EUPHAUSIACEA 2IS 



Percentages have not been worked out as in the case of E. frigida because there is an 

 obvious indication of a tendency to occur in swarms, and the large numbers taken when 

 this is so might give quite a false idea of the relative proportions of the different stages 

 when we have such a limited number of occurrences to consider. The figures give some 

 indication of the course of development during the season and should be compared 

 with the observations made by Ruud (1932) on the earlier stages, calyptopis and first 

 furcilia, in December and January farther to the south. It would seem likely that 

 the larvae are spawned farther to the south, and are carried northwards by the cold 

 polar layer as they develop. Ruud took enormous numbers of calyptopis stages, 

 particularly stages 1 and 2, in his nets used at his two stations Nos. 11 and 12, which 

 were situated almost due south of South Georgia in latitudes 6i° 42' S and 6i° 37' S 

 respectively. 



Ruud (1932) and Wheeler 1 independently, by the measurement of E. superba taken 

 in whale stomachs, have shown the presence of two size-groups, indicating that the 

 species takes two years to come to maturity. 



Since the present survey was made a vast amount of E. superba material, both larval 

 and adult, has been collected during the Discovery investigations, and more detailed 

 reports are in preparation by other workers, so that no further discussion will be given 

 here upon the many interesting problems raised by this species — problems which can 

 only be solved by the consideration of large quantities of material. 



Euphansia triacaiitha, Holt and Tattersall. This species was at times moderately 

 abundant off the north-east and north coast of South Georgia, and between this island 

 and the Falkland Islands. It occurred at only one station off the south coast and was 

 absent from the south-west and west of the island — except for a single specimen taken 

 at St. 161 far to the south-west at a depth of 500-250 m. — below the cold surface layer. 

 The following is a statement of its occurrence : 



Approaching South Georgia from the north-east, February 1926: 

 St. 1 1 (N 70 V) 8 at 500-250 m. 



North-east coast, March-April 1926: 



St. 17 (N 70 V) 1 at 500-250 m. St. 416 (N 70 V) 2 at 265-150 m. 



St. 26 (N 100 H) 61 at 60-0 m. St. 41c (N 70 V) 1 at 240-150 m. 



St. 31 (N 100 H) 30 at 100-0 m. St. 41^ (N 70 V) 1 at 250-100 m. 



(N 70 V) 2 at 220-100 m. St. 44 (N 100 H) 26 at 55-0 m. 

 St. 37 (N 100 H) 153 at 50-0 m. 24 at 110-0 m. 



71 at 90-0 m. 4 at 170-0 in. 



St. 4i« (N 70 V) 2 at 265-150 m. 



North-east coast, November 1926: 



St. WS 20 (N 70 V) 1 at 500-250 m. 



St. WS 22 (N 70 V) 1 at 750-500 m. 



2 at 1000-750 m. 



1 Not yet published but contained in report to the Discovery Committee 1930. 



