938 P. T. CLEVE, S. ATLANTIC PLANKTON. 



Tliere are thus found 57 forms, probably belonging to the 

 styli-plankton of the southern hemisphere, and aniong these not 

 less than 86 per cent also occur in the northern hemisphere, 

 chiefly in the space between the Azores and Iceland. Some of 

 them have been found in the region of Ascension and near Cape 

 Verde, which seems to prove that the water, containing styli- 

 plankton moves as an under-current below the water of the 

 tropical Atlantic, that contains desmo-jjlankton. 



Of forms probably belonging to the antarctic tricho-plankton 

 I found 25 in all. Of these 48 per cent also occur in arctic 

 regions, thus a much smaller percentage than of the styli- 

 plankton. 



These figures seem to me to a.fford a very strong evidence 

 of the correctness of the theory of Chun, -) according to which 

 there is a connection between the arctic and antarctic seas by 

 raeans of under-currents. 



') Die Beziehungen zwischen dem arktischen und antarktischen Plankton, Stutt- 

 gart 1897. 



