274 Notices of Memoirs — Antarctic Exploration. 



species, or thirty species less than the number obtained in eight deep 

 hauls with the trawl and dredge in the Kerguelen region of the 

 Southern Ocean, in depths exceeding 1,260 fathoms, in which eight 

 hauls 272 species were obtained. Observations in other regions of 

 the Great Southern Ocean, where there is a low mean annual 

 temperature, also show that the marine fauna around the land in 

 high southern latitudes appears to be very poor in species down to 

 a depth of 25 fathoms, when compared with the number of species 

 present at the mud-line about 100 fathoms, or even at depths of 

 about two miles. 



" In 1841 Sir James Clark Eoss dredged off the Antarctic 

 continent species which he recognized as the same as he had 

 been in the habit of taking in equally high Northern latitudes, 

 and he suggested that they might have passed from one pole to 

 the other by way of the cold water of the deep sea. Subsequent 

 researches show that, as with pelagic organisms, many of the 

 bottom-living species are identical with, or closely allied to, 

 those of the Arctic regions, and are not represented in the inter- 

 mediate tropical areas. For instance, the most striking character 

 of the shore-fish fauna of the Southern Ocean is the reappearance 

 of types inhabiting the corresponding latitudes of the northern 

 hemisphere, and not found in the intervening tropical zone. This 

 interruption of continuity in the distribution of shore-fishes is 

 exemplified by species as well as genera, and Di-. Giinther enumerates 

 eleven species and twenty-nine genera as illustrating this method of 

 distribution. The genus by which the family Berycidse is repre- 

 sented in the Southern Temperate Zone (Traclncldlnjs) is much more 

 nearly allied to the northern than to the tropical genera. ' As in the 

 Northern Temperate Zone, so in the Southern .... the variety 

 of forms is much less than between the tropics. This is especially 

 apparent on comparing the number of species constituting a genus. 

 In this zone, genera composed of more than ten species are the 

 exception, the majority having only from one to five.' .... 

 ' Polt/prion is one of those extraordinary instances in which a very 

 specialized form occurs at almost opposite points of the globe, without 

 having left a trace of its previous existence in, or of its passage 

 through, the intermediate space.' 



" Speaking of the shore-fishes of the Antarctic Ocean, Giinther 

 says : ' The general character of the fauna of Magelheen's Straits and 

 Kerguelen's Land is extremely similar to that of Iceland and 

 Greenland. As in the Arctic fauna, Chondropterygians are scarce, 

 and represented by Acanihias vulgaris and species of Baj'a .... 

 As to Acanthopterygians, Cataphracti and ScorpEenidee are repre- 

 sented as in the Arctic fauna, two of the genera (^Sebastes and 

 Agonus) being identical. The Cottid^ are replaced by six genera of 

 Trachinidse, remarkably similar in form to Arctic types .... 

 Gadoid fishes reappear, but are less developed ; as usual, they are 

 accompanied by Mijxine. The reappearance of so specialized a genus 

 as Lycodes is most remarkable.' ^ 



1 Giinther, " Study of Fishes," pp. 282-290 ; Edinburgh, 1880. 



