zi8 DISCOVERY REPORTS 



regard to their size and degree of flattening of the valves were also present. Also' I gained a distinct 

 impression of a relative increase in numbers of the stouter form in the warmer waters before re-reading 

 the debatable taxonomic literature. 



Boden (1950) who worked on material from the Atlantic side of Cape Peninsula has also accepted 

 Hustedt's view, but a full study of the earlier synonymy and detailed re-examination of our material 

 in further support thereof would require a separate publication. 



Fragilaria Karsteni Boden nom. nov. instead of F. capensis Karsten. 



Boden (1950, p. 406) has explained that Karsten's term was preoccupied by F. capensis Grunow, 

 1863, which differs structurally and in size from the species under discussion, hence the need for 

 the new name that Boden has established. 



Thalassionema nitzschioides (Grunow) Hustedt, previously very widely known as Thalassiothrix 

 nitzschioides Grun., Van Heurck. 



Hendey (1937, p. 336) points out that although Grunow wrote of the possibility of a need to establish 

 a new genus Thalassionema he did not define this proposed genus at all, and that Hustedt (1927-37, 

 p. 244) was the first to do so. Hendey holds, therefore, that the authority should be ascribed to 

 Hustedt. 



Noctiluca miliaris Suriray, instead of N. scintillans (Macartney) to which this widely known 

 organism is often referred. 



On this vexed question we have accepted Schillers (1933-7) verdict in favour of the later 

 N. miliaris Suriray (1816), 1836, against the earlier synonyms Medusa marina Slabber (1771) 1778, 

 and Medusa scintillans Macartney, 18 10. Kofoid (1919) who first produced good evidence of the 

 dinoflagellate affinities of this enigmatic, heterotrophic form, preferred Macartney's specific name for 

 it. Before that most marine biologists had used Noctiluca miliaris Suriray. 



We have not been able to consult all the early references quoted by Schiller, but if the genus 

 Noctiluca of Suriray is accepted, as it has been by almost all naturalists ever since Ehrenberg used it in 

 1834, ■* seems on ly consistent to use his specific name for the type-species also; since the earlier 

 synonyms placed the organism in a ' false genus '. Under admittedly much more recent interpretations 

 of the ' rules of nomenclature ', they should therefore lapse ; unless Suriray had himself decided to 

 use one or the other in making a 'new Combination'. Most probably he did not know of the earlier 

 descriptions. 



Dinophysis tripos Gourret, previously widely known as Dinophysis homunculus var. tripos (Gourret). 



It is now generally held that Stein's D. homunculus is a synonym, in part, of at least three of the 

 species in the Caudata group of Dinophysis: D. caudata Kent, which should replace homunculus as 

 a specific and as group-name on grounds of priority, D. diegensis Kofoid and D. tripos Gourret. 

 Lebour (1925) has pointed out that in D. tripos the hypotheca always shows a second smaller more 

 dorsal point, in addition to the well-defined ' Tail ' ; whereas in D. caudata varieties the tendency to 

 form a definite projection in the corresponding position is much less pronounced. A single figure of 

 an extreme variety of D. caudata from the Persian Gulf by Dr V. Pietschmann, reproduced by Schiller 

 (1933, p. 157, f. 145, u.) shows a definite secondary 'point', but it is appreciably smaller and less 

 acute than that of D. tripos, even when comparing it with the figures of the latter (several are given by 

 Schiller) in which the feature is least developed. 'Discovery' material both from the east and west 

 coasts of Africa seemed to me (T. J. H.) to be clearly ascribable to D. tripos Gourret, although 

 D. caudata Kent may also be found at some of the localities. 



In the Benguela current, D. tripos was limited to the extreme north of the area covered by our 

 survey, and to the extra stations south of the area that preceded the second survey. It was not observed 

 in the central portion of the coastal current where the heaviest diatom catches were taken and where 



