919 



Öfvcrsift't aC Koiij;;!. Veteti.ska])S-Aku(l(!ini(;iis l'örhinKlliiiniu- ÜIOO, N:o 8. 

 Stocklidliii. 



Plankton from the southern Atlantic and thc southern 

 Indian ocean. 



By P. T. Gleve. 



[Communicated 1900, October 10.] 



I recently received a verv interestirig series of plankton 

 samples, collected by the Dutch frigate »Tromp» on an expedition 

 to Rio Janeiro and Sumatra. 



This collection afFords a good insight into the plankton of the 

 seas near the limit of drifting ice, north of the antarctic regions, 

 for which reason I here will report on the plankton collected from 

 33' S. 31' W. to 30° S. 91' E., in all 35 samples. 



The sample collecting commenced on the 10*^ of October 1899 

 at 48' 31' N. 9° 31' W. and was continued almost every day till 

 the 7*^ of February 1900, when the vessel arrived at Sumatra, 

 and then 95 samples had been collected. 



The first samples, from the point named, contained sparingly 

 some specimens of the styli-type {Centropages typiciis, Paracalanus 

 parvus etc.) Traces of styll-plankton continued to about 43° N. 

 16' W., where the styli-plankton became more plentiful and inter- 

 mingled with rare specimens of the desmo-type. The plankton 

 had the same character to about 33° N. 19° W., a point not far 

 from Madeira, reached on the 18*^ of October. From that point 

 the desmo-planhton predominated and continued so to about 33° 

 S. 31° W., which point was reached on the 8**^ of December. There 

 the water was sterile, On this long route through the region of 



