31° W. 



April. NE. of Jan Mayen. W. and S. of Iceland. SW. 

 of the Färöes. At 62° N. 2° E. (rare). — From 44° N. 41° W. 

 to 40° N. 70° W. 



May. From 78° N. 2° 30' W. to 68° N. 17° W. (abundant 

 SW. of Jan Mayen) — S. of Iceland. N. of the Shetlands. — 

 From 45° N. 41° W. to 40° N. 72° W. (very abundant at 53° - 

 56° W.). 



June. N. of Iceland (68° N. 19° W.) into the Sound of 

 Denmark (65° N. 31° W.). — Fast of Spitzbergen. — At 45° 

 N. 41° W. 



July. From 64° N. 3° W. to 63° N. 1° W. Very rare 

 at 49° N. 22° W., 30° N. 38° W. and 40° N. 67° W. 



August. Rare at the Shetlands and E. of Spitzbergen. 



September. Sparingly N. of Iceland, W. of the Shetlands, 

 at 56° N. 36° W. and '53° N. 49° W. 



c tob er. Very sparingly at 56° N. 31° W. 



^) Ostenfeld's data uot used. 



