256 



DISCOVERY REPORTS 



Patagonian fish fauna and that of Kerguelen and Heard Island were dealt with by Regan (1914, p. 36), 

 who treated the latter as a peripheral district of the Antarctic Zone. Norman (1937, p. 148), reviewing 

 the question with more recent evidence, reached the conclusion that the dissimilarity between the 

 fish faunas of the Kerguelen and Patagonian regions was not so great as Regan had supposed, and 

 pointed to several pairs of species of the closest phylogenetic relationship from the respective regions. 

 However, it is easy to demonstrate similar close relationship between Patagonian species and others 

 from very widely remote regions, as we shall presently show. Norman himself, in a later work (1938, 

 pp. 100 et seq.), summed up the present position in regard to this question with the statement: 'it is 

 clear that, although the coastal fish fauna of the Kerguelen district shows certain features of resem- 

 blance to that of the Patagonian region and the Antipodes, its affinities are mainly with that of 

 Antarctica.' This is precisely what one would expect from our latest knowledge of the hydrology of 

 the regions concerned (Deacon, 1937). 



In strong contrast to the marked differences between the Patagonian fish fauna and that of other 

 regions, some of which have been shown in Table 3, several important and familiar species from 

 better-known grounds can be 'paired-off' with Patagonian species closely allied to them. This feature 

 was first made clear in Gunther's unpublished work, and was subsequently expanded by Norman 

 (i937» P- 146), and by Gunther himself in his address to Section D of the British Association during 

 the following year. These workers were concerned to show the parallels between allied British and 

 Patagonian species, as an aid to general description of the fauna. I have attempted to widen the basis 

 of this comparison with further parallels from the Gulf of Maine and from South Africa. Naturally 

 there are fewer closely allied species from such widely diverse regions. South African waters are 

 subtropical, though with low temperatures in the Benguela current, and the Gulf of Maine is a very 

 specialized ' cold-temperate ' area with exceptionally high summer temperatures due to the influence 

 of the Gulf Stream. Nevertheless, I find these broad comparisons helpful in gaining an idea of the 

 character of the Patagonian fish fauna, especially in conjunction with the roughly quantitative work 

 to be described later. I therefore include them here in the hope that those who read this report may 

 similarly be aided. 



Table 4. Closely allied species from the Patagonian shelf, British seas, 

 the Gulf of Maifie and South African seas 



It IS clear from this table that quite a number of Patagonian species have close relatives elsewhere, 

 but when the quantitative aspect is taken into account we find that with the exceptions of the hake,' 

 Micromezistius and Stromateus,^ the Patagonian species listed are relatively far less numerous than are 

 their nearest counterparts on the better-known grounds we have considered. Thus the differences 



1 Also the Falkland herring, but this could not be adequately sampled by the trawl. 



