KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 36. N:o 8. 17 



New. Total. 



25 



Remnants from 

 April. 



Southern oceanic 3 7 



Southern neritic 6 9 



Northern oceanic 11 4 



Northern neritic 14 7 



36 



Also the North Sea was explored by steamers on different routes. The area be- 

 tween the Orkneys, Newcastle and 58° N. 2° E. was practically sterile in plankton. In 

 other parts of the North Sea there occurred a mixture of several different kinds of 

 plankton, northern and arctic forms apparently predominating. Such plankton ^vith arctic 

 and boreal forms occurred west of Scotland north and noi'th west of the Dogg-er bank, 

 from there to the coast of Holland and along the Danish peninsula. Tripos-plankton 

 occurred in any amount only on a spöt east of Newcastle and north of Jutland. Southern 

 neritic forms intermingled with some styliplankton occurred off the coast of Holland as 

 well as west of Jutland to about 1° E. Typical choetoplankton, which usually occurs at 

 this time of the year between Norway and Scotland, Avas found nowhere. There had 

 evidently occurred great disturbances throughout the North Sea. The forms noted in 

 the North Sea in February and May can be classitied as follows. 



Forms found 

 Forms found -^ February ^''™^' ^''"'^'^ 



in February only. ^^^^ jyj in May only. 



Southern oceanic 8 16 O 



Southern neritic 6 16 6 



Northern oceanic 2 20 5 



Northern neritic 8 29 4 



June 1902. 



Samples were coUected at Väderöboda throughout the month, but at Måseskär only 

 at the beginning of the month. The forms noted were classified as follows: 



Remnants from 

 May. 



Southei'n oceanic 9 2 \ 



Southern neritic 10 il 



Northern oceanic 10 3) 



Northern neritic 12 il 



New. Total. 



22 



26 



The most characteristic forms were Rhizosolenia ijracillhiin and the ordinary forms 

 of the tripos-ly]ye. 



K. Sv. Vet. Akad. Haudl. Baud 36. Nro 8. 



