DISTRIBUTION OF YOUNG STAGES OF EUPHAUSIA SUPERBA 



i6i 



although adults certainly were taken they nowhere occurred in quantity approaching 

 that in which larvae and adolescents were found. 



TIME DISTRIBUTION 



In Fig. 75 is shown the range in time of the different stages of development. The time 

 ranges for the occurrence of eggs, Nauplii and Metanauplius have already been dis- 

 cussed, but they have been inserted in the diagram to show them in relation to later 

 stages. For each stage represented in the diagram there are six horizontal divisions in- 

 dicating the six seasons from which data have been obtained : thus the lowest division 



NOV DEC 



JAN FEB MAR APR MAY J UN JUL AUG SEP 

 Fig. 75. Seasonal distribution of developmental stages of Euphaiisia superba. 



OCT NOV 



DEC 



JAN 



represents the season 1926-7 and the uppermost the season 193 1-2. For most of the 

 seasons observations ended with the end of the southern summer, and for the months 

 of May to mid-August the records of the occurrence of young krill are entirely derived 

 from the circumpolar cruise collections. It is for this reason that there is an apparent 

 abrupt termination in the occurrence of Metanauplius, Calyptopis and Furcilia i and 2. 

 The continuous line indicates half-months in which larvae were found ; the dotted lines 



