KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 32. N:0 3. ) 
Surface-plankton. 
In the following account of the plankton, gathered by the Swedish expedition to 
Spitzbergen in 1898, I distinguish, as usually, with ¢ common, ce very common, cee the 
principal mass, with + neither common nor rare, with 7 rare, and rr some few specimens 
only. In case of scarcity of the plankton I enclose the sign by one or two parentheses and 
where no plankton was found I use 0. 
1. Lindesnas—Lofoten. 
May 27th to June 1th. 
Temperature varying between 7° and 9°. Salinity 33—35 p. m. 
The plankton is of great uniformity, being a mixture of tripos- and northern neritic 
plankton (Jp, Ns). 
The most important species are the following: 
Of triposplankton: Of northern neritic plankton: 
Acartia Clausti +, Acartia longiremis e¢, 
Microsetella atlantica r, Ceratium tripos var. longipes ce, 
Oithona similis +, Peridinium depressum +, 
Evadne Nordmannii c, Coscinodiseus oculus iridis rr. 
E. spinifera ec, 
Podon intermedius 1, 
Halosphera viridis 1, 
Ceratium furca ++, 
C. fusus +, 
C. tripos 1, 
C. trip. v. macroceros ¢, 
Rhizosolenia styliformis rr. 
Common to both: 
Calanus finmarchicus +, 
Temora longicornis +. 
One sample only (63°13'N 5° 15'E.) contained Leptocylindrus danicus in abundance. 
The plankton of this region agrees completely with that of June 1896." If com- 
pared with the plankton of May 1897 in the same region, we mark that the tripos- 
plankton occurred in 1898 in greater abundance. This corresponds with the lower tem- 
perature (5,45—9,72) and salinity (28,05 to 34,11) in the year 1897. 
1 Bib. till K. Sv. Vet.-Akad. Hand]. XXIII, 2, N:o 4. 
K. Sv. Vet. Akad. Ilandl. Baud 32. N:o 3. 5) 
