496 DISCOVERY REPORT ; S 



north of the sub-Antarctic, whereas there are eight from the Malay Archipelago, five 

 from Australia, four from New Zealand and three from Japan. 1 Caber ea and Beania are 

 more widely distributed, but both have their greatest concentration of species in the 

 Australasian region. Information from other groups is scanty. John (1937, p. 87) 

 found South American affinities for the Antarctic Echinoderms, but the few other 

 groups for which I have comparable data 2 seem to show the same tendency as the 

 Polyzoa, the northward part of their range extending around the Australasian and 

 eastern Asiatic land masses rather than around the American continent. 



Table 6 summarizes the distribution of the recent species of the six predominantly 

 Antarctic genera of Cellularine Polyzoa. 



Table 6. Summary of the distribution of the recent species of the six predominantly 

 Antarctic genera of Cellularine Polyzoa 



The figures indicate the number of species recorded from each locality. Those in heavy type were taken at depths 

 greater than 1000 m. 



The Polyzoa of Australasia and the Malay Archipelago have been much more in- 

 tensively studied than those of South America, although the Central and North American 

 Polyzoa are relatively well known, and the rarity of species of these Antarctic genera in 

 South American waters may thus only be apparent. If it were a real peculiarity of distri- 

 bution it could only be explained in relation to the geological history of the region and of 

 the genera. Unfortunately, the Cellularine Polyzoa are not commonly preserved as fos- 

 sils, owing to their delicate structure. Canu's papers on fossils from the Argentine (Canu, 

 1908, 191 1) do not include any Cellularina, but a number of species are described from 

 the Tertiary beds of Australia and New Zealand by MacGillivray, Waters and Maple- 

 stone. Mostly they are difficult to place generically, but typical species of Amastigia and 

 Caberea are recognizable amongst them. For instance, Menipea lineata MacGillivray 



1 See Addendum, p. 501. 



2 Serolidae (Sheppard, 1933^.264), Cephalodiscus (John, 193 1, pp. 256-259), Nototheniiformes (Norman, 

 1938, p. 95). 



