256 DISCOVERY REPORTS 



any quantity of water small enough to permit one to examine it microscopically, the process being 

 accentuated in greater or less degree by addition of all the narcotics or fixatives tried hitherto. Bary 

 and Stuckey (1953) found very dilute hydrogen peroxide the best narcotic, leaving a larger minority 

 of relatively little distorted specimens available for subsequent fixation. When the ciliates burst many 

 of the coloured 'platelets' (Lohmann) 1 are extruded. The enormous numbers of these in the sample 

 from WS 1 107 were observed in the field by Clarke and Currie, and their likeness to Hematococcidae 

 noted. The preserved sample, however, showed the characteristically shrunken remains of many of 

 the ciliates that had not burst (cf. Lohmann, 1908, fig. 7, no. 53, p. 201), so many indeed, that the 

 discoloured water must have contained not less than 13,370 per ml. It seemed pointless to attempt 

 counting of the freed 'platelets' since the vast majority had unquestionably been aggregated (in 

 varying numbers) within ciliates before the sample was taken. A small Gymnodinium sp., one other 

 small dinoflagellate and a Coscinodiscus sp. were present in very small numbers (up to 7 per ml.). 



Table 21. Size inter-relations of organisms from the samples taken off Sandzvich Harbour, 9 March 1950. 

 Selected to cover the dominants and species covering the extremes of variation in volume; others omitted 



Dense swarms of this ciliate have thus been seen near the two ends of the region where the Benguela 

 current is best defined. It seems unlikely from what is known of its proclivities elsewhere, that the 

 conditions of negative anomaly of temperature and salinity in between would prove exclusive to it. 

 Probably, therefore, before long some more fortunate observer will be able to add it to the list of 

 diverse forms now known to give rise to visual discolorations there at various times. 



The distinction between offshore and inshore diatom floras 



Yet another array of the data, based upon arbitrarily selected distance limits, serves to show up the 

 distinctive features of the flora of the inshore and offshore waters during the two surveys, providing 

 a basis for ecological characterization of the species within each of the main diatom groups. Some 

 repetition of points made in discussing distribution at group level is involved here, but seems to the 

 writer (T.J.H.) to be unavoidable if the apparent anomalies due to the cosmopolitan and panthalassic 

 species are to be made clear. 



The arbitrary limits first chosen were: stations within 40 miles from the coast regarded as within 

 an inshore region, and stations more than 100 miles from the coast, regarded as definitely oceanic or 



without fore-knowledge that we were to encounter his ciliate more than a year later, we could hardly be expected to have 

 included it in the small working library carried at sea! I have hoped to clear up some of the misunderstandings following 

 my 1934 letter in a separate publication, but the topic seems dangerous! (T.J.H.). 



1 These were described as 'most probably symbiotic algae', and given the name Erythromonas haltericola by Lohmann 

 (1908). Concerning them also Apstein (1908) wrote 'this is perhaps the alga living symbiotically in Mesodinium rubrum' . 

 I mentioned them as 'Coloured granules some 4/i in diameter, possibly symbiotic zoochlorellae' in ignorance of the earlier 

 work, though this may now seem to be incredible (T.J.H.). 



