HORIZONTAL DISTRIBUTION OF ADOLESCENTS AND ADULTS 317 



is involved. The year has been divided into seasons as follows: summer, December-February; 

 autumn, March-May; winter, June-August; spring, September-November. 



It will be seen from Fig. 4 that, except for the large number taken between 300 and 350 miles 

 north of the convergence in summer, the region of maximum abundance, at least in the upper 100 m., 

 bears very much the same relationship to the convergence throughout the year. The number of 

 observations in each 50-mile interval varies considerably and where these are very low the value 



ftoo 700 too soo 400 joo 100 100 



00 JOO 100 100 A I C '00 100 JOO 400 soo 600700600 



iU^ 



O 'O- 



XX X XI 



JAL 



J 



X X y )C X X 



uL 



P ^v V X X XX X 



^5o7OOb£o~loO~4OO3O01OOIOOA^^lOOJ0O JOO 4O0 lOO 600 TOO 800 

 NOHIH SO"" 



NAUTICAL MIIES 



Fig 4 The seasonal variation in horizontal distribution of adolescent and adult E. triacantha in relation to the Antarctic 

 convergence. The mean number of specimens per 20 min. haul has been calculated for each 50-mile belt north and south 

 of the convergence. Belts in which no observations are available are indicated by crosses. 



Table i. The lines of stations used for Fig. 4, shotving the sectors in which they were worked. 

 The figures in brackets indicate the number of stations used in each line 



Season 



Sector 

 o°-90° E 



90°E-i8o° 



i8o°-90° W 

 90° W-o° 



Summer 

 2492-2500 (5) 

 2531-2541 (6) 

 2565-2576 (8) 

 2582-2592 (8) 



1675-1682 (6) 

 2155-2168 (9) 

 2204-2212 (5) 

 2802-281 1 (9) 



1 222-1 228 (4) 



Autumn 



1361-1369 (9) 

 1772-1781 (8) 

 2311-2320(5) 



2340-2350 (5) 

 2612-2625 (9) 



879- 887 (9) 

 1723-1733 (6) 



1312-1320(5) 



Winter 

 1788-1801 (9) 

 2355-2362 (7) 

 2378-2380 (3) 



2385-2393 (4) 

 2411-2419 (6) 



898- 906 (7) 

 913- 923 (8) 



Spring 



1806-1813 (6) 

 2425-2430 (4) 

 2446-2453 (6) 

 2459-2465 (5) 



946- 951 (6) 

 2736-2745 (8) 



1027-1035 (5) 

 1415-1421 (4) 

 1442-1450 (5) 



