DISTRIBUTION OF YOUNG STAGES OF EUPHAUSIA SUPERB A 157 



(ii) There is a well-marked discontinuity below 100 m. where the cold surface water 

 and the intermediate warm water meet. It might be suggested that this is the barrier 

 which concentrates so large a proportion of the larvae at the surface, but examination of 

 Table XL shows that it is apparently not a sufficiently strong obstacle to prevent the 

 migration of the subsurface larvae which move towards, and actually merge with, the 

 surface group in the D series. In this series the discontinuity is at 230 m. 



Table XL. Catches of young Euphausia superba at St. 461 



Table XL (cont.) 



For the first net of each flight the percentage stated is of the total number in all six nets, for the 

 remaining five nets the percentage is of the total number of individuals in those nets. 



