. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 124 DISCOVERY REPORTS (P- 115) that the larvae later in development than the Metanauplius, undergo a vertical migration diurnally through a column of water greater in depth than 250 m. That they should be absent from water shallower than 250 m. in this survey argues that for reasons connected with light intensity it is essential for them to have greater depths to recede to in the daytime. This will be dealt with in the section on vertical migration. (e) Survey of February-March 1928 (Sts. WS 144
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 124 DISCOVERY REPORTS (P- 115) that the larvae later in development than the Metanauplius, undergo a vertical migration diurnally through a column of water greater in depth than 250 m. That they should be absent from water shallower than 250 m. in this survey argues that for reasons connected with light intensity it is essential for them to have greater depths to recede to in the daytime. This will be dealt with in the section on vertical migration. (e) Survey of February-March 1928 (Sts. WS 144-195). Fig. 44. Very few larvae were taken during this survey; one Calyptopis 2 at St. WS 173 just beyond the shallow water on the Vakop Line and two Calyptopis 1 and 2 at St. WS 182 in the first deep-water station on the Clarke Rocks Line. It was noted above that one egg was taken at St. WS 147 in the 250-100 m. net. This station was on the edge of the continental shelf with a sounding of 274 m., but the previous station (WS 146), taken in almost the same position three days before, gave a sounding of 1096 m., so that both must have been on the very edge of the continental shelf. 38" 53 54 55 .^ âI wsias â¢WSI67. â W5179 I -wsiao wsiai 53 55 38° 36" 3-t" Fig. 44. Distribution of young Euphausia superba, South Georgia survey (70-cm. net hauls), February-March 1928. (/) Prince Olaf lines, March 1931 (Sts. WS 567-575). Fig. 45. Two lines of stations to the northward from Prince Olaf Harbour were made in March 1931, and at two stations, both in deep water, one Calyptopis i and one Furcilia 6 were recorded. {g) South-west side of South Georgia, April 1929 (Sts. WS 417-426). Fig. 46. No larvae were taken at any of the stations. (/?) East side of South Georgia, May 1930 (St. 393). At this station four flights of nets, each from 300 m. to the surface, were made, but only one larva, a Furcilia 5, was taken. Two points are made apparent by these surveys; first that
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