. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 236 DISCOVERY REPORTS Soleniineae were abundant close inshore, present elsewhere in very moderate numbers, becoming of some relative importance only in the very small minimal haul, and again at the outer end of the line. Leptocylindrus danicus, one of the few neritic species in this essentially holoplanktonic group, was mainly responsible for the inshore maximum. Various Rhizosolenia species, among the most cosmopolitan of all plankton diatoms, were present at the minimal station; while right of
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. 236 DISCOVERY REPORTS Soleniineae were abundant close inshore, present elsewhere in very moderate numbers, becoming of some relative importance only in the very small minimal haul, and again at the outer end of the line. Leptocylindrus danicus, one of the few neritic species in this essentially holoplanktonic group, was mainly responsible for the inshore maximum. Various Rhizosolenia species, among the most cosmopolitan of all plankton diatoms, were present at the minimal station; while right offshore the oceanic species Rhizosolenia simplex was the dominant form. 'Pennatae' formed an unusually high proportion of the total diatom count at the inshore peak station and were second only to Chaetoceros among the group totals at the shelf-edge peak. The small 'reversionary plankton forms' Nitzschia spp. and Asterionella japonica were chiefly responsible, with a considerable proportion of the larger Thalassiothrix longissima at the shelf-edge. The latter usually showed a more oceanic distribution than other members of the group in these surveys. WS970 WS969 WS968 W5966 WS965 WS9M I I I. WS975 « TOTAL DIATOMS -» CHAETOCERACEAE -' "PENNATAE" â > BIDDULPHIINEAE o DISCINEAE - SOLENIINEAE so ido SEA MILES FROM LAND Fig. 73. Estimated total diatoms, and diatom group totals, survey I. A. Mowe Point line, 4-5 March 1950. B. Northern Intermediate line, 5 March 1950. On the northern intermediate line, the estimated diatom totals were very moderate throughout, with a slight maximum at the second and third stations seaward, diminishing to the outer end of the line. From the group figures it appears that Discineae were relatively somewhat more important in the small catches here than over the survey area generally. The panthalassic species Thalassiosira excentrica and Planktoniella sol (oceanic) were both among the dominants at the three slightly richer stations at t
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